阅读说明：本技术 一种月桂酰甘氨酸钠的制备装置及生产工艺 (Preparation device and production process of sodium lauroyl glycinate ) 是由 刘兴稳 李飞 贺林 陈莹 葛昌源 于 2021-06-28 设计创作，主要内容包括：本发明涉及氨基酸表面活性剂的加工技术领域,具体公开了一种月桂酰甘氨酸钠的制备装置及生产工艺,包括月桂酰氯高位槽、缩合反应釜、酸化反应釜、离心机、中和反应釜和喷雾干燥机,本发明主要通过缩合反应釜、酸化反应釜、中和反应釜和喷雾干燥机的配合,可以在一次加工中依次完成对原料的缩合、酸化、中和和喷粉干燥工艺,生产出不同型号的月桂酰甘氨酸钠产品,满足市场差异化的需求。(The invention relates to the technical field of processing of amino acid surfactants, and particularly discloses a preparation device and a production process of sodium lauroyl glycinate.)

1. A preparation facilities of lauroyl sodium glycinate which characterized in that: comprises a lauroyl chloride elevated tank (1), a condensation reaction kettle (2), an acidification reaction kettle (3), a centrifuge (4), a neutralization reaction kettle (5) and a spray dryer (6);

a liquid outlet at the bottom of the lauroyl chloride elevated tank (1) is connected with a feed inlet at the top of the condensation reaction kettle (2), a discharge port at the bottom of the condensation reaction kettle (2) is respectively connected with a filter A (7) and the acidification reaction kettle (3) through a three-way valve, a finished product tank I (8) is arranged at a discharge hole of the filter A (7), a discharge hole at the bottom of the acidification reaction kettle (3) is connected with a feed inlet at the top of the centrifuge (4), a discharge hole at the bottom of the centrifuge (4) is connected with a feed hole at the top of the neutralization reaction kettle (5), a discharge hole at the bottom of the neutralization reaction kettle (5) is connected with a filter B (9), the discharge hole of the filter B (9) is respectively connected with the spray dryer (6) and a finished product tank II (10) through a three-way valve, and a finished product tank III (11) is arranged at a discharge hole at the bottom of the spray dryer (6).

2. The device for preparing sodium lauroyl glycinate according to claim 1, wherein a jacket, a serpentine coil and radial and axial stirrers are arranged in the condensation reaction kettle (2), and a circulating pump is arranged between a feeding port and a discharging port of the condensation reaction kettle (2).

3. The device for preparing sodium lauroyl glycinate according to claim 1, wherein a feeding port is arranged at the bottom of the condensation reaction kettle (2), and a sodium hydroxide solvent tank (12) is connected with the feeding port.

4. The apparatus for preparing sodium lauroyl glycinate according to claim 1, wherein a transfer pump is arranged between the condensation reaction kettle (2) and the acidification reaction kettle (3).

5. The device for preparing sodium lauroyl glycinate according to claim 1, wherein a jacket is arranged in the acidification reaction kettle (3), a hydrochloric acid head tank (13) is arranged at a liquid inlet at the top of the acidification reaction kettle (3), and a conveying pump is arranged between the acidification reaction kettle (3) and the centrifuge (4).

6. The device for preparing sodium lauroyl glycinate according to claim 1, wherein a waste water treatment system is connected to a liquid outlet of the centrifugal machine (4), the centrifugal machine (4) is a scraper type centrifugal machine, and the filter cloth specification is 800 meshes.

7. The device for preparing sodium lauroyl glycinate according to claim 1, wherein a sodium hydroxide head tank (14) is arranged at a liquid inlet at the top of the neutralization reaction kettle (5), and a conveying pump is arranged between the neutralization reaction kettle (5) and the spray dryer (6).

8. The apparatus of claim 1, wherein the filter A (7) and the filter B (9) are one of a sheet filter, a bag filter and a precision filter.

