A composite organic acid catalyst for acetate production and a preparation method and application thereof

Abstract

The application relates to the technical field of catalysts, and discloses a composite organic acid catalyst for acetate production, a preparation method and application thereof.The composite organic acid catalyst for acetate production comprises silica-supported organic acid; the silica-supported organic acid is silica-supported methyl sulfonic acid and silica-supported alkane disulfonic acid; and the mass ratio of the silica-supported methyl sulfonic acid and the silica-supported alkane disulfonic acid is 1.5:0.4-1.4.Through the technical scheme, the problem that the yield of acetate is not high due to the insufficient catalytic effect of the solid acid catalyst in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a composite organic acid catalyst for acetate production, its preparation method, and its application. Background Technology

[0002] Acetates are an important class of organic chemical products with excellent solubility, volatility, and low toxicity, finding wide applications in coatings, adhesives, inks, pharmaceuticals, fragrances, textile printing and dyeing, and many other fields. Currently, the mainstream industrial method for synthesizing acetates is esterification, which involves the reaction of acetic acid and alcohol with a catalyst to produce acetate and water. Depending on the catalyst used, esterification can be categorized into concentrated sulfuric acid catalysis, solid acid catalysis, and enzyme catalysis. Each existing acetate synthesis technology has its advantages and disadvantages. Solid acid catalysis, due to its advantages such as easy product separation and reusable catalysts, is considered a promising technology. However, some solid acid catalysts suffer from insufficient support surface area, difficulty in controlling acid strength, and carbon deposition caused by side reactions. These issues lead to insufficient catalytic effect and low acetate yields. Summary of the Invention

[0003] This invention proposes a composite organic acid catalyst for acetate production, its preparation method, and its application, which solves the problem of low acetate yield caused by insufficient catalytic effect of solid acid catalysts in related technologies.

[0004] The technical solution of the present invention is as follows:

[0005] This invention proposes a composite organic acid catalyst for acetate production, comprising silica-supported organic acid;

[0006] The silica-supported organic acids are silica-supported methanesulfonic acid and silica-supported alkane disulfonic acid;

[0007] The mass ratio of the silica-supported methanesulfonic acid to the silica-supported alkane disulfonic acid is 1.5:0.4~1.4.

[0008] As a further technical solution, the mass ratio of the silica-supported methanesulfonic acid and the silica-supported alkane disulfonic acid is 1.5:0.8~1.0.

[0009] In the composite organic acid catalyst of this invention, when the mass ratio of silica-supported methanesulfonic acid to silica-supported alkane disulfonic acid is 1.5:0.8~1.0, the synergistic effect between the two catalyzes the formation of acetate, further increasing its yield. When the mass ratio of silica-supported methanesulfonic acid to silica-supported alkane disulfonic acid is greater than 1.5:0.8, the proportion of silica-supported methanesulfonic acid is too high, which can trigger side reactions and reduce the yield of acetate. Conversely, when the mass ratio is less than 1.5:1.0, the proportion of silica-supported methanesulfonic acid is too low, resulting in a slower reaction rate, lower conversion rate, and reduced acetate yield.

[0010] As a further technical solution, the method for preparing the silica-supported organic acid includes the following steps:

[0011] Tetraethyl orthosilicate and an organic acid solution were added to an ethanol solution, stirred until gel formed, cooled, dried, and calcined to obtain silica-supported organic acid.

[0012] As a further technical solution, the volume ratio of the ethanol solution, tetraethyl orthosilicate and organic acid solution is 40:13:1~1.5.

[0013] As a further technical solution, the organic acid solution has a mass fraction of 55% to 60%.

[0014] As a further technical solution, the mass fraction of the ethanol solution is 45%~55%.

[0015] As a further technical solution, the stirring temperature is 70~85℃ and the stirring speed is 300~400rpm.

[0016] As a further technical solution, the drying temperature is 80~100℃ and the time is 20~25h.

[0017] As a further technical solution, the calcination temperature is 125~145℃ and the time is 20~25h.

[0018] As a further technical solution, the solute in the organic acid solution includes methanesulfonic acid or alkane disulfonic acid.

