In-situ preparation method of a catalyst, catalyst prepared by the method and application thereof
By introducing a gasified mixture containing nitrogen and/or phosphorus into a carrier reactor through an in-situ preparation method, the problem of uneven introduction of catalyst active components is solved, and a uniform distribution of catalyst active centers and improved acetonitrile selectivity are achieved. This method is suitable for the safe and stable production of the reaction between acetate and NH3.
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 catalyst preparation methods make it difficult to achieve uniform introduction of active ingredients or auxiliary substances, resulting in poor performance of supported catalysts. Furthermore, acetonitrile production methods suffer from problems such as strong corrosivity, high cost, and slow reaction rate.
An in-situ preparation method is used to introduce a gasified mixture containing nitrogen and/or phosphorus into a carrier reactor. The active components and additives are uniformly introduced through heat treatment to prepare a catalyst loaded with nitrogen and/or phosphorus for the reaction of acetate with NH3 to produce acetonitrile.
It achieves uniform distribution of catalyst active centers, suppresses side reactions, improves acetonitrile selectivity and atom utilization, avoids corrosion of reaction equipment, and is suitable for continuous, stable, and large-scale production.
Smart Images
Figure BDA0005167088910000061 
Figure BDA0005167088910000071
Abstract
Description
Technical Field
[0001] This application relates to an in-situ preparation method of a catalyst, the catalyst prepared therefrom, and its application, belonging to the field of chemical engineering. Background Technology
[0002] Catalyst preparation is a crucial process and technology for regulating and determining catalyst performance. A key step is the introduction of active and auxiliary substances into a support or the overall composition. For supported catalysts, the primary method for introducing active components or auxiliary substances is a one-time, integral introduction. This involves reacting a precursor solution containing the active component or auxiliary substance with the support, followed by adsorption, surface functional group interactions, and other processes to load the relevant components onto the support surface. Subsequent drying and heat treatment processes then yield the catalyst with the loaded active components.
[0003] Therefore, based on the current state of technology, there is still a need to develop in-situ catalyst preparation methods to achieve uniform introduction of active ingredients or auxiliary substances, thereby realizing a more flexible and controllable method for preparing supported catalysts.
[0004] Currently, acetonitrile is mainly produced as a byproduct of acrylonitrile production. Therefore, its output is limited by acrylonitrile production. Other acetonitrile production methods include ethanol ammoniation and acetic acid ammoniation. These methods suffer from drawbacks such as high corrosivity and high cost, and are not yet industrially applied.
[0005] Therefore, there is still a need to develop new acetonitrile production methods and catalysts that are non-corrosive, have safe operating conditions, fast reaction rates, high reaction conversion and atom utilization rates, and stable reactions. Summary of the Invention
[0006] According to one aspect of this application, a method for in-situ preparation of a catalyst is provided, which can modulate the acid properties of the catalyst to make it suitable for the reaction of acetate with ammonia. The method includes the following steps:
[0007] The nitrogen-containing and / or phosphorus-containing substances are gasified to obtain a mixed gas, which is then introduced into a reactor containing a carrier for heat treatment I, followed by heat treatment II at a different atmosphere to obtain the catalyst.
[0008] The carrier is selected from at least one of alumina, molecular sieve, silicon dioxide, and titanium dioxide.
[0009] The nitrogen-containing substance is selected from at least one of ammonia water, urea aqueous solution, ammonium carbonate aqueous solution, ammonium bicarbonate aqueous solution, and ammonium chloride aqueous solution, with a mass concentration of 0.1% to 5%.
[0010] The phosphorus-containing substance is selected from at least one of phosphoric acid aqueous solution, ammonium phosphate aqueous solution, ammonium hydrogen phosphate aqueous solution, and ammonium dihydrogen phosphate aqueous solution, with a mass concentration of 0.1% to 5%.
[0011] The vaporization temperature is 200–500°C;
[0012] The space velocity of the gas mixture is 500–2000 mlg. -1 h -1 .
[0013] The temperature of heat treatment I is 200–500°C;
[0014] The heat treatment I is performed for 3 to 24 hours.
[0015] The atmosphere for heat treatment II is a nitrogen atmosphere, an oxygen atmosphere, or air;
[0016] The space velocity of the atmosphere in heat treatment II is 50–1000 mlg. -1 h -1 ;
[0017] The temperature of heat treatment II is 200–500°C;
[0018] The heat treatment II lasts for 3 to 24 hours.