9. A process for preparing sodium lauroyl glycinate using a device for preparing sodium lauroyl glycinate as claimed in claims 1 to 8, which comprises the following steps:

s1, firstly, adding sodium glycinate and deionized water into the condensation reaction kettle, then opening a radial stirrer in the condensation reaction kettle to stir and dissolve, and in the stirring process, filling refrigerating fluid into a jacket and a serpentine coil in the condensation reaction kettle to control the reaction temperature to be between 5 and 15 ℃;

s2, after uniformly stirring, opening an axial stirrer of the condensation reaction kettle to stir, and dropwise adding lauroyl chloride into the condensation reaction kettle from a lauroyl chloride overhead tank, wherein the molar ratio of the lauroyl chloride to sodium glycinate is 1: 1-1: 1.1, continuously pumping sodium hydroxide from a sodium hydroxide solvent tank to a feed inlet at the bottom of the condensation reaction kettle, and controlling the pH value of the system to be 9-11; after the dropwise addition of the lauroyl chloride is finished, continuously preserving the heat for 2-3 hours to obtain a mixed solution A;

s3, opening a valve of a discharge port at the bottom of the condensation reaction kettle, enabling the mixed solution A to pass through a three-way valve from the discharge port at the bottom of the condensation reaction kettle, enabling one end of the mixed solution A to enter a filter A, directly obtaining a high-salt liquid finished product with the solid content of 30%, and storing the high-salt liquid finished product in a finished product tank I; the other end of the suspension enters the acidification kettle from a feed inlet at the top of the acidification kettle through a delivery pump, then steam is filled into a jacket of the acidification kettle to raise the temperature in the acidification kettle to 60-70 ℃, and hydrochloric acid is dripped into the acidification kettle from a hydrochloric acid head tank to reduce the pH of the system to 2-3, so as to obtain a suspension B;

s4, adding the suspension liquid B into a centrifuge, centrifuging to obtain a crude lauroyl glycine product, continuously washing a filter cake with hot water at the temperature of 60-70 ℃ in the centrifuging process, and feeding the washed wastewater into a wastewater treatment system from a liquid outlet of the centrifuge;

s5, feeding the washed crude lauroyl glycine into a neutralization reaction kettle from a discharge hole of a centrifuge, adding deionized water, and stirring and dispersing;

s6, filling hot water into a jacket of a neutralization reaction kettle to raise the temperature in the kettle to 40-60 ℃, and then dropwise adding sodium hydroxide into the neutralization reaction kettle from a sodium hydroxide head tank to make the pH value of the system reach 8-10 to obtain a C mixed solution;

filtering the mixed solution of S7 and C by a filter B, and then passing through a three-way valve, wherein one end of the mixed solution directly enters a finished product tank II to obtain a liquid finished product with 30% solid content and low salt content; and the other end is conveyed into a spray dryer through a conveying pump, the mixed solution C is subjected to powder spraying and drying through a spray drying tower, then dry powder is collected, and the powder, namely the powdery sodium lauroyl glycinate finished product, is stored in a finished product tank III.

10. The method of claim 9, wherein the concentration of the hydrochloric acid is 25-35%, and the concentration of the sodium hydroxide is 25-35%.

Technical Field

The invention relates to the technical field of processing of amino acid surfactants, in particular to a preparation device and a production process of sodium lauroyl glycinate.

Background

Sodium lauroyl glycinate is one of the fine products of amino acid surfactants, has the characteristics of mildness, low toxicity, good biodegradability, good compatibility and the like, is widely applied to daily chemical formulas of shower gel, skin care products, shaving cream, facial cleanser, detergents, toothpaste and the like, can also be applied to industries of food additives, metal processing, biological medicines and the like, has wide application range and large demand.

The commercially available sodium lauroyl glycinate product mainly comprises three specifications, including a high salt liquid product with a solid content of 30%, a low salt liquid product with a solid content of 30% and a powdery solid product. At present, manufacturers generally cannot prepare sodium lauroyl glycinate products with different specifications and brands through a set of complete production device, and need to process the sodium lauroyl glycinate products for multiple times through multiple sets of production devices, so that the production cost and time of the sodium lauroyl glycinate are increased, the problems of pollution, oxidation and purity reduction of semi-finished products are easily caused in the processing, storing and transporting processes, and the quality of the finished sodium lauroyl glycinate is influenced. In addition, the method is limited by the existing production equipment and process, the side reaction is serious in the preparation process of the sodium lauroyl glycinate, the impurities of the lauroyl glycinate are excessive, the purity of the finished product of the sodium lauroyl glycinate is reduced, and the downstream application scene is restricted.

