A method for producing ethylamine by reacting hydrogen and acetonitrile
By developing a high-performance catalyst for the hydrogenation of acetonitrile to ethylamine, the problems of high separation cost and narrow product ratio control in the hydroammoniation of ethanol have been solved, achieving efficient preparation of ethylamine and market adaptability. The catalyst has high activity and good selectivity, making it suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-12
AI Technical Summary
The existing ethanol hydroammoniation method for ethylamine production suffers from problems such as high separation costs due to water produced as a byproduct and a narrow range for product ratio control, and insufficient utilization of acetonitrile byproducts.
To develop a high-performance continuous acetonitrile hydrogenation catalyst for the production of ethylamine, the preparation method was optimized to achieve efficient conversion by contacting hydrogen and acetonitrile with the catalyst in a reactor and using an organic-inorganic composite support containing noble metal active components and phosphorus auxiliaries.
It achieves efficient preparation of ethylamine, reduces separation costs, meets market demands, and features a catalyst with high activity, good selectivity, and long lifespan, making it suitable for industrial production.
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Abstract
Description
Technical Field
[0001] This invention relates to a method for producing ethylamine by reacting hydrogen and acetonitrile, belonging to the field of chemical engineering. Background Technology
[0002] Ethylamines typically include ethylamine (EA), diethylamine (DEA), and triethylamine (TEA). These three ethylamines are important fine chemical intermediates, used in the production of numerous pharmaceutical intermediates, dye intermediates, preservatives, emulsifiers, and polymerization inhibitors. Furthermore, triethylamine, as an organic acid-binding agent, is also widely used in the production of vinylene carbonate (VC), an additive in lithium-ion battery electrolytes.
[0003] The main methods for producing ethylamine include ethylene ammoniation, acetaldehyde ammoniation, and ethanol hydroammoniation. Among these, ethanol hydroammoniation is currently the mainstream technology. This technology uses ethanol as a raw material and, through the hydroammoniation reaction, can simultaneously produce three types of ethylamines in one step. Furthermore, the proportion of the three ethylamines in the product is adjustable within a certain range, offering good technical and economic advantages. However, this technology also suffers from the problem of producing water as a byproduct, resulting in a high amount of azeotropic substances in the reactor outlet material, leading to extremely high subsequent separation costs. In addition, the adjustable range of the proportions of the three ethylamines in the product is relatively narrow, making it difficult to adapt to the ever-changing market demand for these three ethylamines.
[0004] Three types of ethylamines can be effectively prepared from acetonitrile via a one-step hydrogenation reaction. The reaction process boasts high atom utilization and produces no byproduct water. Compared to the ethanol hydroammoniation method, this method offers numerous advantages in product distribution and separation. Acetonitrile can be derived as a byproduct of acrylonitrile plants. With the gradual expansion of acrylonitrile production capacity in my country, there is a surplus of this less-used byproduct. Developing a continuous production technology for ethylamine from acetonitrile hydrogenation not only utilizes the acetonitrile byproduct from acrylonitrile plants but also replaces the existing ethanol hydroammoniation technology, reducing subsequent separation costs. Summary of the Invention
[0005] The key to realizing the industrial application of the technology for the continuous hydrogenation of acetonitrile to ethylamine lies in the development of a high-performance catalyst for the continuous hydrogenation of acetonitrile to ethylamine.
[0006] The purpose of this invention is to provide a method for preparing a hydrogenation catalyst and its application in the conversion of acetonitrile to ethylamine, in response to the above-mentioned needs.
[0007] According to one aspect of the present invention, a method for preparing ethylamine by reacting hydrogen and acetonitrile is provided, comprising at least the following steps:
[0008] Hydrogen and acetonitrile are reacted with a catalyst in a reactor to produce ethylamine.
