Preparation and purification method and application of methyl fatty acyl sodium taurate

Abstract

The embodiment of the invention provides a preparation and purification method and application of methyl fatty acyl sodium taurate. The preparation and purification method comprises the following steps: reacting sodium methyl taurate with fatty acid to obtain a reacted material; deacidifying the reacted material to obtain a methyl fatty acyl sodium taurate crude product; dissolving the methyl fatty acyl sodium taurate crude product in water to obtain a methyl fatty acyl sodium taurate solution; adjusting the pH value of the methyl fatty acyl sodium taurate solution to 7.0-9.0; adding the methyl fatty acyl sodium taurate solution of which the pH is adjusted into a jacketed static mixer; the jacket type static mixer cools the methyl fatty acyl sodium taurate solution to obtain a solid-liquid mixture; and dehydrating and drying the solid-liquid mixture to obtain methyl fatty acyl sodium taurate. According to the preparation and purification method, no organic solvent is needed for purification, operation is convenient, the material precipitation time is short, the material precipitation recovery rate is high, and meanwhile the prepared product is higher in purity.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of daily chemical materials, and specifically to a method for preparing and purifying sodium methyl fatty acyl taurate and its application. Background Art

[0002] Sodium fatty acyl methyl taurate is a mild and non-irritating anionic surfactant. It has good stability in weak acids and alkalis, hard water and metal salt solutions, and has good compatibility with anionic, nonionic and amphoteric surfactants.

[0003] At present, the industrial synthesis of sodium methyl fatty acyl taurate products is mainly synthesized by acylation reaction. However, the above synthesis process has the following disadvantages: (1) the synthesis process is complicated and the operation is cumbersome; (2) the acyl chloride has a high risk factor and poor safety during use; (3) sodium hydroxide is used in the synthesis process, and a large amount of sodium chloride remains in the product. In addition, the products synthesized by direct method for sodium methyl fatty acyl taurate are not of high purity, and have poor odor and color, and are not suitable as raw materials for high-end personal care cleaning agents; although the synthesized sodium methyl fatty acyl taurate can be improved by purification process to improve product quality, the purification efficiency and yield are not very ideal, and the production cost is high. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a method for preparing and purifying sodium methyl fatty acyl taurate and its use.

[0005] To achieve the above objectives, the present application proposes the following technical solutions: In a first aspect, the present invention provides a method for preparing and purifying sodium methyl fatty acyl taurate, the method comprising: reacting sodium methyl taurate with fatty acid to obtain a reacted material; deacidifying the reacted material to obtain a crude product of sodium methyl fatty acyl taurate; Dissolving crude sodium methyl fatty acyl taurate in water to obtain a sodium methyl fatty acyl taurate solution; adjusting the pH of the sodium methyl fatty acyl taurate solution to 7.0-9.0; The sodium methyl fatty acyl taurate solution after the pH is adjusted is added into a jacketed static mixer; the jacketed static mixer cools the sodium methyl fatty acyl taurate solution to obtain a solid-liquid mixture; The solid-liquid mixture is dehydrated and dried to obtain sodium methyl fatty acyl taurate.

[0006] As an embodiment, the fatty acid is at least one of caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, and oleic acid.

[0007] As an embodiment, the molar ratio of the fatty acid to sodium methyl taurate is 1-1.5:1.

[0008] As an embodiment, the deacidification of the reacted material to obtain a crude sodium methyl fatty acyl taurate comprises: The reacted material is deacidified at a vacuum degree of -0.1 MPa to -0.092 MPa and a temperature of 190 to 250° C. to obtain a crude product of sodium methyl fatty acyl taurate.

[0009] As an embodiment, the material feed temperature of the jacketed static mixer is 40-60°C, and the discharge temperature of the solid-liquid mixture is 10-30°C.

[0010] As an embodiment, the jacketed static mixer cools the sodium methyl fatty acyl taurate solution to obtain a solid-liquid mixture, comprising: Chilled water is introduced into the jacket of the jacketed static mixer to cool the sodium methyl fatty acyl taurate solution in the jacketed static mixer to obtain a solid-liquid mixture.

[0011] As an implementation mode, the inlet temperature of the chilled water is 5-20°C.

[0012] As an embodiment, the sodium methyl taurate and fatty acid are reacted to obtain a reacted material, comprising: Sodium methyl taurate and fatty acid are put into a reaction kettle, the temperature is raised to 170°C to 240°C, and the reaction is carried out under nitrogen protection to obtain a reacted material.

