A catalyst for the disproportionation of diethylamine to triethylamine, its preparation method and application
By loading catalysts of MgO, ZnO and rare earth oxides onto γ-Al2O3 or ZSM-5 molecular sieves, the problems of insufficient catalyst activity and harsh reaction conditions in the diethylamine disproportionation reaction were solved, achieving efficient preparation of triethylamine and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- THE NORTHWEST RES INST OF CHEM IND
- Filing Date
- 2026-03-06
- Publication Date
- 2026-05-26
AI Technical Summary
In the existing ethylamine production process, the catalyst activity of the diethylamine disproportionation reaction is insufficient, the reaction conditions are harsh, resulting in equipment corrosion and high energy consumption, as well as poor product selectivity and easy generation of by-products.
The catalyst prepared by coprecipitation-impregnation method contains MgO, ZnO and rare earth oxides supported on γ-Al2O3, SiO2 or ZSM-5 molecular sieve supports, and is used for diethylamine disproportionation reaction under the conditions of 120-180℃ and 0.5-2.0MPa, and the reaction products are collected by condensation.
It achieves high conversion rate of diethylamine and high selectivity of triethylamine, and the byproduct monoethylamine can be recycled, significantly reducing the overall cost.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chemical catalyst preparation technology, specifically relating to a catalyst for the disproportionation of diethylamine to triethylamine, its preparation method, and its application. Background Technology
[0002] Ethylamine is a derivative formed by replacing hydrogen atoms in ammonia molecules with ethyl groups. It mainly includes monoethylamine, diethylamine, and triethylamine, and is an important fine chemical intermediate. It can react with various compounds to form derivatives and is widely used in pharmaceuticals, pesticides, chemical auxiliaries, military industry, and new energy sectors. With the continuous increase in my country's lithium battery production capacity in recent years, the demand for ethylene carbonate and the novel lithium salt lithium bis(fluorosulfonyl)imide (LiFSI), which are closely related to triethylamine, has increased significantly, leading to a surge in the market demand for triethylamine. Market research indicates that the demand for triethylamine is expected to increase from 72,100 tons to 103,100 tons in the next five years.
[0003] Industrially, ethylamine is mainly prepared by a hydrogen-pressurized reaction using ethanol and liquid ammonia as raw materials. This process offers advantages such as no side reactions, high product quality, low energy consumption, and the ability to simultaneously produce monoethylamine, diethylamine, and triethylamine. The catalysts used are primarily cobalt- and / or nickel-based catalysts supported on irregularly shaped alumina and / or silica. Chinese patent CN1436596A provides a low-grade aliphatic amine catalyst, in which cobalt, calcium, and other active components are supported on a carrier, with the active components accounting for 10-50% of the catalyst weight. However, this catalyst has a complex preparation process and unsatisfactory selectivity. Chinese patent CN101869836A provides a low-grade aliphatic amine catalyst, its preparation method and its application. The catalyst uses alumina with irregular morphology as a support and the active components include: (1) Co, 10-50%; (2) at least one of Ce, Nd, Pr and Gd, 0.01-5%; (3) at least one of Cr, Ba, Ag, Mn, Ti, Ge and Zr, 0.01-10%. The catalyst shows good ethanol amination reaction performance at a higher reaction temperature (170 °C), but its low-temperature activity and stability need to be improved, and it is also not conducive to the selectivity of ethylamine.
[0004] In the product structure of ethylamine production processes, monoethylamine accounts for approximately 10%, diethylamine for approximately 30%, and triethylamine for approximately 60%. The common practice is to separate the monoethylamine and diethylamine products obtained from the ethylamine mixture prepared by the hydroamination of ethanol and reprocess them for further deep amination reactions to produce triethylamine. However, this requires an additional diethylamine distillation and reprocessing unit, incurring additional energy consumption and costs. There are few reports on how to convert diethylamine to triethylamine to increase the capacity of ethylamine plants. Triethylamine can be produced through the alkylation of diethylamine with ethylene / acetaldehyde, directly introducing a third ethyl group in the presence of a catalyst. However, the toxicity of ethylene / acetaldehyde and its poor reaction selectivity (easily generating high-boiling substances such as tetraethylamine) limit its application.
