A process for the production of acetonitrile
By using catalysts supported by specific molecular sieves, and loading divalent transition metal oxides and alkali metal oxides, the problems of insufficient conversion and selectivity in the acetate amination process were solved, and efficient acetonitrile production was achieved.
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 product separation. In particular, the conversion rate and selectivity of the acetate amination method need to be further improved.
Acetonitrile is prepared by reacting acetate with ammonia using ZSM-5, ZSM-11, ZSM-35, MCM-22, Beta or Y-type molecular sieves as supports and catalysts composed of divalent transition metal oxides, alkaline earth metal oxides and alkali metal oxides. The catalyst is prepared by mixing, molding, drying, calcining and calcining steps.
The catalyst improved the conversion rate of acetate and the selectivity of acetonitrile, and also significantly enhanced the selectivity of alcohols. The catalyst preparation method is simple and easy to scale up for production.
Abstract
Description
Technical Field
[0001] This application relates to a method for producing acetonitrile, which belongs to the field of chemical engineering. Background Technology
[0002] Acetonitrile is an important chemical intermediate and solvent. It can be used to produce a variety of downstream nitrogen-containing compounds. Currently, acetonitrile is mainly produced as a byproduct of acrylonitrile production via the ammoxidation of propylene. To avoid being affected by acrylonitrile production, other methods for directly producing acetonitrile are being developed, including ethanol ammoxidation, acetic acid ammoxidation, and acetylene ammoxidation. However, these methods have 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. During acetate ammoniation, in addition to acetonitrile, corresponding alcohols are also produced, which can be recycled to produce acetate. To improve the overall economic efficiency of the process, the selectivity of the alcohols also needs further improvement. Summary of the Invention
[0004] According to one aspect of this application, a method for producing acetonitrile 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 is composed of a support and divalent transition metal oxides, 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 ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-35 molecular sieve, MCM-22 molecular sieve, Beta molecular sieve, and Y-type molecular sieve;
[0009] The divalent transition metal oxide is selected from at least one of manganese oxide, ferrous oxide, cobalt oxide, nickel oxide, copper oxide, and zinc oxide;
[0010] The alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide and barium oxide;
[0011] The alkali metal oxide is selected from at least one of lithium oxide, sodium oxide, and potassium oxide;
[0012] In the catalyst, the loading of divalent transition metal oxides is 0.01–10 wt%, the loading of alkaline earth metal oxides is 0.01–5 wt%, the loading of alkali metal oxides is 0.01–5 wt%, and the remainder is a support.
[0013] The catalyst is obtained through the following steps:
[0014] (1) Mix the carrier, divalent transition metal oxide, alkaline earth metal oxide and binder, add an acid solution containing alcohol, stir, knead, shape into spheres or strips, dry and calcine to obtain catalyst precursor;
[0015] (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.
[0016] The adhesive is selected from at least one of silicon dioxide or aluminum oxide;
[0017] The alcohol is selected from at least one of ethanol, propanol, and butanol;
[0018] The acids include organic acids and inorganic acids;
[0019] The organic acid is selected from at least one of acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, and benzoic acid;
[0020] The inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, and nitric acid;
[0021] 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;
[0022] 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.
[0023] The drying temperature is 100–140°C;
[0024] The drying time is 12–36 hours;
[0025] The roasting temperature is 300–600°C;
[0026] The roasting time is 3 to 24 hours.
[0027] The alkali metal salt is selected from at least one of lithium nitrate, sodium nitrate, potassium nitrate, lithium chloride, sodium chloride, and potassium chloride.
[0028] The drying temperature is 100–140°C;
[0029] The drying time is 12–36 hours;
[0030] The calcination temperature is 300–600°C;
[0031] The calcination time is 3 to 24 hours.
[0032] The reaction temperature is 200–400°C;
[0033] The reaction pressure is 0.1–1 MPa.
[0034] The space velocity of the acetate is 0.1–3 h⁻¹. -1 ;
[0035] The molar ratio of ammonia to acetate is 1 to 60:1.
[0036] The beneficial effects that this application can produce include:
[0037] 1) The catalyst and preparation method for producing acetonitrile provided in this application can be used in the reaction of acetate with ammonia to produce acetonitrile, and have high acetate conversion rate and acetonitrile selectivity. The acetate conversion rate can reach over 99%, the acetonitrile selectivity can reach over 99.5%, and the alcohol selectivity can also reach over 99.5%.
