Method for preparing ethylenediamine from ethanolamine

Abstract

The invention discloses a method for preparing ethidene diamine from ethanolamine, which comprises the following steps: in the presence of hydrogen and an ammonia source, contacting ethanolamine with a Mn-Co-Cu-HoS-1 catalyst to carry out amination reaction to generate ethidene diamine, a main active component of the catalyst is manganese, auxiliary agents are cobalt and copper, and a carrier of the catalyst is an all-silicon S-1 molecular sieve with a hollow structure, namely, an HoS-1 molecular sieve. By adopting the Mn-Co-Cu HoS-1 catalyst, the amination reaction can be efficiently carried out under relatively mild conditions (140-160 DEG C, 1-5 MPa), and the safety risk and energy consumption of the industrial process are greatly reduced. Under the regulation and control of the catalyst, the reaction shows high selectivity, and the ethanediamine selectivity can reach 51.3%; the activity and selectivity of the catalyst are still stable after continuous operation for 80 hours, and the catalyst shows excellent thermal stability and sintering resistance, is good in thermal stability and long in cycle service life, and has good industrial continuous production application potential.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing ethylenediamine from ethanolamine. Background Technology

[0002] Ethylenediamine (EDA), as an important organic chemical intermediate, has wide applications in the production of pharmaceuticals, chelating agents, surfactants, pesticides, fabric softeners, and resin polymers. Global market analysis shows that the demand for ethylenediamine is showing a continuous growth trend, making it one of the petrochemical products worthy of vigorous development.

[0003] Currently, the main industrial methods for synthesizing ethylenediamine include the dichloroethane method and the ethanolamine (MEA) reductive amination method. The dichloroethane method is gradually being phased out due to the severe equipment corrosion and environmental pollution caused by the use of halogens. The ethanolamine reductive amination method, on the other hand, has attracted widespread attention due to its abundant raw material sources and relatively environmentally friendly approach. However, existing ethanolamine reductive amination methods still face a series of challenges: the reaction is usually carried out under high pressure, requiring sophisticated equipment and consuming a lot of energy; moreover, the catalysts are mostly composed of precious metals (such as Re) or transition metals, resulting in high costs and hindering large-scale production applications. Simultaneously, the long-term operational stability of the catalysts is insufficient; their activity and selectivity rapidly decline during continuous operation, resulting in short lifespans and requiring frequent regeneration or replacement.

[0004] Therefore, developing a catalyst that exhibits high stability, high ethylenediamine selectivity, and reasonable cost under mild conditions is of great significance for promoting the industrial application of the ethanolamine reduction amination process. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, this invention provides a method for preparing ethylenediamine from ethanolamine. This method utilizes a Mn-Co-Cu@HoS-1 catalyst, which achieves high ethylenediamine selectivity under relatively mild reaction conditions. Furthermore, this catalyst exhibits excellent thermal stability and anti-sintering ability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing ethylenediamine from ethanolamine involves an amination reaction in the presence of hydrogen and ammonia, where ethanolamine is contacted with a Mn-Co-Cu@HoS-1 catalyst to generate ethylenediamine. The main active component of the catalyst is manganese, with cobalt and copper as promoters. The catalyst support is a hollow-structured all-silica S-1 molecular sieve, specifically a HoS-1 molecular sieve. In this catalyst, the metal is uniformly encapsulated within the hollow-structured all-silica S-1 molecular sieve. The hollow shell structure stabilizes the metal particles, inhibiting sintering, and promotes the rapid diffusion of ethanolamine molecules towards the metal center, thereby improving the selectivity of ethylenediamine and enhancing the catalytic activity.

[0008] The present invention is further configured such that the Mn-Co-Cu@HoS-1 catalyst is obtained by loading manganese, cobalt and copper onto a HoS-1 molecular sieve support using an equal-volume impregnation method, followed by drying and calcination.

[0009] The present invention is further configured such that the total metal loading in the catalyst is 15-30% of the catalyst mass, preferably 15-25%; the total metal loading is based on elemental metal.

[0010] The present invention is further configured such that, in the Mn-Co-Cu@HoS-1 catalyst, the mass of manganese is 12-20% of the catalyst weight, the mass of cobalt is 1-7% of the catalyst weight, and the mass of copper is 2-5% of the catalyst weight.

[0011] The present invention is further configured such that the ammonia source is ammonia water, and the molar ratio of the ammonia source to ethanolamine is (1-10):1, preferably 5:1.

