A process for the production of acetonitrile by the amination of acetate
By preparing a catalyst with a specific composition for the amination reaction of acetonitrile, the corrosiveness and selectivity problems in the production of acetonitrile in the prior art have been solved, and the production of acetonitrile with high conversion rate and high selectivity has been achieved, with good economic efficiency and simplicity.
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
- 2024-12-02
- Publication Date
- 2026-06-02
AI Technical Summary
Existing acetonitrile production methods suffer from problems such as high corrosivity, low selectivity, and difficulty in separating byproducts. In particular, the conversion rate and alcohol selectivity of the acetate amination method need to be improved.
A catalyst composed of a support and alkaline earth metal oxides and alkali metal oxides supported on the surface of the support is prepared by a specific process for the reaction of acetate with ammonia to produce acetonitrile. The catalyst is composed of supports such as silicon oxide and alumina, and magnesium oxide, calcium oxide, etc., with a loading of 0.01-10 wt%. The reaction conditions are 200-400℃, 0.1-1 MPa, acetate space velocity of 0.1-3 h⁻¹, and a molar ratio of ammonia to acetate of 1-60:1.
It achieves an acetate conversion rate of over 99%, an acetonitrile selectivity of over 99.5%, and a by-product alcohol selectivity of over 99.5%, exhibiting good economic efficiency and simple production characteristics.
Abstract
Description
Technical Field
[0001] This application relates to a method for producing acetonitrile by amination of acetate, which belongs to the field of chemical engineering. Background Technology
[0002] Acetonitrile is an important chemical and solvent used to prepare a variety of downstream chemicals. It is also a good solvent, widely used in industries such as electronic components, plastics, textiles, and cosmetics. Industrially, acetonitrile is primarily produced as a byproduct of acrylonitrile production via ammoxidation of propylene; therefore, acetonitrile production is always limited by acrylonitrile yield. Other acetonitrile production methods include ethanol ammoniation, acetic acid ammoniation, and acetylene ammoniation. However, these methods suffer from drawbacks such as high corrosivity, low selectivity, and difficulty in product separation.
[0003] The ammoniation of acetate to acetonitrile is a non-corrosive, mild reaction condition, and produces few easily separated byproducts, making it a promising route for acetonitrile production. CN113304764 discloses a supported catalyst for the ammoniation and dehydration of methyl acetate containing phosphate, nitrate, and boride to produce acetonitrile. Currently, the conversion rate and selectivity of acetonitrile production via acetate ammoniation still need further improvement. In addition to acetonitrile, acetate ammoniation also produces corresponding alcohols; therefore, to improve the overall economics of the process, the selectivity for alcohols also needs further enhancement. Summary of the Invention
[0004] According to one aspect of this application, a method for preparing acetonitrile by amination of acetate is provided, comprising the following steps:
[0005] In a reactor, acetate, ammonia, and catalyst are brought into contact and reacted to produce acetonitrile.
[0006] The acetate is selected from at least one of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and cyclohexyl acetate;
[0007] The catalyst consists of a support and alkaline earth metal oxides and alkali metal oxides supported on the surface of the support.
[0008] The carrier is selected from at least one of silicon dioxide, aluminum oxide, titanium dioxide, and zirconium oxide;
[0009] The alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide and barium oxide;
[0010] The alkali metal oxide is selected from at least one of lithium oxide, sodium oxide, and potassium oxide;
[0011] In the catalyst, the loading of alkaline earth metal oxide is 0.01-10 wt%, the loading of alkali metal oxide is 0.05-5 wt%, and the remainder is a support.
[0012] The catalyst is obtained through the following steps:
[0013] (1) Mix the carrier precursor with alkaline earth metal oxide, add an acid solution containing alcohol, stir, knead, shape into spheres or strips, dry, and calcine to obtain the catalyst precursor.
[0014] (2) An equal volume of an aqueous solution containing an alkali metal salt is impregnated onto the catalyst precursor, dried, and calcined to obtain the catalyst.
[0015] The carrier precursor is selected from at least one of silica sol, water glass, silica, tetraethyl silicate, γ-alumina, boehmite, aluminum isopropoxide, titanium dioxide, and zirconium dioxide.
[0016] The alcohol is selected from at least one of ethanol, propanol, and butanol;
[0017] The acids include organic acids and inorganic acids;
[0018] The organic acid is selected from at least one of acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, and benzoic acid;
[0019] The inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, and nitric acid;
[0020] In the acid solution containing alcohol, the mass fraction of alcohol is 0.1-10 wt%, the mass fraction of organic acid is 0.1-20 wt%, the mass fraction of inorganic acid is 0.1-30 wt%, and the remainder is water;
[0021] The total mass ratio of the carrier precursor and alkaline earth metal oxide to the mass ratio of the acid solution containing alcohol is 3 to 10:1.