[0038] 2) The catalyst preparation method for producing acetonitrile provided in this application is simple and easy to scale up for production. Detailed Implementation
[0039] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0040] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0041] In the embodiments of this application, the conversion rate and selectivity are calculated as follows:
[0042] Conversion rate of acetate = (1 - moles of acetate in product / moles of acetate in feed) * 100%
[0043] Selectivity of acetonitrile = (moles of acetonitrile in the product / (moles of acetate in the feed - moles of acetate in the product)) * 100%
[0044] Alcohol selectivity = (moles of alcohol in product / (moles of acetate in feed - moles of acetate in product)) * 100%
[0045] Example 1
[0046] 10g of ZSM-5 molecular sieve, 5g of zinc oxide, 2g of magnesium oxide, and 33g of silicon dioxide were mixed evenly and then added to a 5g mixed solution of ethanol-butyric acid-nitric acid, with concentrations of 2%, 1%, and 30% for ethanol, butyric acid, and nitric acid, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 24 hours, and calcined at 450℃ for 12 hours to obtain the catalyst precursor. 0.007g of lithium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor in equal volumes. The solution was dried at 120℃ for 24 hours and calcined at 450℃ for 12 hours to obtain catalyst A. Catalyst A 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 10:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0047] Example 2
[0048] 20g of ZSM-11 molecular sieve, 2.5g of copper oxide, 0.005g of calcium oxide, and 27g of aluminum oxide were mixed evenly, and then 6g of a mixed solution of propanol-acetic acid-hydrochloric acid was added. The concentrations of propanol, acetic acid, and hydrochloric acid were 0.1%, 20%, and 20%, respectively. After mixing evenly, the mixture was shaped into strips, dried at 120℃ for 36 hours, and calcined at 500℃ for 8 hours to obtain the catalyst precursor. 1.2g of lithium nitrate 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 500℃ for 8 hours to obtain catalyst B. Catalyst B was loaded into a tubular reactor and ethyl acetate and ammonia were introduced to react with the catalyst. The reaction temperature was 350℃, the pressure was 0.1MPa, and the ethyl acetate space velocity was 2h⁻¹. -1 The molar ratio of ammonia to ethyl 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.
[0049] Example 3
[0050] 35g of ZSM-35 molecular sieve, 0.005g of nickel oxide, 1g of strontium oxide, and 13g of alumina were mixed evenly and then added to a 16g mixed solution of butanol-malonic acid-hydrochloric acid, with concentrations of butanol, malonic acid, and hydrochloric acid of 0.5%, 1%, and 25%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 100℃ for 12 hours, and calcined at 600℃ for 3 hours to obtain the catalyst precursor. 1.4g of sodium nitrate was prepared into an aqueous solution and impregnated onto the catalyst precursor in equal volume. The solution was dried at 100℃ for 12 hours and calcined at 600℃ for 3 hours to obtain catalyst C. Catalyst C was loaded into a tubular reactor and propyl acetate and ammonia were introduced to react with the catalyst at a reaction temperature of 400℃, a pressure of 1MPa, and a propyl acetate space velocity of 3h⁻¹. -1The molar ratio of ammonia to propyl 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.
[0051] Example 4
[0052] 25g of MCM-22 molecular sieve, 1.5g of cobalt oxide, 0.5g of barium oxide, and 20g of silicon oxide were mixed evenly, and then 9.5g of a mixed solution of ethanol-benzoic acid-sulfuric acid was added. The concentrations of ethanol, benzoic acid, and sulfuric acid were 10%, 0.1%, and 30%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 140℃ for 12 hours, and calcined at 300℃ for 24 hours to obtain the catalyst precursor. 2.4g of sodium chloride was prepared into an aqueous solution, and an equal volume was impregnated onto the catalyst precursor. The solution was dried at 140℃ for 12 hours and calcined at 300℃ for 24 hours to obtain catalyst D. Catalyst D was loaded into a tubular reactor, and butyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 200℃, the pressure was 0.5MPa, and the butyl acetate space velocity was 0.1h. -1 The molar ratio of ammonia to butyl 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.
[0053] Example 5
[0054] 15g of Beta molecular sieve, 3.5g of ferrous oxide, 1.5g of calcium oxide, and 28g of silicon dioxide were mixed evenly, and then 7g of a propanol-oxalic acid-nitric acid mixed solution was added. The concentrations of propanol, oxalic acid, and nitric acid were 1%, 2%, and 25%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 140℃ for 24 hours, and calcined at 400℃ for 18 hours to obtain the catalyst precursor. 1.2g of potassium chloride was prepared into an aqueous solution, and an equal volume was impregnated onto the catalyst precursor. The solution was dried at 140℃ for 24 hours and calcined at 400℃ for 18 hours to obtain catalyst E. Catalyst E was loaded into a tubular reactor and cyclohexyl acetate and ammonia gas were introduced to react with the catalyst. The reaction temperature was 250℃, the pressure was 0.1MPa, and the cyclohexyl acetate space velocity was 0.5h⁻¹. -1 The 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.