[0013] As an implementation mode, the insulation reaction time is 6 to 30 hours.

[0014] In a second aspect, the embodiments of the present application propose the use of sodium methyl fatty acyl taurate prepared by the preparation and purification method described in the first aspect in the preparation of care and cleaning products.

[0015] The embodiments of the present application have at least the following beneficial effects: In the embodiment of the present application, sodium methyl taurate and fatty acids are used as raw materials to prepare sodium methyl fatty acyl taurate. After the sodium methyl taurate and fatty acids react, the material is deacidified to remove the fatty acids in the material, so that in the subsequent dissolution and impurity removal process, there is no need to use an organic solvent, which can avoid the problems of emulsification, the inability to stratify the solution or unclear stratification interface; at the same time, in the embodiment of the present application, a jacketed static mixer is used to cool the sodium methyl fatty acyl taurate solution, and most of the material in the jacketed static mixer is controlled to be discharged in a crystal precipitation state and a small part of the material is discharged in a "molten" state (solid-liquid mixture), so that the target product can be precipitated in the form of crystals, and the purity of the product can be improved by subsequent dehydration, and at the same time, a certain fluidity can be maintained to facilitate the feeding and discharging of the material, thereby ensuring the freezing effect.

[0016] Therefore, the preparation and purification method of the embodiment of the present application does not require the use of organic solvents for purification, and is easy to operate, has a short material precipitation time, a high material precipitation recovery rate, and the obtained product has a higher purity.

[0017] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The preparation and purification process flow chart of this embodiment is shown. DETAILED DESCRIPTION

[0019] The technical scheme in the embodiments will be clearly and completely described below in combination with the embodiments of the present application and the accompanying drawings. Obviously, the embodiments described below are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0021] As used in this application, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0022] The preparation and purification method of sodium methyl fatty acyl taurate of this embodiment and its application are described in detail below.

[0023] First, the preparation and purification method of the first aspect of this embodiment is described.

[0024] Preparation and purification method In the prior art, sodium methyl fatty acyl taurate is usually purified by low-temperature crystallization, followed by solid-phase and liquid-phase separation to remove impurities and improve quality. Among them, sodium methyl fatty acyl taurate synthesized by acylation reaction will itself form a byproduct of sodium chloride, which is easier to precipitate during the freezing precipitation process.

[0025] At present, kettle reactors are commonly used for the selection of purification equipment; however, during the freezing precipitation process, the inner wall of the reactor is prone to form a thick crystal layer, resulting in poor freezing effect of the material outside the crystal layer, slow cooling and long precipitation time, which seriously affects production efficiency.

[0026] The sodium methyl fatty acyl taurate produced by the direct method will not only form a crystal layer on the wall of the autoclave reactor during the freezing precipitation stage, affecting the mass transfer and heat transfer effects, but also result in a low solid-liquid separation yield by filter pressing because the crystals are small or in a "molten" (semi-liquid and semi-solid) state.

[0027] In the freezing crystallization process, in order to maintain a good mass transfer effect, the current kettle reactor needs to control a certain concentration, such as 10~25%. When it is higher than 30%, due to the high precipitation concentration and high viscosity, the mass transfer is poor, the freezing effect is reduced, and the energy consumption and working hours will increase significantly. It is also not conducive to material mixing and conveying filtration.

[0028] In view of this, this embodiment provides a method for preparing and purifying sodium methyl fatty acyl taurate.

[0029] Specifically, see Figure 1 As shown, the preparation and purification method comprises: (1) reacting sodium methyl taurate with fatty acid to obtain a reacted material; and deacidifying the reacted material to obtain a crude product of sodium methyl fatty acyl taurate.

[0030] In step (1), sodium methyl taurate and fatty acid can be put into a conventional reactor for reaction. The material generated after the reaction of sodium methyl taurate and fatty acid will contain a certain amount of fatty acid. In view of this, in this embodiment, the material after the reaction is directly deacidified (removed fatty acid). In this embodiment, the subsequent purification step is simplified by deacidification in the early stage, and the purpose of purification can be achieved by simple dehydration without using an organic solvent.

[0031] Usually, the fatty acid needs to be melted in advance before reacting with sodium methyl taurate.

[0032] For example, taking lauric acid as an example, the lauric acid is first melted in a molten acid kettle at a temperature of 70° C. A nitrogen atmosphere is maintained in the molten acid kettle, and the lauric acid is stirred and melted until it becomes a flowing liquid state and kept warm for later use.

