Method for inhibiting product isomerization in potassium sorbate preparation process
By controlling the neutralization and photocatalytic conditions, the photocatalytic isomerization treatment was performed using TiO2 and ZrO2 composite catalysts, which solved the problem of high isomer content in the finished potassium sorbate product, and improved the purity and anticorrosion effect of the product.
Patent Information
- Application Number
- CN202411475781.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-02-11
AI Technical Summary
In the prior art, the isomer content in the finished potassium sorbate product is high, which affects the purity of the product and the anticorrosion effect.
By controlling the conditions of the neutralization process and photocatalytic conditions, an aqueous potassium sorbate solution was prepared and photocatalytic isomerization was performed using TiO2 and ZrO2 composite catalysts to convert isomer 2Z,4E-potassium sorbate to 2E,4E-potassium sorbate .
The purity and quality of potassium sorbate has been significantly improved, its anticorrosion effect has been improved, and the isomer content has been reduced to 300-500ppm.
Smart Images
Figure BDA0005096068280000051 
Figure BDA0005096068280000052 
Figure BDA0005096068280000053
Abstract
Description
Technical Field
[0001] The invention belongs to the field of chemical industry, and particularly relates to a method for inhibiting product isomerization in the process of preparing potassium sorbate. Background Art
[0002] Potassium sorbate, like sorbic acid, is an internationally recognized low-toxic, highly effective acid-type preservative, and has similar preservative effects to sorbic acid. Compared with sorbic acid, potassium sorbate is more soluble in water, and the solution is relatively stable at room temperature, making it more convenient to use; and potassium sorbate is more stable in the air and not easily oxidized, while sorbic acid is easily oxidized and colored when left in the air for a long time. Potassium sorbate can also effectively inhibit the activity of molds, yeasts and aerobic bacteria, and prevent the growth and reproduction of harmful microorganisms such as Clostridium botulinum, Staphylococcus aureus, and Salmonella, but it is almost ineffective against beneficial microorganisms such as anaerobic spore-forming bacteria and Lactobacillus acidophilus, and its inhibitory effect is stronger than its bactericidal effect. Therefore, potassium sorbate can effectively extend the shelf life of food and maintain the original flavor of the food. Its preservative effect is 5-10 times that of similar products such as sodium benzoate. At present, potassium sorbate has been widely used in food, beverages, pickles, tobacco, medicine, cosmetics, agricultural products, pet and poultry feed and other industries. It has an upward development trend and its application scope is constantly expanding.
[0003] In the prior art of photocatalytic isomerization, CN117304027A discloses an application of hydroxy aromatic aldehyde in light-assisted catalytic cis-isomerization of unsaturated organic matter, and the invention applies hydroxy aromatic aldehyde to light-assisted catalytic isomerization reaction, and the cis-isomer ratio in the reaction product of the present invention is high, and no by-products are generated, which greatly improves the selectivity of the target product. And CN117105741A discloses a method for photocatalytic isomerization of ene ynols, specifically to a method for photoisomerizing trans ene ynols to cis ene ynols, or photoisomerizing cis ene ynols to trans ene ynols. The method can photoisomerize Z-ene ynols to E-ene ynols or photoisomerize E-ene ynols to Z-ene ynols, and avoids the use of UV light sources, and can directly use LED light sources and cheap photosensitizers, and the safety of the reaction is greatly improved.
[0004] In the isomerization preparation of sorbic acid, the preparation process of polyester depolymerization into sorbic acid is also carried out by a photocatalytic isomerization method. For example, CN111437881B discloses a method for preparing sorbic acid by photocatalytic isomerization, which specifically uses a solid base catalyst of a supported anion exchange resin to catalyze and depolymerize sorbic acid polyester under the efficient catalysis of light of different wavelengths. The yield after cooling, crystallization, washing and drying is as high as 95.1%, the purity is 99.3%, and the tar content is 5.3-10.7g. The method has a high yield of sorbic acid prepared by the synergistic effect of light source and catalyst, low tar content, simple operation, and green environmental protection. The method is to photocatalyze the reaction process of polyester depolymerization to prevent the generation of impurity isomers during the reaction process. However, there is no relevant literature report on the isomerization post-treatment of the prepared sorbic acid and potassium sorbate.