[0022] The drying temperature is 100–140°C;
[0023] The drying time is 12–36 hours;
[0024] The roasting temperature is 300–600°C;
[0025] The roasting time is 3 to 24 hours.
[0026] The alkali metal salt is selected from at least one of lithium nitrate, sodium nitrate, potassium nitrate, lithium chloride, sodium chloride, and potassium chloride.
[0027] The drying temperature is 100–140°C;
[0028] The drying time is 12–36 hours;
[0029] The calcination temperature is 300–600°C;
[0030] The calcination time is 3 to 24 hours.
[0031] The reaction temperature is 200–400°C;
[0032] The reaction pressure is 0.1–1 MPa.
[0033] The space velocity of the acetate is 0.1–3 h⁻¹. -1 ;
[0034] The molar ratio of ammonia to acetate is 1 to 60:1.
[0035] The beneficial effects that this application can produce include:
[0036] 1) The catalyst for the production of acetonitrile from acetate provided in this application can achieve a conversion rate of more than 99% for acetate and a selectivity of more than 99.5% for acetonitrile when applied to the reaction of acetate and ammonia to produce acetonitrile.
[0037] 2) The catalyst preparation method for producing acetonitrile provided in this application is simple, easy to scale up, and the selectivity of by-product alcohols can reach more than 99.5%, which has good overall economic benefits. Detailed Implementation
[0038] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0039] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0040] In the embodiments of this application, the conversion rate and selectivity are calculated as follows:
[0041] Conversion rate of acetate = (1 - number of moles of acetate in the product / number of moles of acetate in the raw material) * 100%.
[0042] Selectivity of acetonitrile = (moles of acetonitrile in the product / (moles of acetate in the feed - moles of acetate in the product)) * 100%.
[0043] Alcohol selectivity = (moles of alcohol in product / (moles of acetate in feed - moles of acetate in product)) * 100%.
[0044] Example 1
[0045] 47.5 g of γ-alumina and 2.5 g of calcium oxide were mixed evenly and then added to a mixed solution of propanol-propionic acid-nitric acid, with concentrations of 0.5%, 2%, and 30% for propanol, propionic acid, and nitric acid, respectively. After thorough mixing, the mixture was shaped into spheres, dried at 120 °C for 24 hours, and calcined at 600 °C for 3 hours to obtain the catalyst precursor. 0.05 g of sodium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was then dried at 120 °C for 24 hours and calcined at 600 °C for 3 hours to obtain catalyst A. Catalyst A was loaded into a tubular reactor and reacted with methyl acetate and ammonia gas at a reaction temperature of 200 °C, a pressure of 0.1 MPa, and a methyl acetate space velocity of 0.1 h⁻¹. -1 The molar ratio of ammonia to methyl acetate was 50:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0046] Example 2
[0047] 317g of tetraethyl silicate and 5g of strontium oxide were mixed thoroughly and then added to a mixed solution of ethanol-butyric acid-sulfuric acid, with concentrations of 1%, 0.1%, and 30% for ethanol, butyric acid, and sulfuric acid, respectively. After thorough mixing, the mixture was shaped into spheres, dried at 100℃ for 36 hours, and calcined at 550℃ for 6 hours to obtain the catalyst precursor. 3.4g of sodium nitrate was prepared into an aqueous solution and impregnated onto the catalyst precursor in equal volume. The solution was then dried at 100℃ for 36 hours and calcined at 550℃ for 6 hours to obtain catalyst B. Catalyst B was loaded into a tubular reactor and methyl acetate and ammonia gas were introduced to react with the catalyst at a reaction temperature of 250℃, a pressure of 0.5 MPa, and a methyl acetate space velocity of 1 h⁻¹. -1 The molar ratio of ammonia to methyl acetate was 40:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0048] Example 3
[0049] 48g of silica and 0.005g of magnesium oxide were mixed evenly and then added to a 12g mixed solution of butanol, oxalic acid, and hydrochloric acid. The concentrations of butanol, oxalic acid, and hydrochloric acid were 0.1%, 1%, and 30%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 12 hours, and calcined at 500℃ for 24 hours to obtain the catalyst precursor. 4.6g of lithium nitrate was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was dried at 120℃ for 12 hours and calcined at 500℃ for 24 hours to obtain catalyst C. Catalyst C was loaded into a tubular reactor and reacted with ethyl acetate and ammonia gas at a reaction temperature of 300℃, a pressure of 0.1MPa, and an ethyl acetate space velocity of 3h⁻¹. -1 The molar ratio of ammonia to ethyl acetate was 60:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0050] Example 4
