Preparation method of high-yield sodium acetate trihydrate

Abstract

The application provides a preparation method of high-yield sodium acetate trihydrate, and belongs to the technical field of fine chemical product synthesis. The preparation method comprises the following steps: (1) reacting glacial acetic acid, a sodium-containing alkaline solution and water to obtain an initial sodium acetate solution; (2) reacting the initial sodium acetate solution obtained in the step (1) with a solvent solvent, and performing solid-liquid separation to obtain a solid and a liquid; the solvent solvent is selected from at least one of acetone, ethylene glycol, isopropyl alcohol and ethanol; the mass ratio of the solvent solvent to the initial sodium acetate solution is 0.5-2:1; and (3) washing and drying the solid obtained in the step (2) with a solvent solvent to obtain sodium acetate trihydrate. The sodium acetate trihydrate product with high yield is obtained by adopting a mild reaction temperature and performing the reaction under the action of the solvent with specific types and proportions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fine chemical product synthesis, and particularly relates to a preparation method of high-yield sodium acetate trihydrate. BACKGROUND

[0002] Sodium acetate trihydrate, also known as sodium acetate trihydrate or sodium acetate trihydrate, has a chemical formula of CH3COONa·3H2O and is a white crystalline powder. It is easily soluble in water and diethyl ether, slightly soluble in ethanol, and the aqueous solution is weakly alkaline. Sodium acetate trihydrate, as an organic chemical, is widely used in the fields of cellulose derivatives, dyes, resins, medicines, etc. Sodium acetate trihydrate is one of the raw materials for preparing cellulose anhydride, which is used for the production of cellulose fibers and the manufacture of other cellulose derivatives; sodium acetate trihydrate is also an important raw material for intermediates and catalysts in chemical production; in the pharmaceutical field, it is used for preparing antibiotics; sodium acetate trihydrate can be used as a carbon source in wastewater treatment.

[0003] The traditional production process of sodium acetate trihydrate is to neutralize sodium hydroxide solution and glacial acetic acid under certain ratio conditions, remove water by heating, cool and crystallize to obtain sodium acetate trihydrate crystals. The yield of sodium acetate trihydrate produced by this method is low, and a large amount of sodium acetate liquid is produced, resulting in high production cost. Moreover, the sodium acetate liquid product obtained by the traditional production process is unstable at low temperature. Chinese invention patent CN112174805A discloses a production method of low-temperature non-crystalline sodium acetate, comprising the following steps: (a) adding high-purity water, glacial acetic acid, sodium hydroxide, part of the blending agent and surfactant into a reaction kettle under the control of a DSC system; (b) stirring and reacting; (c) adding part of the antifreeze agent and the remaining blending agent into the reaction kettle; (d) stirring and reacting for a period of time, then adding the remaining antifreeze agent and continuing to stir; (e) obtaining low-temperature non-crystalline sodium acetate after reacting for a period of time. The product obtained by the method of the patent is sodium acetate liquid, not sodium acetate crystal, and the yield and purity of sodium acetate are still low.

[0004] Chinese invention patent CN102351679A discloses a one-step method for producing crystalline sodium acetate, the reactants are components a, b and c; the a is acetic acid or its aqueous solution; the b is sodium hydroxide, sodium carbonate, sodium bicarbonate or one of the aqueous solutions of the three, or a mixture of any of the above; the c is water; wherein the molar ratio of CH3COOH in a to Na in b is 1:1, the amount of c is ≥0, and the sum of the molar amount of solvent water in a, b, the molar amount of water generated by the theoretical reaction of a, b and the molar amount of c is 3.1-3.5:1 to the molar amount of CH3COOH; the reaction steps are as follows: (1) after mixing a, b and c in the reactor, heating to 100-102℃, (2) after the reaction is completed, cooling and crystallizing, (3) when the temperature is reduced to 50-55℃, controlling the vacuum degree to-0.01~-0.02MPa to crystallize, (4) after the crystallization is completed, cooling and discharging. The preparation method has high reaction temperature and the reaction process is relatively dangerous.

[0005] Therefore, it is necessary to provide a new preparation method of sodium acetate trihydrate with mild reaction conditions, high yield and high purity. SUMMARY

[0006] The present application provides a preparation method of sodium acetate trihydrate with high yield, which adopts mild reaction temperature and reacts in solvents with specific types and proportions to obtain sodium acetate trihydrate with high yield.