[0012] The present invention further specifies that the reaction temperature is 140-160 °C, the reaction pressure is 1-5 MPa, and the liquid hourly space velocity of ethanolamine is 0.1-2 h⁻¹. -1 .

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] This invention utilizes a Mn-Co-Cu@HoS-1 catalyst, enabling the amination reaction to proceed efficiently under relatively mild conditions (140-160 °C, 1-5 MPa hydrogen pressure), significantly reducing safety risks and energy consumption in industrial processes. Under the control of this catalyst, the reaction exhibits high selectivity, with an ethylenediamine selectivity of up to 51.3%. Furthermore, the catalyst maintains stable activity and selectivity after 80 hours of continuous operation, demonstrating excellent thermal stability and anti-sintering ability. It exhibits good thermal stability, long cycle life, and promising potential for continuous industrial production applications. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0016] Unless otherwise specified, all conditions in the following examples were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are commercially available products.

[0017] Example 1

[0018] (1) Preparation of 20wt% Mn-Co-Cu@HoS-1 catalyst

[0019] The main active component of the catalyst is 15wt%Mn, and the promoters are 3wt%Co and 2wt%Cu. The metal source is a solution of cobalt, manganese and copper nitrates, and the support is HoS-1 molecular sieve. The metal loading is based on the total amount of catalyst and is calculated as elemental metal.

[0020] S1. Loading stage: Place the HoS-1 molecular sieve in a crucible, add the nitrate solution prepared according to the loading amount dropwise to the crucible, and stir to form a paste-like suspension; the preparation of the HoS-1 molecular sieve can be referred to CN117399049A;

[0021] S2. Drying stage: The crucible containing the sample was opened at room temperature to initially evaporate the moisture. The standing time was 24 h, and then it was transferred to an oven for drying at 110 ℃ for 10 h.

[0022] S3. Calcination stage: The dried product is calcined in a muffle furnace at a temperature of 500-600 ℃ for 6 h.

[0023] (2) 0.50 g of the prepared 20wt% Mn-Co-Cu@HoS-1 catalyst was loaded into a stainless steel fixed-bed reactor and diluted with quartz sand until the catalyst bed height was uniform. Before the reaction, the loaded catalyst was reduced at 250 °C for 2 h under a hydrogen atmosphere (20 mL·min⁻¹), and then cooled to the set reaction temperature. During the reaction, ammonia and ethanolamine were used as the reaction substrates, with an ammonia-to-ethanol ratio (molar ratio of ammonia source to ethanolamine) of 5:1. The reaction was carried out by a high-pressure metering pump at a set liquid hourly space velocity (WHSV) of 0.8 h⁻¹ for ethanolamine. -1 Ammonia and hydrogen were continuously fed into the reactor according to a set ratio via a mass flow controller. The reactor temperature was adjusted to 160 °C, and the total system pressure was controlled at 5 MPa via a back pressure valve. The reaction tail gas and liquid products were collected by a condenser after exiting the reactor, and quantitative analysis was performed by gas chromatography (GC). The GC analysis results of the obtained products are listed in Table 1.

[0024] Example 2

[0025] This embodiment is basically the same as that of embodiment 1. The difference is that in step (1) of this embodiment, the total metal loading is 15wt%, the main active component is 12wt%Mn, the auxiliary agent is 1wt%Co and 2wt%Cu, and the gas chromatography analysis results of the product are shown in Table 1.

[0026] Example 3

[0027] This embodiment is basically the same as that of embodiment 1, except that in step (1) of this embodiment, the total metal loading is 25wt%, the main active component is 15wt%Mn, the auxiliary agents are 5wt%Co and 5wt%Cu, and the gas chromatography analysis results of the product are shown in Table 1.

[0028] Example 4

[0029] This embodiment is basically the same as that of embodiment 1. The difference is that in step (1) of this embodiment, the total metal loading is 30wt%, the main active component is 20wt%Mn, the auxiliary agent is 7wt%Co and 3wt%Cu, and the gas chromatography analysis results of the product are shown in Table 1.

[0030] Comparative Example 1

[0031] This embodiment is basically the same as that of embodiment 1, except that in step (1) of this embodiment, the total metal loading is 0.3wt%, the main active component is 0.1wt%Mn, the auxiliary agents are 0.1wt%Co and 0.1wt%Cu, and the gas chromatography analysis results of the product are shown in Table 1.

