Solid complex copper catalyst and preparation and application thereof

Abstract

The invention relates to the technical field of preparation of isopentenoic acid intermediates, in particular to a solid complex copper catalyst, preparation of the solid complex copper catalyst and application of the solid complex copper catalyst in synthesis of the isopentenoic acid intermediates. The catalyst is prepared by stirring a copper-based catalyst and organic amine at room temperature until the copper-based catalyst and the organic amine are completely dissolved; adding an adhesive and a carrier into the system, uniformly mixing, tabletting, and calcining to obtain a solid catalyst; wherein the copper-based catalyst accounts for 5%-10% of the mass of the whole catalyst. According to the preparation method, the solid complex copper catalyst and the fixed reaction bed are adopted, continuous synthesis is achieved, the reaction yield is increased by 90% or above, the whole reaction period is shortened by 60% or above, zero wastewater discharge is achieved through aftertreatment, the production cost is reduced, and the national requirements for energy and consumption reduction and green chemical engineering are met.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of isopentanic acid intermediates, in particular to a solid complex copper catalyst and its preparation and application in synthesizing an isopentanic acid intermediate (1,1,1,3-tetrachloro-3-methylbutane). Background Art

[0002] Mesotrione (common name: mesotrione) is the second triketone herbicide successfully developed by Syngenta after sulcotrione. It is a leading product among HPPD inhibitor herbicides, and the third largest herbicide and the largest selective herbicide in the world. Among them, isopentanic acid is an important synthetic raw material for cyclohexanedione, an intermediate of mesotrione, and can also be used in the synthesis of pyrethroid pesticides; isopentanic acid, chemical name: 3-methyl-2-butenoic acid, currently the main domestic process uses 3-methyl-2-butenal as the starting material, copper catalyst and air oxidation to obtain 3-methyl-2-butenoic acid;

[0003] In the prior art, the preparation process of 3-methyl-2-butenoic acid is to use 3-methyl-2-butenal as the starting material and oxidize it with air using a copper catalyst. This preparation process has some defects:

[0004] 1. In the post-treatment process, the copper catalyst in the reaction liquid is removed, because after the reaction, the catalyst and a small amount of other components are bonded to form a viscous tar with high viscosity, and the filter cloth needs to be replaced frequently, which pollutes the environment;

[0005] 2. The reaction cycle is long and the reaction conversion rate is only 70% to 80%. The viscous tar produced in the process is not completely separated from the product. The viscous tar is easily entrained, which reduces the product yield and quality;

[0006] 3. Tarry substances are difficult to recycle and need to be disposed of as hazardous waste, which not only pollutes the environment but also increases costs.

[0007] 4. The oxidation process is a high-risk process with high safety risks. Summary of the invention

[0008] In order to solve the above technical problems, the present invention aims to provide a solid complex copper catalyst and its preparation and application in the synthesis of isopentenic acid intermediate (1,1,1,3-tetrachloro-3-methylbutane).

[0009] To achieve the above purpose, the present invention adopts the following technical solution:

[0010] A method for preparing a solid complex copper catalyst comprises the following steps: stirring a copper catalyst and an organic amine at room temperature until they are completely dissolved; adding an adhesive and a carrier to the system, mixing them evenly, pressing them into tablets, and calcining them to obtain a solid catalyst; wherein the copper catalyst accounts for 5% to 10% of the mass of the entire catalyst.

[0011] The calcination condition is calcination at 400° C. for 2 to 5 hours.

[0012] The copper catalyst is one or more of cuprous iodide, cuprous chloride, cuprous bromide, copper powder, and cupric acetate; preferably cuprous iodide, cuprous bromide

[0013] The organic amine is one or more of n-butylamine, tributylamine, ethanolamine, diisopropylamine, and triethylamine; preferably n-butylamine, ethanolamine

[0014] The molar ratio of the copper catalyst to the organic amine is 1-1.5:1, and the mass ratio of the organic amine to the whole catalyst is 5-15%.