[0009] The ethylamine is selected from at least one of ethylamine, diethylamine, and triethylamine;
[0010] The catalyst is obtained through the following steps:
[0011] The organic-inorganic composite support was mixed with an aqueous solution containing a noble metal active component precursor and a phosphorus source, allowed to stand, dried, and reduced with hydrogen to obtain the catalyst.
[0012] The noble metal active component precursor is selected from at least one of ruthenium trichloride, ammonium hexachlororuthenate, chloroiridic acid, sodium chloroiridate, ruthenium nitrate, ammonium chloroiridate, tetraammineplatinum chloride, chloroplatinic acid, and platinum nitrate.
[0013] The substance is selected from at least one of phosphoric acid, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate;
[0014] The mass ratio of the noble metal element in the noble metal active component precursor to the organic-inorganic composite carrier is 0.001 to 0.02:1.
[0015] The mass ratio of phosphorus in the phosphoric acid to the organic-inorganic composite carrier is 0.005 to 0.03:1.
[0016] The temperature of the drying process I is 60–80°C;
[0017] The drying time for step I is 8–20 hours;
[0018] The temperature for hydrogen reduction is 300–400°C;
[0019] The hydrogen reduction time is 1 to 10 hours.
[0020] The organic-inorganic composite carrier is obtained through the following steps:
[0021] The organic precursor, inorganic precursor, additive A, additive B are mixed with water, stirred, pulped and milled to form a slurry, dehydrated, extruded into strips, dried (II), and then treated at temperature I for 2-10 hours, temperature II for 2-4 hours, and temperature III for 1-3 hours under an inert atmosphere to obtain the carrier.
[0022] The organic precursor is selected from at least one of starch, polyvinyl alcohol, polyethylene glycol and guar gum;
[0023] The inorganic precursor is selected from at least one of sepiolite and attapulgite.
[0024] The auxiliary agent A is selected from at least one of basic magnesium carbonate, basic calcium carbonate, basic nickel carbonate, and basic cobalt carbonate.
[0025] The auxiliary agent B is selected from at least one of stearic acid, palmitic acid, sodium stearate, sodium palmitate, and sodium pyrophosphate;
[0026] The mass ratio of the organic precursor, inorganic precursor, auxiliary agent A, and auxiliary agent B is 20–35:5–10:1–2:1.
[0027] The temperature of the drying II process is 100–130°C;
[0028] The drying time for step II is 3–8 hours;
[0029] The temperature I is 200–300°C;
[0030] The temperature II is 400–600°C;
[0031] The temperature III is 800–900°C.
[0032] The reactor is selected from at least one of fixed bed, fluidized bed, suspended bed and moving bed.
[0033] The reaction temperature is 100–300°C;
[0034] The reaction pressure is 0.1–3.0 MPa;
[0035] The mass hourly space velocity (MSV) of the acetonitrile is 0.1–8 h⁻¹. -1 ;
[0036] The molar ratio of hydrogen to acetonitrile is 2 to 10:1.
[0037] The beneficial effects that this invention can produce include:
[0038] 1) The noble metal active component in the hydrogenation catalyst provided by the present invention is a composite metal active site containing iridium and / or ruthenium and / or platinum elements dispersed on an optimized organic-inorganic composite support, which can effectively adsorb and activate hydrogen molecules and acetonitrile molecules and catalyze their efficient conversion.
[0039] 2) The phosphorus-containing additive in the hydrogenation catalyst provided by this method can stabilize the metal active sites and modulate the composition of the product.
[0040] 3) The organic-inorganic composite support in the catalyst provided by this invention can not only achieve efficient dispersion and stabilization of the noble metal active components, but also provide an effective pore structure and specific surface area for the reaction, meet the requirements of mass and heat transfer, and improve the catalyst's resistance to coking.
[0041] 4) The catalyst preparation method provided by this invention is simple, has good repeatability, and is suitable for large-scale industrial production.
