Preparation method of solid peracetic acid

Abstract

The invention relates to the technical field of disinfectant preparation, and particularly discloses a preparation method of solid peracetic acid. Firstly, hydrogen peroxide and acetic anhydride are subjected to an oxidation reaction to prepare anhydrous peracetic acid, and then sodium perborate and anhydrous peracetic acid are subjected to an esterification reaction to prepare solid peracetic acid. Compared with the prior art, the method has the advantages that the use of high-concentration hydrogen peroxide is avoided, the solid peracetic acid is obtained by a safer, simpler and more convenient method, and the method is suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of disinfectant manufacturing, and specifically to a preparation method of solid peracetic acid. Background Art

[0002] Peracetic acid (CH 3 COOOH) is a fast-acting, highly efficient, low-toxic, and broad-spectrum disinfectant with wide applications, which can kill various bacteria, molds, viruses, and spores. Pure peracetic acid is extremely unstable and will explode violently at -20°C. Therefore, most commercially available peracetic acid is a peracetic acid solution with a content of about 20%. However, its properties are also very unstable, with an explosion risk and inconvenient for transportation.

[0003] Compared with liquid peracetic acid, using solid peracetic acid for disinfection has greater development potential. Sodium perborate acetylacetonate (APB) is the solid form of peracetic acid, with characteristics such as good stability, convenient transportation, and easy use. Currently, there are relatively few literature reports on the synthesis of sodium perborate acetylacetonate (APB). However, there are relatively few scientific literatures on the synthesis of sodium perborate acetylacetonate (APB) currently, which limits its further research and development and application. Most of the currently known synthesis methods rely on reacting high-concentration (80%) hydrogen peroxide with acetic acid to generate high-concentration peracetic acid, and then esterifying with sodium perborate to obtain sodium perborate acetylacetonate (APB). However, in this process, the use of high-concentration hydrogen peroxide is extremely likely to cause safety accidents, becoming the bottleneck restricting the large-scale production of sodium perborate acetylacetonate (APB). In view of the above problems, it is particularly important to explore a safe and reliable synthesis route for solid peracetic acid, which not only concerns the production safety of the product but also directly affects its wide application in the disinfection field. Therefore, it is imperative to study the safe synthesis route of solid peracetic acid. Summary of the Invention

[0004] The present invention provides a preparation method of solid peracetic acid, which at least includes the following steps:

[0005] (1) Oxidation reaction: Add hydrogen peroxide to the reactor. After the temperature stabilizes, add acetic anhydride dropwise. After the addition is completed, continue to keep the temperature constant for reaction to obtain anhydrous peracetic acid;

[0006] (2) Esterification reaction: Add sodium perborate and acetic acid to the reactor. After the temperature stabilizes, add the prepared anhydrous peracetic acid dropwise. After the addition is completed, continue to keep the temperature constant for reaction;

[0007] (3) Separation and purification: After the temperature-constant reaction is completed, perform separation to obtain a wet crude product. The wet crude product is slurried and washed with a washing solvent, and then dried to obtain the product.

[0008] As a preferred technical solution, the ratio of the sum of the number of moles of hydrogen peroxide and water in hydrogen peroxide to the number of moles of acetic anhydride in the oxidation reaction is 1:(1.5 - 2.5).

[0009] As a preferred technical solution, the mass concentration of hydrogen peroxide in the oxidation reaction is 30 - 50 wt%.

[0010] As a preferred technical solution, the temperature in the oxidation reaction is 20 - 50 °C, and the holding time of the oxidation reaction is 2 - 2.5 h. Preferably, the temperature of the oxidation reaction is 30 - 50 °C.

[0011] As a preferred technical solution, the peracetic acid anhydride prepared in the oxidation reaction contains 23 - 27% of peracetic acid, and the water content in the peracetic acid anhydride prepared in the oxidation reaction is less than 0.5%.

[0012] As a preferred technical solution, the mass ratio of sodium perborate to acetic acid in the esterification reaction is 1:(1 - 3), the temperature in the esterification reaction is 10 - 40 °C, and the holding time of the esterification reaction is 3 - 5 h. Preferably, the temperature of the esterification reaction is 20 - 40 °C.

[0013] As a preferred technical solution, the molar ratio of sodium perborate to peracetic acid in the esterification reaction is 1:(1.3 - 1.8).

[0014] As a preferred technical solution, the drying temperature in the separation and purification is 50 - 70 °C, and the drying time is 12 h - 18 h.

[0015] As a preferred technical solution, the washing solvent used in the separation and purification is selected from one or a combination of ethanol, petroleum ether, methyl tert-butyl ether, ethyl acetate, tetrahydrofuran, and dichloromethane.

