Development of a catalyst and its application in the dehydrogenative amination of ethanol to acetonitrile
By using tin oxide and alumina catalysts, combined with impregnation treatment with aluminum salts and citric acid, and optimizing reaction conditions, the problems of insufficient activity and selectivity of existing catalysts were solved, and the production of high-purity acetonitrile was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YULIN ZHONGKE CLEAN ENERGY INNOVATION RES INST
- Filing Date
- 2026-03-18
- Publication Date
- 2026-06-09
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Figure SMS_4
Abstract
Description
Technical Field
[0001] This application relates to a catalyst for the dehydrogenation and amination of ethanol to produce acetonitrile, belonging to the field of chemical catalyst preparation technology. Background Technology
[0002] Acetonitrile is a widely used organic chemical raw material. Besides its use in petrochemicals as an extractant for butadiene and isoprene from olefins and alkanes, it is also widely used as a raw material in the synthesis of organic chemicals, pharmaceuticals, pesticides, surfactants, dyes, and other fine chemicals. Furthermore, it serves as a mobile phase solvent in thin-layer chromatography, paper chromatography, spectroscopy, polarography, and high-performance liquid chromatography (HPLC). More recently, it has been used as a purification solvent for DNA synthesis, a solvent for the synthesis of organic EL materials, and a cleaning solvent for electronic components such as chips. These applications require a high purity of acetonitrile (≥99.9%). Acetonitrile with a purity of ≥99.9% is highly sought after in the market and has a wide range of applications, accounting for over 66% of total consumption.
[0003] Currently, globally, acetonitrile is mainly recovered as a crude byproduct during the ammoxidation of propylene to produce acrylonitrile. However, one ton of acrylonitrile yields only 20-30 kg of acetonitrile, with low purity, especially difficult to achieve a purity ≥99.9%. Ethanol ammoniation dehydrogenation to produce acetonitrile is a beneficial supplement to acetonitrile production. Compared to other methods of obtaining acetonitrile, ethanol ammoniation dehydrogenation to produce acetonitrile is a simple process with low energy consumption, high atom utilization, high acetonitrile selectivity, few side reactions, low investment, low operating costs, and can be industrialized. The catalysts used in the dehydrogenation and amination of ethanol to produce acetonitrile are divided into two categories: dehydrogenation / hydrogenation catalysts and dehydration catalysts. Dehydrogenation / hydrogenation catalysts typically use Ni, Cu, Fe, Cr, Co, Rh, Zr, Pb, and Ag as the main active components, with cobalt and nickel being the most widely used. Secondary and tertiary components, such as Cu, Na, Mg, and Ca, as well as rare earth elements, are usually added as co-catalysts, resulting in a complex elemental composition of the catalysts. Summary of the Invention
[0004] This application aims to develop a highly active and selective catalyst for the dehydrogenation and amination of ethanol to produce acetonitrile.
[0005] According to one aspect of this application, a method for producing acetonitrile by dehydrogenation and ammoniaation of ethanol is provided, wherein a mixed feedstock containing ethanol and ammonia is contacted with a catalyst and reacted to obtain a product containing acetonitrile. The catalyst comprises tin oxide and aluminum oxide (impregnated twice).
[0006] Optionally, the mass of the tin is 1.0 to 55 wt% of the mass of the catalyst.
[0007] Optionally, the mass of tin is any value or a range between two values from 1.0 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt% of the catalyst mass.
[0008] Optionally, the catalyst is prepared by impregnating alumina with a tin salt dissolved in an ethanol solution and calcining it to obtain a SnAl2O3 intermediate, which is then soaked in an aluminum salt solution, dried and calcined to obtain the catalyst. Optionally, in the solution containing the tin salt precursor, the mass ratio of the tin salt precursor to the volume ratio of ethanol is 1 g: 2~4 mL.
[0009] Optionally, in the solution containing the tin salt precursor, the mass ratio of the tin salt precursor to the volume of ethanol is any value among 1g:2mL, 1g:3mL, and 1g:4mL, or a range between two values.
[0010] Optionally, the aluminum salt accounts for 3 to 15 wt% of the catalyst based on aluminum oxide.
[0011] Optionally, the aluminum salt, calculated as alumina, is any value or a range between two values from 3.0 wt%, 5.0 wt%, 7.5 wt%, 10.0 wt%, 12.5 wt%, and 15 wt% of the catalyst mass.
