Method for preparing acid through aldehyde oxidation by using CoMoOx-APO-34 catalyst

Abstract

The invention provides a method for preparing acid through aldehyde oxidation by using a CoMoOx-APO-34 catalyst. The method comprises the following steps: mixing a phosphorus source, an aluminum source, a cobalt source, a molybdenum source and a first solution to obtain a Co-Mo-P-Al precursor; mixing the Co-Mo-P-Al precursor, a structure-directing agent, a seed crystal and a second solution, and obtaining a CoMoOx-APO-34 molecular sieve; the method comprises the following steps: mixing a CoMoOx-APO-34 molecular sieve with a target solution, carrying out selective oxidation, and carrying out filtration treatment after selective oxidation to obtain a target product. The method can efficiently catalyze synthesis of isononanoic acid, inhibit Bayer-Villeger side reaction, promote catalytic conversion of peroxide, reduce the concentration of peroxide to 0.1% or less, and improve the yield of isononanoic acid. Meanwhile, the conversion rate of isononanoic aldehyde and the selectivity of isononanoic acid are effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical products, and particularly relates to a method for preparing acid by aldehyde oxidation using a CoMoOx-APO-34 catalyst. Background Art

[0002] Isononanoic acid, as an important organic synthesis raw material, has been widely used in industries such as fragrances, pharmaceuticals, lubricants, and plasticizers. Moreover, isononanoic acid is a basic raw material for organic synthesis and can be used as a raw material for synthetic lubricants, metal soaps, and metal working fluids, a rust inhibitor additive, and a modifier for alkyd resins. Its metal salts can be used in paint driers, tire adhesion aids, and esters such as isononyl isononanoate, a synthetic surfactant. Isononanoic acid can also be used as an intermediate for synthetic ester base oils, paint and coating driers, esters for producing lubricants and plasticizers, and a peroxide as a polymerization catalyst. Isononanoic acid is an important raw material for preparing polyol ester type refrigeration oils, and its efficient preparation is of great significance.

[0003] The oxidation of isononanal is the main process for preparing isononanoic acid. However, in this process, the Bayer-Villeger side reaction is likely to occur, thereby reducing the selectivity and yield of isononanoic acid. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing acid by aldehyde oxidation using a CoMoOx-APO-34 catalyst to solve the problems in the above background art.

[0005] The invention provides the following technical solutions. A method for preparing acid by aldehyde oxidation using a CoMoOx-APO-34 catalyst, the method comprising the following steps:

[0006] Mix a phosphorus source, an aluminum source, a cobalt source, a molybdenum source, and a first solution to obtain a first treatment solution. Under closed conditions, sequentially perform a first stirring treatment, a first hydrothermal treatment, a first filtration treatment, a first drying treatment, and a first calcination treatment on the first treatment solution to obtain a Co-Mo-P-Al precursor;

[0007] Mix the Co-Mo-P-Al precursor, a structure-directing agent, seeds, and a second solution to obtain a second treatment solution. Under closed conditions, sequentially perform a second stirring treatment, a second hydrothermal treatment, a second filtration treatment, a second drying treatment, and a second calcination treatment on the second treatment solution to obtain CoMoOx-APO-34 molecular sieve;

[0008] Mix the CoMoOx-APO-34 molecular sieve with a target solution and place it in a reaction kettle. Stir in the reaction kettle and perform selective oxidation under the premise of a first preset temperature and a first preset reaction condition. After selective oxidation, perform a filtration treatment to obtain a target product.

[0009] Compared with the prior art, the beneficial effects of the present application are as follows: The CoMoOx-APO-34 molecular sieve in the present application has a unique self-supporting three-dimensional space. Its large specific surface area and spatial confinement effect are beneficial to improving the dispersion degree of active components, effectively preventing the aggregation of active centers, so that the CoMoOx-APO-34 molecular sieve can efficiently catalyze the synthesis of isononanoic acid, inhibit the Bayer-Villeger side reaction, and promote the catalytic conversion of peroxides. At the same time, the concentration of peroxides is reduced to less than 0.1%, and the conversion rate of isononaldehyde and the selectivity of isononanoic acid are effectively improved.

[0010] Preferably, the phosphorus source is phosphoric acid or phosphorous acid, the aluminum source is pseudoboehmite, aluminum hydroxide, aluminum nitrate, aluminum sulfate or aluminum sol, the cobalt source is cobalt nitrate, cobalt chloride or cobalt sulfate, and the molybdenum source is ammonium molybdate, molybdenum nitrate or molybdenum acetylacetonate.