[0032] Comparative Example 2

[0033] This embodiment is basically the same as that of embodiment 1. The difference is that in step (1) of this embodiment, S-1 molecular sieve is used as a support to prepare catalyst 20wt%Mn-Co-Cu / S-1. The gas chromatography analysis results of the product are shown in Table 1.

[0034] Comparative Example 3

[0035] 0.50 g of 20 wt% Co / SiO2 catalyst, prepared by the equal-volume impregnation method, was packed into a stainless steel fixed-bed reactor and diluted with quartz sand until the catalyst bed height was uniform. Before the reaction, the packed catalyst was placed under a hydrogen atmosphere (20 mL / min). -1 The reaction mixture was reduced at 250 °C for 2 h, and then cooled to the set reaction temperature. During the reaction, ammonia and ethanolamine were used as the reaction substrates, with an ammonia-to-ethanol ratio of 5:1. The reaction was carried out using a high-pressure metering pump at a set liquid hourly space velocity (WHSV) of 0.8 h⁻¹. -1 Ammonia and hydrogen were continuously fed into the reactor according to a set ratio via a mass flow controller. The reactor temperature was adjusted to 160 °C, and the total system pressure was controlled at 5 MPa via a back pressure valve. The reaction tail gas and liquid products were collected by a condenser after exiting the reactor, and quantitative analysis was performed by gas chromatography (GC). The GC analysis results of the obtained products are listed in Table 1.

[0036] Comparative Example 4

[0037] 0.50 g of 10 wt% Ni3Re / Al(OH)3 catalyst, prepared by the equal-volume impregnation method, was packed into a stainless steel fixed-bed reactor and diluted with quartz sand until the catalyst bed height was uniform. Before the reaction, the packed catalyst was placed under a hydrogen atmosphere (20 mL / min). -1 The reaction mixture was reduced at 250 °C for 2 h, and then cooled to the set reaction temperature. During the reaction, ammonia and ethanolamine were used as the reaction substrates, with an ammonia-to-ethanol ratio of 5:1. The reaction was carried out using a high-pressure metering pump at a set liquid hourly space velocity (WHSV) of 0.8 h⁻¹. -1 Ammonia and hydrogen were continuously fed into the reactor according to a set ratio via a mass flow controller. The reactor temperature was adjusted to 160 °C, and the total system pressure was controlled at 5 MPa via a back pressure valve. The reaction tail gas and liquid products were collected by a condenser after exiting the reactor, and quantitative analysis was performed by gas chromatography (GC). The GC analysis results of the obtained products are listed in Table 1.

[0038] Table 1. Reaction conditions and gas chromatographic analysis results of products in Examples 1-4 and Comparative Examples 1-4.

[0039]

[0040] As shown in Table 1, the reaction results are optimal when the catalyst is supported by HoS-1 and the total metal loading is 20wt%, with the highest ethylenediamine selectivity of 51.3% and the conversion rate of 42.1%.

[0041] Example 5

[0042] This embodiment is basically the same as Embodiment 1, except that in step (2) of this embodiment, the reaction pressure is 5 MPa, the reaction temperature is 160 ℃, the ammonia-to-ethanol ratio is 1:1, and the space velocity is 2 h⁻¹. -1 The gas chromatographic analysis results of the products are shown in Table 2.

[0043] Example 6

[0044] This embodiment is basically the same as Embodiment 1, except that in step (2) of this embodiment, the reaction pressure is 4 MPa, the reaction temperature is 155 ℃, the ammonia-to-ethanol ratio is 2:1, and the space velocity is 1.5 h⁻¹. -1 The gas chromatographic analysis results of the products are shown in Table 2.

[0045] Example 7

[0046] This embodiment is basically the same as Embodiment 1, except that in step (2) of this embodiment, the reaction pressure is 3 MPa, the reaction temperature is 150 ℃, the ammonia-to-ethanol ratio is 5:1, and the space velocity is 1 h. -1The gas chromatographic analysis results of the products are shown in Table 2.

[0047] Example 8

[0048] This embodiment is basically the same as Embodiment 1, except that in step (2) of this embodiment, the reaction pressure is 2 MPa, the reaction temperature is 145 ℃, the ammonia-to-ethanol ratio is 8:1, and the space velocity is 0.5 h⁻¹. -1 The gas chromatographic analysis results of the products are shown in Table 2.

[0049] Example 9

[0050] This embodiment is basically the same as Embodiment 1, except that in step (2) of this embodiment, the reaction pressure is 1 MPa, the reaction temperature is 140 ℃, the ammonia-to-ethanol ratio is 10:1, and the space velocity is 0.1 h⁻¹. -1 The gas chromatographic analysis results of the products are shown in Table 2.