[0051] 66g of boehmite and 4g of barium oxide were mixed evenly, and then 13g of a mixed solution of ethanol-benzoic acid-hydrochloric acid was added. The concentrations of ethanol, benzoic acid, and hydrochloric acid were 10%, 0.5%, and 30%, respectively. After mixing evenly, the mixture was shaped into strips, dried at 140℃ for 15 hours, and calcined at 300℃ for 12 hours to obtain the catalyst precursor. 0.005g of potassium nitrate was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was dried at 140℃ for 15 hours and calcined at 300℃ for 12 hours to obtain catalyst D. Catalyst D was loaded into a tubular reactor and propyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 350℃, the pressure was 0.1MPa, and the propyl acetate space velocity was 1h. -1 The molar ratio of ammonia to propyl acetate was 20:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0052] Example 5
[0053] 350g of aluminum isopropoxide and 3.5g of calcium oxide were mixed evenly and then added to a 39g mixed solution of propanol-acetic acid-nitric acid, with concentrations of 2%, 20%, and 0.1% for propanol, acetic acid, and nitric acid, respectively. After thorough mixing, the mixture was shaped into spheres, dried at 120℃ for 15 hours, and calcined at 400℃ for 15 hours to obtain the catalyst precursor. 0.2g of potassium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was then dried at 120℃ for 15 hours and calcined at 400℃ for 15 hours to obtain catalyst E. Catalyst E was loaded into a tubular reactor and reacted with butyl acetate and ammonia gas at a reaction temperature of 400℃, a pressure of 0.1MPa, and a butyl acetate space velocity of 0.5h⁻¹. -1 The molar ratio of ammonia to butyl acetate was 1:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0054] Example 6
[0055] 48g of titanium dioxide and 1g of magnesium oxide were mixed evenly and then added to a mixed solution of ethanol-acetic acid-sulfuric acid, with concentrations of 5%, 10%, and 10% for ethanol, acetic acid, and sulfuric acid, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 12 hours, and calcined at 450℃ for 24 hours to obtain the catalyst precursor. 2.1g of lithium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was dried at 120℃ for 12 hours and calcined at 450℃ for 24 hours to obtain catalyst F. Catalyst F was loaded into a tubular reactor and cyclohexyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 350℃, the pressure was 0.1MPa, and the space velocity of cyclohexyl acetate was 2h⁻¹. -1The molar ratio of ammonia to cyclohexyl acetate was 30:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0056] Example 7
[0057] 46g of zirconium dioxide and 2.5g of calcium oxide were mixed evenly and then added to 8g of a mixed solution of ethanol-malonic acid-hydrochloric acid, with concentrations of 3%, 0.5%, and 25% for ethanol, malonic acid, and hydrochloric acid, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 24 hours, and calcined at 350℃ for 24 hours to obtain the catalyst precursor. 1.4g of sodium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was then dried at 120℃ for 24 hours and calcined at 350℃ for 24 hours to obtain catalyst G. Catalyst G was loaded into a tubular reactor and methyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 300℃, the pressure was 0.5MPa, and the methyl acetate space velocity was 1h⁻¹. -1 The molar ratio of ammonia to methyl acetate was 20:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0058] Example 8
[0059] 130g of 35% water glass and 3g of magnesium oxide were mixed thoroughly and then added to a 17g mixed solution of propanol-acetic acid-hydrochloric acid, with concentrations of 2%, 10%, and 20% for propanol, acetic acid, and hydrochloric acid, respectively. After thorough mixing, the mixture was shaped into spheres, dried at 140℃ for 12 hours, and calcined at 550℃ for 6 hours to obtain the catalyst precursor. 1.2g of potassium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was then dried at 140℃ for 12 hours and calcined at 550℃ for 6 hours to obtain catalyst H. Catalyst H was loaded into a tubular reactor and ethyl acetate and ammonia were introduced to react with the catalyst at a reaction temperature of 350℃, a pressure of 0.1MPa, and an ethyl acetate space velocity of 2h⁻¹. -1 The molar ratio of ammonia to ethyl acetate was 25:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0060] Example 9
[0061] 152g of 30% silica sol and 2.5g of calcium oxide were mixed evenly, and then 15g of a mixed solution of ethanol-acetic acid-nitric acid was added. The concentrations of ethanol, acetic acid, and nitric acid were 1%, 5%, and 30%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 36 hours, and calcined at 600℃ for 8 hours to obtain the catalyst precursor. 2.8g of lithium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was dried at 120℃ for 36 hours and calcined at 600℃ for 8 hours to obtain catalyst I. Catalyst I was loaded into a tubular reactor and methyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 400℃, the pressure was 0.1MPa, and the methyl acetate space velocity was 3h⁻¹. -1 The molar ratio of ammonia to methyl acetate was 45:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0062] Example 10