[0019] According to another aspect of this application, a catalyst prepared by the above-described preparation method is provided, wherein the catalyst is the support supported on nitrogen and / or phosphorus.
[0020] According to another aspect of this application, a method for producing acetonitrile by reacting acetate with NH3 is provided, wherein a raw material containing acetate and NH3 is contacted with a catalyst in a reactor and reacted to obtain a product containing acetonitrile.
[0021] The acetate esters include at least one selected from methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and cyclohexyl acetate;
[0022] The catalyst is the catalyst described above;
[0023] The reaction pressure is 0.1–1.0 MPa;
[0024] The reaction temperature is 200–450°C;
[0025] In the raw materials, the molar ratio of acetate to NH3 is 40 to 1:1;
[0026] In the raw materials, the space velocity of acetate is 0.1-5.0 g. . g -1. h -1 .
[0027] The beneficial effects that this application can produce include:
[0028] 1) The catalyst preparation method provided in this application can achieve uniform introduction of active components and additives, and the active centers of the prepared catalyst are uniformly distributed, which is beneficial to improving the activity and selectivity of the catalyst.
[0029] 2) The catalyst prepared by the catalyst preparation method provided in this application can suppress side reactions in the reaction of acetate and NH3, and achieve high acetonitrile selectivity.
[0030] 3) The acetonitrile preparation reaction system of acetate-NH3 provided in this application avoids corrosion of reaction equipment, has mild reaction conditions, high atom utilization, and is suitable for continuous, stable large-scale production. Detailed Implementation
[0031] The present invention will be further described below with reference to embodiments, but this application is not limited to these embodiments. Unless otherwise specified, the raw materials used in the embodiments of this application were all purchased commercially.
[0032] In the embodiments of this application, the conversion rate and selectivity are calculated as follows:
[0033] Conversion rate of acetate = (1 - moles of acetate in product / moles of acetate in feed) * 100%
[0034] Selectivity of acetonitrile = (moles of acetonitrile in the product / (moles of acetate in the feed - moles of acetate in the product)) * 100%
[0035] Example 1
[0036] A 2% ammonia solution was vaporized at 200°C and then passed into a tubular reactor containing a carrier bed of 50 g ZSM-5 molecular sieve carrier. The gas space velocity was 1500 ml / g. -1 h -1 After being treated at 200℃ for 10 hours, the atmosphere was switched to air, with a gas hourly space velocity of 500 ml / g. -1 h -1 Catalyst A was prepared by treating the mixture at 400℃ for 8 hours. Catalyst A was then used in the reaction of methyl acetate with NH3, with a feed space velocity of 1 g for methyl acetate. . g -1. h -1 The molar ratio of urethane to amino ester was 10, the reaction temperature was 350℃, and the reaction pressure was 0.5MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0037] Example 2
[0038] A 5% urea aqueous solution was vaporized at 300°C and then passed into a tubular reactor containing a carrier bed of 50 g silica carrier. The gas space velocity was 2000 ml / g. -1 h -1 After treating at 350℃ for 3 hours, the atmosphere was switched to nitrogen, with a gas hourly space velocity (GHSV) of 50 ml / g. -1 h -1 Catalyst B was prepared by treating the mixture at 200℃ for 24 hours. Catalyst B was then used in the reaction of ethyl acetate with NH3, with a feed space velocity of 0.5 g / L for ethyl acetate. . g -1. h -1 The reaction mixture had a urethane molar ratio of 5, a reaction temperature of 300℃, and a reaction pressure of 0.3MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0039] Example 3
[0040] A 1% ammonium carbonate aqueous solution was vaporized at 400°C and then passed into a tubular reactor containing a supported bed of 50 g alumina. The gas space velocity was 1000 ml / g. -1 h -1 After being treated at 450℃ for 12 hours, the atmosphere was switched to oxygen, with a gas hourly space velocity (GHSV) of 200 ml / g. -1 h -1 Catalyst C was prepared by treating the mixture at 300℃ for 12 hours. Catalyst C was then used in the reaction of propyl acetate with NH3, with a propyl acetate feed space velocity of 0.1 g / L. . g -1. h -1 The reaction mixture was prepared with a urethane molar ratio of 1, at a temperature of 400℃ and a pressure of 0.1 MPa. The chromatographic analysis of the reaction products is shown in Table 1.