[0033] Sodium methyl taurate is usually added in the form of a sodium methyl taurate solution, for example, a 40% sodium methyl taurate aqueous solution; (2) Dissolving the crude sodium methyl fatty acyl taurate in water to obtain a sodium methyl fatty acyl taurate solution; adjusting the pH of the sodium methyl fatty acyl taurate solution to 7.0-9.0.

[0034] As mentioned above, this embodiment simplifies the subsequent purification by the preliminary deacidification; therefore, in step (2), this embodiment can directly dissolve the crude sodium methyl fatty acyl taurate after deacidification in water for the subsequent next purification step, while also avoiding the problems of emulsification, the inability to separate the solution into layers, or unclear separation interfaces.

[0035] Specifically, in step (2), the pH of the sodium methyl fatty acyl taurate solution is further adjusted to 7.0-9.0; in this embodiment, the pH adjustment can be achieved by adding sodium hydroxide or a sodium hydroxide solution.

[0036] It is understandable that by adjusting the pH in step (2), the fatty acids can be converted into water-soluble substances, and then the fatty acids can be eluted through subsequent purification.

[0037] For example, the adjusted pH of the sodium methyl fatty acyl taurate solution may be 7.0, 7.2, 7.5, 8.0, 8.3, 8.5, 8.7, 8.9, or 9.0. At the same time, since this embodiment uses a jacketed static mixer for freezing precipitation, a sodium methyl fatty acyl taurate solution with a higher concentration (up to 35%) can be prepared in step (2). Not only is the subsequent wastewater discharge less, but the output per unit time is also significantly improved; (3) adding the sodium methyl fatty acyl taurate solution into a jacketed static mixer; the jacketed static mixer cools the sodium methyl fatty acyl taurate solution to obtain a solid-liquid mixture; In step (3), the jacketed static mixer cools the sodium methyl fatty acyl taurate solution in the jacketed static mixer; in particular, the jacketed static mixer is controlled to discharge most of the material in a crystallized state and a small portion of the material in a "molten" state (solid-liquid mixture).

[0038] In this step, most of the material is discharged from the jacketed static mixer in a crystal precipitation state and a small part of the material is in a "melted" state, which can not only make the target product precipitate in the form of crystals, but also improve the purity of the product by subsequent dehydration. At the same time, the material can maintain a certain fluidity for easy feeding and discharging, solving the defects of high concentration precipitation and easy solidification, high viscosity and unsuitable feeding in the traditional purification process; and can effectively avoid the disadvantages of the material forming a crystal layer on the wall of the reactor after freezing and crystallization, resulting in poor mass transfer, long freezing and precipitation working hours, low efficiency, etc., and can effectively ensure the freezing effect; (4) The solid-liquid mixture is dehydrated and dried to obtain sodium methyl fatty acyl taurate.

[0039] After the material completes the "crystallization" and "melting" states, solid-liquid separation can be achieved through dehydration to complete purification; among them, the organic matter content in the wastewater is less than 1.0%, which can effectively improve the yield of the product.

[0040] The dehydration and drying of this embodiment can be achieved by using existing known equipment or processes. For example, dehydration can be achieved by using a centrifuge to separate solids from liquids; and drying can be achieved by using a fluidized bed to dry the solids after centrifugation.

[0041] In this embodiment, not only the prepared sodium methyl fatty acyl taurate has higher purity (greater than 95%) and yield, but also the organic matter content in the wastewater is less than 1.0%.

[0042] It can be understood that the preparation and purification method of this embodiment is a process of removing impurities from sodium methyl fatty acyl taurate by a purification method during the preparation of sodium methyl fatty acyl taurate to improve the purity and quality of sodium methyl fatty acyl taurate.

[0043] Based on the above steps, in this embodiment, sodium methyl taurate and fatty acids are used as raw materials to prepare sodium methyl fatty acyl taurate. After the sodium methyl taurate and fatty acids react, the generated material is deacidified to remove the fatty acids in the material, so that in the subsequent dissolution and impurity removal process, there is no need to use an organic solvent, which can avoid the problems of emulsification, the inability to stratify the solution or unclear stratification interface; at the same time, the embodiment of the present application uses a jacketed static mixer to cool the sodium methyl fatty acyl taurate solution, and controls most of the material in the jacketed static mixer to be discharged in a crystal precipitation state and a small part of the material in a "molten" state (solid-liquid mixture), so that the target product can be precipitated in the form of crystals, and the purity of the product can be improved by subsequent dehydration, and at the same time, a certain fluidity can be maintained to facilitate the feeding and discharging of the material, thereby ensuring the freezing effect.

