CN113049540B

CN113049540B - Method for determining taurine content in solution and method for purifying taurine

Info

Publication number: CN113049540B
Application number: CN201911376904.3A
Authority: CN
Inventors: 孙华君; 江汝泳; 谈敏; 郭晨; 何本斌; 钱志强; 熊先胜
Original assignee: Hubei Yuanda Life Science And Technology Co ltd
Current assignee: Hubei Yuanda Life Science And Technology Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2023-05-30
Anticipated expiration: 2039-12-27
Also published as: CN113049540A

Abstract

The invention provides a method for determining taurine content in a solution and a method for purifying taurine. Wherein the method comprises determining the refractive index of a solution to be tested, the solution to be tested containing taurine or a salt thereof and impurities including at least one selected from ethylene glycol, sodium isethionate, sodium sulfate, polyethylene glycol; establishing a standard curve of taurine concentration in the taurine solution based on the refractive index; and carrying out optical detection on the solution to be detected, and determining the taurine or salt content of the taurine according to the position of the obtained optical detection value in the standard curve. By this method, the content of taurine in each taurine solution having a complicated composition can be effectively detected.

Description

Method for determining taurine content in solution and method for purifying taurine

Technical Field

The invention relates to the field of biological products, in particular to a method for determining taurine content in a solution and a method for purifying taurine.

Background

The synthesis method of taurine has practical application value and is concentrated on an ethanolamine method and an ethylene oxide method. The ethanolamine method has a long reaction period, wherein the sulfonation reaction needs more than 30 hours, and the cost is high, so that the reaction is gradually eliminated before the vigorous market competition. The cost of raw materials of the ethylene oxide method is lower than that of the ethanolamine method, the industrialization in China at present reaches a certain scale, and more than 60% of taurine raw materials in the world are prepared by the ethylene oxide method in China. The ethylene oxide process for preparing taurine generally comprises the following steps: ethylene oxide is taken as an initial raw material, and ethylene oxide and sodium bisulphite undergo an addition reaction to obtain sodium isethionate; then ammonolysis reaction is carried out on the sodium isethionate and ammonia to obtain sodium taurate.

In the preparation and purification of taurine, the content of taurine and salts thereof is continuously detected, and conventional detection methods are an acid-base titration method (GB/75009) and a liquid chromatography method. The acid-base titration method can realize the detection of one sample within two minutes, but has the advantages of large sample quantity, complicated sampling, and low accuracy by judging the end point through visual color change. Because of the liquid chromatography, the sample needs to be subjected to pre-column derivatization, and the time required by the derivatization process is not equal to 3-24 hours, so that the method cannot be well utilized in industrial production. CN108490087a discloses a high performance liquid chromatography method for determining taurine content in taurine particles or taurine eye drops based on a differential refraction detector, wherein the differential refraction detector in the method must determine the concentration of the pure solution by detecting the difference between the refractive index of the pure solution and the refractive index of the reference solution. Before detection, a standard curve of the difference between the refractive indexes of the pure product and the reference product is established, during detection, the sample is required to be separated and purified, during detection, the purified sample is placed in a detection cell, the reference product is placed in a reference cell, and the concentration of the sample after separation and purification is determined by combining the standard curve through the difference between the refractive index of the pure product solution and the refractive index of the reference product solution. And the conventional differential detector has the defects that the incident light source is white light, the optical prism adopts transparent glass, the anti-interference capability is weak, and the conventional differential detector is not suitable for industrial production.

Thus, a method for determining the content of taurine and purifying taurine still needs to be further improved.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present invention is to propose a method capable of accurately and conveniently determining taurine in a solution and a method of purifying taurine.