[0012] Optionally, the aluminum salt is selected from one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, and aluminum phosphate.
[0013] Optionally, the citric acid accounts for 0.1 to 0.5 wt% of the catalyst.
[0014] Optionally, the citric acid accounts for any value or a range between two values from 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt% of the catalyst mass.
[0015] Optionally, the calcination temperature is selected from 500~800 ℃, and the calcination time is 2~4 h.
[0016] Optionally, the molar ratio of ammonia to ethanol is 2 to 8.
[0017] Optionally, the molar ratio of ammonia to ethanol is any value among 2, 3, 4, 5, 6, 7, and 8, or a range between two values.
[0018] Optionally, the mass hourly space velocity (MSV) of the ethanol is 0.1 to 1.0 h⁻¹. -1 .
[0019] Optionally, the mass hourly space velocity (MSV) of the ethanol is 0.1 h⁻¹. -1 0.2 h -1 0.3 h -1 0.4 h -1 0.5 h -1 0.6 h -1 0.7h -1 0.8 h -1 0.9 h -1 1.0 h -1 Any value in the range or between two values.
[0020] Optionally, the reaction pressure is 0.1~0.5 MPa, and the reaction temperature is 350~500 °C.
[0021] Optionally, the reaction pressure is selected from any value or a range between two values from 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa.
[0022] Optionally, the reaction temperature is selected from any value or a range between two values from 350 ℃, 400 ℃, 450 ℃, 460 ℃, 480 ℃, and 550 ℃.
[0023] The beneficial effects that this application can produce include: The catalyst prepared in this application is used in the process of ethanol dehydrogenation amination to produce acetonitrile. Compared with conventional SnAl2O3 catalysts, it exhibits higher ethanol conversion, higher acetonitrile selectivity, and lower content of high-boiling substances. Detailed Implementation
[0024] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0025] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0026] The analysis method in the embodiments of this application is as follows: The products were analyzed using an Agilent 7890A gas chromatograph.
[0027] In the embodiments of this application, the catalyst activity evaluation indicators, namely ethanol conversion rate, ammonia conversion rate, and acetonitrile selectivity, are all calculated based on mass: Ethanol conversion rate: ; Ammonia conversion rate: ; Acetonitrile selectivity: ; In the above formula, m represents mass.
[0028] Comparative Example 1 According to the tin content of the active component, a certain amount of SnCl2·2H2O was weighed and dissolved in ethanol, wherein the ratio of ethanol to SnCl2 (volume / mass) was 3 ml / g. Then, it was gradually added dropwise to a sealed container containing a certain amount of alumina, dried at 120 ℃ for 6 hours, and calcined at 700 ℃ in air for 3 hours to obtain a catalyst Cat-A1 with a tin content of 20 wt%.
[0029] Comparative Example 2 According to the tin content of the active component, a certain amount of SnCl2·2H2O was weighed and dissolved in ethanol, wherein the ratio of ethanol to SnCl2 (volume / mass) was 3 ml / g. This solution was then gradually added dropwise to a sealed container containing a certain amount of alumina. The mixture was dried at 120 °C for 6 hours and calcined in air at 700 °C for 3 hours to obtain an intermediate. This intermediate was then immersed in an aluminum nitrate solution, and the amount of aluminum salt impregnated, calculated as alumina, was 5 wt% of the total catalyst mass. o Dry at C for 3 hours, 550 o The catalyst Cat-A2, prepared by calcining C for 4 hours, has a tin content of 20 wt%.
[0030] Example 1 According to the tin content of the active component, a certain amount of SnCl2·2H2O was weighed and dissolved in ethanol, wherein the ratio of ethanol to SnCl2 (volume / mass) was 3 ml / g. This solution was then gradually added dropwise to a sealed container containing a certain amount of alumina. The mixture was dried at 120 °C for 6 hours and calcined in air at 700 °C for 3 hours to obtain an intermediate. This intermediate was then immersed in a solution of aluminum nitrate and citric acid. The amount of aluminum salt impregnated, calculated as alumina, was 5 wt% of the total catalyst mass, and the amount of citric acid was 0.3 wt% of the total catalyst mass. The solution was then 150 °C. o Dry at C for 3 hours, 550 o The catalyst Cat-B, prepared by calcining C for 4 hours, has a tin content of 20 wt%.