[0016] As a preferred technical solution, the amount of the washing solvent used in the separation and purification is 2 - 4 times the mass of sodium perborate, and the separation in the separation and purification is suction filtration separation.

[0017] The technical solution of the present invention uses hydrogen peroxide with a mass concentration of 30 - 50 wt% to replace high-concentration hydrogen peroxide to prepare solid peracetic acid, avoiding the use of raw materials such as high-concentration hydrogen peroxide that are prone to cause safety accidents, reducing the safety risks in the production process, and ensuring the life safety of production staff.

[0018] In the process of preparing solid peracetic acid in the present invention, high temperature and high pressure are not involved, the process control is simple, and it is more suitable for industrial production. Solid peracetic acid has better stability compared with liquid peracetic acid. It is not only convenient for long-term storage, but also can reduce the explosion risk caused by factors such as bumps and temperature changes during transportation. The solid form simplifies the packaging and transportation process, reduces the logistics cost, and at the same time, it is more convenient for users during use, without worrying about the leakage or splashing problems that may be caused by liquid peracetic acid. And the safe and simple synthesis route also makes it possible for the large-scale industrial production of solid peracetic acid, which helps to meet the growing market demand for high-efficiency and broad-spectrum disinfectants, improves the safety and stability of the product, and promotes the convenience of its production, transportation and use. Detailed implementation manners

[0019] To better understand the content of the present invention, the following further illustrates with specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention, rather than limiting the present invention.

[0020] Example 1:

[0021] Add 100 g of hydrogen peroxide with a concentration of 30% to the reactor, heat up and stir. When the temperature is stable at 30 - 35 °C, slowly drop 734 g of acetic anhydride, and keep the temperature for reaction for 2.5 h to obtain 830 g of anhydrous peracetic acid. After detection, the peracetic acid content is 24.6% and the water content is 0.36%.

[0022] Add 191.5 g of sodium perborate and 383 g of acetic acid to the reactor, heat up and stir. When the temperature is stable at 20 - 25 °C, drop the above-prepared anhydrous peracetic acid into the reactor, and keep the temperature for reaction for 5 h. Then carry out suction filtration to obtain the wet crude product.

[0023] The wet crude product is slurried and washed with 400 g of washing solvent ethanol, suction filtered, and dried at a drying temperature of 50 °C for 18 h to obtain solid peracetic acid. After detection, the peracetic acid content is 27.5%.

[0024] Example 2:

[0025] Add 50 g of hydrogen peroxide with a concentration of 50% to the reactor, heat up and stir. When the temperature is stable at 30 - 35 °C, slowly drop 326.8 g of acetic anhydride, and keep the temperature for reaction for 2.5 h to obtain 374 g of anhydrous peracetic acid. After detection, the peracetic acid content is 26.1% and the water content is 0.21%.

[0026] Add 94.4 g of sodium perborate and 189 g of acetic acid to the reactor, heat up and stir. When the temperature is stable at 20 - 25 °C, drop the above-prepared anhydrous peracetic acid into the reactor, and keep the temperature for reaction for 5 h. Then carry out suction filtration to obtain the wet crude product.

[0027] The crude wet material was slurried and washed with 200 g of washing solvent ethanol, filtered by suction, and dried at a drying temperature of 50 °C for 18 h to obtain solid peracetic acid. The content of peracetic acid was detected to be 27.8%.

[0028] Example 3:

[0029] 100 g of hydrogen peroxide with a concentration of 30% was added to the reactor, heated and stirred. When the temperature was stabilized at 45 - 50 °C, 734 g of acetic anhydride was slowly added dropwise, and the reaction was kept warm for 2 h to obtain 827 g of anhydrous peracetic acid. The content of peracetic acid was detected to be 26.3%, and the water content was 0.24%.

[0030] 204.5 g of sodium perborate and 612 g of acetic acid were added to the reactor, heated and stirred. When the temperature was stabilized at 35 - 40 °C, the above-prepared anhydrous peracetic acid was added dropwise to the reactor, and the reaction was kept warm for 3 h. Then, filtration by suction was carried out to obtain the crude wet material.

[0031] The crude wet material was slurried and washed with 816 g of washing solvent (m 乙醇 : m 乙酸乙酯 = 2:1), filtered by suction, and dried at a drying temperature of 70 °C for 12 h to obtain solid peracetic acid. The content of peracetic acid was detected to be 28.1%.

[0032] Example 4:

[0033] 50 g of hydrogen peroxide with a concentration of 50% was added to the reactor, heated and stirred. When the temperature was stabilized at 45 - 50 °C, 436 g of acetic anhydride was slowly added dropwise, and the reaction was kept warm for 2 h to obtain 482 g of anhydrous peracetic acid. The content of peracetic acid was detected to be 26.7%, and the water content was 0.24%.