Disclosure of Invention

The invention aims to provide a preparation device and a production process of sodium lauroyl glycinate, which can finish condensation, acidification, neutralization and powder spraying drying processes of raw materials in one-time processing by matching a condensation reaction kettle, an acidification reaction kettle, a neutralization reaction kettle and a spray dryer mainly, so as to produce sodium lauroyl glycinate products with different models and meet the demand of market differentiation.

In order to solve the technical problem, the invention provides a preparation device of sodium lauroyl glycinate, which comprises a lauroyl chloride elevated tank, a condensation reaction kettle, an acidification reaction kettle, a centrifugal machine, a neutralization reaction kettle and a spray dryer;

the bottom liquid outlet of lauroyl chloride elevated tank with condensation reation kettle's top feed inlet is connected, condensation reation kettle's bottom discharge gate be connected with filter A respectively through the three-way valve with acidizing reation kettle, filter A's discharge gate is equipped with finished product jar I, acidizing reation kettle's bottom discharge gate with centrifuge's top feed inlet is connected, centrifuge's bottom discharge gate with neutralization reation kettle's top feed inlet is connected, neutralization reation kettle's bottom discharge gate is connected with filter B, filter B's discharge gate is connected with respectively through the three-way valve spray drier and finished product jar II, spray drier's bottom discharge gate is equipped with finished product jar III.

Preferably, a jacket, a serpentine coil, a radial stirrer and an axial stirrer are arranged in the condensation reaction kettle, and a circulating pump is arranged between a feed port and a discharge port of the condensation reaction kettle.

Preferably, the bottom of the condensation reaction kettle is provided with a feed inlet, and the feed inlet is connected with a sodium hydroxide solvent tank.

Preferably, a delivery pump is arranged between the condensation reaction kettle and the acidification reaction kettle.

Preferably, a jacket is arranged in the acidification reaction kettle, a hydrochloric acid elevated tank is arranged at a liquid inlet at the top of the acidification reaction kettle, and a conveying pump is arranged between the acidification reaction kettle and the centrifuge.

Preferably, the liquid outlet of the centrifuge is connected with a wastewater treatment system, the centrifuge is a scraper centrifuge, and the filter cloth specification is 800 meshes.

Preferably, a liquid inlet at the top of the neutralization reaction kettle is provided with a sodium hydroxide elevated tank, and a delivery pump is arranged between the neutralization reaction kettle and the spray dryer.

Preferably, the filter a and the filter B are one of a sheet filter, a bag filter and a precision filter.

Preferably, according to another aspect of the present invention, there is provided a process for preparing sodium lauroyl glycinate, which comprises the following steps:

s1, firstly, adding sodium glycinate and deionized water into the condensation reaction kettle, then opening a radial stirrer in the condensation reaction kettle to stir and dissolve, and in the stirring process, filling refrigerating fluid into a jacket and a serpentine coil in the condensation reaction kettle to control the reaction temperature to be between 5 and 15 ℃;

s2, after uniformly stirring, opening an axial stirrer of the condensation reaction kettle to stir, and dropwise adding lauroyl chloride into the condensation reaction kettle from a lauroyl chloride overhead tank, wherein the molar ratio of the lauroyl chloride to sodium glycinate is 1: 1-1: 1.1, continuously pumping sodium hydroxide from a sodium hydroxide solvent tank to a feed inlet at the bottom of the condensation reaction kettle, and controlling the pH value of the system to be 9-11; after the dropwise addition of the lauroyl chloride is finished, continuously preserving the heat for 2-3 hours to obtain a mixed solution A;

s3, opening a valve of a discharge port at the bottom of the condensation reaction kettle, enabling the mixed solution A to pass through a three-way valve from the discharge port at the bottom of the condensation reaction kettle, enabling one end of the mixed solution A to enter a filter A, directly obtaining a high-salt liquid finished product with the solid content of 30%, and storing the high-salt liquid finished product in a finished product tank I; the other end of the suspension enters the acidification kettle from a feed inlet at the top of the acidification kettle through a delivery pump, then steam is filled into a jacket of the acidification kettle to raise the temperature in the acidification kettle to 60-70 ℃, and hydrochloric acid is dripped into the acidification kettle from a hydrochloric acid head tank to reduce the pH of the system to 2-3, so as to obtain a suspension B;