[0055] Example 6
[0056] 19g of Y-type molecular sieve, 0.5g of manganese monoxide, 0.25g of magnesium oxide, and 19g of aluminum oxide were mixed evenly, and then 12g of a mixed solution of ethanol-propionic acid-nitric acid was added. The concentrations of ethanol, propionic acid, and nitric acid were 5%, 1%, and 30%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 24 hours, and calcined at 550℃ for 6 hours to obtain the catalyst precursor. 0.3g of potassium nitrate was prepared into an aqueous solution, and an equal volume was impregnated onto the catalyst precursor. The solution was dried at 120℃ for 24 hours and calcined at 550℃ for 6 hours to obtain catalyst F. Catalyst F 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 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.
[0057] Example 7
[0058] 25g of ZSM-5 molecular sieve, 0.25g of ferrous oxide, 0.05g of magnesium oxide, and 25g of aluminum oxide were mixed evenly and then added to 10g of a mixed solution of ethanol-acetic acid-hydrochloric acid. The concentrations of ethanol, acetic acid, and hydrochloric acid were 8%, 20%, and 0.1%, respectively. After mixing evenly, the mixture was shaped into spheres, dried at 100℃ for 18 hours, and calcined at 600℃ for 4 hours to obtain the catalyst precursor. 0.05g of sodium chloride was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was dried at 100℃ for 18 hours and calcined at 600℃ for 4 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 400℃, the pressure was 0.1MPa, and the methyl acetate space velocity was 0.5h⁻¹. -1 The molar ratio of ammonia to methyl 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.
[0059] Example 8
[0060] 20g of Y-type molecular sieve, 1g of zinc oxide, 0.5g of calcium oxide, and 28g of silicon dioxide were mixed evenly and then added to a 17g mixed solution of propanol-acetic acid-nitric acid, with concentrations of 2%, 10%, and 20% for propanol, acetic acid, and nitric acid, respectively. After thorough mixing, the mixture was shaped into spheres, dried at 120℃ for 30 hours, and calcined at 500℃ for 10 hours to obtain the catalyst precursor. 0.7g of sodium nitrate was prepared into an aqueous solution and impregnated onto the catalyst precursor by an equal volume. The solution was then dried at 120℃ for 30 hours and calcined at 500℃ for 10 hours to obtain catalyst H. Catalyst H was loaded into a tubular reactor and methyl acetate and ammonia gas were introduced to react with the catalyst at a reaction temperature of 350℃, a pressure of 0.3MPa, and a methyl acetate space velocity of 1 h⁻¹. -1The molar ratio of ammonia to methyl acetate was 15:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0061] Comparative Example 1
[0062] 10g of ZSM-5 molecular sieve, 5g of zinc oxide, and 33g of silicon dioxide were mixed evenly, and then 5g of nitric acid solution (30% concentration) was added. After mixing evenly, the mixture was shaped into spheres, dried at 120℃ for 24 hours, and calcined at 450℃ for 12 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 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 10:1. The composition of the reaction products was analyzed by gas chromatography, and the calculated reaction results are listed in Table 1.
[0063] Table 1 Results of acetate amination reaction
[0064] Serial Number Conversion rate % Acetonitrile selectivity % Alcohol selectivity % Example 1 99.3 99.6 99.6 Example 2 99.4 99.5 99.7 Example 3 99.2 99.7 99.6 Example 4 99.5 99.6 99.5 Example 5 99.4 99.8 99.8 Example 6 99.1 99.5 99.8 Example 7 99.6 99.8 99.6 Example 8 99.5 99.6 99.7 Example 9 99.7 99.5 99.5 Example 10 99.3 99.8 99.6 Comparative Example 1 99.2 92.4 81.2
[0065] 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, 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 is composed of a support and divalent transition metal oxides, alkaline earth metal oxides and alkali metal oxides supported on the surface of the support. The carrier is selected from at least one of ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-35 molecular sieve, MCM-22 molecular sieve, Beta molecular sieve, and Y-type molecular sieve; The divalent transition metal oxide is selected from at least one of manganese oxide, ferrous oxide, cobalt oxide, nickel oxide, copper oxide, and zinc 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 divalent transition metal oxides is 0.01–10 wt%, the loading of alkaline earth metal oxides is 0.01–5 wt%, the loading of alkali metal oxides is 0.01–5 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, divalent transition metal oxide, alkaline earth metal oxide and binder, add an acid solution containing alcohol, stir, knead, shape into spheres or strips, dry and calcine to obtain 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 1, characterized in that, The adhesive is selected from at least one of silicon dioxide or aluminum oxide; 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.