[0005] The disproportionation reaction of diethylamine is a potentially efficient route for the preparation of triethylamine. Under specific conditions, diethylamine undergoes intermolecular rearrangement, with some diethylamine losing an ethyl group to form monoethylamine, while another portion gains an ethyl group to form triethylamine. The advantages of this reaction are: it uses a single starting material (diethylamine), requires no additional olefins / aldehydes, the byproduct is only low-value monoethylamine (which can be further converted through recycling), and it offers higher selectivity for the target product, triethylamine.
[0006] However, existing disproportionation reaction technologies suffer from the following bottlenecks: First, insufficient catalyst activity. While traditional alkaline catalysts (such as sodium hydroxide and alumina) can catalyze the reaction, they suffer from poor product selectivity (easily generating polymerization byproducts) and are prone to deactivation. Second, demanding reaction conditions, typically requiring high temperatures (>200℃) or high pressures (>5MPa), leading to equipment corrosion and excessive energy consumption. Furthermore, traditional alkaline catalysts can cause side reactions; diethylamine is prone to dealkylation to generate ethane and ammonia, or polymerization to generate polyethylamine, reducing the yield of the target product. Summary of the Invention
[0007] To address the shortcomings of existing technologies, this invention provides a catalyst for the disproportionation of diethylamine to triethylamine, its preparation method, and its application, enabling the efficient and highly selective preparation of triethylamine from diethylamine as a raw material.
[0008] A catalyst for the disproportionation of diethylamine to triethylamine, the catalyst comprising a support, and MgO, ZnO and rare earth oxides supported on the support, wherein the content of each component, by mass of the catalyst, is as follows: support 80-85%, MgO 5-10%, ZnO 5-10%, rare earth metal oxides 2-5%.
[0009] Preferably, the rare earth metal oxide is CeO2 or La2O3.
[0010] Preferably, the support is γ-Al2O 3、Any one of SiO2, ZSM-5 molecular sieve, or ZSM-11 molecular sieve.
[0011] Preferably, the particle size of the carrier is 200-400 mesh.
[0012] The preparation method of the catalyst for the disproportionation of diethylamine to triethylamine adopts a co-precipitation-impregnation method, including the following steps: (1) Dissolve the magnesium precursor, zinc precursor and rare earth metal precursor in deionized water, add the carrier and stir evenly; (2) Add a precipitant to adjust the pH of the system to 8-9. After precipitation, age the system at 20-90℃ for 12-24 hours. (3) Filter, wash the obtained solid precipitate with deionized water, dry it, and calcine it.
[0013] Preferably, the precursors for magnesium, zinc, and rare earth metals are all metal-specific nitrates.
[0014] Preferably, the precipitant is sodium carbonate.
[0015] Preferably, the drying conditions are drying at 100-120℃ for 10-12 hours, and the calcination conditions are calcination at 500-600℃ for 4-6 hours.
[0016] A method for producing triethylamine by disproportionation of diethylamine involves loading a catalyst into a fixed-bed reactor, introducing diethylamine, reacting at 120-180°C and 0.5-2.0 MPa, condensing, and collecting the liquid reaction product; the catalyst is the catalyst described above.
[0017] Preferably, the mass hourly space velocity (MSV) of the diethylamine is 0.2-3 h⁻¹. -1 .
[0018] Advantages of this invention: The catalyst provided by this invention has a high conversion rate of diethylamine and a high selectivity for the product triethylamine during the disproportionation of diethylamine. The reaction products are separated into triethylamine, diethylamine and monoethylamine by vacuum distillation. Unreacted diethylamine can be recycled, and monoethylamine can be collected separately or recycled back to the diethylamine synthesis unit, which significantly reduces the overall cost. Detailed Implementation
[0019] Example 1: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: 85% γ-Al₂O₃ support, 5% MgO, 5% ZnO, and 5% rare earth metal oxide CeO₂; wherein the particle size of the support is 200-400 mesh. The catalyst is prepared as follows: (1) Dissolve 3.18g of magnesium nitrate (Mg(NO3)2·6H2O), 1.83g of zinc nitrate (Zn(NO3)2·6H2O), and 1.26g of cerium nitrate (Ce(NO3)3·6H2O) in 50mL of deionized water, add 8.5g of γ-Al2O3 carrier, and stir for 30min until homogeneous; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 8, and after precipitation, age at 80℃ for 18h; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 550°C for 5 hours to obtain the catalyst, which is denoted as 5MgO-5ZnO-5CeO2 / γ-Al2O3.