The present invention has been completed based on the following findings by the inventors:

in the production process of taurine, the content of taurine needs to be monitored so as to regulate and control the production process. At present, the content of taurine is usually detected by an acid-base titration method, pre-column derivatization-liquid chromatography detection and the like. However, in the large-scale industrial production of taurine, particularly in the purification of taurine, various processes such as evaporation, neutralization, dissolution, desalination and the like are required to determine the endpoint of the treated material in real time by detecting the taurine content. The inventors of the present invention found that both acid-base titration and pre-column derivatization-liquid chromatography detection are not suitable for the requirement of large-scale continuous production of taurine during the production process. Specifically, neither acid-base titration nor pre-column derivatization-liquid chromatography detection can meet the requirement of real-time monitoring of taurine-containing solutions, for example, for pre-column derivatization-liquid chromatography detection, pre-column derivatization is required for a sample, but pre-column derivatization usually takes 3-24 hours, and cannot be applied to industrial continuous production. The acid-base titration method can realize the detection of the sample in a short time, but has complicated sampling due to large sample amount, and the accuracy is not high due to the fact that the end point is judged by visual color change. Particularly, for a plurality of posts such as evaporation, neutralization, dissolution, desalination and the like, a great deal of manpower and material cost is consumed. For this reason, the inventors of the present invention conducted intensive studies on the method for detecting the content of taurine and compared various detection methods, for example, experiments and comparisons of methods such as a density method, an ultrasonic method, a conductivity method, an infrared, an ultraviolet absorption spectrophotometer method, a chromatography method, etc., found that since the components of the mother liquor in each section of taurine production, particularly the evaporation liquid in the evaporation stage and the concentration stage, are complicated, 5 to 6 kinds of impurities are contained, the components of the impurities are not too stable, and these methods are difficult to adapt to the process conditions of taurine production.

During the course of the study, the inventors have unexpectedly found that the refraction method can be adapted to the detection of taurine content over a large concentration range, for example, taurine content of 5 to 50% by weight can be effectively distinguished and determined by the refraction method. Thus, the inventor creatively proposes a method for online detection of taurine by a refraction method, and applies the method to the industrial production process of taurine.

In view of this, in a first aspect of the present invention, the present invention provides a method for determining the content of taurine or a salt thereof in a solution, the method comprising determining the refractive index of a solution to be tested, the solution to be tested containing taurine or a salt thereof and an impurity, the impurity comprising at least one selected from the group consisting of ethylene glycol, sodium isethionate, sodium sulfate, ethanolamine; and determining the content of taurine or salt thereof in the solution to be tested based on the refractive index and the standard curve. As previously mentioned, the inventors have unexpectedly found that the refraction method can accommodate detection of taurine or its salt content over a wide concentration range, e.g., 5 to 50% by weight taurine content can be effectively distinguished and determined by the refraction method. Thus, the method can effectively detect the content of taurine in various taurine solutions with complex components. And the solution of taurine or salt thereof with known content and containing impurities is detected by a refraction method and a manual titration method through a simulation experiment, the detection accuracy of the refraction method can reach more than 95 percent, almost no accidental error exists, the accuracy of the manual detection method is about 90 percent, and the accidental error is larger.

In addition, the inventor creatively proposes a method for online detection of taurine by a refraction method, and applies the method to the industrial production process of taurine. To this end, the invention proposes a process for purifying taurine comprising: (1) Evaporating and drying the solution containing taurine; (2) Neutralizing the product subjected to the evaporation drying treatment; (3) Dissolving the solid product subjected to the neutralization treatment; and (4) subjecting the neutralized liquid product and the dissolved product to a desalting treatment to obtain purified taurine; wherein at least one of step (1), step (2), step (3) and step (4) comprises performing taurine content detection according to the method of the first aspect. It can be appreciated by those skilled in the art that by the method for determining the content of taurine or the salt thereof in the solution provided in the first aspect, the concentration of taurine in the solution can be effectively monitored in real time through the refractive index of the solution, and the method is applied to the industrial production of taurine, particularly in the purification process, so that a great deal of manpower and material cost is saved, the cost for producing taurine is reduced, the efficiency is improved, and the method is suitable for large-scale industrial production requirements, thereby being applicable to the process of automatic production. For example, the data of the refractometer can be used for judging the evaporation end point at the evaporation position, the steam consumption is adjusted according to the taurine concentration change curve, and the acid consumption for the neutralization position is calculated in advance according to the concentration value of the end point, so that the neutralization efficiency and the neutralization accuracy are improved, the yield of taurine is improved, and the purification difficulty is reduced. In the dissolution post, the purpose is through dissolving taurine crude again, purifies taurine through recrystalization, and the in-process of dissolving then accessible refractometer judges whether the volume of adding taurine crude is suitable, and the in-process of cooling crystallization also can real-time supervision taurine content to judge the terminal point of cooling crystallization. The desalting station also increases the solubility of taurine by heating the taurine mother solution and reduces the solubility of sodium sulfate, thereby achieving the purpose of desalting, and the end point of the desalting station can be judged by a refractometer in the heating process.