[0007] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0008] The present application provides a preparation method of sodium acetate trihydrate with high yield, which includes the following steps:

[0009] (1) reacting glacial acetic acid, sodium-containing alkaline solution and water to obtain an initial sodium acetate solution;

[0010] (2) reacting the initial sodium acetate solution of step (1) with a solvent to separate the solid and liquid;

[0011] (3) washing the solid obtained in step (2) with a solvent and drying to obtain sodium acetate trihydrate.

[0012] Preferably, in step (1), the mass ratio of glacial acetic acid, sodium-containing alkaline solution and water is 1:1.8-2.5:0.8-1.2.

[0013] Further preferably, in step (1), the mass ratio of glacial acetic acid, sodium-containing alkaline solution and water is 1:2-2.2:1.05.

[0014] Preferably, in step (1), the water used is high-purity water with an electrical conductivity of ≤5μs / cm.

[0015] Preferably, in step (1), the sodium-containing alkaline solution is a solution of sodium hydroxide or sodium carbonate.

[0016] Further preferably, in step (1), the mass fraction of the sodium-containing alkaline solution is 30%-35%.

[0017] More preferably, in step (1), the mass fraction of the sodium-containing alkaline solution is 30%.

[0018] Preferably, in step (1), the reaction is carried out in a reaction kettle, and the reaction conditions are: temperature 60-90°C, stirring for 1-3h, and pressure is normal pressure.

[0019] Further preferably, in step (1), the reaction conditions are: temperature 65-75°C, stirring for 1.5-2.5h, and pressure is normal pressure.

[0020] More preferably, in step (1), the reaction conditions are: temperature 65°C, stirring for 2h, and pressure is normal pressure.

[0021] Preferably, in step (1), the content of the initial sodium acetate solution is 30%-40%.

[0022] Further preferably, in step (1), the content of the initial sodium acetate solution is 30%-35%.

[0023] Preferably, in step (2), the solvent solvent is selected from at least one of acetone, ethylene glycol, isopropyl alcohol, and ethanol.

[0024] Further preferably, in step (2), the solvent solvent is a mixture of acetone, ethylene glycol, and isopropyl alcohol.

[0025] More preferably, in step (2), in the solvent solvent, the mass ratio of acetone, ethylene glycol, and isopropyl alcohol is 6-8:1:1-3.

[0026] More preferably, in step (2), in the solvent solvent, the mass ratio of acetone, ethylene glycol, and isopropyl alcohol is 7:1:2.

[0027] Preferably, in step (2), the mass ratio of the solvent solvent to the initial sodium acetate solution in the reaction is 0.5-2:1.

[0028] Further preferably, in step (2), the mass ratio of the solvent solvent to the initial sodium acetate solution in the reaction is 0.75-2:1.

[0029] More preferably, in step (2), the mass ratio of the solvent solvent to the initial sodium acetate solution in the reaction is 1-2:1.

[0030] In the technical scheme of the present application, the mass ratio of the solvent to the initial sodium acetate solution is 0.75-2:1; the amount of the water for injection includes any range of values, real numbers and end values in the range, for example but not limited to 0.75-2:1, 0.75-1:1, 1-2:1, 0.75:1, 1:1, 1.5:1, 2:1.

[0031] Preferably, in step (2), the reaction conditions are: 20-60℃, pH=5.5-9, stirring for 1-3h until a large amount of sodium acetate trihydrate solid crystallizes out.

[0032] Further preferably, in step (2), the reaction conditions are: 25-40℃, pH=6-9, stirring for 1-3h until a large amount of sodium acetate trihydrate solid crystallizes out.

[0033] More preferably, in step (2), the reaction conditions are: 25℃, pH=7-8, stirring for 1.5-2h until a large amount of sodium acetate trihydrate solid crystallizes out.

[0034] Preferably, in step (2), the solid-liquid separation technology is a conventional technology used in the art, not limited to gravity filtration, pressure filtration, centrifugal separation or vacuum filtration.

[0035] Preferably, in step (3), the drying temperature is 40-123℃.

[0036] Further preferably, in step (3), the drying temperature is 45-60℃.

[0037] Preferably, in the preparation method of the present application, an automatic control system (DCS) is used to realize full automation of feeding and reaction.