[0042] 5) The catalyst provided by this invention has the characteristics of high catalytic activity, good selectivity and long life. It can catalyze the hydrogenation of acetonitrile to prepare ethylamine in one step with high efficiency, and can realize the adjustment of the production ratio of ethylamine, diethylamine and triethylamine. It has strong adaptability to market demand. Detailed Implementation
[0043] The present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments. Unless otherwise specified, the raw materials used in the embodiments are all commercially available.
[0044] Example 1: Preparation of carriers S1 to S5
[0045] Preparation of carrier S1:
[0046] 20 parts by weight of polyethylene glycol, 10 parts by weight of guar gum, 8 parts by weight of attapulgite, 1 part by weight of basic magnesium carbonate, 0.5 parts by weight of basic nickel carbonate, and 1 part by weight of sodium palmitate were added to deionized water, stirred, pulped, and glue-milled to prepare a slurry with a solid content of 60 wt%. The slurry was dehydrated to a semi-dry state under vacuum conditions of 60°C and -40 kPa, then kneaded, extruded into strips, and dried in an oven at 120°C for 4 hours to obtain a carrier semi-finished product.
[0047] The dried carrier semi-finished product was placed in a quartz tube and treated at 260°C for 8 hours under a nitrogen atmosphere, then heated to 500°C for 3 hours, and finally heated to 850°C for 2 hours to obtain carrier S1.
[0048] Preparation of carrier S2:
[0049] 20 parts by weight of polyethylene glycol, 5 parts by weight of starch, 10 parts by weight of polyvinyl alcohol, 5 parts by weight of sepiolite, 0.5 parts by weight of basic calcium carbonate, 0.5 parts by weight of basic cobalt carbonate, and 1 part by weight of sodium pyrophosphate were added to deionized water, stirred, pulped, and glue-milled to prepare a slurry with a solid content of 60 wt%. The slurry was dehydrated to a semi-dry state under vacuum conditions of 60°C and -40 kPa, then kneaded, extruded into strips, and dried in an oven at 100°C for 8 hours to obtain a carrier semi-finished product.
[0050] The dried carrier semi-finished product was placed in a quartz tube and treated at 200°C for 8 hours under a nitrogen atmosphere, then heated to 400°C for 4 hours, and finally heated to 900°C for 1 hour to obtain carrier S2.
[0051] Preparation of carrier S3:
[0052] 10 parts by weight of polyethylene glycol, 5 parts by weight of starch, 5 parts by weight of guar gum, 10 parts by weight of attapulgite, 0.5 parts by weight of basic magnesium carbonate, 1.2 parts by weight of basic nickel carbonate, 0.5 parts by weight of palmitic acid, and 0.5 parts by weight of stearic acid were added to deionized water, stirred, pulped, and glue-milled to prepare a slurry with a solid content of 60 wt%. The slurry was dehydrated to a semi-dry state under vacuum conditions of 60°C and -40 kPa, then kneaded, extruded into strips, and dried in an oven at 130°C for 3 hours to obtain a carrier semi-finished product.
[0053] The dried carrier semi-finished product was placed in a quartz tube and treated at 300°C for 2 hours under a nitrogen atmosphere, then heated to 600°C for 2 hours, and finally heated to 800°C for 3 hours to obtain carrier S3.
[0054] Preparation of carrier S4:
[0055] 15 parts by weight of polyvinyl alcohol, 15 parts by weight of starch, 7 parts by weight of attapulgite, 1.5 parts by weight of basic calcium carbonate, 0.5 parts by weight of basic cobalt carbonate, and 1 part by weight of sodium stearate were added to deionized water, stirred, pulped, and glue-milled to prepare a slurry with a solid content of 60 wt%. The slurry was dehydrated to a semi-dry state under vacuum conditions of 60°C and -40 kPa, then kneaded, extruded into strips, and dried in an oven at 120°C for 4 hours to obtain a carrier semi-finished product.
[0056] The dried carrier semi-finished product was placed in a quartz tube and treated at 270°C for 5 hours under a nitrogen atmosphere, then heated to 550°C for 3 hours, and finally heated to 850°C for 2 hours to obtain carrier S4.