[0005] The existing technology mainly improves the quality of potassium sorbate by improving the production process and equipment. In the current technology for preparing potassium sorbate, the isomer content in the finished potassium sorbate product prepared from crude sorbic acid reaches 0.1%-0.5%, and due to the different physical properties of its isomers, the purity of the product is affected, and the preservative effect of potassium sorbate is also reduced. For the preservative effect of potassium sorbate, 2E, 4E-potassium sorbate has the best antibacterial performance. Therefore, it is necessary to develop a method for inhibiting product isomerization in the process of preparing potassium sorbate, improve the purity of the finished potassium sorbate product (2E, 4E-potassium sorbate), and enhance the preservative effect of potassium sorbate, thereby broadening the application of potassium sorbate. Summary of the invention
[0006] The invention provides a method for inhibiting product isomerization in the process of preparing potassium sorbate, aiming to solve the problem that the isomer content in the finished potassium sorbate product is high and affects the purity of the product. By controlling the conditions of the neutralization process and photocatalyzing the potassium sorbate solution, the content of the isomer (2Z, 4E-potassium sorbate) in the finished potassium sorbate product is effectively reduced, the purity and quality of potassium sorbate are significantly improved, and the antiseptic effect of potassium sorbate is enhanced.
[0007] In order to achieve the above technical effects, the present invention provides a method for inhibiting product isomerization during the preparation of potassium sorbate, comprising the following steps:
[0008] (1) Preparation of potassium sorbate aqueous solution:
[0009] Add water and sorbic acid to the reaction kettle and stir, then start to drop potassium hydroxide solution to adjust the pH; then add activated carbon for decolorization, and continue to drop potassium hydroxide solution to adjust the pH; after filtering the activated carbon, obtain potassium sorbate aqueous solution;
[0010] (2) Preparation of solid base catalyst:
[0011] Mixing TiO2 and ZrO2 nanopowders with deionized water, wherein the mass ratio of TiO2 and ZrO2 nanopowders is 1:2-5, and the amount of deionized water is 2-10wt% (mass percentage); crushing and drying the mixed particles, and then sieving to obtain particles, and then roasting the particles to obtain a solid base catalyst;
[0012] (3) Preparation of potassium sorbate finished product:
[0013] Irradiate with light having a wavelength of 280-1550 nm at a temperature of 75-85° C., and pass the potassium sorbate aqueous solution obtained in step (1) through the solid base catalyst obtained in step (2); and then filter through a membrane and spray dry to obtain a potassium sorbate product.
[0014] After testing, the potassium sorbate content in the finished potassium sorbate product reached 99.90%-99.95%, and the isomer content was only 300-500ppm.
[0015] Furthermore, the addition of water and sorbic acid in step (1) refers to 16-60 parts by mass of water and 25 parts by mass of sorbic acid (equivalent to a water to sorbic acid mass ratio of 16-60:25); the stirring conditions are a stirring rate of 200-400 r / min and a stirring temperature of 20-40° C., preferably a stirring temperature of 20-30° C.
[0016] Furthermore, the concentration of the potassium hydroxide solution in step (1) is 48 wt %, and the titration conditions are as follows: the pH value is maintained at 10.0-10.5 during the dropwise addition, and the pH value is preferably 10-10.2; the temperature is maintained at 20-40° C., and the dropwise addition is completed within 1.5-2.5 h. The amount of potassium hydroxide solution added is adjusted according to the pH value.
[0017] Furthermore, the amount of activated carbon used in step (1) is 1 part by weight, the decolorization conditions are a decolorization temperature of 50-70° C. and a decolorization time of 0.5-1.5 h; the concentration of the potassium hydroxide solution continued to be added dropwise is still 48wt%, and the pH is adjusted to 11.5-12.0, and the pH value is preferably 11.5-11.7.
[0018] Furthermore, the potassium sorbate content in the potassium sorbate aqueous solution in step (1) is 30.16-49.97%.
