A system and catalyst for the oxidation of isononal to prepare isononanoic acid

Abstract

This invention provides a system and catalyst for the oxidation of isononanaldehyde to prepare isononanoic acid, comprising an oxidation reaction system, a main catalyst recovery system, a co-catalyst recovery system, and a product separation system. In the oxidation reaction system, isononanaldehyde is oxidized to isononanoic acid. The reaction gas phase is vented, and the liquid phase enters the main catalyst recovery system. The main catalyst recovery system recovers the catalyst from the reactants and returns the catalyst to the oxidation reaction system, while simultaneously replenishing the catalyst consumed by the system. The reaction liquid phase, having lost its catalyst, enters the co-catalyst recovery system, which separates the co-catalyst and recycles it back to the oxidation reaction system. The crude product enters the product separation system, where it undergoes purification to obtain isononanoic acid. The system and catalyst for the oxidation of isononanaldehyde to prepare isononanoic acid described in this invention provide relatively mild reaction conditions, a simple process, and few byproducts, making it suitable for large-scale continuous industrial production.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, and in particular relates to a system and catalyst for the oxidation of isononal to prepare isononanoic acid. Background Technology

[0002] Isononanoic acid, also known as 3,5,5-trimethylhexanoic acid, is widely used in organic synthesis, primarily in the plasticizer, fragrance, and lubricant industries. It is also widely used as a raw material in various fields, including rust inhibitors, lubricants, metal soaps and gold driers, polyvinyl chloride stabilizers, and preservatives. It can be used to produce isonononate esters, which are widely used in the cosmetics industry.

[0003] The main production processes for isononanoic acid include aldehyde oxidation and hydroformylation. Hydroformylation uses Co as a catalyst and octene as a raw material to produce the corresponding acid through a hydroformylation reaction. However, this process has significant drawbacks, such as high Co catalyst loss and low acid yield. Aldehyde oxidation uses isononanal (3,5,5-trimethylhexanal) as a raw material, which reacts with oxygen to produce 3,5,5-trimethylhexanoic acid. This method is highly dependent on the catalyst.

[0004] Patent CN201711396736.5 discloses a system and method for preparing isononanoic acid and a method for preparing a metal-organic framework catalyst, including an oxidation reactor, a cooler, a metal ion separation device, a peroxide decomposer, and a distillation device. The catalyst preparation involves mixing a metal salt, a template agent, an organic solvent, and water, drying the mixture to obtain precursor crystals, calcining the precursor crystals, and cooling them to room temperature to obtain the metal-organic framework catalyst. This method features high selectivity and high yield, but requires catalyst preparation, the catalyst is susceptible to acid and alkali instability, the process is lengthy, and the production cost is high. Patent CN202110084627.X discloses a method for preparing isononanoic acid using sulfonated mesoporous silica-carbon composite material as a catalyst and hydrogen peroxide as an oxidant. This method features mild reaction conditions, few byproducts, high product purity, and good economic benefits, but the catalyst used is expensive, and the process requires sodium hydroxide and hydrogen peroxide, further increasing the cost. The product yield is not ideal. Summary of the Invention

[0005] In view of this, the present invention aims to solve the problems of high cost and unsatisfactory product yield in the preparation of isononanoic acid.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A catalyst for the oxidation of isononanaldehyde to prepare isononanoic acid, comprising a main catalyst and a secondary catalyst;

[0008] The main catalyst is one or more of manganese acetate, cobalt acetate, ferric acetate, copper acetate, manganese naphthenate, cobalt naphthenate, ferric naphthenate, and copper naphthenate.

[0009] The co-catalyst is one or more of hydrochloric acid, acetic acid, propionic acid, butyric acid, and isobutyric acid.

[0010] Preferably, the catalyst is manganese acetate and hydrochloric acid, and the ratio of manganese acetate to hydrochloric acid is 1:(30-200), more preferably, the ratio is 1:(100-200).

[0011] The amount of the main catalyst X is 0.01-1% of the volume of the reactant 3,5,5-trimethylhexanal, preferably 0.05-0.5%.

[0012] The amount of co-catalyst Y is 1-50% of the mass of the reactant 3,5,5-trimethylhexanal, preferably 5-40%.

[0013] The reaction mechanism for the oxidation of isononanal to isononanoic acid can be explained by a free radical reaction mechanism. At room temperature, isononanal can spontaneously absorb oxygen from the air at a very slow rate and be oxidized to peroxyisononanoic acid. Peroxyisononanoic acid is very unstable and decomposes under the catalysis of the main catalyst, simultaneously oxidizing another molecule of isononanal to produce two molecules of isononanoic acid.

