A process for the production of iso-nonyl acid from diisobutene
By using nano-cobalt-based catalysts and alumina catalysts in a fixed-bed reactor to carry out the hydrogen esterification of diisobutylene and the hydrolysis of methyl isononanoate, the problem of poor catalyst stability was solved, and the industrial application of efficient synthesis of isononanoic acid was realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LANZHOU INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2023-10-13
- Publication Date
- 2026-07-31
AI Technical Summary
Existing methods for preparing isononanoic acid from diisobutylene suffer from poor catalyst stability, difficulty in reusing, and challenges in product separation, which limits their industrial application.
The hydrogen esterification of diisobutylene and the hydrolysis of methyl isononanoate were carried out in a fixed-bed reactor using nano-cobalt-based catalysts and alumina catalysts, respectively. By controlling the reaction conditions, isononanoic acid was synthesized efficiently.
This approach improves catalyst stability and isononanoic acid selectivity, simplifies the reaction process, makes it suitable for large-scale industrial production, and reduces separation costs.
Abstract
Description
Technical Field
[0001] This invention relates to the field of isononanoic acid synthesis technology, and more particularly to a method for generating isononanoic acid from diisobutylene. Background Technology
[0002] Isonononic acid, also known as 3,5,5-trimethylhexanoic acid, has a wide range of applications. It can be used as a raw material for synthesizing high-grade lubricating oils, pharmaceutical intermediates, and metalworking fluids. It can also be used to modify alkyd resins, significantly improving the oxidation resistance and impact resistance of resin materials. Furthermore, isonononoic acid is used in cosmetics, stabilizers, and plasticizers. For example, isonononate esters prepared by the esterification reaction of isonononoic acid with diols can be used as plasticizers for PVC or PVA; esters prepared by the condensation of isonononoic acid with ethylene can be used as polymer monomers to improve the properties of polymers such as polyvinyl acetate, polyvinyl chloride, polystyrene, and polyacrylates.
[0003] Currently, the main synthetic methods for preparing isononanoic acid from diisobutylene include two combined pathways: hydroformylation and oxidation, and hydrogen esterification and hydrolysis. Patent CN 201910818275.9 discloses a rhodium / organophosphine ligand catalytic system using a batch reactor, which can achieve high yields and high N / I ratios of isononanal and isononol under mild reaction conditions. Patent CN 202011641462.3 reports a method for preparing a palladium catalyst supported on activated carbon, which can efficiently catalyze the oxidation of isononanal and isononol to isononanoic acid. In the hydroformylation reaction, expensive rhodium is often used as the active center, increasing the production cost of the catalyst; in the oxidation process, oxygen is used as the oxidant, posing an explosion risk and limiting the widespread application of this process.
[0004] Two types of homogeneous catalytic systems, consisting of cobalt carbonyl / nitrogen-containing ligands (Fine Chemicals, 2001, 18, 109) and rhodium carbonyl / organophosphorus ligands (CN201810616930.8), exhibit excellent catalytic performance in the hydrogen esterification of diisobutylene to isonononate. However, due to problems such as poor stability, inability to be reused, and difficulty in product separation during the reaction, the homogeneous catalytic process is greatly limited in large-scale industrial applications.
[0005] In recent years, the study of heterogeneous catalysts for the hydroformylation and hydrogen esterification of diisobutylene has attracted widespread attention. CN201911220649.3 discloses a polymer catalyst that can be used for the hydroformylation reaction of diisobutylene, in which the active components Rh and Co are dispersed in a solid organic ligand polymer through coordination. However, the weak interaction between the metal ions and the ligand polymer results in poor catalyst stability. CN 202210919867.1 discloses a cobalt-based catalyst dispersed in a vinylpyridine or imidazole polymer. However, in the hydrogen esterification reaction of diisobutylene, the catalyst also suffers from poor stability and difficulty in application.
[0006] Therefore, developing more efficient and stable solid catalytic systems will help promote the further industrial application of diisobutylene carbonylation. Summary of the Invention
[0007] In view of this, the purpose of the present invention is to provide a method for producing isononanoic acid from diisobutylene. The method uses diisobutylene as raw material and synthesizes isononanoic acid efficiently through a two-step reaction of hydrogen esterification and hydrolysis under the action of a stable solid-phase catalyst.