[0019] Furthermore, the ratio of TiO2 to ZrO2 in step (2) is preferably 1:2-1:3.
[0020] Furthermore, in step (2), the drying temperature is 70-90° C., and the drying time is 2-4 h.
[0021] Furthermore, the mesh size of the particles obtained by sieving in step (2) is 20-100 mesh, and the mesh size of the particles is preferably 20-50 mesh.
[0022] Furthermore, in step (2), the calcination temperature is 800-1000° C., preferably 900-1000° C.; the calcination time is 10-12.0 h, preferably 11-12 h; after calcination, the particles are allowed to cool to 20-25° C.
[0023] Furthermore, the photocatalytic temperature in step (3) is preferably 75-80°C.
[0024] Furthermore, the wavelength of light used for photocatalysis in step (3) is preferably 280-350 nm.
[0025] Furthermore, the photocatalytic time in step (3) is preferably 40 min-1 h.
[0026] Furthermore, in step (3), the residence time of the potassium sorbate aqueous solution passing through the solid base catalyst is 20 min-1 h; and the membrane filtration is performed using any one of 0.22 μm, 0.45 μm, and 0.8 μm water filter membranes.
[0027] Preferably, the present invention provides a method for inhibiting product isomerization during the preparation of potassium sorbate, comprising the following steps:
[0028] (1) Preparation of potassium sorbate aqueous solution:
[0029] Add 16 parts by weight of water and 25 parts by weight of sorbic acid to the reactor (i.e., the mass ratio of water to sorbic acid is 16:25), start stirring at a stirring rate of 300 r / min, and heat to 20°C;
[0030] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.0, and the temperature was still maintained at 20°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0031] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 11.5. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 49.97%.
[0032] (2) Preparation of solid base catalyst:
[0033] The TiO2 and ZrO2 nanopowders were mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides was 1:2), 5wt% water was added, and the mixture was crushed by an extruder, dried in a drying oven at 80°C for 3h, and 20-30 mesh particles were sieved, and then the particles were calcined at a temperature of 1000°C for 12.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0034] (3) Preparation of potassium sorbate finished product:
[0035] At 75°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 330 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 1 hour, and is filtered through a 0.45 micron water filter membrane and spray-dried to obtain a finished potassium sorbate product.
[0036] After testing, the potassium sorbate content in the finished potassium sorbate product reached 99.95%, and the isomer content was only 300ppm.
[0037] The invention effectively limits the isomer conversion of potassium sorbate in the preparation process by controlling the temperature and pH value in the reaction process, and converts the isomer of 2Z, 4E-potassium sorbate into 2E, 4E-potassium sorbate by photocatalytic treatment of the aqueous solution, thereby further reducing the accumulation of impurities and improving the quality of potassium sorbate.
[0038] Beneficial Effects
[0039] (1) The isomer content prepared by the technical solution of the present invention is 300-500 ppm, and the potassium sorbate content in the potassium sorbate finished product reaches 99.90%-99.95%.
[0040] (2) The present invention controls the reaction temperature at a relatively low temperature of 20-40° C. and always maintains an alkaline condition of pH=10-10.5. Control of these reaction conditions can effectively reduce the isomerization conversion of the potassium sorbate aqueous solution during the preparation process.
[0041] (3) The present invention selects TiO2 and ZrO2 composite catalysts and optimizes the compounding ratio of the two, and performs photocatalytic isomerization treatment of potassium sorbate aqueous solution, converting the isomer 2Z, 4E-potassium sorbate into 2E, 4E-potassium sorbate by photocatalysis, thereby further reducing the accumulation of impurities and improving the quality of potassium sorbate.
[0042] (4) The reaction stage and the post-treatment stage of the present invention reduce the accumulation of impurities, effectively reduce the content of the isomer 2Z, 4E-potassium sorbate in the finished potassium sorbate product, significantly improve the purity and quality of potassium sorbate, and enhance the antiseptic effect of potassium sorbate. DETAILED DESCRIPTION
[0043] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.