[0044] Therefore, the preparation and purification method of this embodiment does not require the use of organic solvents for purification, and is easy to operate, has a short material precipitation time, a high material precipitation recovery rate, and the obtained product has a higher purity.

[0045] Below, the relevant steps of the above-mentioned preparation and purification method will be further described.

[0046] In step (1), sodium methyl taurate and fatty acid are reacted to obtain a reacted material, comprising: Sodium methyl taurate and fatty acid are put into a reaction kettle, the temperature is raised to 170°C to 240°C, and the reaction is carried out under nitrogen protection to obtain a reacted material.

[0047] Wherein, the fatty acid is at least one of caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid and oleic acid. The nitrogen flow rate is 5-20 L / min.

[0048] As an embodiment, the molar ratio of the fatty acid to sodium methyl taurate is 1-1.5:1.

[0049] Illustratively, the molar ratio of fatty acid to sodium methyl taurate is 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1.

[0050] Generally, during the reaction of sodium methyl taurate and fatty acids, after the temperature is raised to a preset temperature (170°C to 240°C), the reaction needs to be kept warm for 6 to 30 hours to obtain the reacted material.

[0051] Exemplarily, the insulation reaction time is 6h, 8h, 10h, 11h, 12h, 16h, 18h, 20h, 21h, 23h, 25h, 27h, 28h, 29h, 30h.

[0052] As mentioned above, the material generated after the reaction of sodium methyl taurate and fatty acid contains a certain amount of fatty acid. In this embodiment, the generated material is directly deacidified in this step.

[0053] It should be understood that the deacidification step can be carried out directly in the reaction vessel.

[0054] As an embodiment, the deacidification of the reacted material to obtain a crude sodium methyl fatty acyl taurate comprises: In the reactor, the reacted material is deacidified at a vacuum degree of -0.1 MPa to -0.092 MPa and a temperature of 190 to 250° C. to obtain a crude product of sodium methyl fatty acyl taurate.

[0055] In this embodiment, the vacuum system can be used to remove excess fatty acid components in the material.

[0056] As a preferred embodiment, in this embodiment, after vacuum deacidification until the content of active matter (sodium methyl fatty acyl taurate) is greater than 85.0%, the next step of purification process can be entered.

[0057] In step (2) of this embodiment, the crude sodium methyl fatty acyl taurate after deacidification is dissolved, and the pH is adjusted with sodium hydroxide to obtain a sodium methyl fatty acyl taurate solution, so as to facilitate subsequent freezing and impurity removal.

[0058] Exemplarily, the preparation process of sodium methyl fatty acyl taurate solution comprises: The deacidified material in the reactor (hereinafter referred to as reactor A) of step (1) is maintained at 180-230° C., and water in an amount of 1-4 times the weight of the material in reactor A is added to another reactor (hereinafter referred to as reactor B). While reactor B is in a stirring state, the material in reactor A is placed in reactor B. After the material is added, stirring is continued for 60-120 minutes, and sodium hydroxide is added to adjust the pH to 7.0-9.0 to prepare a sodium methyl fatty acyl taurate solution; In step (3), after the sodium methyl fatty acyl taurate solution is prepared, the sodium methyl fatty acyl taurate solution is added into a jacketed static mixer; wherein the feeding temperature of the material (sodium methyl fatty acyl taurate solution) into the jacketed static mixer is 40-60°C.

[0059] In this embodiment, the sodium methyl fatty acyl taurate solution is cooled by a jacketed static mixer to obtain a solid-liquid mixture.

[0060] The jacketed static mixer used in this embodiment is a known jacketed static mixer, and the length of the jacketed static mixer is 2 to 10 meters; wherein, the jacketed static mixer can be a straight tube type or a U-shaped type, or a combination of a straight tube type and a U-shaped type.

[0061] The jacketed static mixer cools the sodium methyl fatty acyl taurate solution to obtain a solid-liquid mixture, comprising: Chilled water is introduced into the jacket of the jacketed static mixer to cool the sodium methyl fatty acyl taurate solution in the jacketed static mixer to obtain a solid-liquid mixture.

[0062] As an implementation mode, the inlet temperature of the chilled water is 5-20°C.

[0063] It can be understood that the solid-liquid mixture of this embodiment is a mixed material in a "crystallized" and "molten" state. In this embodiment, the jacketed static mixer cools the sodium methyl fatty acyl taurate solution entering therein, and most of the cooled material is discharged from the jacketed static mixer in a crystallized state and a small part of the material is in a "molten" state. In view of this, the discharge temperature of the solid-liquid mixture is set to 10-30°C in this embodiment.