[0057] Preparation of carrier S5:
[0058] 15 parts by weight of polyvinyl alcohol, 5 parts by weight of starch, 8 parts by weight of sepiolite, 1.8 parts by weight of basic nickel carbonate, 0.2 parts by weight of stearic acid and 0.8 parts by weight of sodium stearate pyrophosphate were added to deionized water, stirred, pulped and glue-milled to prepare a slurry with a solid content of 60 wt%. The slurry was dehydrated to a semi-dry state under vacuum of 60°C and -40 kPa, then kneaded, extruded into strips, and dried in an oven at 120°C for 4 hours to obtain a carrier semi-finished product.
[0059] The dried carrier semi-finished product was placed in a quartz tube and treated at 240°C for 8 hours under a nitrogen atmosphere, then heated to 500°C for 4 hours, and finally heated to 880°C for 2 hours to obtain carrier S5.
[0060] Example 2: Preparation of catalysts Cat.1 to Cat.8
[0061] The saturated water absorption of the carrier in Example 1 was determined using the saturated water absorption method. Then, based on the saturated water absorption, the target loading of the noble metal active component, and the target loading of the phosphorus-containing auxiliary component, the concentrations of the noble metal precursor and the phosphorus-containing auxiliary precursor in the modified solution were calculated. Based on the above calculation results, a modified solution containing the noble metal active component precursor and the phosphorus-containing auxiliary precursor was prepared.
[0062] The modified solution was uniformly added to the carrier prepared in Example 1 until adsorption saturation, then allowed to stand at room temperature for 24 hours, dried in a vacuum oven, and then subjected to a volume hourly space velocity (VHSV) of 800 h⁻¹. -1 Reduction in a hydrogen atmosphere yields catalysts Cat.1 to Cat.8.
[0063] The preparation conditions for the catalysts, including the type of support used, the type and loading of the noble metal active component precursor (based on metal element), the type and loading of the phosphorus-containing auxiliary precursor (based on phosphorus element), the drying temperature and drying time, and the hydrogen reduction temperature and reduction time, are shown in Table 1.
[0064] Table 1. Preparation conditions of catalysts Cat.1 to Cat.8
[0065]
[0066] Comparative Example 1
[0067] Using the support S1 in Example 1 as the support, and following the preparation method of catalyst Cat.1 in Example 2, the loading of the noble metal component was omitted to prepare catalyst Comparative Example 1.
[0068] Comparative Example 2
[0069] Using the support S1 in Example 1 as the support, and following the preparation method of catalyst Cat.1 in Example 2, the loading of phosphorus-containing auxiliary agent was omitted to prepare catalyst Comparative Example 2.
[0070] Comparative Example 3
[0071] Using S1 in Example 1 as a carrier, and following the preparation method of Cat.1 in Example 2, the loading of noble metals ruthenium and palladium was increased by 3 times to prepare catalyst of Comparative Example 3.
[0072] Example 3: Evaluation of the acetonitrile hydrogenation activity of the catalyst
[0073] The acetonitrile hydrogenation activity of catalysts Cat.1–Cat.8 prepared in Example 2 and the comparative catalyst was evaluated using a fixed-bed reactor with an inner diameter of 9 mm and a catalyst loading of 2 mL. Methyl acrylate and hydrogen were introduced to evaluate the reaction. The products were analyzed online using an Agilent 7890A chromatograph. The catalyst activity was evaluated based on indicators such as the conversion rate of acetonitrile in the feed and the selectivity of ethylamines (ethylamine, diethylamine, and triethylamine). The calculation methods for each indicator are as follows:
[0074]
[0075] [Acetonitrile] 进 The molar flow rate (mol / h) of acetonitrile at the reactor inlet; [acetonitrile] 出 [Ethylamine] 出 [Diethylamine] 出 and [triethylamine] 出 The values represent the molar flow rates (mol / h) of acetonitrile, ethylamine, diethylamine, and triethylamine at the reactor outlet, respectively. The catalysts, reaction conditions, and catalyst activities for experiments exp1–exp13 are shown in Table 2.