[0044] Raw materials and equipment used in the embodiments:
[0045] The sorbic acid involved in the following examples is from Nantong Acetic Acid Chemical Co., Ltd., CAS No. 110-44-1;
[0046] The TiO2 nanopowder and ZrO2 nanopowder involved in the following examples were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with CAS numbers of 13463-67-7 and 1314-23-4, respectively;
[0047] The light source device involved in the following embodiments is a laser frequency converter with a wavelength of 280-1550nm.
[0048] The detection methods involved in the following embodiments are as follows:
[0049] Detection method of potassium sorbate content in potassium sorbate aqueous solution:
[0050] Analyze using liquid chromatography.
[0051] The method for detecting the content of potassium sorbate isomers (2E, 4E-potassium sorbate) in potassium sorbate finished products is based on the "National Food Safety Standard Food Additive Potassium Sorbate" (GB 1886.39-2015).
[0052] The chemical reaction formulas and structural formulas involved in the following embodiments are:
[0053] 2Z,4E-Potassium sorbate:
[0054]
[0055] 2E,4E-Potassium Sorbate:
[0056]
[0057] The chemical reaction formula for the conversion of isomer 2Z,4E-potassium sorbate to 2E,4E-potassium sorbate is:
[0058]
[0059] The following is a specific implementation of a method for inhibiting product isomerization in the process of preparing potassium sorbate provided by the present invention.
[0060] Example 1: A method for inhibiting product isomerization during the preparation of potassium sorbate
[0061] The specific implementation is as follows:
[0062] (1) Preparation of potassium sorbate aqueous solution:
[0063] Add 16 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 20°C;
[0064] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.0, and the temperature was still maintained at 20°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0065] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 11.5. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 49.97%.
[0066] (2) Preparation of solid base catalyst:
[0067] The TiO2 and ZrO2 nanopowders were mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides was 1:2), 5wt% water was added, and the mixture was crushed by an extruder, dried in a drying oven at 80°C for 3h, and 20-30 mesh particles were sieved, and then the particles were calcined at a temperature of 1000°C for 12.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0068] (3) Preparation of potassium sorbate finished product:
[0069] At 75°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 330 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 1 hour, and is filtered through a 0.45 micron water filter membrane and spray-dried to obtain a finished potassium sorbate product.
[0070] The result showed that the isomer content in the finished potassium sorbate product was 300 ppm, and the content of potassium sorbate reached 99.95%.
[0071] Example 2: A method for inhibiting product isomerization during the preparation of potassium sorbate
[0072] The specific implementation is as follows:
[0073] (1) Preparation of potassium sorbate aqueous solution:
[0074] Add 20 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 24°C;
[0075] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.1, and the temperature was still maintained at 24°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0076] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 11.6. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 47.16%.
[0077] (2) Preparation of solid base catalyst:
[0078] The TiO2 and ZrO2 nanopowders were mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides was 1:3), 5wt% water was added, and the mixture was crushed by an extruder, dried in a drying oven at 80°C for 3h, and 40-50 mesh particles were sieved, and then the particles were calcined at 960°C for 11.5h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0079] (3) Preparation of potassium sorbate finished product:
[0080] At 77°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 335 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 52 minutes, and is filtered through a 0.45 micron water filter membrane and spray-dried to obtain a finished potassium sorbate product.
[0081] The result showed that the isomer content in the finished potassium sorbate product was 340 ppm, and the content of potassium sorbate reached 99.94%.
[0082] Example 3: A method for inhibiting product isomerization during the preparation of potassium sorbate
[0083] The specific implementation is as follows:
[0084] (1) Preparation of potassium sorbate aqueous solution:
[0085] Add 28 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 28°C;
[0086] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.2, and the temperature was still maintained at 28°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0087] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 11.7. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 42.38%.
[0088] (2) Preparation of solid base catalyst:
[0089] The TiO2 and ZrO2 nanopowders were mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides was 1:4), 5wt% water was added, and the mixture was crushed by an extruder, dried in a drying oven at 80°C for 3h, and 50-60 mesh particles were sieved, and then the particles were calcined at 920°C for 11.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0090] (3) Preparation of potassium sorbate finished product:
[0091] At 79° C., the potassium sorbate aqueous solution is irradiated with light of a wavelength of 510 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 44 minutes, and is filtered through a 0.45 μm water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0092] The result showed that the isomer content in the finished potassium sorbate product was 380 ppm, and the content of potassium sorbate reached 99.93%.