[0008] The present invention provides a method for producing isononanoic acid from diisobutylene, comprising the following steps:
[0009] Step 1: Diisobutylene hydrogen esterification reaction:
[0010] Nano-cobalt-based catalyst was added to the reaction tube of a fixed-bed continuous flow reactor, and then diisobutylene, methanol and carbon monoxide were passed together through the catalyst bed to carry out a hydrogen esterification reaction to generate methyl isononanoate under the conditions of reaction temperature of 70-250℃ and reaction pressure of 0.5-15MPa.
[0011] Step 2: Hydrolysis reaction of methyl isononanoate:
[0012] An alumina catalyst is added to the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water, and nitrogen are passed through the catalyst bed together. The hydrolysis reaction is carried out at a reaction temperature of 100–300℃ and a reaction pressure of 0.5–5 MPa to produce isononanoic acid.
[0013] Preferably, the preparation method of the nano-cobalt-based catalyst in step one includes the following steps:
[0014] (1) Add cobalt nitrate and melamine to deionized water at a mass ratio of 1:4 to 5 to form a uniformly dispersed solution;
[0015] (2) Under vigorous stirring, add a formaldehyde solution with a mass concentration of 37wt% to the solution in step (1), heat to 75-85℃ and maintain for 24 hours; the mass ratio of the formaldehyde solution to cobalt nitrate is 5-7:1-2.
[0016] (3) Evaporate the moisture at 75-85℃, and dry the resulting solid at 110-115℃ for 12 hours;
[0017] (4) The solid dried in step (3) is calcined at 800°C for 4 hours in a nitrogen flow of 40 mL / min to obtain the nano-cobalt-based catalyst.
[0018] Preferably, the mass hourly space velocity (HHSV) of diisobutylene in step one is 0.1–5 h⁻¹. -1 The mass hourly space velocity (MSV) of methanol is 1.8–10 h⁻¹. -1 The carbon monoxide flow rate is 5–250 L / h.
[0019] Preferably, the particle size of the nano-cobalt-based catalyst in step one is 40-60 mesh.
[0020] Preferably, the preparation method of the alumina catalyst in step two includes the following steps:
[0021] S1. Dissolve aluminum nitrate in deionized water to obtain an aluminum nitrate solution with a concentration of 20 g / L;
[0022] S2. Add ammonia solution to the aluminum nitrate solution in step S1 and adjust the pH value to ≥9 to obtain a mixed solution; the concentration of ammonia solution is 1 mol / L.
[0023] S3. The mixed solution described in step S2 is aged at room temperature for 4 hours, filtered, and the filter cake is pulped and washed. This process is repeated several times until the pH of the filtrate is 7, resulting in a neutral filter cake.
[0024] S4. The neutral filter cake obtained in step S3 is dried at 110°C for 12 hours, and then calcined in air at 400°C for 4 hours to obtain the alumina catalyst.
[0025] Preferably, the particle size of the alumina catalyst in step two is 40-60 mesh.
[0026] Preferably, the mass hourly space velocity (HSV) of the methyl isononanoate in step two is 0.1–10 h⁻¹. -1 Nitrogen volume hourly space velocity is 20–2000 h⁻¹ -1 The mass hourly space velocity (MSV) of deionized water is 0.2–20 h⁻¹. -1 .
[0027] Compared with the prior art, the present invention has the following beneficial effects:
[0028] This invention provides a method for producing isononanoic acid from diisobutylene. In a fixed-bed reactor, diisobutylene, carbon monoxide, and methanol undergo a carbonylation reaction in the presence of a hydrogen esterification catalyst to generate methyl isononanoate. Subsequently, methyl isononanoate reacts with water in the presence of a solid acid catalyst to generate isononanoic acid. The above steps utilize a cobalt nano-based catalyst and an alumina catalyst to achieve the hydrogen esterification reaction of diisobutylene and the hydrolysis reaction of isononanoate, respectively, exhibiting excellent catalytic activity and selectivity for isononanoic acid. Both types of catalysts demonstrate good stability, are easily recyclable, and the continuous reaction process is simple and suitable for large-scale industrial production. Detailed Implementation
[0029] The present invention will be further described below with reference to the embodiments.
[0030] Example 1
[0031] A method for producing isononanoic acid from diisobutylene, comprising the following steps:
[0032] Step 1: Diisobutylene hydrogen esterification reaction:
[0033] After pressing the nano-cobalt-based catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Then, diisobutylene, methanol and carbon monoxide are passed through the catalyst bed together. Under the conditions of reaction temperature of 150℃ and reaction pressure of 6MPa, a hydrogen esterification reaction is carried out to generate methyl isononanoate.