[0038] Compared with the prior art, the present application has the following beneficial effects:

[0039] (1) In the method of the present application, the solvent is added to change the polarity of the reaction system, which reduces the solubility of sodium acetate in the reaction system and improves the yield of sodium acetate trihydrate crystals; the solvent used in the present application is volatile, which can remove the residual impurities on the surface of sodium acetate trihydrate crystals while the small amount of solvent on the surface of the crystals can volatilize, reducing the adhesion on the surface of sodium acetate trihydrate crystals and improving the purity of sodium acetate trihydrate crystals.

[0040] (2) The present application uses a specific kind and ratio of solvent to react with the initial sodium acetate solution, which improves the yield and purity of sodium acetate trihydrate crystals.

[0041] (3) The reaction condition of the method is mild, the reaction is stable and easy to control, and the solvent can be reused multiple times; the automatic control system is used to realize the full automation of feeding and reaction, the operation is simple, the control is accurate, the product purity and yield are improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is the reaction flow chart of the method of the present application. DETAILED DESCRIPTION

[0043] The following non-limiting examples can make those skilled in the art more fully understand the present application, but do not limit the present application in any way. The following content is only an exemplary description of the scope of the present application, and those skilled in the art can make various changes and modifications to the present application based on the disclosed content, which should also belong to the scope of the present application.

[0044] When the example gives a numerical range, it should be understood that, unless otherwise stated by the present application, each numerical range of two endpoints and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0045] The present application will be further described in the following specific examples. The various chemical reagents used in the examples of the present application are obtained by conventional commercial routes unless otherwise specified. The products of different manufacturers do not have a significant effect on the results.

[0046] Example 1

[0047] The preparation method of sodium acetate trihydrate crystals is:

[0048] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water are added into the reactor through airtight feeding technology under the control of the DCS automatic control system, stirred at 65℃ for 2h, and an initial sodium acetate solution is obtained;

[0049] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, 15 kg of solvent solvent is added during stirring, the temperature of the reaction system is controlled at 25℃, pH=7.5, and stirred for 2h until a large amount of sodium acetate trihydrate solid crystals are precipitated. The solid and liquid are separated by pressure filtration. The solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 7:1:2;

[0050] (3) The solid obtained in step (2) is washed with solvent solvent and dried at 45℃ to obtain sodium acetate trihydrate crystals.

[0051] Figure 1 is a reaction flow chart of the method of the present application.

[0052] Example 2

[0053] The preparation method of the sodium acetate trihydrate crystal is as follows:

[0054] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water are added into a reactor through a closed feeding technique under the control of a DCS automatic control system, stirred at 65°C for 2 h, and an initial sodium acetate solution is obtained;

[0055] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, 18 kg of solvent solvent is added during the stirring process, the temperature of the reaction system is controlled at 25°C, pH = 7.0, and stirring is performed for 2 h until a large amount of sodium acetate trihydrate solid crystallizes, and the solid-liquid separation is performed by pressure filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 7:1:2;

[0056] (3) The solid obtained in step (2) is washed with the solvent solvent and dried at 45°C to obtain the sodium acetate trihydrate crystal.

[0057] Example 3

[0058] The preparation method of the sodium acetate trihydrate crystal is as follows:

[0059] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water are added into a reactor through a closed feeding technique under the control of a DCS automatic control system, stirred at 65°C for 2 h, and an initial sodium acetate solution is obtained;

[0060] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, 22.5 kg of solvent solvent is added during the stirring process, the temperature of the reaction system is controlled at 25°C, pH = 7.3, and stirring is performed for 2 h until a large amount of sodium acetate trihydrate solid crystallizes, and the solid-liquid separation is performed by pressure filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 7:1:2;

[0061] (3) The solid obtained in step (2) is washed with the solvent solvent and dried at 45°C to obtain the sodium acetate trihydrate crystal.

[0062] Example 4

[0063] The preparation method of the sodium acetate trihydrate crystal is as follows:

[0064] (1) glacial acetic acid 7.008 kg, sodium hydroxide solution 15.6 kg (mass concentration 32%) and 7.392 kg high-purity water were added into the reactor by closed feeding technology under the control of the DCS automatic control system, stirred at 65 °C for 2 h, to obtain an initial sodium acetate solution;

[0065] (2) the initial sodium acetate solution of step (1) was stirred in a solvent reactor, and 30 kg of solvent solvent was added during stirring, the temperature of the reaction system was controlled at 25 °C, pH = 7.7, and stirring was carried out for 2 h until a large amount of sodium acetate trihydrate solid was crystallized, and the solid-liquid separation was carried out by pressure filtration to obtain a solid and a liquid; the solvent solvent was a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 7:1:2;

[0066] (3) the solid obtained in step (2) was washed with solvent solvent and dried at 45 °C to obtain sodium acetate trihydrate crystals.