[0093] Example 4: A method for inhibiting product isomerization during the preparation of potassium sorbate
[0094] The specific implementation is as follows:
[0095] (1) Preparation of potassium sorbate aqueous solution:
[0096] Add 36 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 32°C;
[0097] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.3, and the temperature was still maintained at 32°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0098] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 11.8. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 38.49%.
[0099] (2) Preparation of solid base catalyst:
[0100] The TiO2 and ZrO2 nanopowders were uniformly mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides was 1:3.8), 5wt% water was added, and the mixture was crushed by an extruder, dried in a drying oven at 80°C for 3h, and 60-70 mesh particles were sieved, and then the particles were calcined at 960°C for 11.5h, and cooled to room temperature to obtain a recyclable solid base catalyst;
[0101] (3) Preparation of potassium sorbate finished product:
[0102] At 81° C., the potassium sorbate aqueous solution is irradiated with light of a wavelength of 565 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 36 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0103] The result showed that the isomer content in the finished potassium sorbate product was 420 ppm, and the content of potassium sorbate reached 99.92%.
[0104] Example 5: A method for inhibiting product isomerization during the preparation of potassium sorbate
[0105] The specific implementation is as follows:
[0106] (1) Preparation of potassium sorbate aqueous solution:
[0107] Add 47 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 36°C;
[0108] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.4, and the temperature was still maintained at 36°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0109] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 11.9. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 34.00%.
[0110] (2) Preparation of solid base catalyst:
[0111] The TiO2 and ZrO2 nanopowders were mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides was 1:3.8), 5wt% water was added, and the mixture was crushed by an extruder, dried in a drying oven at 80°C for 3h, and 80-90 mesh particles were sieved, and then the particles were calcined at 840°C for 10.5h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0112] (3) Preparation of potassium sorbate finished product:
[0113] At 83° C., the potassium sorbate aqueous solution is irradiated with light of a wavelength of 700 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 28 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a potassium sorbate product.
[0114] The result showed that the isomer content in the finished potassium sorbate product was 460 ppm, and the content of potassium sorbate reached 99.91%.
[0115] Example 6: A method for inhibiting product isomerization during the preparation of potassium sorbate
[0116] The specific implementation is as follows:
[0117] (1) Preparation of potassium sorbate aqueous solution:
[0118] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0119] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0120] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0121] (2) Preparation of solid base catalyst:
[0122] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0123] (3) Preparation of potassium sorbate finished product:
[0124] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0125] The result showed that the isomer content in the finished potassium sorbate product was 500 ppm, and the content of potassium sorbate reached 99.90%.
[0126] Comparative Example 1 (according to Example 6, investigating the reaction temperature conditions)
[0127] The specific implementation is as follows:
[0128] (1) Preparation of potassium sorbate aqueous solution:
[0129] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 45°C;
[0130] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 45°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0131] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0132] (2) Preparation of solid base catalyst:
[0133] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0134] (3) Preparation of potassium sorbate finished product:
[0135] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0136] The result showed that the isomer content in the finished potassium sorbate product was 800 ppm, and the content of potassium sorbate reached 99.70%.
[0137] Comparative Example 2 (according to Example 6, investigating the pH conditions of the reaction process)
[0138] (1) Preparation of potassium sorbate aqueous solution:
[0139] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0140] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 11.0, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0141] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0142] (2) Preparation of solid base catalyst:
[0143] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0144] (3) Preparation of potassium sorbate finished product:
[0145] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0146] The result showed that the isomer content in the finished potassium sorbate product was 700 ppm, and the content of potassium sorbate reached 99.75%.