[0076] Table 2. Reaction conditions and catalyst activity for experiments exp1–exp13
[0077]
[0078]
[0079] In the experiments shown in Table 2, samples were taken and analyzed every 5 hours. The results in the table are the average values over 100 hours. Experiment exp1 was run continuously for 2000 hours, and no significant decrease in conversion or selectivity was observed, indicating that the catalyst has good stability.
[0080] The above description is merely a few embodiments of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any modifications or alterations made by those skilled in the art without departing from the scope of the technical solution of the present invention using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing ethylamine by reacting hydrogen and acetonitrile, characterized in that, At least the following steps are included: Hydrogen and acetonitrile are reacted with a catalyst in a reactor to produce ethylamine. The ethylamine is selected from at least one of ethylamine, diethylamine, and triethylamine; The catalyst is obtained through the following steps: The organic-inorganic composite support was mixed with an aqueous solution containing a noble metal active component precursor and a phosphorus source, allowed to stand, dried, and reduced with hydrogen to obtain the catalyst.
2. The method according to claim 1, characterized in that, The noble metal active component precursor is selected from at least one of ruthenium trichloride, ammonium hexachlororuthenate, chloroiridic acid, sodium chloroiridate, ruthenium nitrate, ammonium chloroiridate, tetraammineplatinum chloride, chloroplatinic acid, and platinum nitrate. The substance is selected from at least one of phosphoric acid, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate; The mass ratio of the noble metal element in the noble metal active component precursor to the organic-inorganic composite carrier is 0.001 to 0.02:
1. The mass ratio of phosphorus in the phosphoric acid to the organic-inorganic composite carrier is 0.005 to 0.03:
1. The temperature of the drying process I is 60–80°C; The drying time for step I is 8–20 hours; The temperature for hydrogen reduction is 300–400°C; The hydrogen reduction time is 1 to 10 hours.
3. The method according to claim 1, characterized in that, The organic-inorganic composite carrier is obtained through the following steps: The organic precursor, inorganic precursor, additive A, additive B are mixed with water, stirred, pulped and milled to form a slurry, dehydrated, extruded into strips, dried (II), and then treated at temperature I for 2-10 hours, temperature II for 2-4 hours, and temperature III for 1-3 hours under an inert atmosphere to obtain the carrier.
4. The method according to claim 3, characterized in that, The organic precursor is selected from at least one of starch, polyvinyl alcohol, polyethylene glycol and guar gum; The inorganic precursor is selected from at least one of sepiolite and attapulgite. The auxiliary agent A is selected from at least one of basic magnesium carbonate, basic calcium carbonate, basic nickel carbonate, and basic cobalt carbonate. The auxiliary agent B is selected from at least one of stearic acid, palmitic acid, sodium stearate, sodium palmitate, and sodium pyrophosphate; The mass ratio of the organic precursor, inorganic precursor, auxiliary agent A, and auxiliary agent B is 20–35:5–10:1–2:
1.
5. The method according to claim 3, characterized in that, The temperature of the drying II process is 100–130°C; The drying time for step II is 3–8 hours; The temperature I is 200–300°C; The temperature II is 400–600°C; The temperature III is 800–900°C.
6. The method according to claim 1, characterized in that, The reactor is selected from at least one of fixed bed, fluidized bed, suspended bed and moving bed.
7. The method according to claim 1, characterized in that, The reaction temperature is 100–300°C; The reaction pressure is 0.1–3.0 MPa; The mass hourly space velocity (MSV) of the acetonitrile is 0.1–8 h⁻¹. -1 ; The molar ratio of hydrogen to acetonitrile is 2 to 10:1.