[0064] Illustratively, the discharge temperature may be 10°C, 12°C, 15°C, 16°C, 18°C, 19°C, 20°C, 21°C, 22°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C or 30°C.

[0065] Therefore, in step (3), the target product can be precipitated in the form of crystals, and the purity of the product can be improved by subsequent dehydration. At the same time, the material can maintain a certain fluidity to facilitate feeding and discharging, thereby solving the defects of the traditional purification process such as easy solidification of high concentration precipitation and high viscosity that is not suitable for feeding. Moreover, it can effectively avoid the disadvantages of poor mass transfer, long freezing precipitation working time, low efficiency, etc., which can effectively ensure the freezing effect. In step (4), after cooling to obtain the "crystallized" and "molten" mixed material, the mixed material can be directly dehydrated and dried to obtain the sodium methyl fatty acyl taurate product.

[0066] Among them, in the dehydration step, the "crystallized" and "molten" mixed materials can be directly pumped into a centrifuge for dehydration and purification, and a solid with a solid content of not less than 85% is formed after dehydration and purification.

[0067] Next, the dehydrated material (solid) is placed in a fluidized bed for drying to obtain a sodium methyl fatty acyl taurate product with a purity of more than 95%.

[0068] In summary, the preparation and purification method of this embodiment does not require the use of organic solvents for purification, and is easy to operate, has a short material precipitation time, a high material precipitation recovery rate, and the obtained product has a higher purity.

[0069] Next, the purpose of the second aspect of this embodiment will be described.

[0070] use As described in the first aspect, the sodium methyl fatty acyl taurate directly prepared in this embodiment has a higher purity. The sodium methyl fatty acyl taurate with a higher purity can be used to synthesize / make personal care cleaning products, such as foam facial cleansers, foam baths, shampoos and other products; sodium methyl fatty acyl taurate has good detergency and emulsification ability, good foam performance, can give hair and skin a mild, moisturizing and refreshing feeling, and has good compatibility and hard water resistance. The water-soluble and easy thickening properties make the application more convenient.

[0071] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate / explain the present application and are not used to limit the scope of the present application.

[0072] In the following examples, the materials, reagents and instruments used can be purchased from commercial sources unless otherwise specified.

[0073] In the following examples, the fatty acid is lauric acid and sodium methyl lauroyl taurate is used as an exemplary product to further illustrate the preparation method of this example; the colorimeter used in the following examples is: Lovibond PFX-i Series (Platinum-Cobalt D1209).

[0074] It should be noted that, unless otherwise specified, the detection method used in the following embodiments is as follows: Solid content detection: Weigh 1.0 g of sample into a weighing bottle, accurate to 1 mg, crush it and place it in an oven at 105℃±1℃ to dry for 3 hours. After cooling to room temperature, weigh it and calculate the solid content.

[0075] Active substance detection method: Weigh 1g of sample, accurate to 1mg, and measure according to GB / T 5173. The molecular weight of sodium methyl lauroyl taurate is 343.

[0076] Lauric acid content detection method: (1) Standard series solutions Weigh 0.5 g of lauric acid into a 100 mL volumetric flask, accurate to 1 mg, add 50 mL of water and 3 mL of concentrated aqueous ammonia, heat in a 50°C water bath to dissolve, cool (if the solution is turbid, add aqueous ammonia until transparent), dilute to the mark with water, and shake well.

[0077] Pipette 1.00mL, 2.00mL, 4.00mL, 6.00mL and 8.00mL of the above lauric acid solution into a series of 50mL volumetric flasks, add 35mL of acetonitrile and 1mL of 10% phosphoric acid, then add water until about 1cm from the scale line, let it stand for 20 minutes, then dilute to the scale with water and shake well.