[0019] As a further technical solution, in the silica-supported alkane disulfonic acid, the alkane disulfonic acid is one of 1,4-butanedisulfonic acid, 1,3-propanedisulfonic acid, and 1,2-ethanedisulfonic acid.

[0020] Preferably, the alkane disulfonic acid is 1,4-butanedisulfonic acid.

[0021] In the composite organic acid catalyst of this invention, when the alkane disulfonic acid is 1,4-butanedisulfonic acid, the composite organic acid catalyst prepared by supporting methanesulfonic acid with silica and supporting 1,4-butanedisulfonic acid with silica is applied to the production of acetate, resulting in a better yield of acetate. This is because 1,4-butanedisulfonic acid has a 4-carbon alkyl chain, which increases the hydrophobicity of the molecule. During the reaction, it is not easily deactivated by absorbing water. Compared with other alkane disulfonic acids, 1,4-butanedisulfonic acid has better water resistance and stability, resulting in the best catalytic effect.

[0022] This invention also proposes a method for preparing a composite organic acid catalyst for acetate production, comprising the following steps:

[0023] The silica-supported methanesulfonic acid and the silica-supported alkane disulfonic acid are mixed to obtain the composite organic acid catalyst for acetate production.

[0024] The present invention also proposes the application of the composite organic acid catalyst for acetate production described above, or the composite organic acid catalyst for acetate production prepared by the above preparation method, in acetate production.

[0025] The working principle and beneficial effects of this invention are as follows:

[0026] In this invention, silica-supported methanesulfonic acid and silica-supported alkane disulfonic acid are used together as a composite organic acid catalyst for acetate production, which significantly improves the yield of acetate. Among them, the silica-supported methanesulfonic acid has strong acidity and good stability, which can ensure the rapid start of the esterification reaction. The silica-supported alkane disulfonic acid has two sulfonic acid groups, which can further enhance the proton transfer efficiency and promote the reaction to proceed in a more efficient direction. Therefore, the use of silica-supported methanesulfonic acid and silica-supported alkane disulfonic acid together improves the catalytic effect and increases the yield of acetate. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] A method for preparing a composite organic acid catalyst for acetate production includes the following steps:

[0030] A composite organic acid catalyst for acetate production was obtained by mixing silica-supported methanesulfonic acid and silica-supported 1,2-ethanedisulfonic acid in a mass ratio of 1.5:0.4.

[0031] The method for preparing silica-supported methanesulfonic acid includes the following steps:

[0032] Tetraethyl orthosilicate and a 55% methanesulfonic acid solution were added to a 45% ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and methanesulfonic acid solution was 40:13:1). The mixture was stirred at 70°C and 400 rpm until gelation occurred. The mixture was then cooled to room temperature, dried at 80°C for 25 h, and finally calcined at 125°C for 25 h to obtain silica-supported methanesulfonic acid.

[0033] The method for preparing silica-supported 1,2-ethanedisulfonic acid includes the following steps:

[0034] Tetraethyl orthosilicate and a 55% (w / w) solution of 1,2-ethanedisulfonic acid were added to a 45% (w / w) ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and 1,2-ethanedisulfonic acid solution was 40:13:1). The mixture was stirred at 70°C and 400 rpm until gelation occurred. The mixture was then cooled to room temperature, dried at 80°C for 25 h, and finally calcined at 125°C for 25 h to obtain silica-supported 1,2-ethanedisulfonic acid.

[0035] Example 2

[0036] A method for preparing a composite organic acid catalyst for acetate production includes the following steps:

[0037] A composite organic acid catalyst for acetate production was obtained by mixing silica-supported methanesulfonic acid and silica-supported 1,2-ethanedisulfonic acid in a mass ratio of 1.5:1.4.

[0038] The method for preparing silica-supported methanesulfonic acid includes the following steps:

[0039] Tetraethyl orthosilicate and a 60% methanesulfonic acid solution were added to a 55% ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and methanesulfonic acid solution was 40:13:1.5). The mixture was stirred at 85°C and 300 rpm until gelation occurred. The mixture was then cooled to room temperature, dried at 100°C for 20 h, and finally calcined at 145°C for 20 h to obtain silica-supported methanesulfonic acid.