[0011] Preferably, both the first solution and the second solution are water.

[0012] Preferably, the mixing ratio of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source is 1:1:(0.0001-0.03):(0.0001-0.03).

[0013] Preferably, the temperature of the first hydrothermal treatment is 60°C to 160°C, and the time of the first hydrothermal treatment is 2h to 24h.

[0014] Preferably, the mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution is 1:(1-5):(0.5-5).

[0015] Preferably, the temperature of the second hydrothermal treatment is 150°C to 220°C, and the time of the second hydrothermal treatment is 12h to 240h.

[0016] Preferably, the target solution is specifically 0.1%wt to 8%wt of isononaldehyde, and the target product is isononanoic acid.

[0017] Preferably, the first preset temperature is 40°C to 120°C.

[0018] Preferably, the first preset reaction condition is an O2 condition of 0.1Mpa - 3Mpa. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a flowchart of the method for preparing acid by aldehyde oxidation using the CoMoOx-APO-34 catalyst provided by the embodiment of the present invention.

[0021] The following will further illustrate the present invention in conjunction with the drawings and the description of the drawings. Specific Embodiments

[0022] The following details the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0023] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0025] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0026] In one embodiment of the present invention, as Figure 1 shown, a method for preparing an acid from aldehyde oxidation using a CoMoOx-APO-34 catalyst, the method comprising the following steps:

[0027] S1. Mix a phosphorus source, an aluminum source, a cobalt source, a molybdenum source and a first solution to obtain a first treatment solution, and sequentially perform a first stirring treatment, a first hydrothermal treatment, a first filtration treatment, a first drying treatment and a first calcination treatment on the first treatment solution under closed conditions to obtain a Co-Mo-P-Al precursor;

[0028] Specifically, in step S1, the phosphorus source is phosphoric acid or phosphorous acid, the aluminum source is pseudo-boehmite, aluminum hydroxide, aluminum nitrate, aluminum sulfate or aluminum sol, the cobalt source is cobalt nitrate, cobalt chloride or cobalt sulfate, the molybdenum source is ammonium molybdate, molybdenum nitrate or molybdenum acetylacetonate. Preferably, the phosphorus source is phosphoric acid, the aluminum source is aluminum hydroxide, the cobalt source is cobalt nitrate, the molybdenum source is molybdenum acetylacetonate, the first solution is water, and the mixing ratio of the phosphorus source, the aluminum source, the cobalt source and the molybdenum source is 1:1:0.02:0.02. The temperature of the first hydrothermal treatment is 60°C to 160°C, and the time of the first hydrothermal treatment is 2h to 24h. Preferably, the temperature of the first hydrothermal treatment is 90°C, and the time of the first hydrothermal treatment is 12h.

[0029] S2. Mix the Co-Mo-P-Al precursor, a structure-directing agent, seeds and a second solution to obtain a second treatment solution, and sequentially perform a second stirring treatment, a second hydrothermal treatment, a second filtration treatment, a second drying treatment and a second calcination treatment on the second treatment solution under closed conditions to obtain a CoMoOx-APO-34 molecular sieve;

[0030] Specifically, the second solution is water, the structure-directing agent is tetraethylammonium hydroxide, triethylamine, diethylamine, ethylamine, triethanolamine or ethanolamine. In this embodiment, the structure-directing agent is triethylamine. The mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent and the second solution is 1:2:1. The temperature of the second hydrothermal treatment is 150°C to 220°C, and the time of the second hydrothermal treatment is 12h to 240h. Preferably, the temperature of the second hydrothermal treatment is 200°C, and the time of the second hydrothermal treatment is 72h.

[0031] It should be noted that the seed crystal is a tiny crystal of the CoMoOx-APO-34 molecular sieve, which is obtained by pre-synthesis. By setting the seed crystal, it provides the same crystal structure and pore topology as the CoMoOx-APO-34 molecular sieve, ensuring the directional growth of crystals in subsequent reactions, avoiding the generation of impurity phases. And by setting the seed crystal, it can serve as a ready-made crystal nucleus, reducing the nucleation induction period and shortening the acquisition time of the CoMoOx-APO-34 molecular sieve.

[0032] S3. Mix the CoMoOx-APO-34 molecular sieve with the target solution and place it in a reaction kettle. Stir in the reaction kettle and perform selective oxidation under the premise of the first preset temperature and the first preset reaction conditions. After selective oxidation, perform filtration to obtain the target product.