[0078] The concentrations of lauric acid were: 0.10 mg / mL, 0.20 mg / mL, 0.40 mg / mL, 0.60 mg / mL and 0.8 mg / mL; filtered with a 0.2 µm sample filter; (2) Sample preparation Weigh 0.2 g of sample (accurate to 1 mg) into a 50 mL volumetric flask. The remaining steps are the same as those for standard sample treatment. (3) Chromatographic analysis 3.1, Agilent 1260 liquid chromatograph with UV detector; 3.2. The chromatographic column is Agilent ZORBAX SB-C8, with a length of 250 mm, an inner diameter of 4.6 mm, and a particle diameter of 5 μm. According to the chromatographic conditions set in Table 1, after the instrument is ready, first add the standard sample series solution to make the external standard method standard calibration curve, and then add the sample for analysis. Among them, the lauric acid content in the sample can be obtained by substituting the measured peak area into the standard calibration curve; Table 1: project Reference value Detection wavelength 214nm Injection volume 20μL Column temperature 30℃ Flow rate 1mL / min Mobile phase A: 70%, B: 30%; mobile phase A is acetonitrile; mobile phase B is water: acetonitrile: phosphoric acid = 90:10:2 (volume ratio), and the phosphoric acid is 85% phosphoric acid. Run time 10min Color detection method Weigh 30.0 g of sample in a beaker, add 70 g of 5.0% isopropanol aqueous solution, heat to dissolve, cool to room temperature, pour the sample solution into a 50 mm cuvette, wipe the sample outside the cuvette with lens paper, and call up the Pt-Co determination option according to the operating procedures of the colorimeter for determination.

[0079] Example 1 This embodiment provides a method for preparing sodium methyl lauroyl taurate, which comprises: 1.1. Preparation of crude sodium methyl lauroyl taurate: 40% sodium methyl taurate (molecular formula C 13 H 252820.0 kg of NaO2 (7000.0 mol) aqueous solution was put into a 6000 L stainless steel reactor A, the vacuum was controlled at -0.095 MPa, stirring was started (30 RPM), the temperature was gradually raised to 80 °C at a rate of 2 °C / min to remove water; then nitrogen was introduced at a flow rate of 25 L / min to release the pressure to normal pressure, and the pre-melted lauric acid (molecular formula C 12 H 24 O2, 10500.0mol) liquid 2100.0Kg was pumped into reactor A, and the temperature was raised to 170°C at a rate of 2°C / min by programmed heating, and the reaction was kept warm for 30 hours; after the reaction, the vacuum was controlled to -0.098MPa, and the temperature was raised to 230°C to remove excess lauric acid. The sampling and testing indicators are as follows: Solid content: 98.3%, sodium methyl lauroyl taurate: 91.2%, lauric acid: 3.2%, color (30% pt-co): 80; 1.2. Preparation of sodium methyl lauroyl taurate solution: Add 3855.0 kg of pure water to a 10000 L stainless steel reactor B, start stirring at 20±2 RPM, and start cooling water in the reactor; put the material in the stainless steel reactor A into reactor B, and after the material is put in, continue stirring and cooling for 60 minutes until the material temperature reaches 40° C., and adjust the pH to 8.0 with sodium hydroxide to obtain a sodium methyl lauroyl taurate solution; 1.3. Precipitation and centrifugal separation and purification: The material (sodium methyl lauroyl taurate solution) in reactor B is pumped into a jacketed static mixer through a feed pump (frequency 10 Hz), and then passed through a 6-meter-long straight-tube jacketed static mixer, and chilled water is introduced into the jacketed static mixer for cooling; the inlet temperature of the jacketed mixer chilled water is 12°C, and the discharge temperature of the "crystallized" and "melted" mixtures after freezing is 20°C; the "crystallized" and "melted" mixtures are pumped into a centrifuge (10000±2000RPM) for centrifugal solid-liquid separation to obtain a purified solid. The purified solid is tested for solid content, sodium methyl lauroyl taurate, and lauric acid.

[0080] The test results are as follows: Solid content: 89.5%, sodium methyl lauroyl taurate: 87.3%, lauric acid: 1.06%; 1.4 Drying: The centrifuged material (purified solid) was placed in a fluidized bed and dried at 140±5°C to obtain sodium methyl lauroyl taurate powder. The sampling and testing indicators are as follows: Solid content: 99.1%, Sodium methyl lauroyl taurate: 96.7%, Lauric acid: 1.17%, Color (30% pt-co): 8.