[0014] The role of co-catalysts: Peroxides are unstable under strongly acidic conditions and decompose rapidly. They are relatively stable under weakly acidic conditions. Adding a co-catalyst can increase the acid value of the system, accelerate the decomposition of peroxides, and facilitate the reaction. The combined use of the main catalyst and co-catalyst can significantly shorten the reaction time and improve the conversion rate of isonononal and the selectivity of isonononic acid.

[0015] A system for the oxidation of isononanaldehyde to prepare isononanoic acid, using the above-mentioned catalyst, characterized in that it includes an oxidation reaction system, a main catalyst recovery system, a co-catalyst recovery system, and a product separation system.

[0016] In the oxidation reaction system, isononalaldehyde is oxidized to isononanoic acid. The reaction gas phase is vented, and the liquid phase enters the main catalyst recovery system. The main catalyst recovery system recovers the catalyst from the reactants and returns the catalyst to the oxidation reaction system. At the same time, it replenishes the catalyst consumed by the system. The reaction liquid phase, from which the catalyst has been removed, enters the co-catalyst recovery system. The co-catalyst recovery system separates the co-catalyst and recycles it back to the oxidation reaction system. The crude product enters the product separation system, where it is purified to obtain isononanoic acid.

[0017] Furthermore, the oxidation reaction system includes an oxidation reactor, which is a 1-5 stage series reactor, preferably a 2-4 stage series reactor.

[0018] Furthermore, the temperature of the oxidation reactor is 20-120℃, preferably 40-100℃.

[0019] Furthermore, the pressure of the oxidation reactor is 0-3 MPa, preferably 0.2-2.5 MPa.

[0020] Furthermore, the reaction space velocity in the oxidation reactor is 0.1-6 h⁻¹. -1 Preferably 0.3-4h -1 .

[0021] At room temperature, isonononal can automatically absorb oxygen from the air at a very slow rate and be oxidized to peroxyisonononanoic acid. Peroxyisonononanoic acid is very unstable and decomposes under the catalysis of a catalyst, simultaneously oxidizing another molecule of isonononal to produce two molecules of isononanoic acid.

[0022] Furthermore, the oxygen-containing gas is either air or oxygen.

[0023] Compared with the prior art, the system and catalyst for the oxidation of isononanal to prepare isononanoic acid described in this invention have the following beneficial effects:

[0024] 1. This invention enables the direct oxidation of isononanoic acid from isononal to produce isononal, using air as the oxidant, and the oxidation reactor is a series reactor of 1-5 stages, resulting in low production costs.

[0025] 2. The present invention is equipped with a main catalyst recovery system and a co-catalyst recovery system, which are used in combination to improve catalytic efficiency. It is also equipped with a first catalyst circulation pipe and a second catalyst circulation pipe, which enables the catalyst to be recycled, resulting in low cost and high reaction yield.

[0026] 3. The reaction conditions of this invention are relatively mild, the process is simple, and few by-products are generated, which is conducive to large-scale continuous industrial production. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 This is a schematic diagram of the system and catalyst for the oxidation of isononal to prepare isononanoic acid according to an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Isonononaldehyde feed pipe; 2. Oxygen-containing gas feed pipe; 3. Liquid outlet pipe; 4. First catalyst circulation pipe; 5. Supplementary material pipe; 6. Gas outlet pipe; 7. Reactant flow outlet pipe; 8. Second catalyst circulation pipe; 9. By-product outlet pipe; 10. Crude product pipe; 11. Isonononoic acid product outlet pipe; 12. Heavy component outlet pipe; A. Oxidation reaction system; B. Main catalyst recovery system; C. Co-catalyst recovery system; D. Product separation system. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] A catalyst for the oxidation of isononanaldehyde to prepare isononanoic acid, comprising a main catalyst and a secondary catalyst;

[0034] The main catalyst is one or more of manganese acetate, cobalt acetate, ferric acetate, copper acetate, manganese naphthenate, cobalt naphthenate, ferric naphthenate, and copper naphthenate; the co-catalyst is one or more of hydrochloric acid, acetic acid, propionic acid, butyric acid, and isobutyric acid. The amount of main catalyst X is 0.01-1% of the volume of the reactant 3,5,5-trimethylhexanal, preferably 0.05-0.5%. The amount of co-catalyst Y is 1-50% of the mass of the reactant 3,5,5-trimethylhexanal, preferably 5-40%.