s4, adding the suspension liquid B into a centrifuge, centrifuging to obtain a crude lauroyl glycine product, continuously washing a filter cake with hot water at the temperature of 60-70 ℃ in the centrifuging process, and feeding the washed wastewater into a wastewater treatment system from a liquid outlet of the centrifuge;

s5, feeding the washed crude lauroyl glycine into a neutralization reaction kettle from a discharge hole of a centrifuge, adding deionized water, and stirring and dispersing;

s6, filling hot water into a jacket of a neutralization reaction kettle to raise the temperature in the kettle to 40-60 ℃, and then dropwise adding sodium hydroxide into the neutralization reaction kettle from a sodium hydroxide head tank to make the pH value of the system reach 8-10 to obtain a C mixed solution;

filtering the mixed solution of S7 and C by a filter B, and then passing through a three-way valve, wherein one end of the mixed solution directly enters a finished product tank II to obtain a liquid finished product with 30% solid content and low salt content; and the other end is conveyed into a spray dryer through a conveying pump, the mixed solution C is subjected to powder spraying and drying through a spray drying tower, then dry powder is collected, and the powder, namely the powdery sodium lauroyl glycinate finished product, is stored in a finished product tank III.

Preferably, the concentration of the hydrochloric acid is 25-35%, and the concentration of the sodium hydroxide is 25-35%.

The invention has the beneficial effects that:

1. through the matching of the condensation reaction kettle, the acidification reaction kettle, the neutralization reaction kettle and the spray dryer, the processes of condensation, acidification, neutralization and powder spraying drying of raw materials can be sequentially completed in one-time processing, and sodium lauroyl glycinate products with different models can be produced;

2. the yield of products of various types can be flexibly regulated and controlled according to market demands in the processing and production process, and the variable market demands are fully met;

3. the sodium lauroyl glycinate does not need to be transported and stored in the processing process, so that the problems of pollution, oxidation and purity reduction of semi-finished products are avoided, the production efficiency is improved, the production cost is reduced, and the quality of finished products is improved;

4. the traditional stirring reaction kettle is optimized and modified, because the condensation reaction of the lauroyl chloride and the sodium glycinate is an exothermic reaction, the cooling provided by a reaction kettle jacket is difficult to maintain the temperature of materials in the kettle within the control requirement, the temperature of the system can be reduced only by the slower dropping speed of the lauroyl chloride or the temporary stop of adding the lauroyl chloride, the production efficiency is reduced, and the reaction uniformity is also influenced. In contrast, by adding the coil pipe in the kettle, the heat exchange area is effectively increased, the stable operation of production is ensured, and the yield of sodium lauroyl glycinate is favorably improved;

5. by adding the circulating pump and the axial stirrer in the condensation reaction kettle, the concentration gradient of each component in the reaction kettle is reduced, the material uniformity is accelerated, the added lauroyl chloride and sodium glycinate are more fully reacted, sodium hydroxide for maintaining the pH value is more fully dispersed in a system, the reaction is continuously carried out in the forward direction, the side reaction is reduced, and the yield of sodium lauroyl glycinate is improved;

6. by adjusting the conventional top addition to the bottom addition of sodium hydroxide, the problem that sodium laurate byproducts are generated after direct contact due to the fact that lauroyl chloride and sodium hydroxide are dripped from the top simultaneously and cannot be dispersed in time is solved, and the yield of sodium lauroyl glycinate is improved;

7. by optimizing the parameters such as temperature, time, molar ratio, pH and the like in the reaction process, the side reaction and the impurity content can be reduced, and the yield of the sodium lauroyl glycinate is improved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of a production apparatus for sodium lauroyl glycinate;