[0041] Example 4
[0042] A 1.5% ammonium bicarbonate aqueous solution was vaporized at 400°C and then passed into a tubular reactor containing a supported bed of 50 g titanium dioxide. The gas hourly space velocity (HSV) was 1500 ml / g. -1 h -1 After being treated at 500℃ for 8 hours, the atmosphere was switched to air, with a gas hourly space velocity of 1000 mlg / g. -1 h -1 Catalyst D was prepared by treating the mixture at 500℃ for 8 hours. Catalyst D was then used in the reaction of butyl acetate with NH3, with a feed space velocity of 2 g / L for butyl acetate. . g -1. h -1 The reaction mixture had a molar ratio of 1:5 for urethane and ester, a reaction temperature of 450℃, and a reaction pressure of 1 MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0043] Example 5
[0044] A 3% ammonium chloride aqueous solution was vaporized at 350°C and then passed into a tubular reactor containing a carrier bed of 50 g Y-type molecular sieve carrier. The gas space velocity was 1000 ml / g. -1 h -1 After continuous treatment at 400℃ for 12 hours, the atmosphere was switched to nitrogen, with a gas hourly space velocity (GHSV) of 700 ml / g. -1 h -1 Catalyst E was prepared by treating the mixture at 400℃ for 16 hours. Catalyst E was then used in the reaction of cyclohexyl acetate with NH3, with a feed space velocity of 1 g for cyclohexyl acetate. . g -1. h -1 The molar ratio of urethane to acetone was 20, the reaction temperature was 450℃, and the reaction pressure was 0.6 MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0045] Example 6
[0046] A 3% aqueous solution of phosphoric acid was vaporized at 450°C and then passed into a tubular reactor containing a supported bed of 50 g of Beta-type molecular sieve support. The gas hourly space velocity (HSV) was 500 ml / g. -1 h -1 After being treated at 450℃ for 16 hours, the atmosphere was switched to oxygen, with a gas hourly space velocity (GHSV) of 300 ml / g. -1 h -1 Catalyst F was prepared by treating the mixture at 300℃ for 8 hours. Catalyst F was then used in the reaction of cyclopentyl acetate with NH3, with a feed space velocity of 1 g for cyclohexyl acetate. . g -1. h -1 The reaction mixture had a urethane molar ratio of 30, a reaction temperature of 350℃, and a reaction pressure of 0.4 MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0047] Example 7
[0048] A 0.5% ammonium phosphate aqueous solution was vaporized at 500°C and then passed into a tubular reactor containing a supported bed of 50 g silica support. The gas hourly space velocity (HSV) was 800 ml / g. -1 h -1 After being treated at 500℃ for 6 hours, the atmosphere was switched to air, with a gas hourly space velocity of 600 mlg. -1 h -1 Catalyst G was prepared by treating the mixture at 400℃ for 6 hours. Catalyst G was then used in the reaction of methyl acetate with NH3, with a feed space velocity of 5 g / L for cyclohexyl acetate. . g -1. h -1The molar ratio of urethane to amino ester was 40, the reaction temperature was 450℃, and the reaction pressure was 0.3MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0049] Example 8
[0050] A 0.1% diammonium hydrogen phosphate aqueous solution was vaporized at 500°C and then passed into a tubular reactor containing a supported bed of 50 g alumina. The gas hourly space velocity (HSV) was 1200 ml / g. -1 h -1 After continuous treatment at 500℃ for 4 hours, the atmosphere was switched to nitrogen with a gas hourly space velocity (GHSV) of 100 ml / g. -1 h -1 Catalyst H was prepared by treating the mixture at 300℃ for 12 hours. Catalyst H was then used in the reaction of methyl acetate with NH3, with a feed space velocity of 2 g for cyclohexyl acetate. . g -1. h -1 The molar ratio of urethane to amino ester was 30, the reaction temperature was 350℃, and the reaction pressure was 0.1MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0051] Example 9
[0052] A 0.2% aqueous solution of ammonium dihydrogen phosphate was vaporized at 500°C and then passed into a tubular reactor containing a supported bed of 50 g titanium dioxide. The gas hourly space velocity (HSV) was 600 ml / g. -1 h -1 After being treated at 500℃ for 12 hours, the atmosphere was switched to oxygen, with a gas hourly space velocity (GHSV) of 400 ml / g. -1 h -1 Catalyst I was prepared by treating the mixture at 200℃ for 8 hours. Catalyst I was used in the reaction of methyl acetate with NH3, with a feed space velocity of 1 g for cyclohexyl acetate. . g -1. h -1 The molar ratio of urethane to amino ester was 20, the reaction temperature was 250℃, and the reaction pressure was 0.1MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0053] Example 10