[0034] The mass hourly space velocity (HHSV) of diisobutylene during the reaction was 0.2 h⁻¹. -1 The mass hourly space velocity (MSV) of methanol is 1.8 h⁻¹. -1 The carbon monoxide flow rate is 100 L / h.
[0035] The conversion rate of diisobutylene was 95.2%, and the selectivity of methyl isononanoate was 86.8%.
[0036] Step 2: Hydrolysis reaction of methyl isononanoate:
[0037] After pressing the alumina catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water and nitrogen are passed through the catalyst bed together, and hydrolysis reaction is carried out at a reaction temperature of 200℃ and a reaction pressure of 2MPa to generate isononanoic acid.
[0038] The mass hourly space velocity of the methyl isononanoate was 2 h⁻¹. -1 The nitrogen volume hourly space velocity is 2000 h⁻¹. -1 The mass hourly space velocity (MSV) of deionized water is 2 h⁻¹. -1 ;
[0039] The conversion rate of methyl isononanoate was 90.2%, and the selectivity of isononanoic acid was 99.5%.
[0040] The preparation method of the nano-cobalt-based catalyst described in step one is as follows:
[0041] (1) Add 10g Co(NO3)2·6H2O and 43g melamine to 350mL of deionized water to form a uniformly dispersed solution;
[0042] (2) Add 60g of formaldehyde solution (37wt%) to the solution obtained in step (1) under vigorous stirring, heat to 80℃ and keep for 24 hours;
[0043] (3) Evaporate the moisture at 80°C, and dry the resulting solid at 110°C for 12 hours;
[0044] (4) The sample obtained in step (3) is calcined at 800°C for 4 hours in a nitrogen flow of 40 mL / min to obtain the nano-cobalt-based catalyst.
[0045] The preparation method of the alumina catalyst described in step two is as follows:
[0046] S1. Dissolve 50g of Al(NO3)3·9H2O in deionized water to obtain an aluminum nitrate solution with a concentration of 20g / L;
[0047] S2. Add an ammonia solution with a concentration of 1 mol / L to the aluminum nitrate solution described in step S1, adjust the pH to 9, and obtain a mixed solution;
[0048] S3. The mixed solution described in step S2 is aged at room temperature for 4 hours, filtered, and the filter cake is pulped and washed. This process is repeated several times until the pH of the filtrate is 7, resulting in a neutral filter cake.
[0049] S4. The neutral filter cake obtained in step S3 is dried at 110°C for 12 hours, and then calcined in air at 400°C for 4 hours to obtain the alumina catalyst.
[0050] Example 2
[0051] A method for producing isononanoic acid from diisobutylene, comprising the following steps:
[0052] Step 1: Diisobutylene hydrogen esterification reaction:
[0053] After pressing the nano-cobalt-based catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Then, diisobutylene, methanol and carbon monoxide are passed through the catalyst bed together. Under the conditions of reaction temperature of 70℃ and reaction pressure of 6MPa, a hydrogen esterification reaction is carried out to generate methyl isononanoate.
[0054] The mass hourly space velocity (HHSV) of diisobutylene during the reaction was 0.1 h⁻¹. -1The mass hourly space velocity (MSV) of methanol is 9.9 h⁻¹. -1 The carbon monoxide flow rate is 100 L / h.
[0055] The conversion rate of diisobutylene was 60.8%, and the selectivity of methyl isononanoate was 92.5%.
[0056] Step 2: Hydrolysis reaction of methyl isononanoate:
[0057] After pressing the alumina catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water and nitrogen are passed through the catalyst bed together, and hydrolysis reaction is carried out at a reaction temperature of 100℃ and a reaction pressure of 2MPa to generate isononanoic acid.
[0058] The mass hourly space velocity (HSV) of the methyl isononanoate is 0.1 h⁻¹. -1 The nitrogen volume hourly space velocity is 400 h⁻¹. -1 The mass hourly space velocity (MSV) of deionized water is 0.2 h⁻¹. -1 ;
[0059] The conversion rate of methyl isononanoate was 61.5%, and the selectivity of isononanoate was 99.6%.
[0060] The preparation methods for the nano-cobalt-based catalyst and the alumina catalyst are the same as in Example 1.
[0061] Example 3
[0062] A method for producing isononanoic acid from diisobutylene, comprising the following steps:
[0063] Step 1: Diisobutylene hydrogen esterification reaction:
[0064] After pressing the nano-cobalt-based catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Then, diisobutylene, methanol and carbon monoxide are passed through the catalyst bed together. Under the conditions of reaction temperature of 250℃ and reaction pressure of 6MPa, a hydrogen esterification reaction is carried out to generate methyl isononanoate.