[0067] Example 5

[0068] The preparation method of sodium acetate trihydrate crystals is:

[0069] (1) glacial acetic acid 7.008 kg, sodium hydroxide solution 15.6 kg (mass concentration 32%) and 7.392 kg high-purity water were added into the reactor by closed feeding technology under the control of the DCS automatic control system, stirred at 65 °C for 2 h, to obtain an initial sodium acetate solution;

[0070] (2) the initial sodium acetate solution of step (1) was stirred in a solvent reactor, and 45 kg of solvent solvent was added during stirring, the temperature of the reaction system was controlled at 25 °C, pH = 7.5, and stirring was carried out for 2 h until a large amount of sodium acetate trihydrate solid was crystallized, and the solid-liquid separation was carried out by pressure filtration to obtain a solid and a liquid; the solvent solvent was a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 7:1:2;

[0071] (3) the solid obtained in step (2) was washed with solvent solvent and dried at 45 °C to obtain sodium acetate trihydrate crystals.

[0072] Example 6

[0073] The preparation method of sodium acetate trihydrate crystals is:

[0074] (1) glacial acetic acid 7.008 kg, sodium hydroxide solution 15.6 kg (mass concentration 32%) and 7.392 kg high-purity water were added into the reactor by closed feeding technology under the control of the DCS automatic control system, stirred at 65 °C for 2 h, to obtain an initial sodium acetate solution;

[0075] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, and 60 kg of solvent solvent is added during stirring, the temperature of the reaction system is controlled at 25℃, pH = 7.7, and stirring is carried out for 2 h until a large amount of sodium acetate trihydrate solid is crystallized, and the solid-liquid separation is carried out by pressurized filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol with a mass ratio of 7:1:2;

[0076] (3) The solid obtained in step (2) is washed with solvent solvent and dried at 45℃ to obtain sodium acetate trihydrate crystals.

[0077] Example 7

[0078] The preparation method of sodium acetate trihydrate crystals is:

[0079] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water are added into the reactor through airtight feeding technology under the control of the DCS automatic control system, and stirred at 65℃ for 2 h to obtain an initial sodium acetate solution;

[0080] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, and 30 kg of solvent solvent is added during stirring, the temperature of the reaction system is controlled at 40℃, pH = 7.7, and stirring is carried out for 2 h until a large amount of sodium acetate trihydrate solid is crystallized, and the solid-liquid separation is carried out by pressurized filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol with a mass ratio of 7:1:2;

[0081] (3) The solid obtained in step (2) is washed with solvent solvent and dried at 45℃ to obtain sodium acetate trihydrate crystals.

[0082] Example 8

[0083] The preparation method of sodium acetate trihydrate crystals is:

[0084] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water are added into the reactor through airtight feeding technology under the control of the DCS automatic control system, and stirred at 65℃ for 2 h to obtain an initial sodium acetate solution;

[0085] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, and 30 kg of solvent solvent is added during stirring, the temperature of the reaction system is controlled at 25℃, pH = 7.7, and stirring is carried out for 2 h until a large amount of sodium acetate trihydrate solid is crystallized, and the solid-liquid separation is carried out by pressurized filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol with a mass ratio of 6:1:3;

[0086] (3) The solid obtained in step (2) is washed with the solvent solvent and dried at 45°C to obtain sodium acetate trihydrate crystals.

[0087] Example 9

[0088] The preparation method of sodium acetate trihydrate crystals is as follows:

[0089] (1) Glacial acetic acid 7.008 kg, sodium hydroxide solution 15.6 kg (mass concentration 32%) and 7.392 kg of high-purity water are added into a reactor through a closed feeding technique under the control of a DCS automatic control system, stirred at 65°C for 2 h to obtain an initial sodium acetate solution;

[0090] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, and 30 kg of solvent solvent is added during stirring, the temperature of the reaction system is controlled at 25°C, pH = 7.7, and stirring is carried out for 2 h until a large amount of sodium acetate trihydrate solid is crystallized, and the solid-liquid separation is carried out by pressure filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 8:1:1;

[0091] (3) The solid obtained in step (2) is washed with the solvent solvent and dried at 45°C to obtain sodium acetate trihydrate crystals.