[0015] The binder is one or more of aluminum sol, polyethylene glycol, methyl cellulose, and vinyl acetate resin, preferably vinyl acetate resin and aluminum sol; wherein the mass ratio of the binder to the copper catalyst is 2 to 5:1, and the binder accounts for 10 to 50% of the total catalyst mass ratio;

[0016] The carrier is one or more of kaolin, activated clay, activated carbon, diatomaceous earth and alumina, preferably alumina and activated carbon.

[0017] A solid complex copper catalyst prepared by the method is a flaky solid complex copper catalyst prepared by the method, which can be loaded into a fixed reaction bed, and continuous tubular catalytic synthesis replaces intermittent kettle synthesis, thereby avoiding the loss of copper-based catalysts and continuously maintaining high catalytic activity.

[0018] 1. Application of the catalyst, application of the catalyst in the synthesis of isopentanic acid.

[0019] The catalyst is used in synthesizing an isopentenic acid intermediate.

[0020] A method for synthesizing an isopentanic acid intermediate comprises the following steps: filling a catalyst into a three-dimensional reaction bed, maintaining the pressure in the reaction bed at 1-5 MPa by nitrogen punching, maintaining the temperature of the reaction bed at 100-250° C., mixing raw materials of isobutylene and carbon tetrachloride and adding them to the reaction bed, controlling the residence time at 1-20 min, and subjecting the outlet material to two-stage condensation and desolvation to obtain an isopentanic acid intermediate (1,1,1,3-tetrachloro-3-methylbutane).

[0021] The molar ratio of isobutylene to carbon tetrachloride is 1-1.2:1.

[0022] The catalyst loading amount is 5‰ to 1% of the total amount of the synthesized materials.

[0023] A method for synthesizing isopentanic acid, which uses the isopentanic acid intermediate (1,1,1,3-tetrachloro-3-methylbutane) prepared by using the above-obtained catalyst as a raw material and hydrolyzes it with acid to obtain 3-methyl-2-butenoic acid.

[0024] The above-obtained 1,1,1,3-tetrachloro-3-methylbutane was mixed with 98% concentrated sulfuric acid, heated to 80-100°C, water and liquid alkali were slowly added dropwise, and the temperature was kept for 2 hours after the addition. The pH was adjusted to 4 with 30% liquid alkali, and the temperature was slowly lowered to 0-10°C. White crystalline isopentenic acid was obtained by suction filtration.

[0025] The method of the present invention replaces the traditional esterification method, and specifically solves the problems of the original long process route, high production cost, serious equipment corrosion, large amount of three wastes, serious environmental pollution, etc., and creatively replaces the intermittent kettle reaction with a continuous tubular reaction, shortens the reaction cycle, improves the reaction yield, and reduces energy and consumption, and has good application prospects.

[0026] Beneficial effects of the present invention:

[0027] (1) The solid catalyst of the present invention is in the form of a pressed sheet and loaded into a fixed reaction bed for continuous tubular reaction. The reaction rate is controlled by the residence time. Compared with the original powdered catalyst, the catalyst loss is reduced and the catalytic activity is maintained for a long time. At the same time, the influence of the copper catalyst on impurities in the subsequent process is avoided.

[0028] (2) The present invention uses a new solid catalyst for continuous synthesis, simplifies the processing technology, and improves the yield of isopentenic acid intermediates. After multiple experiments, the average yield can reach more than 90%, which is a great improvement and improvement compared to the yield of about 70-80% in the prior art.

[0029] (3) The method for synthesizing isopentanic acid of the present invention solves the problems of long batch-type synthesis cycle, low reaction conversion rate, difficulty in reusing and treating existing catalysts, and low intrinsic safety by adopting fixed reaction bed and microchannel continuous technology, thereby successfully shortening the reaction cycle by 60% and achieving zero wastewater discharge. DETAILED DESCRIPTION

[0030] The specific implementation modes of the present invention are further described below in conjunction with examples. It should be noted that the specific implementation modes described here are only for illustrating and explaining the present invention, and are not limited to the present invention.