[0065] The mass hourly space velocity (HHSV) of diisobutylene during the reaction was 5 h⁻¹. -1 The mass hourly space velocity (MSV) of methanol is 5 h⁻¹. -1 The carbon monoxide flow rate is 100 L / h.
[0066] Diisobutylene conversion >99%, methyl isononanoate selectivity 70.5%;
[0067] Step 2: Hydrolysis reaction of methyl isononanoate:
[0068] After pressing the alumina catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water and nitrogen are passed through the catalyst bed together, and hydrolysis reaction is carried out at a reaction temperature of 300℃ and a reaction pressure of 2MPa to generate isononanoic acid.
[0069] The mass hourly space velocity of the methyl isononanoate was 10 h⁻¹. -1 The nitrogen volume hourly space velocity is 400 h⁻¹. -1 The deionized water mass hourly space velocity is 20 h⁻¹. -1 ;
[0070] The conversion rate of methyl isononanoate was 85.5%, and the selectivity of isononanoate was 81.0%.
[0071] The preparation methods for the nano-cobalt-based catalyst and the alumina catalyst are the same as in Example 1.
[0072] Example 4
[0073] A method for producing isononanoic acid from diisobutylene, comprising the following steps:
[0074] Step 1: Diisobutylene hydrogen esterification reaction:
[0075] After pressing the nano-cobalt-based catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Then, diisobutylene, methanol and carbon monoxide are passed through the catalyst bed together. Under the conditions of reaction temperature of 150℃ and reaction pressure of 0.5MPa, a hydrogen esterification reaction is carried out to generate methyl isononanoate.
[0076] The mass hourly space velocity (HHSV) of diisobutylene during the reaction was 0.2 h⁻¹. -1 The mass hourly space velocity (MSV) of methanol is 1.8 h⁻¹. -1 The carbon monoxide flow rate is 250 L / h.
[0077] The conversion rate of diisobutylene was 80.4%, and the selectivity of methyl isononanoate was 80.1%.
[0078] Step 2: Hydrolysis reaction of methyl isononanoate:
[0079] After pressing the alumina catalyst into tablets, grind it to 40-60 mesh. Take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water and nitrogen are passed through the catalyst bed together. Hydrolysis reaction is carried out under the conditions of reaction temperature of 200℃ and reaction pressure of 0.5MPa to generate isononanoic acid.
[0080] The mass hourly space velocity of the methyl isononanoate was 2 h⁻¹. -1 The nitrogen volume hourly space velocity is 1000 h⁻¹. -1 The mass hourly space velocity (MSV) of deionized water is 2 h⁻¹. -1 ;
[0081] The conversion rate of methyl isononanoate was 88.4%, and the selectivity of isononanoic acid was 99.2%.
[0082] The preparation methods for the nano-cobalt-based catalyst and the alumina catalyst are the same as in Example 1.
[0083] Example 5
[0084] A method for producing isononanoic acid from diisobutylene, comprising the following steps:
[0085] Step 1: Diisobutylene hydrogen esterification reaction:
[0086] After pressing the nano-cobalt-based catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Then, diisobutylene, methanol and carbon monoxide are passed through the catalyst bed together. Under the conditions of reaction temperature of 150℃ and reaction pressure of 15MPa, a hydrogen esterification reaction is carried out to generate methyl isononanoate.
[0087] The mass hourly space velocity (HHSV) of diisobutylene during the reaction was 0.2 h⁻¹. -1 The mass hourly space velocity (MSV) of methanol is 1.8 h⁻¹. -1 The carbon monoxide flow rate is 5 L / h.
[0088] The conversion rate of diisobutylene was 90.6%, and the selectivity of methyl isononanoate was 91.2%.
[0089] Step 2: Hydrolysis reaction of methyl isononanoate:
[0090] After pressing the alumina catalyst into tablets, grind it to 40-60 mesh, take 5g and put it into the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water and nitrogen are passed through the catalyst bed together, and hydrolysis reaction is carried out at a reaction temperature of 200℃ and a reaction pressure of 5MPa to generate isononanoic acid.
[0091] The mass hourly space velocity of the methyl isononanoate was 2 h⁻¹. -1 The nitrogen volume hourly space velocity is 0.20 h⁻¹. -1 The mass hourly space velocity (MSV) of deionized water is 2 h⁻¹. -1 ;
[0092] The conversion rate of methyl isononanoate was 70.1%, and the selectivity of isononanoate was 99.8%.