[0031] Example 2 According to the tin content of the active component, a certain amount of SnCl4·5H2O and SnCl2·2H2O were weighed and dissolved in ethanol, wherein the mass ratio of SnCl4·5H2O to SnCl2·2H2O was 1 / 1, and the volume / mass ratio of ethanol to (SnCl2+SnCl4) was 2 ml / g. This solution was then gradually added dropwise to a sealed container containing a certain amount of alumina. The mixture was dried at 110 ℃ for 12 hours and calcined at 500 ℃ for 4 hours to obtain an intermediate. This intermediate was then immersed in an aluminum chloride solution. The amount of aluminum salt impregnated, calculated as alumina, was 3.0 wt% of the catalyst mass, and citric acid accounted for 0.1 wt% of the total catalyst mass. The solution was then 120... o Dry at C for 4 hours, 500 o The catalyst Cat-C, prepared by calcining C for 4 hours, has a tin content of 1.0 wt%.
[0032] Example 3 According to the tin content of the active component, a certain amount of SnSO4 was weighed and dissolved in ethanol, wherein the ratio of ethanol to SnSO4 (volume / mass) was 4 ml / g. This solution was then gradually added dropwise to a sealed container containing a certain amount of alumina. The mixture was dried at 130 ℃ for 8 hours and calcined at 600 ℃ for 2 hours to obtain an intermediate. This intermediate was then immersed in an aluminum phosphate solution. The amount of aluminum salt impregnated, calculated as alumina, was 10.0 wt% of the catalyst mass, and citric acid accounted for 0.2 wt% of the total catalyst mass. The solution was then 145... o Dry at C for 5 hours, 800 o The catalyst Cat-D, prepared by calcining C for 2 hours, has a tin content of 30 wt%.
[0033] Example 4 According to the tin content of the active component, a certain amount of SnCl4·5H2O was weighed and dissolved in ethanol, wherein the ratio of ethanol to SnCl4 (volume / mass) was 3 ml / g. This solution was then gradually added dropwise to a sealed container containing a certain amount of alumina. The mixture was dried at 125 ℃ for 10 hours and calcined at 750 ℃ for 3 hours to obtain an intermediate. This intermediate was then immersed in a mixed solution of aluminum phosphate and aluminum nitrate. The amount of aluminum salt impregnated, calculated as alumina, was as follows: aluminum phosphate 7.7 wt%, aluminum nitrate 7.3 wt%, citric acid 0.5 wt% of the total catalyst mass. The solution was then 155... o Dry at C for 3 hours, 550 o After calcining C for 4 hours, the tin content in the catalyst Cat-E was 55 wt%.
[0034] Example 5 The performance of the catalysts prepared in Comparative Examples 1 and 2 for the dehydrogenation and ammoniaation of ethanol to acetonitrile was evaluated using a self-made small-scale reaction apparatus. The reactor diameter was 9 mm, the catalyst loading was 2 g, and the temperature was increased to 430 °C at a rate of 10 °C / min under a nitrogen atmosphere. Ethanol and ammonia were introduced, and the evaluation time was 74 h. The reaction conditions were: temperature 430 °C, pressure 0.1 MPa, and ethanol mass hourly space velocity (HHSV) 1.0 h⁻¹. -1 The molar ratio of ammonia to ethanol was 4:1. The products were analyzed using an Agilent 7890A GC, and the specific evaluation results are shown in Table 1.
[0035] Example 6 The performance of the catalyst prepared in Example 1 for the dehydrogenation and ammoniaation of ethanol to acetonitrile was evaluated using a self-made small-scale reaction apparatus. The reactor diameter was 9 mm, the catalyst loading was 2 g, and the temperature was increased to 430 °C at a rate of 10 °C / min under a nitrogen atmosphere. Ethanol and ammonia were introduced, and the evaluation time was 74 h. The reaction conditions were: temperature 430 °C, pressure 0.1 MPa, and ethanol mass hourly space velocity (HHSV) 1.0 h⁻¹. -1 The molar ratio of ammonia to ethanol was 4:1. The products were analyzed using an Agilent 7890A GC, and the specific evaluation results are shown in Table 1.