[0147] Comparative Example 3 (according to Example 6, investigating the pH conditions at the reaction end point)
[0148] (1) Preparation of potassium sorbate aqueous solution:
[0149] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0150] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0151] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 13.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0152] (2) Preparation of solid base catalyst:
[0153] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0154] (3) Preparation of potassium sorbate finished product:
[0155] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0156] The result showed that the isomer content in the finished potassium sorbate product was 1000 ppm, and the content of potassium sorbate reached 99.62%.
[0157] Comparative Example 4 (Based on Example 6, the ratio of TiO2 and ZrO2 metal oxides was investigated)
[0158] (1) Preparation of potassium sorbate aqueous solution:
[0159] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0160] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0161] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0162] (2) Preparation of solid base catalyst:
[0163] TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides is 1:6.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then these particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0164] (3) Preparation of potassium sorbate finished product:
[0165] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0166] The result showed that the isomer content in the finished potassium sorbate product was 1100 ppm, and the content of potassium sorbate reached 99.53%.
[0167] Comparative Example 5 (Based on Example 6, the mesh size of two metal oxide particles of TiO2 and ZrO2 was examined)
[0168] (1) Preparation of potassium sorbate aqueous solution:
[0169] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0170] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0171] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0172] (2) Preparation of solid base catalyst:
[0173] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 120-130 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0174] (3) Preparation of potassium sorbate finished product:
[0175] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0176] The result showed that the isomer content in the finished potassium sorbate product was 600 ppm, and the content of potassium sorbate reached 99.80%.
[0177] Comparative Example 6 (according to Example 6, investigating the roasting temperature)
[0178] (1) Preparation of potassium sorbate aqueous solution:
[0179] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 40°C;
[0180] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0181] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0182] (2) Preparation of solid base catalyst:
[0183] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 700°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0184] (3) Preparation of potassium sorbate finished product:
[0185] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0186] The result showed that the isomer content in the finished potassium sorbate product was 1300 ppm, and the content of potassium sorbate reached 99.45%.
[0187] Comparative Example 7 (Based on Example 6, investigating the photocatalytic temperature)
[0188] (1) Preparation of potassium sorbate aqueous solution:
[0189] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0190] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0191] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0192] (2) Preparation of solid base catalyst:
[0193] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0194] (3) Preparation of potassium sorbate finished product:
[0195] At 90° C., the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550 nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0196] The result showed that the isomer content in the finished potassium sorbate product was 1200 ppm, and the content of potassium sorbate reached 99.50%.
[0197] Comparative Example 8 (according to Example 6, investigating the photocatalytic residence time)
[0198] (1) Preparation of potassium sorbate aqueous solution:
[0199] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and heat to 40°C;
[0200] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0201] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0202] (2) Preparation of solid base catalyst:
[0203] The TiO2 and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (the mass ratio of TiO2 and ZrO2, the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, sieved to obtain particles of 90-100 mesh, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0204] (3) Preparation of potassium sorbate finished product:
[0205] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 10 minutes, and is filtered through a 0.45 micron water filter membrane and spray-dried to obtain a finished potassium sorbate product.
[0206] The result showed that the isomer content in the finished potassium sorbate product was 2400 ppm, and the content of potassium sorbate reached 99.25%.
[0207] Comparative Example 9 (according to Example 6, ZrO2 is omitted and only TiO2 is used)
[0208] (1) Preparation of potassium sorbate aqueous solution:
[0209] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 40°C;
[0210] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0211] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0212] (2) Preparation of solid base catalyst:
[0213] The TiO2 nanopowder is mixed with a binder (deionized water) and 5 wt% water is added. After being crushed by an extruder, the powder is dried in a drying oven at 80°C for 3 hours, and the particles of 90-100 mesh are sieved. The particles are then calcined at 800°C for 10.0 hours and cooled to room temperature to obtain a recyclable solid base catalyst.
[0214] (3) Preparation of potassium sorbate finished product:
[0215] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0216] The result showed that the isomer content in the finished potassium sorbate product was 1500 ppm, and the content of potassium sorbate reached 99.39%.