[0035] A system for preparing isonononalic acid by oxidation of isononal, using the aforementioned catalyst, is characterized by comprising an oxidation reaction system, a main catalyst recovery system, a co-catalyst recovery system, and a product separation system; in the oxidation reaction system, isonononal is oxidized to isonononalic acid, the reaction gas phase is vented, and the liquid phase enters the main catalyst recovery system, which recovers the catalyst from the reactants and returns the catalyst to the oxidation reaction system, while simultaneously replenishing the catalyst consumed by the system; the reaction liquid phase, from which the catalyst has been removed, enters the co-catalyst recovery system, which separates the co-catalyst and recycles it back to the oxidation reaction system; the crude product enters the product separation system, where isonononalic acid is obtained through product purification.

[0036] The oxidation reaction system includes an oxidation reactor, which is a series reactor of 1-5 stages, preferably a series reactor of 2-4 stages.

[0037] The temperature of the oxidation reactor is 20-120℃, preferably 40-100℃.

[0038] The pressure of the oxidation reactor is 0-3 MPa, preferably 0.2-2.5 MPa.

[0039] The reaction space velocity in the oxidation reactor is 0.1-6 h⁻¹. -1 Preferably 0.3-4h -1 .

[0040] Oxygen-containing gas is either air or oxygen.

[0041] like Figure 1 The system for preparing isononanoic acid by oxidizing isononal includes an oxidation reaction system A, a main catalyst recovery system B, a co-catalyst recovery system C, and a product separation system D. The oxidation reaction system A is connected to the main catalyst recovery system B, the top of the main catalyst recovery system B is connected to the co-catalyst recovery system C, the bottom of the main catalyst recovery system B is connected to the oxidation reaction system A, the top of the co-catalyst recovery system C is connected to the oxidation reaction system A, and the bottom of the co-catalyst recovery system C is connected to the product separation system D.

[0042] The oxidation reaction system A includes an oxidation reactor, isonononaldehyde feed pipe 1, oxygen-containing gas feed pipe 2, gas outlet pipe 6, and liquid outlet pipe 3. The isonononaldehyde feed pipe 1 and oxygen-containing gas feed pipe 2 are sequentially arranged on one side of the oxidation reactor. The gas outlet pipe 6 is located at the top of the oxidation reactor. The oxidation reactor is connected to the main catalyst recovery system B via the liquid outlet pipe 3. The oxidation reactor comprises 1-5 stages of reactors in series, preferably 2-4 stages.

[0043] The main catalyst recovery system B includes a first reactor, a first catalyst circulation pipe 4, a supplementary material pipe 5, and a reactant discharge pipe 7. The first catalyst circulation pipe 4 is located at the bottom of the first reactor, and the other end of the first catalyst circulation pipe 4 is connected to one side of the oxidation reactor. The supplementary material pipe 5 is connected to the first catalyst circulation pipe 4 and is located on one side of the first catalyst circulation pipe 4. The first reactor is connected to the co-catalyst recovery system C through the reactant discharge pipe. The reactant discharge pipe is located at the top of the first reactor. The co-catalyst recovery system C includes a second reactor, a second catalyst circulation pipe 8, and a crude product pipe 10. One end of the second catalyst circulation pipe 8 is located at the top of the second reactor, and the other end of the second catalyst circulation pipe 8 is located on the isononal feed pipe 1. The second reactor is connected to the product separation system D through the crude product pipe 10.

[0044] The second catalyst circulation pipeline 8 is equipped with a by-product discharge pipe 9. The product separation system D includes a third reactor, an isononanoic acid product discharge pipe 11, and a heavy component discharge pipe 12; the second reactor is connected to the third reactor through a crude product pipeline 10, the isononanoic acid product discharge pipe 11 is located at the top of the third reactor, and the heavy component discharge pipe 12 is located at the top of the third reactor.

[0045] Oxidation reaction system A comprises one or more reactors. Isonononal and oxygen-containing gas are introduced into the reactors, and the reactants are sent to the main catalyst recovery system B. The recycled catalyst obtained from the main catalyst recovery system B is returned to oxidation reaction system A, while the remaining materials enter the co-catalyst recovery system C. The catalyst recovery system separates the co-catalyst and unreacted raw materials, returning them to oxidation reaction system A, and includes a byproduct discharge outlet. The crude product obtained from this separation enters the product separation system D. The separation system yields isonononic acid and heavy byproducts. This method for producing isonononic acid features mild reaction conditions, a simple process, and high product yield. The catalysts used are a main catalyst and a co-catalyst, used in combination, resulting in low cost and good performance.