[0033] Specifically, the target solution is specifically 0.1%wt - 8%wt isononanal, and the target product is isononanoic acid. Preferably, the target solution is specifically 1.5%wt isononanal, the first preset temperature is 40°C - 120°C, and the first preset reaction conditions are O2 conditions of 0.1 Mpa - 3 Mpa. Preferably, the first preset temperature is 70°C and the first preset reaction conditions are O2 conditions of 0.5 Mpa.

[0034] The CoMoOx-APO-34 molecular sieve in this application has a unique self-supporting three-dimensional space. Its large specific surface area and space confinement effect are conducive to improving the dispersion degree of active components, effectively preventing the aggregation of active centers. Thereby, the CoMoOx-APO-34 molecular sieve can efficiently catalyze the synthesis of isononanoic acid, inhibit the Bayer-Villeger side reaction, and promote the catalytic conversion of peroxides. At the same time, the peroxide concentration is reduced to less than 0.1%, and at the same time, the conversion rate of isononanal and the selectivity of isononanoic acid are effectively improved.

[0035] Example 2

[0036] This example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0037] The mixing ratio of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source is 1:1:0.0001:0.0001.

[0038] Example 3

[0039] This example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0040] The mixing ratio of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source is 1:1:0.03:0.03.

[0041] Example 4

[0042] This example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0043] The mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution is 1:1:0.5.

[0044] Example 5

[0045] This example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0046] The mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution is 1:5:5.

[0047] Control Example 1

[0048] This control example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0049] The mixing ratio of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source is 1:1:0.00005:0.00005.

[0050] Control Example 2

[0051] This control example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0052] The mixing ratio of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source is 1:1:0.04:0.04.

[0053] Control Example 3

[0054] This comparative example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0055] The mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution is 1:0.8:0.4.

[0056] Comparative Example 4

[0057] This comparative example provides a method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0058] The mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution is 1:5.5:5.5.

[0059] Comparative Example 5

[0060] This comparative example provides a method for oxidizing aldehyde to acid, which is different from the method for oxidizing aldehyde to acid using a CoMoOx-APO-34 catalyst provided in Example 1 in that:

[0061] Prepare an acid catalyst, specifically sulfuric acid, mix isononanal, water with the acid catalyst, and carry out a stirring reaction at a certain temperature, and then carry out separation and purification to obtain isononanoic acid.

[0062] It should be noted that the method of Comparative Example 5 is a commonly used method for preparing isononanoic acid from isononanal in the prior art, and its reaction reagents, reaction steps and reaction conditions are the same as those in the prior art, so they will not be elaborated here.

[0063] The corresponding isononanoic acids were prepared by the methods provided in the above Examples 1-5 and Comparative Examples 1-5, and the following items were detected: the conversion rate of isononaldehyde, the selectivity of isononanoic acid, and the concentration of peroxide. For the conversion rate of isononaldehyde, it can be determined according to the ratio of isononaldehyde converted to isononanoic acid in the reaction. For the selectivity of isononanoic acid, in a complex reaction system, there may be multiple parallel or consecutive reaction pathways, resulting in different products. The selectivity of the catalyst reflects the preference degree of the catalyst for a specific reaction pathway, that is, while promoting the overall reaction, it can preferentially promote the reaction to form the target product and inhibit the occurrence of other side reactions. It can be determined by the following formula: (the yield of isononanoic acid / (the amount of isononaldehyde converted / the total amount of isononaldehyde in the feed flowing through the catalyst bed)) * 100%. For the concentration of peroxide, peroxide is an important intermediate in aldehyde oxidation, but also a key factor affecting the safety of the process. Therefore, it is necessary to measure the concentration of peroxide. The specific detection results are shown in Table 1 below:

[0064]

[0065]