[0036] Example 7 The performance of the catalyst prepared in Example 2 for the dehydrogenation and ammoniaation of ethanol to acetonitrile was evaluated using a self-made small-scale reaction apparatus. The reactor diameter was 9 mm, the catalyst loading was 2 g, and the temperature was increased to 500 °C at a rate of 10 °C / min under a nitrogen atmosphere. Ethanol and ammonia were introduced, and the evaluation time was 74 h. The reaction conditions were: temperature 500 °C, pressure 0.1 MPa, and ethanol mass hourly space velocity (HHSV) 0.1 h⁻¹. -1 The molar ratio of ammonia to ethanol was 2:1. The products were analyzed using an Agilent 7890A GC, and the specific evaluation results are shown in Table 1.
[0037] Example 8 The performance of the catalyst prepared in Example 3 for the dehydrogenation and ammoniaation of ethanol to acetonitrile was evaluated using a self-made small-scale reaction apparatus. The reactor diameter was 9 mm, the catalyst loading was 2 g, and the temperature was increased to 450 °C at a rate of 10 °C / min under a nitrogen atmosphere. Ethanol and ammonia were introduced, and the evaluation time was 74 h. The reaction conditions were: temperature 550 °C, pressure 0.3 MPa, and ethanol mass hourly space velocity (HHSV) 0.3 h⁻¹. -1 The molar ratio of ammonia to ethanol was 4:1. The products were analyzed using an Agilent 7890A GC, and the specific evaluation results are shown in Table 1.
[0038] Example 9 The performance of the catalyst prepared in Example 4 for the dehydrogenation and amination of ethanol to acetonitrile was evaluated using a self-made small-scale reaction apparatus. The reactor diameter was 9 mm, the catalyst loading was 2 g, and the temperature was increased to 400 °C at a rate of 10 °C / min under a nitrogen atmosphere. Ethanol was then introduced, and the evaluation time was 74 h. The reaction conditions were: temperature 350 °C, pressure 0.5 MPa, and ethanol mass hourly space velocity (HHSV) 1.0 h⁻¹. -1 The molar ratio of ammonia to ethanol was 8:1. The products were analyzed using an Agilent 7890A GC, and the specific evaluation results are shown in Table 1.
[0039] Table 1 Catalyst Reaction Performance
[0040] The experimental results in Table 1 show that, compared with Comparative Example 1 Cat-A1 (single-loaded) and Comparative Example Cat-A2 (single-loaded and single-immersion in aluminum salt solution only), the catalyst prepared by double-immersion in a mixture of aluminum salt and citric acid (Cat-B) has significantly higher ethanol conversion and acetonitrile selectivity, but significantly lower high-boiling-point selectivity. Under the reaction conditions investigated, the prepared Cat-C, Cat-D and Cat-E catalysts exhibit excellent reaction performance.
[0041] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application 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 producing acetonitrile by dehydrogenation and amination of ethanol, characterized in that, A mixture of raw materials containing ethanol and ammonia is contacted with a catalyst and reacted to obtain a product containing acetonitrile. The catalyst includes tin oxide and aluminum oxide.
2. The method according to claim 1, characterized in that, The mass of tin is 1.0~55wt% of the catalyst mass, and the mass ratio of tin salt to ethanol is 1g:2~4mL.
3. The method according to claim 1, characterized in that, The catalyst is prepared by impregnating an alumina support with a tin salt dissolved in an ethanol solution, calcining it to obtain a SnAl2O3 intermediate, then soaking it in an aluminum salt and citric acid solution, and calcining it again to obtain the catalyst.
4. The method according to claim 3, characterized in that, The catalyst is soaked in an equal amount of aluminum salt, which accounts for 3 to 15 wt% of the catalyst mass based on aluminum oxide, and citric acid accounts for 0.1 to 0.5 wt% of the catalyst mass.
5. The method according to claim 3, characterized in that, The aluminum salt is selected from one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, and aluminum phosphate.
6. The method according to claim 3, characterized in that, The roasting temperature is selected from 500~800 ℃, and the roasting time is 2~4 h.
7. The method according to claim 1, characterized in that, The molar ratio of ammonia to ethanol is 2 to 8.
8. The method according to claim 1, characterized in that, The mass hourly space velocity (MSV) of the ethanol is 0.1–1.0 h⁻¹. -1 .
9. The method according to claim 1, characterized in that, The reaction pressure is 0.1~0.5MPa, and the reaction temperature is 350~500℃.