[0046] Example 1

[0047] Manganese acetate was used as a catalyst at 0.1% of the mass of 3,5,5-trimethylhexanal, and hydrochloric acid was used as a co-catalyst at 20% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 90℃, the reaction pressure was 1 MPa, and the reaction time was 1 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 85%, and the selectivity of 3,5,5-trimethylhexanoic acid was 94%.

[0048] Example 2

[0049] Cobalt acetate was used as a catalyst at 0.2% of the mass of 3,5,5-trimethylhexanal, and acetic acid was used as a co-catalyst at 10% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 80℃, the reaction pressure was 1.5 MPa, and the reaction time was 1 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 83%, and the selectivity of 3,5,5-trimethylhexanoic acid was 92%.

[0050] Example 3

[0051] Ferric acetate was used as a catalyst at 0.3% of the mass of 3,5,5-trimethylhexanal, and propionic acid was used as a co-catalyst at 15% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 100℃, the reaction pressure was 1.2 MPa, and the reaction time was 1.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 87%, and the selectivity of 3,5,5-trimethylhexanoic acid was 89%.

[0052] Example 4

[0053] Copper acetate was used as a catalyst at 0.5% of the mass of 3,5,5-trimethylhexanal, and propionic acid was used as a co-catalyst at 30% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 110℃, the reaction pressure was 1.3 MPa, and the reaction time was 2 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 89%, and the selectivity of 3,5,5-trimethylhexanoic acid was 87%.

[0054] Example 5

[0055] Manganese naphthenate was used as a catalyst at 0.5% of the mass of 3,5,5-trimethylhexanal, and butyric acid was used as a co-catalyst at 25% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 80℃, the reaction pressure was 1.8 MPa, and the reaction time was 2.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 92%, and the selectivity of 3,5,5-trimethylhexanoic acid was 91%.

[0056] Example 6

[0057] Cobalt naphthenate was used as a catalyst at 0.2% of the mass of 3,5,5-trimethylhexanal, and isobutyric acid was used as a co-catalyst at 30% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 90℃, the reaction pressure was 1.5 MPa, and the reaction time was 2.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 93%, and the selectivity of 3,5,5-trimethylhexanoic acid was 89%.

[0058] Example 7

[0059] Ferric naphthenate was used as a catalyst at 0.4% of the mass of 3,5,5-trimethylhexanal, and isobutyric acid was used as a co-catalyst at 15% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 70℃, the reaction pressure was 1 MPa, and the reaction time was 1.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 88%, and the selectivity of 3,5,5-trimethylhexanoic acid was 87%.

[0060] Example 8

[0061] Copper naphthenate was used as a catalyst at 0.4% of the mass of 3,5,5-trimethylhexanal, and acetic acid was used as a co-catalyst at 20% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 75℃, the reaction pressure was 0.8 MPa, and the reaction time was 2.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 90%, and the selectivity of 3,5,5-trimethylhexanoic acid was 90%.

[0062] Example 9

[0063] Manganese acetate and copper acetate were used as catalysts, each at 0.2% of the mass of 3,5,5-trimethylhexanal. Hydrochloric acid was used as a co-catalyst at 20% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 75℃, the reaction pressure was 0.8 MPa, and the reaction time was 2.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 90%, and the selectivity of 3,5,5-trimethylhexanoic acid was 92%.

[0064] Example 10

[0065] Ferric naphthenate and copper naphthenate were used as catalysts. Ferric naphthenate accounted for 0.15% of the mass of 3,5,5-trimethylhexanal, and copper naphthenate accounted for 0.25% of the mass of 3,5,5-trimethylhexanal. Butyric acid was used as a co-catalyst at 30% of the volume of 3,5,5-trimethylhexanal. The reaction temperature was 95℃, the reaction pressure was 1.5 MPa, and the reaction time was 1.5 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 91%, and the selectivity of 3,5,5-trimethylhexanoic acid was 90%.

[0066] Comparative Example 1

[0067] Cobalt acetate was used as a catalyst at a concentration of 0.5% of the mass of 3,5,5-trimethylhexanal. The reaction temperature was 90℃, the reaction pressure was 1 MPa, and the reaction time was 1 h. After the reaction, the conversion rate of 3,5,5-trimethylhexanal was 45%, and the selectivity of 3,5,5-trimethylhexanoic acid was 73%.

[0068] Without the addition of a co-catalyst, the reaction system has a low acid value, and peroxyisonononanoic acid is relatively stable and decomposes slowly. Consequently, the reaction rate is slow, the reaction time is prolonged, and there are more side reactions, which leads to a decrease in the conversion rate of isonononal and the selectivity of isonononanoic acid.