[0063] 70g of boehmite and 0.5g of calcium oxide were mixed evenly, and then 24g of a mixed solution of ethanol-acetic acid-nitric acid was added. The concentrations of ethanol, acetic acid, and nitric acid were 0.5%, 5%, and 30%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 36 hours, and calcined at 550℃ for 5 hours to obtain the catalyst precursor. 0.47g of sodium chloride was prepared into an aqueous solution, and an equal volume was impregnated onto the catalyst precursor. The solution was dried at 120℃ for 36 hours and calcined at 550℃ for 5 hours to obtain catalyst J. Catalyst J was loaded into a tubular reactor, and methyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 300℃, the pressure was 0.1MPa, and the methyl acetate space velocity was 1h⁻¹. -1 The molar ratio of ammonia to methyl acetate was 30:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0064] Comparative Example 1
[0065] 47.5 g of γ-alumina and 2.5 g of calcium oxide were mixed thoroughly and then added to a 30% nitric acid solution (16.7 g of nitric acid). After thorough mixing, the mixture was shaped into spheres, dried at 120 °C for 24 hours, and calcined at 600 °C for 3 hours to obtain catalyst K. Catalyst K was loaded into a tubular reactor and reacted with methyl acetate and ammonia gas at 200 °C and 0.1 MPa, with a methyl acetate space velocity of 0.1 h⁻¹. -1 The molar ratio of ammonia to methyl acetate was 50:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0066] Table 1 Results of acetate amination reaction
[0067] No. Conversion % Acetonitrile selectivity % Alcohol selectivity % Example 1 99.2 99.6 99.5 Example 2 99.4 99.7 99.7 Example 3 99.6 99.5 99.5 Example 4 99.3 99.6 99.6 Example 5 99.5 99.8 99.8 Example 6 99.4 99.7 99.8 Example 7 99.2 99.7 99.6 Example 8 99.6 99.6 99.7 Example 9 99.1 99.5 99.5 Example 10 99.5 99.5 99.6 Comparative Example 1 99.3 87.5 91.4
[0068] 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 preparing acetonitrile by amination of acetate, characterized in that, Includes the following steps: In a reactor, acetate, ammonia, and catalyst are brought into contact and reacted to produce acetonitrile. The acetate is selected from at least one of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and cyclohexyl acetate; The catalyst consists of a support and alkaline earth metal oxides and alkali metal oxides supported on the surface of the support. The carrier is selected from at least one of silicon dioxide, aluminum oxide, titanium dioxide, and zirconium oxide; The alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide and barium oxide; The alkali metal oxide is selected from at least one of lithium oxide, sodium oxide, and potassium oxide; In the catalyst, the loading of alkaline earth metal oxide is 0.01-10 wt%, the loading of alkali metal oxide is 0.05-5 wt%, and the remainder is a support.
2. The method according to claim 1, characterized in that, The catalyst is obtained through the following steps: (1) Mix the carrier precursor with alkaline earth metal oxide, add an acid solution containing alcohol, stir, knead, shape into spheres or strips, dry, and calcine to obtain the catalyst precursor. (2) An equal volume of an aqueous solution containing an alkali metal salt is impregnated onto the catalyst precursor, dried, and calcined to obtain the catalyst.
3. The method according to claim 2, characterized in that, The carrier precursor is selected from at least one of silica sol, water glass, silica, tetraethyl silicate, γ-alumina, boehmite, aluminum isopropoxide, titanium dioxide, and zirconium dioxide. The alcohol is selected from at least one of ethanol, propanol, and butanol; The acids include organic acids and inorganic acids; The organic acid is selected from at least one of acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, and benzoic acid; The inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, and nitric acid; In the acid solution containing alcohol, the mass fraction of alcohol is 0.1-10 wt%, the mass fraction of organic acid is 0.1-20 wt%, the mass fraction of inorganic acid is 0.1-30 wt%, and the remainder is water; The total mass ratio of the carrier precursor and alkaline earth metal oxide to the mass ratio of the acid solution containing alcohol is 3 to 10:
1. The drying temperature is 100–140°C; The drying time is 12–36 hours; The roasting temperature is 300–600°C; The roasting time is 3 to 24 hours.
4. The method according to claim 2, characterized in that, The alkali metal salt is selected from at least one of lithium nitrate, sodium nitrate, potassium nitrate, lithium chloride, sodium chloride, and potassium chloride. The drying temperature is 100–140°C; The drying time is 12–36 hours; The calcination temperature is 300–600°C; The calcination time is 3 to 24 hours.
5. The method according to claim 1, characterized in that, The reaction temperature is 200–400°C; The reaction pressure is 0.1–1 MPa.
6. The method according to claim 1, characterized in that, The space velocity of the acetate is 0.1–3 h⁻¹. -1 ; The molar ratio of ammonia to acetate is 1 to 60:1.