[0031] Embodiment 1:

[0032] In a 250ml three-necked flask equipped with an electric stirrer and a thermometer, add 12.38g (0.125×1mol) of cuprous iodide and 9.13g (0.125×1mol) of n-butylamine, stir at room temperature for 1 hour until all of them are dissolved, add 37.14g of vinyl acetate resin and 123.8g of aluminum chloride, mix well, and use a tablet press to form a flake catalyst, which is then sent to a muffle furnace and calcined at 400°C for 2 hours to obtain a solid complex copper catalyst.

[0033] Embodiment 2:

[0034] In a 500ml three-necked flask equipped with an electric stirrer and a thermometer, add 24.76g (0.25×1mol) of cuprous iodide and 18.26g (0.25×1mol) of n-butylamine, stir at room temperature for 1 hour until all are dissolved, add 74.28g of vinyl acetate resin and 247.6g of aluminum chloride, mix well, press into a flake catalyst, and send to a muffle furnace for calcination at 400°C for 2 hours to obtain a solid complex copper catalyst.

[0035] Embodiment 3:

[0036] In a 500ml three-necked flask equipped with an electric stirrer and a thermometer, add 24.76g (0.25×1mol) of cuprous iodide and 18.26g (0.25×1mol) of n-butylamine, stir at room temperature for 1 hour until all are dissolved, add 74.28g of vinyl acetate resin and 247.6g of aluminum chloride, mix well, press into a flake catalyst, and send to a muffle furnace for calcination at 400°C for 2 hours to obtain a solid complex copper catalyst.

[0037] Example 4

[0038] In a 500ml three-necked flask equipped with an electric stirrer and a thermometer, add 35.75g (0.25×1mol) cuprous bromide and 15.25g (0.25×1mol) ethanolamine, stir at room temperature for 1 hour until all are dissolved, add 74.28g aluminum sol and 247.6g activated carbon, mix well, press into a flake catalyst, and send to a muffle furnace for calcination at 400°C for 2 hours to obtain a solid complex copper catalyst.

[0039] Example 5

[0040] 60 g of the calcined catalyst obtained in Example 1 was taken and filled into a fixed reaction bed (vertical tubular reactor, with an internal filling tube of 20 mm in diameter and 50 cm in length, and a heating jacket), and nitrogen was filled into the reaction bed to maintain a pressure of 3 MPa, and the temperature was raised to 150° C. In another 250 ml three-necked flask equipped with an electric stirrer and a thermometer, 28.0 g (0.5×1 mol) of isobutylene and 88.45 g (0.5×1.15 mol) of carbon tetrachloride were added, and the mixture was stirred evenly at room temperature, and the mixture was pumped into the fixed reaction bed using a horizontal flow pump, and the flow rate was controlled to remain at 10 min, and the discharge port receiving bottle was coated with 0° C. ice water for cooling. After the operation was completed, the temperature was raised and negative stripping was performed to obtain 105.93 g of 1,1,1,3-tetrachloro-3-methylbutane, with a normalized content of 98.5% and a yield of about 90%;

[0041] Embodiment 6:

[0042] 120 g of the calcined catalyst obtained in Example 2 was taken and filled into a fixed reaction bed, and nitrogen was charged into the reaction bed to maintain a pressure of 3 MPa, and the temperature was raised to 150° C. In another 250 ml three-necked flask equipped with an electric stirrer and a thermometer, 56.0 g (1×1 mol) of isobutylene and 176.9 g (1×1.15 mol) of carbon tetrachloride were added, and the mixture was stirred evenly at room temperature, and the mixture was pumped into the fixed reaction bed using a horizontal flow pump, and the flow rate was controlled to stay at 10 min. The discharge port receiving bottle was covered with 0° C. ice water for cooling. After the operation was completed, the temperature was raised and negative stripping was performed to obtain 211.86 g of 1,1,1,3-tetrachloro-3-methylbutane, with a normalized content of 96% and a yield of about 90.1%;

[0043] Embodiment 7:

[0044] 120 g of the calcined catalyst of Example 3 was taken and filled into a fixed reaction bed, and nitrogen was charged into the reaction bed to maintain a pressure of 3 MPa, and the temperature was raised to 150° C. In another 250 ml three-necked flask equipped with an electric stirrer and a thermometer, 56.0 g (1×1 mol) of isobutylene and 176.9 g (1×1.15 mol) of carbon tetrachloride were added, and the mixture was stirred evenly at room temperature, and the mixture was pumped into the fixed reaction bed using a horizontal flow pump, and the flow rate was controlled to stay at 10 min. The discharge port receiving bottle was covered with 0° C. ice water for cooling. After the operation was completed, the temperature was raised and negative stripping was performed to obtain 212.0 g of 1,1,1,3-tetrachloro-3-methylbutane, with a normalized content of 96% and a yield of about 90.3%;

[0045] Example 8

[0046] In a 500ml three-necked flask equipped with an electric stirrer and a thermometer, add 210g (1mol) 1,1,1,3-tetrachloro-3-methylbutane and 2.1g 98% concentrated sulfuric acid, heat to 80-100°C, slowly drop 40g water, 600g 30% liquid caustic soda tail gas absorption, keep warm for 2h after the dropwise addition, adjust the pH to 4 with 30% liquid caustic soda, slowly cool to 0-10°C, filter and obtain 98.3g white crystalline isopentenic acid, the analytical content is 97.11%, and the yield is about 95.8%

[0047] The above embodiments are only for illustrating the technical concept and technical features of the present invention, and cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a solid complex copper catalyst, characterized in that: The copper catalyst and organic amine are stirred at room temperature until they are completely dissolved; then a binder and a carrier are added to the system, mixed evenly, pressed into tablets, and calcined to obtain a solid catalyst; wherein the copper catalyst accounts for 5% to 10% of the total catalyst mass ratio.

2. The method for preparing a solid complex copper catalyst according to claim 1, characterized in that: The copper-based catalyst is one or more of cuprous iodide, cuprous chloride, cuprous bromide, copper powder, and cupric acetate; The organic amine is one or more of n-butylamine, tributylamine, ethanolamine, diisopropylamine and triethylamine; The molar ratio of the copper catalyst to the organic amine is 1-1.5:1, and the mass ratio of the organic amine to the whole catalyst is 5-15%.

3. The method for preparing a solid complex copper catalyst according to claim 1, characterized in that: The binder is one or more of aluminum sol, polyethylene glycol, methyl cellulose, and vinyl acetate resin; wherein the mass ratio of the binder to the copper catalyst is 2 to 5:1, and the binder accounts for 10 to 50% of the total catalyst mass ratio; The carrier is one or more of kaolin, activated clay, activated carbon, diatomaceous earth and alumina.

4. A solid complex copper catalyst prepared by the method of claim 1, characterized in that: The obtained flake-shaped solid complex copper catalyst is prepared by the method of claim 1.

5. An application of the catalyst according to claim 1, characterized in that: The catalyst is used in the synthesis and preparation of isopentanic acid.

6. The use of the catalyst according to claim 1, characterized in that: The catalyst is used in synthesizing an isopentenic acid intermediate.

7. A method for synthesizing an isopentenic acid intermediate, characterized in that: The catalyst described in claim 4 is filled into a three-dimensional reaction bed, and the pressure in the reaction bed is maintained at 1-5 MPa by nitrogen pressing, and the temperature of the reaction bed is maintained at 100-250° C., and the raw materials of isobutylene and carbon tetrachloride are mixed and added to the reaction bed, and the residence time is controlled at 1-20 min. The outlet material is subjected to two-stage condensation and desolvation to obtain an isopentenic acid intermediate (1,1,1,3-tetrachloro-3-methylbutane).

8. The method for synthesizing an isopentenic acid intermediate according to claim 7, characterized in that: The molar ratio of isobutylene to carbon tetrachloride is 1-1.2:

1.

9. A method for synthesizing isopentenic acid, characterized in that: The isopentenic acid intermediate (1,1,1,3-tetrachloro-3-methylbutane) prepared by using the catalyst of claim 4 is used as a raw material and subjected to acid hydrolysis to obtain 3-methyl-2-butenoic acid.