[0093] The preparation methods for the nano-cobalt-based catalyst and the alumina catalyst are the same as in Example 1.
[0094] The results above demonstrate that the method for preparing isononanoic acid from diisobutylene provided by this invention exhibits excellent reactivity and selectivity for isononanoic acid due to the use of nano-cobalt-based catalysts and alumina catalysts in the hydrogen esterification and esterification hydrolysis stages, respectively. The reaction also demonstrates good stability and reduces the cost of separating the catalyst from reactants and products. Furthermore, the continuous reaction process is simple and easy to implement, making it suitable for large-scale industrial production. This method allows for the production of high-value chemical isononanoic acid from diisobutylene through a two-step heterogeneous hydrogen esterification and esterification hydrolysis reaction. This method has high economic value and broad prospects for industrial application.
[0095] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A process for the production of isononanoic acid from diisobutene, characterized in that, Includes the following steps: Step 1: Diisobutylene hydrogen esterification reaction: Nano-cobalt-based catalyst was added to the reaction tube of a fixed-bed continuous flow reactor, and then diisobutylene, methanol and carbon monoxide were passed together through the catalyst bed to carry out a hydrogen esterification reaction to generate methyl isononanoate under the conditions of reaction temperature of 70~250 ℃ and reaction pressure of 0.5~15 MPa. Step 2: Hydrolysis reaction of methyl isononanoate: An alumina catalyst is added to the reaction tube of a fixed-bed continuous flow reactor. Methyl isononanoate, water, and nitrogen are passed through the catalyst bed together. The hydrolysis reaction is carried out at a reaction temperature of 100~300 ℃ and a reaction pressure of 0.5~5 MPa to produce isononanoic acid. The preparation method of the nano-cobalt-based catalyst described in step one includes the following steps: (1) Add cobalt nitrate and melamine to deionized water at a mass ratio of 1:4~5 to form a uniformly dispersed solution; (2) Under vigorous stirring, add a formaldehyde solution with a mass concentration of 37 wt% to the solution in step (1), heat to 75~85 ℃ and maintain for 24 hours; the mass ratio of the formaldehyde solution to cobalt nitrate is 5~7:1~2; (3) Evaporate the moisture at 75~85 ℃, and dry the resulting solid at 110~115 ℃ for 12 hours; (4) The solid dried in step (3) is calcined at 800 °C for 4 hours in a nitrogen flow of 40 mL / min to obtain the nano-cobalt-based catalyst.
2. The method of producing isononoic acid from diisobutene according to claim 1, characterized by, In step one, the mass hourly space velocity (HHSV) of diisobutylene is 0.1–5 h⁻¹. -1 The mass hourly space velocity (MSV) of methanol is 1.8–10 h⁻¹. -1 The carbon monoxide flow rate is 5~250 L / h.
3. The method of producing isononoic acid from diisobutene according to claim 1, wherein, The particle size of the nano-cobalt-based catalyst described in step one is 40-60 mesh.
4. The method of producing isononoic acid from diisobutene according to claim 1, wherein The preparation method of the alumina catalyst described in step two includes the following steps: S1. Dissolve aluminum nitrate in deionized water to obtain an aluminum nitrate solution with a concentration of 20 g / L; S2. Add ammonia solution to the aluminum nitrate solution described in step S1 to adjust the pH value to ≥9, thereby obtaining a mixed solution; the concentration of the ammonia solution is 1 mol / L; S3. The mixed solution described in step S2 is aged at room temperature for 4 hours, filtered, and the filter cake is pulped and washed. This process is repeated several times until the pH of the filtrate is 7, resulting in a neutral filter cake. S4. The neutral filter cake obtained in step S3 is dried at 110 °C for 12 hours, and then calcined in air at 400 °C for 4 hours to obtain the alumina catalyst.
5. The method of producing isononoic acid from diisobutene according to claim 1, wherein, The alumina catalyst described in step two has a particle size of 40-60 mesh.
6. The method for producing isononanoic acid from diisobutylene according to claim 1, characterized in that, The mass hourly space velocity (HSV) of the methyl isononanoate used in step two is 0.1–10 h⁻¹. -1 Nitrogen volume hourly space velocity is 20~2000 h⁻¹ -1 The mass hourly space velocity (MSV) of deionized water is 0.2–20 h⁻¹. -1 .