[0054] A 1% ammonia solution and a 0.5% phosphoric acid solution were vaporized at 400°C and then passed into a tubular reactor containing a supported bed of 50 g alumina. The gas hourly space velocity (HSV) was 800 ml / g. -1 h -1 After treating at 450℃ for 6 hours, the atmosphere was switched to nitrogen, with a gas hourly space velocity (GHSV) of 800 ml / g. -1 h -1Catalyst J was prepared by treating the mixture at 400℃ for 12 hours. Catalyst J was then used in the reaction of methyl acetate with NH3, with a feed space velocity of 0.5 g for cyclohexyl acetate. . g -1. h -1 The molar ratio of urethane to amino ester was 10, the reaction temperature was 300℃, and the reaction pressure was 0.1MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0055] Comparative Example 1
[0056] 50 g of ZSM-5 molecular sieve support was added to 600 g of 2% ammonia water, stirred at 80°C for 10 hours, filtered, dried, and calcined at 200°C for 10 hours. The treated support was then loaded into the bed of a tubular reactor and pumped at a space velocity of 500 ml / g. -1 h -1 Catalyst K was prepared by treating air at 400°C for 8 hours. Catalyst K was then used in the reaction of methyl acetate with NH3, with a feed space velocity of 1 g / L for methyl acetate. . g -1. h -1 The molar ratio of urethane to amino ester was 10, the reaction temperature was 350℃, and the reaction pressure was 0.5MPa. The chromatographic analysis results of the reaction products are listed in Table 1.
[0057] Table 1
[0058]
[0059]
[0060] 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 in-situ preparation of a catalyst, characterized in that, Includes the following steps: The nitrogen-containing and / or phosphorus-containing substances are gasified to obtain a mixed gas, which is then introduced into a reactor containing a carrier. The mixture is subjected to heat treatment I, followed by heat treatment II at a different atmosphere, to obtain the catalyst.
2. The preparation method according to claim 1, characterized in that, The carrier is selected from at least one of alumina, molecular sieve, silicon dioxide, and titanium dioxide.
3. The preparation method according to claim 1, characterized in that, The nitrogen-containing substance is selected from at least one of ammonia water, urea aqueous solution, ammonium carbonate aqueous solution, ammonium bicarbonate aqueous solution, and ammonium chloride aqueous solution, with a mass concentration of 0.1% to 5%. The phosphorus-containing substance is selected from at least one of phosphoric acid aqueous solution, ammonium phosphate aqueous solution, ammonium hydrogen phosphate aqueous solution, and ammonium dihydrogen phosphate aqueous solution, with a mass concentration of 0.1% to 5%.
4. The preparation method according to claim 1, characterized in that, The vaporization temperature is 200–500°C; The space velocity of the gas mixture is 500–2000 mlg. -1 h -1 .
5. The preparation method according to claim 1, characterized in that, The temperature of heat treatment I is 200–500°C; The heat treatment time is 3 to 24 hours.
6. The preparation method according to claim 1, characterized in that, The atmosphere for heat treatment II is a nitrogen atmosphere, an oxygen atmosphere, or air; The space velocity of the atmosphere in heat treatment II is 50–1000 mlg. -1 h -1 ; The temperature of heat treatment II is 200–500°C; The heat treatment II lasts for 3 to 24 hours.
7. A catalyst prepared by the method according to any one of claims 1 to 6, characterized in that, The catalyst is the support loaded with nitrogen and / or phosphorus.
8. A method for producing acetonitrile by reacting acetate with NH3, characterized in that, In a reactor, a raw material containing acetate and NH3 is brought into contact with a catalyst and reacted to obtain a product containing acetonitrile. The catalyst is the catalyst according to claim 7; The acetate esters include at least one of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and cyclohexyl acetate.
9. The method according to claim 8, characterized in that, The reaction pressure is 0.1–1.0 MPa; The reaction temperature is 200–450°C.
10. The method according to claim 8, characterized in that, In the raw materials, the molar ratio of acetate to NH3 is 40 to 1:1; In the raw materials, the space velocity of acetate is 0.1-5.0 g. . g -1 . h -1 .