[0051] Table 2. Reaction conditions and gas chromatographic analysis results of products in Examples 5-9

[0052]

[0053] Catalyst stability test

[0054] The catalysts prepared in Example 1, Comparative Example 3, and Comparative Example 4 were subjected to continuous operation stability tests: 20 wt% Mn-Co-Cu@HoS-1 catalyst, 20 wt% Mn-Co-Cu / S-1 catalyst, and 10 wt% Ni3Re / Al(OH)3 catalyst were respectively loaded into fixed-bed reactors. After pretreatment according to the reduction method of Example 1, the catalysts were subjected to the same reaction conditions (temperature 160℃, hydrogen pressure 5 MPa, ammonia-to-methanol ratio 5:1, and liquid hourly space velocity 0.8 h⁻¹). -1 The reaction was run continuously for 80 hours. Samples were taken every 5 hours during the reaction to record the conversion rate of ethanolamine (MEA), the selectivity of ethylenediamine (EDA), and the selectivity of piperazine (PIP). Some results are listed in Table 3.

[0055] Table 3 Stability Evaluation

[0056]

[0057] The data in Table 3 show that the 20wt% Mn-Co-Cu@HoS-1 catalyst of Example 1 exhibited good stability during 80 h of continuous operation: the ethanolamine conversion rate slowly decreased from 42.1% to 40.9%, the ethylenediamine selectivity decreased from 51.3% to 50.4%, and the piperazine selectivity remained basically stable. Furthermore, no obvious metal sintering was observed after the reaction. In contrast, although the 10wt% Ni3Re / Al(OH)3 catalyst of Comparative Example 4 showed high activity and selectivity in the early stages of the reaction (MEA conversion rate of 45.3% and EDA selectivity of 61.2% at 20 h), its stability was significantly insufficient. After 80 h of reaction, the MEA conversion rate decreased to 35.8%, and the EDA selectivity decreased significantly to 35.8%. The 20wt% Mn-Co-Cu / S-1 catalyst of Comparative Example 3 not only showed much lower activity and selectivity than Example 1 in the early stages of the reaction, but also continued to decline throughout the entire operation, exhibiting similarly poor stability.

[0058] The above results demonstrate that the Mn-Co-Cu@HoS-1 catalyst of the present invention possesses excellent thermal stability and cycle life.

[0059] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing ethylenediamine from ethanolamine, characterized in that, In the presence of hydrogen and ammonia, ethanolamine is contacted with Mn-Co-Cu@HoS-1 catalyst to undergo an amination reaction to generate ethylenediamine; the main active component of the catalyst is manganese, the auxiliary agents are cobalt and copper, and its support is a hollow all-silica S-1 molecular sieve, namely HoS-1 molecular sieve.

2. The method for preparing ethylenediamine from ethanolamine according to claim 1, characterized in that, The Mn-Co-Cu@HoS-1 catalyst was obtained by loading manganese, cobalt, and copper onto a HoS-1 molecular sieve support using an equal-volume impregnation method, followed by drying and calcination.

3. The method for preparing ethylenediamine from ethanolamine according to claim 2, characterized in that, The total metal loading in the catalyst is 15-30% of the catalyst mass; the total metal loading is based on elemental metals.

4. The method for preparing ethylenediamine from ethanolamine according to claim 2, characterized in that, The total metal loading in the catalyst is 15-25% of the catalyst mass; the total metal loading is based on elemental metals.

5. The method for preparing ethylenediamine from ethanolamine according to claim 3 or 4, characterized in that, In the Mn-Co-Cu@HoS-1 catalyst, the mass of manganese is 12-20% of the catalyst weight, the mass of cobalt is 1-7% of the catalyst weight, and the mass of copper is 2-5% of the catalyst weight.

6. The method for preparing ethylenediamine from ethanolamine according to claim 1, characterized in that, The ammonia source is ammonia water, and the molar ratio of the ammonia source to ethanolamine is (1-10):

1.

7. The method for preparing ethylenediamine from ethanolamine according to claim 1, characterized in that, The ammonia source is ammonia water, and the molar ratio of the ammonia source to ethanolamine is 5:

1.

8. The method for preparing ethylenediamine from ethanolamine according to claim 1, characterized in that, The reaction temperature was 140-160 °C, the reaction pressure was 1-5 MPa, and the volume hourly space velocity (VHSV) of ethanolamine was 0.1-2 h⁻¹. -1 .

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