[0092] Example 10

[0093] The preparation method of sodium acetate trihydrate crystals is as follows:

[0094] (1) Glacial acetic acid 7.008 kg, sodium hydroxide solution 15.6 kg (mass concentration 32%) and 7.392 kg of high-purity water are added into a reactor through a closed feeding technique under the control of a DCS automatic control system, stirred at 65°C for 2 h to obtain an initial sodium acetate solution;

[0095] (2) The initial sodium acetate solution of step (1) is stirred in a solvent reactor, and 30 kg of solvent solvent is added during stirring, the temperature of the reaction system is controlled at 25°C, pH = 7.7, and stirring is carried out for 2 h until a large amount of sodium acetate trihydrate solid is crystallized, and the solid-liquid separation is carried out by pressure filtration to obtain a solid and a liquid; the solvent solvent is a mixture of acetone, ethylene glycol and isopropyl alcohol in a mass ratio of 8:1:1;

[0096] (3) The solid obtained in step (2) is washed with the solvent solvent and dried at 45°C to obtain sodium acetate trihydrate crystals.

[0097] Comparative Example 1

[0098] The solvent solvent is not added in this comparative example.

[0099] The preparation method of sodium acetate trihydrate crystals is as follows:

[0100] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water were added into the reactor through airtight feeding technology under the control of the DCS automatic control system, stirred at 65 °C for 2 h, and an initial sodium acetate solution was obtained;

[0101] (2) The initial sodium acetate solution of step (1) was continuously stirred in the reactor, the temperature of the reaction system was controlled at 25 °C, and the pH was 7.5, and the stirring reaction was carried out for 2 h; after the reaction was completed, no sodium acetate trihydrate crystals were precipitated.

[0102] Comparative Example 2

[0103] According to the technical solution described in the Chinese invention patent with publication number CN112174805A, sodium acetate was prepared, specifically as follows:

[0104] The DCS control system automatically controlled the addition of 42.24 kg of high-purity water, 11.76 kg of glacial acetic acid, 26 kg of 30% sodium hydroxide solution, 8.2 g of calcium acetate, 40 g of a mixture of fatty alcohol polyoxyethylene and polyoxypropylene ether (mass ratio 2:1) into the reactor through airtight feeding technology under the control of the DCS system; after stirring for 10 minutes, the heat of neutralization reaction was released to the system temperature to 68 °C; continue to stir for 25 min, and add 18.2 g of sodium acetate and 15 g of propylene glycol during the stirring process; after stirring for 25 min, add 8 g of propylene glycol, continue to stir for 5 min, and obtain a low-temperature non-crystalline sodium acetate solution, which cannot obtain sodium acetate trihydrate solid.

[0105] Comparative Example 3

[0106] In this comparative example, the solvent used is methanol.

[0107] The preparation method of sodium acetate trihydrate crystals is as follows:

[0108] (1) 7.008 kg of glacial acetic acid, 15.6 kg of sodium hydroxide solution (mass concentration 32%) and 7.392 kg of high-purity water were added into the reactor through airtight feeding technology under the control of the DCS automatic control system, stirred at 65 °C for 2 h, and an initial sodium acetate solution was obtained;

[0109] (2) The initial sodium acetate solution of step (1) was continuously stirred in the reactor, the temperature of the reaction system was controlled at 25 °C, and the pH was 7.5, and the stirring reaction was carried out for 2 h; after the reaction was completed, no sodium acetate trihydrate crystals were precipitated.

[0110] (3) The solid obtained in step (2) was washed with a solvent, and dried at 45 °C to obtain sodium acetate trihydrate crystals.

[0111] Test 1 Yield and content determination of sodium acetate trihydrate

[0112] Detection method: The sample was acidified with excess sulfuric acid, heated to remove sulfuric acid, and then back-titrated with sodium hydroxide standard titration solution using phenolphthalein as indicator.