[0217] Comparative Example 10 (according to Example 6, TiO2 is omitted and only ZrO2 is used)
[0218] (1) Preparation of potassium sorbate aqueous solution:
[0219] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 40°C;
[0220] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0221] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0222] (2) Preparation of solid base catalyst:
[0223] The ZrO2 nanopowder was mixed with a binder (deionized water) and 5 wt% water was added. After being crushed by an extruder, the powder was dried in a drying oven at 80°C for 3 hours, and the particles of 90-100 mesh were sieved. The particles were then calcined at 800°C for 10.0 hours and cooled to room temperature to obtain a recyclable solid base catalyst.
[0224] (3) Preparation of potassium sorbate finished product:
[0225] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0226] The result showed that the isomer content in the finished potassium sorbate product was 1600 ppm, and the content of potassium sorbate reached 99.32%.
[0227] Comparative Example 11 (According to Example 6, ZrO2 is adjusted to Al2O3)
[0228] (1) Preparation of potassium sorbate aqueous solution:
[0229] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 40°C;
[0230] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0231] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0232] (2) Preparation of solid base catalyst:
[0233] The TiO2 and Al2O3 nanopowders are uniformly mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, and 90-100 mesh particles are sieved, and then the particles are calcined at 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0234] (3) Preparation of potassium sorbate finished product:
[0235] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0236] The result showed that the isomer content in the finished potassium sorbate product was 1200 ppm, and the content of potassium sorbate reached 99.52%.
[0237] Comparative Example 12 (According to Example 6, TiO2 is adjusted to ZnO)
[0238] (1) Preparation of potassium sorbate aqueous solution:
[0239] Add 60 parts by weight of water and 25 parts by weight of sorbic acid to the reactor, start stirring at a rate of 300 r / min, and raise the temperature to 40°C;
[0240] Then, 48% potassium hydroxide was added dropwise, and the addition was completed within 2 hours. During the addition, the pH value was maintained at 10.5, and the temperature was still maintained at 40°C. The amount of potassium hydroxide solution was adjusted according to the pH value.
[0241] Add 1 part by weight of activated carbon for decolorization at 60°C for 1 hour, and add 48% potassium hydroxide dropwise to adjust the pH to 12.0. The total amount of potassium hydroxide solution used is about 26 parts by weight. After filtering the activated carbon, the content of the potassium sorbate aqueous solution is 30.16%.
[0242] (2) Preparation of solid base catalyst:
[0243] The ZnO and ZrO2 nanopowders are uniformly mixed with a binder (deionized water) (TiO2 and ZrO2, the mass ratio of the two metal oxides is 1:5.0), 5wt% water is added, and the mixture is crushed by an extruder, dried in a drying oven at 80°C for 3h, and 90-100 mesh particles are sieved, and then the particles are calcined at a temperature of 800°C for 10.0h, and then cooled to room temperature to obtain a recyclable solid base catalyst;
[0244] (3) Preparation of potassium sorbate finished product:
[0245] At 85°C, the potassium sorbate aqueous solution is irradiated with light of a wavelength of 1550nm, and passes through a packing column filled with a solid base catalyst for a residence time of 20 minutes, and is filtered through a 0.45 micron water filter membrane, and spray-dried to obtain a finished potassium sorbate product.
[0246] The result showed that the isomer content in the finished potassium sorbate product was 2000 ppm, and the content of potassium sorbate reached 99.30%.
[0247] The present invention mainly aims at the problem that potassium sorbate is easy to form isomers during the production process, and the isomers thereof affect the antiseptic effect of the product due to different physical properties, and provides a method for reducing the isomer content during the preparation of potassium sorbate. By controlling the temperature and pH during the reaction process, the isomer conversion of potassium sorbate during the preparation process is effectively limited, and by photocatalytic treatment of the aqueous solution, the isomer 2Z, 4E-potassium sorbate is converted into 2E, 4E-potassium sorbate through photocatalysis, further reducing the accumulation of impurities, improving the purity and quality of potassium sorbate, and improving the antiseptic effect of the product.
[0248] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.