[0081] Example 2 This embodiment provides a method for preparing sodium methyl lauroyl taurate, which comprises: 2.1. Preparation of crude sodium methyl lauroyl taurate: 40% sodium methyl taurate (molecular formula C 13 H 25 1400.0 kg of NaO2 (7000.0 mol) aqueous solution was put into a 6000 L stainless steel reactor A, the vacuum was controlled at -0.095 MPa, stirring was started (30 RPM), the temperature was gradually raised to 80 °C at a rate of 2 °C / min to remove water; then nitrogen was introduced at a flow rate of 25 L / min to release the pressure to normal pressure, and the pre-melted lauric acid (molecular formula C 12 H 24 O2, 7000.0mol) liquid 2100.0Kg was pumped into reactor A, and the temperature was raised to 240℃ at a rate of 2℃ / min by programmed heating, and the reaction was kept warm for 6 hours; after the reaction, the vacuum was controlled to -0.098MPa, and the temperature was raised to 230℃ to remove the excess lauric acid. The sampling and testing indicators are as follows: Solid content: 97.4%, sodium methyl lauroyl taurate: 85.2%, lauric acid: 5.2%, color (30% pt-co): 100; 2.2. Preparation of sodium methyl lauroyl taurate solution: Add 3855.0 kg of pure water to a 10000 L stainless steel reactor B, start stirring at 20±2 RPM, and start cooling water in the reactor; put the material in the stainless steel reactor A into reactor B, and after the material is put in, stir and cool for 60 minutes until the material temperature reaches 40° C., and adjust the pH to 7.0 with sodium hydroxide to obtain a sodium methyl lauroyl taurate solution; 2.3. Precipitation and centrifugal separation and purification: The material (sodium methyl lauroyl taurate solution) in reactor B is pumped into a jacketed static mixer through a feed pump (frequency 10 Hz), and then passed through a 2-meter-long U-shaped jacketed static mixer, and chilled water is introduced into the jacketed static mixer for cooling; the inlet temperature of the jacketed mixer chilled water is 20°C, and the discharge temperature of the "crystallized" and "melted" mixtures after freezing is 30°C; the "crystallized" and "melted" mixtures are pumped into a centrifuge (10000±2000RPM) for solid-liquid separation to obtain a purified solid. The purified solid is tested for solid content, sodium methyl lauroyl taurate, and lauric acid.

[0082] The test results are as follows: Solid content: 88.5%, sodium methyl lauroyl taurate: 85.3%, lauric acid: 1.16%; 2.4 Drying: The centrifuged material (purified solid) was placed in a fluidized bed and dried at 140±5°C to obtain sodium methyl lauroyl taurate powder. The sampling and testing indicators are as follows: Solid content: 98.6%, Sodium methyl lauroyl taurate: 95.03%, Lauric acid: 1.29%, Color (30% pt-co): 12.

[0083] Example 3 This embodiment provides a method for preparing sodium methyl lauroyl taurate, which comprises: 3.1. Preparation of crude sodium methyl lauroyl taurate: 40% sodium methyl taurate (molecular formula C 13 H 25 1400.0 kg of NaO2 (7000.0 mol) aqueous solution was put into a 6000 L stainless steel reactor A, the vacuum was controlled at -0.095 MPa, stirring was started (30 RPM), the temperature was gradually raised to 80 °C at a rate of 2 °C / min to remove water; then nitrogen was introduced at a flow rate of 25 L / min to release the pressure to normal pressure, and the pre-melted lauric acid (molecular formula C 12 H 24 O2, 7000.0mol) liquid 1750.0Kg was pumped into the reactor A, and the temperature was raised to 210℃ at a rate of 2℃ / min by programmed heating, and the reaction was kept warm for 18 hours; after the reaction, the vacuum was controlled to -0.098MPa, and the temperature was raised to 230℃ to remove the excess lauric acid. The sampling and testing indicators are as follows: Solid content: 96.7%, sodium methyl lauroyl taurate: 88.2%, lauric acid: 3.3%, color (30% pt-co): 90; 3.2. Preparation of sodium methyl lauroyl taurate solution: Add 3855.0 kg of pure water to a 10000 L stainless steel reactor B, start stirring at 20±2 RPM, and start cooling the reactor; put the material in the stainless steel reactor A into reactor B, and after the material is put in, stir and cool for 60 minutes until the material temperature reaches 40° C., and adjust the pH to 9.0 with sodium hydroxide to obtain a sodium methyl lauroyl taurate solution; 3.3, precipitation and centrifugal separation and purification: The material (sodium methyl lauroyl taurate solution) in reactor B is pumped into a jacketed static mixer through a feed pump (frequency 10 Hz), and then passed through a 10-meter-long straight-tube jacketed static mixer, and chilled water is introduced into the jacketed static mixer for cooling; the inlet temperature of the jacketed mixer chilled water is 5°C, and the discharge temperature of the "crystallized" and "melted" mixtures after freezing is 10°C; the "crystallized" and "melted" mixtures are pumped into a centrifuge (10000±2000RPM) for solid-liquid separation to obtain a purified solid. The purified solid is tested for solid content, sodium methyl lauroyl taurate, and lauric acid.