FIG. 2 is a flow diagram of a process for the production of sodium lauroyl glycinate;

in the figure: 1-lauroyl chloride elevated tank, 2-condensation reaction kettle, 3-acidification reaction kettle, 4-neutralization reaction kettle, 5-centrifuge, 6-spray dryer, 7-filter A, 8-finished product tank I, 9-filter B, 10-finished product tank II, 11-finished product tank III, 12-sodium hydroxide solvent tank, 13-hydrochloric acid elevated tank and 14-sodium hydroxide elevated tank.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the specification of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, in an embodiment of the present invention, a preparation apparatus for sodium lauroyl glycinate comprises a lauroyl chloride head tank 1, a condensation reaction kettle 2, an acidification reaction kettle 3, a centrifuge 4, a neutralization reaction kettle 5 and a spray dryer 6;

a liquid outlet at the bottom of the lauroyl chloride elevated tank 1 is connected with a feed inlet at the top of the condensation reaction kettle 2, a spare feed inlet is further arranged at the top of the condensation reaction kettle 2, a jacket, a serpentine coil, a radial stirrer and an axial stirrer are arranged in the condensation reaction kettle 2, a circulating pump is arranged between the feed inlet and the discharge outlet of the condensation reaction kettle 2, a feed inlet is arranged at the bottom of the condensation reaction kettle 2, the feed inlet is connected with a sodium hydroxide solvent tank 12, a conveying pump is arranged between the condensation reaction kettle 2 and the acidification reaction kettle 3, a discharge outlet at the bottom of the condensation reaction kettle 2 is respectively connected with a filter A7 and the acidification reaction kettle 3 through a three-way valve, the filter A7 is one of a sheet filter, a bag filter or a precision filter, the bag filter is selected in the embodiment, the jacket is arranged in the acidification reaction kettle 3, a hydrochloric acid elevated tank 13 is arranged at a liquid inlet at the top of the acidification reaction kettle 3, and a conveying pump is arranged between the acidification reaction kettle 3 and the centrifuge 4, a liquid outlet of the centrifuge 4 is connected with a wastewater treatment system, the centrifuge 4 is a scraper centrifuge, the specification of filter cloth is 800 meshes, a discharge outlet of a filter A7 is provided with a finished product tank I8, a bottom discharge outlet of the acidification reaction kettle 3 is connected with a top feed inlet of the centrifuge 4, a bottom discharge outlet of the centrifuge 4 is connected with a top feed inlet of the neutralization reaction kettle 5, a top liquid inlet of the neutralization reaction kettle 5 is provided with a sodium hydroxide elevated tank 14, a conveying pump is arranged between the neutralization reaction kettle 5 and the spray dryer 6, a bottom discharge outlet of the neutralization reaction kettle 5 is connected with a filter B9, and the filter B9 is a sheet filter, one of the bag filter and the precision filter is selected from the bag filter in the embodiment, the discharge port of the filter B9 is respectively connected with the spray dryer 6 and the finished product tank II 10 through a three-way valve, and the finished product tank III 11 is arranged at the discharge port at the bottom of the spray dryer 6.

As shown in fig. 2, example 1, a process for preparing sodium lauroyl glycinate, the process comprises the following steps:

s1, firstly, adding sodium glycinate and deionized water into the condensation reaction kettle, then opening a radial stirrer in the condensation reaction kettle to stir and dissolve, and in the stirring process, filling refrigerating fluid into a jacket and a serpentine coil in the condensation reaction kettle to control the reaction temperature to be about 10 ℃;

s2, after uniformly stirring, opening an axial stirrer of the condensation reaction kettle to stir, and dropwise adding lauroyl chloride into the condensation reaction kettle from a lauroyl chloride overhead tank, wherein the molar ratio of the lauroyl chloride to sodium glycinate is 1: 1.05, continuously pumping 30% sodium hydroxide from a sodium hydroxide solvent tank to a feed inlet at the bottom of the condensation reaction kettle, and controlling the pH value of the system to be 9.5-10.5; after the dropwise addition of the lauroyl chloride is finished, continuously preserving the heat for 2.5 hours to obtain a mixed solution A;

s3, opening a valve of a discharge port at the bottom of the condensation reaction kettle, enabling the mixed solution A to pass through a three-way valve from the discharge port at the bottom of the condensation reaction kettle, enabling one end of the mixed solution A to enter a filter A, directly obtaining a high-salt liquid finished product with the solid content of 30%, and storing the high-salt liquid finished product in a finished product tank I; the other end of the suspension enters the acidification kettle from a feed inlet at the top of the acidification kettle through a delivery pump, then steam is filled into a jacket of the acidification kettle to raise the temperature in the acidification kettle to 60 ℃, and hydrochloric acid is dropwise added into the acidification kettle from a hydrochloric acid head tank to reduce the pH of the system to 2-3, so as to obtain a suspension B;