[0034] 120.7 g of sodium perborate and 362 g of acetic acid were added to the reactor, heated and stirred. When the temperature was stabilized at 35 - 40 °C, the above-prepared anhydrous peracetic acid was added dropwise to the reactor, and the reaction was kept warm for 3 h. Then, filtration by suction was carried out to obtain the crude wet material.

[0035] The crude wet material was slurried and washed with 483 g of washing solvent (m 乙醇 : m 乙酸乙酯 = 2:1), filtered by suction, and dried at a drying temperature of 60 °C for 14.5 h to obtain solid peracetic acid. The content of peracetic acid was detected to be 28.6%.

[0036] Example 5:

[0037] 50 g of hydrogen peroxide solution with a concentration of 50% was added to the reactor, and the temperature was raised with stirring. When the temperature stabilized at 45 - 50 °C, 542 g of acetic anhydride was slowly added dropwise, and the reaction was carried out with heat preservation for 2 h to obtain 589 g of peracetic anhydride. After detection, the peracetic acid content was 26.8% and the water content was 0.19%.

[0038] 115.2 g of sodium perborate and 230 g of acetic acid were added to the reactor, and the temperature was raised with stirring. When the temperature stabilized at 35 - 40 °C, the above-prepared peracetic anhydride was added dropwise to the reactor, and the reaction was carried out with heat preservation for 3 h. Then, suction filtration was carried out to obtain the wet crude product.

[0039] The wet crude product was slurried and washed with 346 g of washing solvent ethyl acetate, suction filtered, and dried at a drying temperature of 55 °C for 16 h to obtain solid peracetic acid. After detection, the peracetic acid content was 28.4%.

[0040] The above are only the preferred embodiments of the present invention, and are not limitations on the present invention. Any person skilled in the art may use the disclosed technical content to make changes or equivalent changes to equivalent embodiments. However, as long as it does not depart from the technical solution content of the present invention, simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing solid peracetic acid, characterized in that: The following steps are involved: (1) Oxidation reaction: Add hydrogen peroxide to the reactor, add acetic anhydride dropwise until the temperature stabilizes, and continue to keep warm at the same temperature to obtain anhydrous peracetic acid; (2) Esterification reaction: Sodium perborate and acetic acid are added to a reactor, and the prepared anhydrous peracetic acid is added dropwise after the temperature stabilizes. After the addition is completed, the reaction is continued at the same temperature; (3) Separation and purification: After the heat preservation reaction is completed, separation is performed to obtain a crude wet material, and the crude wet material is pulped and washed with a washing solvent and then dried.

2. A method for preparing solid peracetic acid according to claim 1, characterized in that: In the oxidation reaction, the ratio of the sum of the moles of hydrogen peroxide and water in hydrogen peroxide to the mole of acetic anhydride is 1:(1.5-2.5).

3. A method for preparing solid peracetic acid according to claim 1, characterized in that: The mass concentration of hydrogen peroxide in the oxidation reaction is 30-50wt%.

4. A method for preparing solid peracetic acid according to claim 1, characterized in that: The temperature in the oxidation reaction is 20-50° C., and the heat preservation time in the oxidation reaction is 2-2.5 hours.

5. A method for preparing solid peracetic acid according to claim 1, characterized in that: The anhydrous peracetic acid prepared in the oxidation reaction contains 23-27% of peracetic acid, and the anhydrous peracetic acid prepared in the oxidation reaction contains less than 0.5% of water.

6. A method for preparing solid peracetic acid according to claim 1, characterized in that: The mass ratio of sodium perborate to acetic acid in the esterification reaction is 1:(1-3), the temperature in the esterification reaction is 10-40° C., and the heat preservation reaction time in the esterification reaction is 3-5 hours.

7. A method for preparing solid peracetic acid according to claim 1, characterized in that: The molar ratio of sodium perborate to peracetic acid in the esterification reaction is 1:(1.3-1.8).

8. A method for preparing solid peracetic acid according to claim 1, characterized in that: The drying temperature in the separation and purification is 50-70° C., and the drying time is 12 h-18 h.

9. A method for preparing solid peracetic acid according to claim 1, characterized in that: The washing solvent used in the separation and purification is selected from one or more combinations of ethanol, petroleum ether, methyl tert-butyl ether, ethyl acetate, tetrahydrofuran and dichloromethane.

10. The method for preparing solid peracetic acid according to claim 1, characterized in that: The amount of washing solvent used in the separation and purification is 2-4 times the mass of sodium perborate, and the separation in the separation and purification is suction filtration separation.