Claims
1. A method for preparing a low-isomerization potassium sorbate finished product, characterized in that: The steps include: (1) Preparation of potassium sorbate aqueous solution: Mix water and sorbic acid, adjust the pH to 10.0-10.5, add activated carbon for decolorization, and adjust the pH to 11.5-12.0 during decolorization; filter to obtain a potassium sorbate aqueous solution; (2) Preparation of solid base catalyst: Mixing TiO2 and ZrO2 nanopowders with deionized water, wherein the mass ratio of TiO2 and ZrO2 nanopowders is 1:2-5, and the amount of deionized water is 2-10wt%; crushing and drying the mixed particles, and then sieving to obtain particles, and then roasting the particles to obtain a solid base catalyst; (3) Preparation of potassium sorbate finished product: The potassium sorbate aqueous solution obtained in step (1) is irradiated with light having a wavelength of 280-1550 nm at a temperature of 75-85° C., and the solid base catalyst obtained in step (2) is added to the potassium sorbate aqueous solution for reaction for 20 min-1 h. After the reaction is completed, the solution is filtered and dried to obtain a potassium sorbate product.
2. The method according to claim 1, characterized in that In step (1), water and sorbic acid refer to 16-60 parts by weight of water and 25 parts by weight of sorbic acid; the amount of activated carbon used is 1 part by weight, and the decolorization conditions are a decolorization temperature of 50-70° C. and a decolorization time of 0.5-1.5 h.
3. The method according to claim 1, characterized in that The potassium sorbate content in the potassium sorbate aqueous solution in step (1) is 30.16-49.97%.
4. The method according to claim 1, characterized in that: In step (2), the drying temperature is 70-90°C and the drying time is 2-4h; the mesh size of the sieved particles is 20-100 mesh; the roasting temperature is 800-1000°C and the roasting time is 10-12.0h, and after roasting, the particles are cooled to 20-25°C.
5. The method according to claim 1, characterized in that The filtration in step (3) is performed by using any one of 0.22 micron, 0.45 micron, and 0.8 micron water filter membranes.
6. A method for inhibiting isomerization of potassium sorbate product, characterized in that: The steps include: (1) Preparation of potassium sorbate aqueous solution: Mix water and sorbic acid, adjust the pH to 10.0-10.5, add activated carbon for decolorization, and adjust the pH to 11.5-12.0 during decolorization; filter to obtain a potassium sorbate aqueous solution; (2) Preparation of solid base catalyst: Mixing TiO2 and ZrO2 nanopowders with deionized water, wherein the mass ratio of TiO2 and ZrO2 nanopowders is 1:2-5, and the amount of deionized water is 2-10wt%; crushing and drying the mixed particles, and then sieving to obtain particles, and then roasting the particles to obtain a solid base catalyst; (3) Preparation of potassium sorbate finished product: The potassium sorbate aqueous solution obtained in step (1) is irradiated with light having a wavelength of 280-1550 nm at a temperature of 75-85° C., and the solid base catalyst obtained in step (2) is added to the potassium sorbate aqueous solution for reaction for 20 min-1 h. After the reaction is completed, the solution is filtered and dried to obtain a potassium sorbate product.
7. The method according to claim 6, characterized in that In step (1), water and sorbic acid refer to 16-60 parts by weight of water and 25 parts by weight of sorbic acid; the amount of activated carbon used is 1 part by weight, and the decolorization conditions are a decolorization temperature of 50-70° C. and a decolorization time of 0.5-1.5 h.
8. The method according to claim 6, characterized in that The potassium sorbate content in the potassium sorbate aqueous solution in step (1) is 30.16-49.97%.
9. The method according to claim 6, characterized in that In step (2), the drying temperature is 70-90°C and the drying time is 2-4h; the mesh size of the sieved particles is 20-100 mesh; the roasting temperature is 800-1000°C and the roasting time is 10-12.0h, and after roasting, the particles are cooled to 20-25°C.
10. The method according to claim 6, characterized in that The filtration in step (3) is performed by using any one of 0.22 micron, 0.45 micron, and 0.8 micron water filter membranes.
Citation Information
Patent Citations
A method for photo-efficient catalytic isomerization to prepare sorbic acid
CN111437881B
Method for photocatalytic isomerization of eneynol
CN117105741A