[0084] The test results are as follows: Solid content: 89.5%, sodium methyl lauroyl taurate: 87.3%, lauric acid: 1.32%; 3.4 Drying: The centrifuged material (purified solid) was placed in a fluidized bed and dried at 140±5°C to obtain sodium methyl lauroyl taurate powder. The sampling and testing indicators are as follows: Solid content: 98.2%, Sodium methyl lauroyl taurate: 95.79%, Lauric acid: 1.45%, Color (30% pt-co): 10.

[0085] Combined with the test results of Examples 1-3, it can be obtained that the preparation method of this embodiment not only does not require the use of an organic solvent for purification, but is also easy to operate, has a short material precipitation time, and a high material precipitation recovery rate. At the same time, the obtained product has a higher purity (greater than 95%) and a better color.

[0086] In summary, in this embodiment, sodium methyl taurate and fatty acids are used as raw materials to prepare sodium methyl fatty acyl taurate. After the sodium methyl taurate and fatty acids react, the generated material is deacidified to remove the fatty acids in the material, so that in the subsequent dissolution and impurity removal process, there is no need to use an organic solvent, which can avoid the problems of emulsification, the inability to stratify the solution or unclear stratification interface; at the same time, in this embodiment, a jacketed static mixer is used to cool the sodium methyl fatty acyl taurate solution, and most of the material in the jacketed static mixer is controlled to be discharged in a crystal precipitation state and a small part of the material is discharged in a "melted" state, so that the target product can be precipitated in the form of crystals, and the purity of the product can be improved by subsequent dehydration, and at the same time, a certain fluidity can be maintained to facilitate the feeding and discharging of the material, thereby ensuring the freezing effect.

[0087] The technical solutions provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present application. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present application. At the same time, for those skilled in the art, according to the embodiments of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present application.

Claims

1. A method for preparing and purifying sodium methyl fatty acyl taurate, characterized in that: The preparation and purification method comprises: reacting sodium methyl taurate with fatty acid to obtain a reacted material; deacidifying the reacted material to obtain a crude product of sodium methyl fatty acyl taurate; Dissolving crude sodium methyl fatty acyl taurate in water to obtain a sodium methyl fatty acyl taurate solution; adjusting the pH of the sodium methyl fatty acyl taurate solution to 7.0-9.0; The sodium methyl fatty acyl taurate solution after the pH is adjusted is added into a jacketed static mixer; the jacketed static mixer cools the sodium methyl fatty acyl taurate solution to obtain a solid-liquid mixture; The solid-liquid mixture is dehydrated and dried to obtain sodium methyl fatty acyl taurate.

2. The preparation and purification method according to claim 1, characterized in that: The fatty acid is at least one of caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid and oleic acid.

3. The preparation and purification method according to claim 1 or 2, characterized in that: The molar ratio of the fatty acid to sodium methyl taurate is 1-1.5:

1.

4. The preparation and purification method according to claim 1, characterized in that: The method of deacidifying the reacted material to obtain a crude sodium methyl fatty acyl taurate comprises: The reacted material is deacidified at a vacuum degree of -0.1 MPa to -0.092 MPa and a temperature of 190 to 250° C. to obtain a crude product of sodium methyl fatty acyl taurate.

5. The preparation and purification method according to claim 1, characterized in that: The material feeding temperature of the jacketed static mixer is 40-60°C, and the material discharging temperature of the solid-liquid mixture is 10-30°C.

6. The preparation and purification method according to claim 1, characterized in that: The jacketed static mixer cools the sodium methyl fatty acyl taurate solution to obtain a solid-liquid mixture, comprising: Chilled water is introduced into the jacket of the jacketed static mixer to cool the sodium methyl fatty acyl taurate solution in the jacketed static mixer to obtain a solid-liquid mixture.

7. The preparation and purification method according to claim 6, characterized in that: The inlet temperature of the chilled water is 5-20°C.

8. The preparation and purification method according to claim 1, characterized in that: The method of reacting sodium methyl taurate with fatty acid to obtain a reacted material comprises: Sodium methyl taurate and fatty acid are put into a reaction kettle, the temperature is raised to 170°C to 240°C, and the reaction is carried out under nitrogen protection to obtain a reacted material.

9. The preparation and purification method according to claim 8, characterized in that: The insulation reaction time is 6 to 30 hours.

10. Use of sodium methyl fatty acyl taurate prepared according to the preparation and purification method according to any one of claims 1 to 9 in the preparation of care and cleaning products.

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