[0020] Example 2: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: support SiO2 85%, MgO 5%, ZnO 5%, rare earth metal oxide La2O3 5%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 3.18g of magnesium nitrate (Mg(NO3)2·6H2O), 1.83g of zinc nitrate (Zn(NO3)2·6H2O), and 0.66g of lanthanum nitrate (La(NO3)3·6H2O) in 50mL of deionized water, add 8.5g of SiO2 support, and stir for 30min until homogeneous; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 8.5, and after precipitation, age at 60℃ for 12h; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 500°C for 6 hours to obtain the catalyst, which is denoted as 5MgO-5ZnO-5La2O3 / SiO2.
[0021] Example 3: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: support ZSM-583%, MgO 10%, ZnO 5%, rare earth metal oxide CeO2 2%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 6.36g of magnesium nitrate (Mg(NO3)2·6H2O), 1.83g of zinc nitrate (Zn(NO3)2·6H2O), and 0.5g of cerium nitrate (Ce(NO3)3·6H2O) in 50mL of deionized water, add 8.3g of ZSM-5 carrier, and stir for 30min until homogeneous; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 8.5, and after precipitation, age at 40℃ for 20h; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 550°C for 6 hours to obtain the catalyst, which is denoted as 10MgO-5ZnO-2CeO2 / ZSM-5.
[0022] Example 4: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: support ZSM-11 80%, MgO 10%, ZnO 5%, rare earth metal oxide La2O3 5%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 6.36g of magnesium nitrate (Mg(NO3)2·6H2O), 1.83g of zinc nitrate (Zn(NO3)2·6H2O), and 0.66g of lanthanum nitrate (La(NO3)3·6H2O) in 50mL of deionized water, add 8.0g of ZSM-11 carrier, and stir for 30min until homogeneous; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 9, and after precipitation, age at 20°C for 24 hours; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 550°C for 4 hours to obtain the catalyst, which is denoted as 10MgO-5ZnO-5La2O3 / ZSM-11.
[0023] Example 5: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: γ-Al2O3 support 80%, MgO 5%, ZnO 10%, rare earth metal oxide CeO2 5%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 3.18 g of magnesium nitrate (Mg(NO3)2·6H2O), 3.65 g of zinc nitrate (Zn(NO3)2·6H2O), and 1.26 g of cerium nitrate (Ce(NO3)3·6H2O) in 50 mL of deionized water, add 8.0 g of γ-Al2O3 support, and stir for 30 min; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 8.5. After precipitation, age at 65℃ for 15h. (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 600°C for 4 hours to obtain the catalyst, which is denoted as 5MgO-10ZnO-5CeO2 / γ-Al2O3.
[0024] Example 6: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: support SiO2 80%, MgO 5%, ZnO 10%, rare earth metal oxide La2O3 5%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 3.18g of magnesium nitrate (Mg(NO3)2·6H2O), 3.65g of zinc nitrate (Zn(NO3)2·6H2O), and 0.66g of lanthanum nitrate (La(NO3)3·6H2O) in 50mL of deionized water, add 8.0g of SiO2 support, and stir for 30min until homogeneous; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 9, and after precipitation, age at 80℃ for 20h; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 580°C for 4 hours to obtain the catalyst, which is denoted as 5MgO-10ZnO-5La2O3 / SiO2.
[0025] Example 7: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: support ZSM-580%, MgO 8%, ZnO 7%, rare earth metal oxide CeO2 5%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 5.09 g of magnesium nitrate (Mg(NO3)2·6H2O), 2.56 g of zinc nitrate (Zn(NO3)2·6H2O), and 1.26 g of cerium nitrate (Ce(NO3)3·6H2O) in 50 mL of deionized water, add 8.0 g of ZSM-5 carrier, and stir for 30 min; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 8.5, and after precipitation, age at 90℃ for 24h; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 120°C for 12 hours, and calcine it at 550°C for 6 hours to obtain the catalyst, which is denoted as 8MgO-7ZnO-5CeO2 / ZSM-5.