s4, adding the suspension liquid B into a centrifuge, centrifuging to obtain a crude lauroyl glycine product, continuously washing a filter cake with hot water at 70 ℃ in the centrifuging process, and feeding the washed wastewater into a wastewater treatment system from a liquid outlet of the centrifuge;

s5, feeding the washed crude lauroyl glycine into a neutralization reaction kettle from a discharge hole of a centrifuge, adding deionized water, and stirring and dispersing;

s6, filling hot water into a jacket of a neutralization reaction kettle to raise the temperature in the kettle to 60 ℃, and then dropwise adding 32% sodium hydroxide into the neutralization reaction kettle from a sodium hydroxide head tank to make the pH value of the system reach 8-10 to obtain a C mixed solution;

filtering the mixed solution of S7 and C by a filter B, and then passing through a three-way valve, wherein one end of the mixed solution directly enters a finished product tank II to obtain a liquid finished product with 30% solid content and low salt content; and the other end is conveyed into a spray dryer through a conveying pump, the mixed solution C is subjected to powder spraying and drying through a spray drying tower, then dry powder is collected, and the powder, namely the powdery sodium lauroyl glycinate finished product, is stored in a finished product tank III.

Example 2, the procedure and procedure of this example were substantially the same as in example 1, except that S1, S2,

s1, firstly, adding sodium glycinate and deionized water into the condensation reaction kettle, then opening a radial stirrer in the condensation reaction kettle to stir and dissolve, and in the stirring process, filling refrigerating fluid into a jacket and a serpentine coil in the condensation reaction kettle to control the reaction temperature to be about 5 ℃;

s2, after uniformly stirring, opening an axial stirrer of the condensation reaction kettle to stir, and dropwise adding lauroyl chloride into the condensation reaction kettle from a lauroyl chloride overhead tank, wherein the molar ratio of the lauroyl chloride to sodium glycinate is 1: 1.05, continuously pumping 30% sodium hydroxide from a sodium hydroxide solvent tank to a feed inlet at the bottom of the condensation reaction kettle, and controlling the pH value of the system to be 9.5-10.5; after the dropwise addition of the lauroyl chloride is finished, continuously preserving the heat for 3 hours to obtain a mixed solution A;

example 3, the procedure and procedure of this example were substantially the same as in example 1, except that S1, S2,

s1, firstly, adding sodium glycinate and deionized water into the condensation reaction kettle, then opening a radial stirrer in the condensation reaction kettle to stir and dissolve, and in the stirring process, filling refrigerating fluid into a jacket and a serpentine coil in the condensation reaction kettle to control the reaction temperature to be about 15 ℃;

s2, after uniformly stirring, opening an axial stirrer of the condensation reaction kettle to stir, and dropwise adding lauroyl chloride into the condensation reaction kettle from a lauroyl chloride overhead tank, wherein the molar ratio of the lauroyl chloride to sodium glycinate is 1: 1.02, continuously pumping 30% sodium hydroxide from a sodium hydroxide solvent tank to a feed inlet at the bottom of the condensation reaction kettle, and controlling the pH value of the system to be 9.5-10.5; after the dropwise addition of the lauroyl chloride is finished, continuously preserving the heat for 2.0 hours to obtain a mixed solution A;

comparative example 1, the preparation process and procedure of this comparative example are substantially the same as in example 1, except that S2,

s2, after uniformly stirring, dropwise adding lauroyl chloride into the condensation reaction kettle from the lauroyl chloride head tank, wherein the molar ratio of the lauroyl chloride to the sodium glycinate is 1: 1.05, continuously pumping 30% sodium hydroxide from a sodium hydroxide solvent tank to a standby feed inlet at the top of the condensation reaction kettle, controlling the pH value of the system to be 9.5-10.5, and axially stirring and closing in the whole dripping and reaction processes; after the dropwise addition of the lauroyl chloride is finished, continuously preserving the heat for 2 hours to obtain a mixed solution A;

the performance index test was performed on the mixed solutions a of example 1, example 2, example 3 and comparative example 1, and the test results are as follows:

from the analysis of the above table, it is found that when the axial stirring is absent in comparative example 1 and sodium hydroxide is added dropwise from the top in parallel with lauroyl chloride, the side reaction is significantly increased and the sodium laurate content exceeds the reference value.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.