[0040] The method for preparing silica-supported 1,2-ethanedisulfonic acid includes the following steps:

[0041] Tetraethyl orthosilicate and a 60% (w / w) solution of 1,2-ethanedisulfonic acid were added to a 55% (w / w) ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and 1,2-ethanedisulfonic acid solution was 40:13:1.5). The mixture was stirred at 85°C and 300 rpm until gelation occurred. The mixture was cooled to room temperature, dried at 100°C for 20 h, and finally calcined at 145°C for 20 h to obtain silica-supported 1,2-ethanedisulfonic acid.

[0042] Example 3

[0043] A method for preparing a composite organic acid catalyst for acetate production includes the following steps:

[0044] A composite organic acid catalyst for acetate production was obtained by mixing silica-supported methanesulfonic acid and silica-supported 1,2-ethanedisulfonic acid in a mass ratio of 1.5:0.6.

[0045] The method for preparing silica-supported methanesulfonic acid includes the following steps:

[0046] Tetraethyl orthosilicate and a 60% methanesulfonic acid solution were added to a 50% ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and methanesulfonic acid solution was 40:13:1.2). The mixture was stirred at 80°C and 350 rpm until gelation occurred. The mixture was cooled to room temperature, dried at 90°C for 24 h, and finally calcined at 135°C for 24 h to obtain silica-supported methanesulfonic acid.

[0047] The method for preparing silica-supported 1,2-ethanedisulfonic acid includes the following steps:

[0048] Tetraethyl orthosilicate and a 60% (w / w) solution of 1,2-ethanedisulfonic acid were added to a 50% (w / w) ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and 1,2-ethanedisulfonic acid solution was 40:13:1.2). The mixture was stirred at 80°C and 350 rpm until gelation occurred. The mixture was cooled to room temperature, dried at 90°C for 24 h, and finally calcined at 135°C for 24 h to obtain silica-supported 1,2-ethanedisulfonic acid.

[0049] Example 4

[0050] The only difference between this embodiment and Embodiment 3 is that the mass ratio of silica-supported methanesulfonic acid and silica-supported 1,2-ethanedisulfonic acid is 1.5:0.8.

[0051] Example 5

[0052] The only difference between this embodiment and Embodiment 3 is that the mass ratio of silica-supported methanesulfonic acid and silica-supported 1,2-ethanedisulfonic acid is 1.5:1.0.

[0053] Example 6

[0054] The only difference between this embodiment and Embodiment 3 is that the mass ratio of silica-supported methanesulfonic acid and silica-supported 1,2-ethanedisulfonic acid is 1.5:1.2.

[0055] Example 7

[0056] The only difference between this embodiment and Embodiment 5 is that the silica-supported 1,2-ethanedisulfonic acid is replaced with an equal amount of silica-supported 1,3-propanedisulfonic acid.

[0057] The method for preparing silica-supported 1,3-propanedisulfonic acid includes the following steps:

[0058] Tetraethyl orthosilicate and a 60% (w / w) solution of 1,3-propanedisulfonic acid were added to a 50% (w / w) ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and 1,3-propanedisulfonic acid solution was 40:13:1.2). The mixture was stirred at 80°C and 350 rpm until gelation occurred. The mixture was cooled to room temperature, dried at 90°C for 24 h, and finally calcined at 135°C for 24 h to obtain silica-supported 1,3-propanedisulfonic acid.

[0059] Example 8

[0060] The only difference between this embodiment and Embodiment 5 is that the silica-supported 1,2-ethanedisulfonic acid is replaced with an equal amount of silica-supported 1,4-butanedisulfonic acid.

[0061] The method for preparing silica-supported 1,4-butanedisulfonic acid includes the following steps:

[0062] Tetraethyl orthosilicate and a 60% (w / w) solution of 1,4-butadisulfonic acid were added to a 50% (w / w) ethanol solution (the volume ratio of ethanol solution, tetraethyl orthosilicate and 1,4-butadisulfonic acid solution was 40:13:1.2). The mixture was stirred at 80°C and 350 rpm until gelation occurred. The mixture was cooled to room temperature, dried at 90°C for 24 h, and finally calcined at 135°C for 24 h to obtain silica-supported 1,4-butadisulfonic acid.