[0026] Example 8: A catalyst for the disproportionation of diethylamine to triethylamine, comprising the following components in the following proportions: ZSM-11 support 82%, MgO 8%, ZnO 7%, rare earth metal oxide La2O3 3%; wherein the particle size of the support is 200-400 mesh; The catalyst is prepared as follows: (1) Dissolve 5.09 g of magnesium nitrate (Mg(NO3)2·6H2O), 2.56 g of zinc nitrate (Zn(NO3)2·6H2O), and 0.4 g of lanthanum nitrate (La(NO3)3·6H2O) in 50 mL of deionized water, add 8.2 g of ZSM-11 carrier, and stir for 30 min until homogeneous; (2) Add 1 mol / L sodium carbonate solution to adjust the pH of the system to 8.5, and after precipitation, age at 50℃ for 22h; (3) Filter the solid precipitate, wash it three times with deionized water, dry it at 100°C for 10 hours, and calcine it at 550°C for 5 hours to obtain the catalyst, which is denoted as 8MgO-7ZnO-3La2O3 / ZSM-11.
[0027] Example 9: A method for producing triethylamine by disproportionation of diethylamine, comprising loading a catalyst into a fixed-bed reactor, introducing diethylamine with a purity of 99%, reacting at a reaction temperature of 120-180℃ and a reaction pressure of 0.5-2.0 MPa, condensing, and collecting the liquid reaction product; the catalyst is the same as that in the above example; the reaction product is collected as a liquid phase after condensation, and analyzed by gas chromatography; the catalyst performance evaluation results are shown in Table 1. Table 1 Reaction conditions and results ; This invention achieves highly efficient and selective conversion of diethylamine to triethylamine using a supported composite metal oxide catalyst, achieving a diethylamine conversion rate of >94% and a triethylamine selectivity of >82% under mild conditions; simultaneously, the byproduct monoethylamine can be recycled, demonstrating significant industrial application value.
Claims
1. A catalyst for the disproportionation of diethylamine to triethylamine, characterized in that: The catalyst includes a support, and MgO, ZnO and rare earth oxides supported on the support. The mass of the catalyst is 100%, and the content of each component is as follows: support 80~85%, MgO 5~10%, ZnO 5~10%, rare earth metal oxides 2~5%.
2. The catalyst for the disproportionation of diethylamine to triethylamine according to claim 1, characterized in that: The rare earth metal oxide is CeO2 or La2O3.
3. The catalyst for the disproportionation of diethylamine to triethylamine according to claim 1, characterized in that: The carrier is γ-Al₂O₃ 3、 Any one of SiO2, ZSM-5 molecular sieve, or ZSM-11 molecular sieve.
4. The catalyst for the disproportionation of diethylamine to triethylamine according to claim 3, characterized in that: The particle size of the carrier is 200-400 mesh.
5. The method for preparing the catalyst for the disproportionation of diethylamine to triethylamine according to claim 1, characterized in that: The co-precipitation-impregnation method includes the following steps: (1) Dissolve the magnesium precursor, zinc precursor and rare earth metal precursor in deionized water, add the carrier and stir evenly; (2) Add a precipitant to adjust the pH of the system to 8-9. After precipitation, age the system at 20-90℃ for 12-24 hours. (3) Filter, wash the obtained solid precipitate with deionized water, dry it, and calcine it.
6. The method for preparing the catalyst for the disproportionation of diethylamine to triethylamine according to claim 5, characterized in that: The precursors for magnesium, zinc, and rare earth metals are all nitrates corresponding to the metals.
7. The method for preparing the catalyst for the disproportionation of diethylamine to triethylamine according to claim 5, characterized in that: The precipitant is sodium carbonate.
8. The method for preparing the catalyst for the disproportionation of diethylamine to triethylamine according to claim 5, characterized in that: The drying conditions are drying at 100-120℃ for 10-12 hours, and the calcination conditions are calcination at 500-600℃ for 4-6 hours.
9. A method for preparing triethylamine by disproportionation of diethylamine, characterized in that: The catalyst is loaded into a fixed-bed reactor, diethylamine is introduced, and the reaction is carried out at 120-180℃ and 0.5-2.0MPa. The reaction product is condensed and collected in liquid phase. The catalyst is the catalyst described in claim 1.
10. The method for producing triethylamine by disproportionation of diethylamine according to claim 9, characterized in that: The mass hourly space velocity (MSV) of the diethylamine is 0.2-3.0 h⁻¹. -1 .