Claims

1. A method for using a catalyst for the oxidation of isononanal to prepare isononanoic acid, characterized in that: Including main catalyst and secondary catalyst; The main catalyst is one or more of cobalt acetate, iron acetate, copper acetate, manganese naphthenate, cobalt naphthenate, iron naphthenate, and copper naphthenate; The co-catalyst is one or more of hydrochloric acid, propionic acid, butyric acid, and isobutyric acid; Alternatively, the main catalyst is manganese acetate and the co-catalyst is hydrochloric acid; Alternatively, the main catalyst can be manganese acetate and copper acetate, and the co-catalyst can be hydrochloric acid; Alternatively, the main catalyst can be cobalt acetate, and the co-catalyst can be acetic acid; Alternatively, the main catalyst can be copper naphthenate, and the co-catalyst can be acetic acid; This method includes a system for the oxidation of isononanaldehyde to prepare isononanoic acid, using a catalyst for the oxidation of isononanaldehyde to prepare isononanoic acid as described above, including an oxidation reaction system, a main catalyst recovery system, a co-catalyst recovery system, and a product separation system; In the oxidation reaction system, isononalaldehyde is oxidized to isononanoic acid. The reaction gas phase is vented, and the liquid phase enters the main catalyst recovery system. The main catalyst recovery system recovers the catalyst from the reactants and returns the catalyst to the oxidation reaction system. At the same time, it replenishes the catalyst consumed by the system. The reaction liquid phase, from which the catalyst has been removed, enters the co-catalyst recovery system. The co-catalyst recovery system separates the co-catalyst and recycles it back to the oxidation reaction system. The crude product enters the product separation system, where it is purified to obtain isononanoic acid.

2. The method of using the catalyst for the oxidation of isononanal to prepare isononanoic acid according to claim 1, characterized in that: The amount of the main catalyst used is 0.01-1% of the volume of the reactant 3,5,5-trimethylhexanal.

3. The method of using the catalyst for the oxidation of isononanal to prepare isononanoic acid according to claim 2, characterized in that: The amount of the main catalyst used is 0.05-0.5% of the volume of the reactant 3,5,5-trimethylhexanal.

4. The method of using the catalyst for the oxidation of isononanal to prepare isononanoic acid according to claim 1, characterized in that: The amount of co-catalyst used is 1-50% of the mass of the reactant 3,5,5-trimethylhexanal.

5. The method of using the catalyst for the oxidation of isononanal to prepare isononanoic acid according to claim 1, characterized in that: The amount of co-catalyst used is 5-40% of the mass of the reactant 3,5,5-trimethylhexanal.

6. A system for the oxidation of isononanal to prepare isononanoic acid, comprising a method of using a catalyst for the oxidation of isononanal to prepare isononanoic acid as described in any one of claims 1-5, characterized in that: This includes an oxidation reaction system, a main catalyst recovery system, a co-catalyst recovery system, and a product separation system. In the oxidation reaction system, isononalaldehyde is oxidized to isononanoic acid. The reaction gas phase is vented, and the liquid phase enters the main catalyst recovery system. The main catalyst recovery system recovers the catalyst from the reactants and returns the catalyst to the oxidation reaction system. At the same time, it replenishes the catalyst consumed by the system. The reaction liquid phase, from which the catalyst has been removed, enters the co-catalyst recovery system. The co-catalyst recovery system separates the co-catalyst and recycles it back to the oxidation reaction system. The crude product enters the product separation system, where it is purified to obtain isononanoic acid.

7. The system according to claim 6, characterized in that: The oxidation reaction system includes an oxidation reactor, which is a series reactor consisting of 1 to 5 stages.

8. The system according to claim 7, characterized in that: The oxidation reactor is a 2-4 stage series reactor.

9. The system according to claim 6, characterized in that: The temperature of the oxidation reactor is 20-120℃.

10. The system according to claim 6, characterized in that: The temperature of the oxidation reactor is 40-100℃.

11. The system according to claim 6, characterized in that: The pressure in the oxidation reactor is 0-3 MPa.

12. The system according to claim 6, characterized in that: The pressure of the oxidation reactor is 0.2-2.5 MPa.

13. The system according to claim 6, characterized in that: The reaction space velocity in the oxidation reactor is 0.1-6 h⁻¹. -1 .

14. The system according to claim 13, characterized in that: The reaction space velocity in the oxidation reactor is 0.3-4 h⁻¹. -1 .

15. The system according to claim 6, characterized in that: Oxygen-containing gas is either air or oxygen.

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