[0066] According to the content in Table 1 above, the concentrations of the peroxides corresponding to Examples 1-5 are all below 0.1%, the conversion rate of isononanal is above 99%, and the selectivity of isononanoic acid is above 99%. Among them, Example 1 is the best, with the peroxide concentration being 0.03%, the conversion rate of isononanal being 99.8%, and the selectivity of isononanoic acid being 99.7%. From Examples 2-4, it can be known that the mixing ratios of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source, as well as the mixing ratios of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution, will all have a certain impact on the conversion rate of isononanal, the selectivity of isononanoic acid, and the concentration of the peroxide. Moreover, the degree of influence of the mixing ratios of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source is greater than that of the mixing ratios of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution. The reason is that the mixing ratios of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source will directly affect the overall structure of the CoMoOx-APO-34 molecular sieve, thereby affecting its activity and catalytic ability. According to Comparative Examples 1-4, when the mixing ratios of the phosphorus source, the aluminum source, the cobalt source, and the molybdenum source, as well as the mixing ratios of the Co-Mo-P-Al precursor, the structure-directing agent, and the second solution, are not within the mixing ratio range of this application, they will have a huge impact on the conversion rate of isononanal, the selectivity of isononanoic acid, and the concentration of the peroxide, resulting in the peroxide concentration being above 0.2%, and both the conversion rate of isononanal and the selectivity of isononanoic acid being below 90%. From Comparative Example 5, it can be seen that when the existing method is used for aldehyde oxidation to acid, the changes in the conversion rate of isononanal, the selectivity of isononanoic acid, and the concentration of the peroxide are the most obvious. Therefore, it can be known that the CoMoOx-APO-34 molecular sieve in this application has a unique self-supporting three-dimensional space, and its large specific surface area and space confinement effect are conducive to improving the dispersion degree of the active components, effectively preventing the aggregation of active centers, so that the CoMoOx-APO-34 molecular sieve can efficiently catalyze the synthesis of isononanoic acid, inhibit the Bayer-Villeger side reaction, and promote the catalytic conversion of the peroxide, while reducing the peroxide concentration to below 0.1%, and at the same time effectively improving the conversion rate of isononanal and the selectivity of isononanoic acid.

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing acid by oxidizing aldehyde with a CoMoOx-APO-34 catalyst, characterized in that, The method includes the following steps: Mix a phosphorus source, an aluminum source, a cobalt source, a molybdenum source and a first solution to obtain a first treatment solution. Under closed conditions, perform a first stirring treatment, a first hydrothermal treatment, a first filtration treatment, a first drying treatment and a first calcination treatment on the first treatment solution in sequence to obtain a Co-Mo-P-Al precursor; Mix the Co-Mo-P-Al precursor, a structure-directing agent, seeds and a second solution to obtain a second treatment solution. Under closed conditions, perform a second stirring treatment, a second hydrothermal treatment, a second filtration treatment, a second drying treatment and a second calcination treatment on the second treatment solution in sequence to obtain a CoMoOx-APO-34 molecular sieve; Mix the CoMoOx-APO-34 molecular sieve with a target solution and place it in a reaction kettle. Stir in the reaction kettle and perform selective oxidation under the premise of a first preset temperature and a first preset reaction condition. After selective oxidation, perform a filtration treatment to obtain a target product.

2. The method for preparing acid by aldehyde oxidation using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The phosphorus source is phosphoric acid or phosphorous acid, the aluminum source is pseudo-boehmite, aluminum hydroxide, aluminum nitrate, aluminum sulfate or aluminum sol, the cobalt source is cobalt nitrate, cobalt chloride or cobalt sulfate, and the molybdenum source is ammonium molybdate, molybdenum nitrate or molybdenum acetylacetonate.

3. The method for preparing acid by aldehyde oxidation using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, Both the first solution and the second solution are water.

4. The method for preparing acid by aldehyde oxidation using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The mixing ratio of the phosphorus source, the aluminum source, the cobalt source and the molybdenum source is 1:1:(0.0001 - 0.03):(0.0001 - 0.03).

5. The method for preparing acid by aldehyde oxidation using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The temperature of the first hydrothermal treatment is 60°C - 160°C, and the time of the first hydrothermal treatment is 2h - 24h.

6. The method for preparing acid by aldehyde oxidation using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The mixing ratio of the Co-Mo-P-Al precursor, the structure-directing agent and the second solution is 1:(1 - 5):(0.5 - 5).

7. The method for oxidizing aldehyde to acid using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The temperature of the second hydrothermal treatment is 150°C - 220°C, and the time of the second hydrothermal treatment is 12h - 240h.

8. The method for preparing acid by oxidizing aldehyde with the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The target solution is specifically 0.1%wt - 8%wt of isononanal, and the target product is isononanoic acid.

9. The method for preparing an acid by oxidizing an aldehyde using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The first preset temperature is 40°C - 120°C.

10. The method for oxidizing aldehyde to acid using the CoMoOx-APO-34 catalyst according to claim 1, characterized in that, The first preset reaction condition is an O2 condition of 0.1Mpa - 3Mpa.

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