[0063] Comparative Example 1

[0064] The only difference between this comparative example and Example 3 is that the silica-supported 1,2-ethanedisulfonic acid is replaced with an equal amount of silica-supported methanesulfonic acid.

[0065] Comparative Example 2

[0066] The only difference between this comparative example and Example 3 is that silica-supported methanesulfonic acid is replaced with an equal amount of silica-supported 1,2-ethanedisulfonic acid.

[0067] The composite organic acid catalysts for acetate production prepared in Examples 1-8 and Comparative Examples 1-2 were applied to the production of ethyl acetate, and the yields were calculated.

[0068] The production process of ethyl acetate includes the following steps:

[0069] The production process includes the following equipment: a reaction vessel, an esterification reactive distillation column, a phase separation column, a dehydration column, and a purification column. Ethanol and acetic acid, with a molar ratio of 1:1, are fed into the reaction vessel and the middle section of the esterification reactive distillation column, respectively. This column is packed with a composite organic acid catalyst, allowing for simultaneous reactive distillation. Preliminary purification is performed simultaneously with esterification, yielding crude ethyl acetate from the top of the column. The crude ethyl acetate then enters the phase separation column to separate crude ethyl acetate from water. The crude ethyl acetate is then sent to the dehydration column to remove water, and finally enters the purification column (top temperature 77.1℃) to obtain the product ethyl acetate. The reaction process is as follows:

[0070] Esterification reaction: CH3COOH + CH3CH2OH CH3COOC2H5+H2O

[0071] The test results are shown in Table 1:

[0072] Table 1 Test Results

[0073]

[0074] 1. Compared with Comparative Examples 1-2, when the composite organic acid catalyst for acetate production prepared in Examples 1-8 is applied to the production of ethyl acetate, the yield of ethyl acetate is higher than that in Comparative Examples 1-2. This indicates that using silica-supported methanesulfonic acid and silica-supported alkane disulfonic acid together as catalysts can improve the yield of acetate.

[0075] 2. Compared with Examples 5 and 7-8, when the composite organic acid catalyst for acetate production prepared in Example 8 was applied to the production of ethyl acetate, the yield of ethyl acetate was higher than that in Examples 5 and 7, reaching as high as 99.2%. This indicates that when the silica-supported alkane disulfonic acid used is silica-supported 1,4-butanedisulfonic acid, the yield of ethyl acetate is further improved.

[0076] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The application of a composite organic acid catalyst in the production of acetate, characterized in that, Composite organic acid catalysts, including silica-supported organic acids; The silica-supported organic acids are silica-supported methanesulfonic acid and silica-supported alkane disulfonic acid; The mass ratio of the silica-supported methanesulfonic acid to the silica-supported alkane disulfonic acid is 1.5:0.8~1.0; The preparation method of the composite organic acid catalyst includes the following steps: The silica-supported methanesulfonic acid and the silica-supported alkane disulfonic acid are mixed to obtain the composite organic acid catalyst; In the silica-supported alkane disulfonic acid, the alkane disulfonic acid is one of 1,4-butanedisulfonic acid, 1,3-propanedisulfonic acid, and 1,2-ethanedisulfonic acid.

2. The application of the composite organic acid catalyst according to claim 1 in the production of acetate, characterized in that, The method for preparing the silica-supported organic acid includes the following steps: Tetraethyl orthosilicate and an organic acid solution were added to an ethanol solution, stirred until gel formed, cooled, dried, and calcined to obtain the silica-supported organic acid. The solute in the organic acid solution includes methanesulfonic acid or alkane disulfonic acid.

3. The application of the composite organic acid catalyst according to claim 2 in the production of acetate, characterized in that, The volume ratio of the ethanol solution, tetraethyl orthosilicate, and organic acid solution is 40:13:1~1.

5.

4. The application of the composite organic acid catalyst according to claim 2 in the production of acetate, characterized in that, The organic acid solution has a mass fraction of 55% to 60%.

5. The application of the composite organic acid catalyst according to claim 2 in the production of acetate, characterized in that, The stirring temperature is 70~85℃ and the stirring speed is 300~400rpm; The drying temperature is 80~100℃, and the time is 20~25h; The roasting temperature is 125~145℃ and the time is 20~25h.

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