[0113] Sodium hydroxide standard titration solution: c(NaOH) = 0.1000 mol / L;

[0114] Sulfuric acid standard solution: c(1 / 2H2SO4) = 0.1000 mol / L;

[0115] Phenolphthalein indicator solution: P = 1 g / L ethanol solution.

[0116] Weigh 5 g of sample to 0.0001 g, dilute to 500 mL in a volumetric flask, take 10.00 mL, add 1-2 drops of phenolphthalein as indicator, if red, titrate with sulfuric acid standard solution, the solution changes from red to light red, accurately add 30.00 mL of sulfuric acid standard solution, heat on an electric stove until nearly dry, (if heated too much, white smoke is generated in the bottle, then the test should be repeated), cool, add 20 mL of water along the inner wall of the bottle, shake well, add 2-3 drops of phenolphthalein indicator, titrate with sodium hydroxide standard solution to light red. At the same time, a blank test is performed.

[0117] The mass fraction (content) X1 of sodium acetate in sodium acetate trihydrate is expressed in % and calculated as follows:

[0118]

[0119] In the formula:

[0120] V0 - volume of sodium hydroxide standard titration solution consumed in the blank test, mL;

[0121] V - volume of sodium hydroxide standard titration solution consumed in the titration of the sample, mL;

[0122] C - molar concentration of sodium hydroxide standard titration solution, mol / L;

[0123] m - sample weight, g;

[0124] 0.08203 - the mass of sodium acetate in grams equivalent to 1.00 mL of sodium hydroxide standard titration solution.

[0125] The yield and content of sodium acetate trihydrate prepared in each example and comparative example were determined, and the test results are shown in Table 1.

[0126] Table 1

[0127]

[0128] From the results of Table 1, it can be seen that the obtained sodium acetate trihydrate content is between 58%-60%, and the sodium acetate trihydrate yield of Examples 3-10 of the present application is significantly higher than that of Examples 1-2 and Comparative Examples; in particular, the sodium acetate trihydrate yield of the method without adding solvent in Comparative Example 1 is only 6.9%, and the method of the present application greatly improves the yield of sodium acetate trihydrate.

[0129] The present application adopts reasonable formula production system and production control program and process, adds a solvent that changes the polarity of the reaction system in the formula, reduces the solubility of sodium acetate in the reaction system, and improves the crystallization yield of sodium acetate trihydrate. The neutralization reaction process of the present application is stable and easy to control, the production operation has high automation degree, and the obtained sodium acetate trihydrate crystalline product has high purity and high yield.

[0130] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A process for the preparation of high yield sodium acetate trihydrate, characterized by, The method comprises the steps of: (1) reacting glacial acetic acid, a sodium-containing alkaline solution and water to obtain an initial sodium acetate solution; the mass ratio of the glacial acetic acid, the sodium-containing alkaline solution and water is 1:1.8-2.5:0.8-1.2; In step (1), the sodium-containing alkaline solution is a solution of sodium hydroxide or sodium carbonate; the mass fraction of the sodium-containing alkaline solution is 30%-35%; (2) reacting the initial sodium acetate solution of step (1) with a solvent to obtain a solid and a liquid after solid-liquid separation; the mass ratio of the solvent to the initial sodium acetate solution is 0.75-2:1; the content of the initial sodium acetate solution is 30%-40%; The reaction conditions are as follows: 20-60℃, pH equal to 7-9, stirring for 1-3h until a large amount of sodium acetate trihydrate solid is crystallized and precipitated; (3) washing the solid obtained in step (2) with a solvent and drying to obtain sodium acetate trihydrate; In the solvent, the mass ratio of acetone, ethylene glycol and isopropyl alcohol is 6-8:1:1-3.

2. The production method according to claim 1, characterized by, In step (1), the mass ratio of the glacial acetic acid, the sodium-containing alkaline solution and water is 1:2-2.2:1.

05.

3. The preparation method according to claim 1, characterized in that, In step (1), the reaction is carried out in a reaction kettle, and the reaction conditions are as follows: temperature 60℃-90℃, stirring for 1-3h, and normal pressure.

4. The production method according to claim 1, characterized by, In the solvent, the mass ratio of acetone, ethylene glycol and isopropyl alcohol is 7:1:

2.

5. The method of claim 1, wherein, In step (2), the mass ratio of the solvent to the initial sodium acetate solution is 1-2:

1.

6. The method of claim 1, wherein, In step (3), the drying temperature is 40-123℃.

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