In another aspect of the invention, the invention provides a method of determining the content of taurine or a salt thereof in a solution, comprising: determining the refractive index of a taurine solution containing taurine or a salt thereof and impurities including at least one selected from the group consisting of ethylene glycol, sodium isethionate, sodium sulfate, ethanolamine; establishing a standard curve of taurine concentration in the taurine solution based on the refractive index; and carrying out optical detection on the solution to be detected, and determining the content of taurine or salt thereof in the solution to be detected according to the position of the obtained optical detection value in the standard curve. As previously mentioned, the inventors have unexpectedly found that the refraction method can accommodate detection of taurine or its salt content over a wide concentration range, e.g., 5 to 50% by weight taurine content can be effectively distinguished and determined by the refraction method. Thus, the method can effectively detect the content of taurine in various taurine solutions with complex components. And the solution of taurine or salt thereof with known content and containing impurities is detected by a refraction method and a manual titration method through a simulation experiment, the detection accuracy of the refraction method can reach more than 95 percent, almost no accidental error exists, the accuracy of the manual detection method is about 90 percent, and the accidental error is larger.

According to an embodiment of the present invention, the specific step of determining the refractive index of the taurine solution includes: placing a probe with an optical prism on a refractometer into the taurine solution; detecting a critical angle of an incident light source; and determining the refractive index of the taurine solution according to the critical angle.

According to a preferred embodiment of the invention, the refractometer is provided with electronic components having a calculation function.

According to a preferred embodiment of the invention, the optical prism is made of diamond. More preferably, the diamond contains boron. The diamond added with the boron element has stronger weather resistance and good anti-interference capability, thereby obtaining accurate refractive index value.

According to an embodiment of the present invention, a self-cleaning device is installed around the optical prism. The self-cleaning device is arranged around the optical prism, so that particles around the optical prism, especially particles on the probe, can be conveniently removed, and an accurate refractive index value can be obtained.

According to an embodiment of the present invention, the step of establishing a standard curve of taurine concentration in the taurine solution based on the refractive index specifically includes:

1) Acquiring content data of a plurality of taurine solutions with known concentrations; obtaining refractive index data for the plurality of taurine solutions of known concentrations; fitting the content data and the refractive index data respectively to obtain corresponding fitting data; modeling and correcting according to the fitting data, and establishing a standard curve of taurine concentration; wherein the plurality of taurine or salt solutions thereof of known concentrations comprises 5 wt%, 10 wt%, 15 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, 40 wt%, 45 wt% and 50 wt% taurine solutions.

2) The fitting process comprises the steps of preparing a background solution capable of simulating impurities contained in the taurine production process, measuring the refractive index of the background solution, adding different amounts of taurine or salts thereof into the simulated solution, measuring the refractive index of the background solution, and establishing a standard curve of the corrected taurine content relative to the refractive index based on the refractive index of the simulated solution and the refractive index of the pure taurine solution;

3) And measuring the refractive index of the solution to be measured, and obtaining the content of taurine or the salt thereof corresponding to the solution to be measured from the fitted standard curve.

According to an embodiment of the invention, the solution to be tested is a process product of a taurine production process.

According to an embodiment of the present invention, the test solution contains not less than 10% by mass of the taurine or a salt thereof, and optionally, the test solution contains not less than 5% by mass of the taurine or a salt thereof.

According to an embodiment of the present invention, the solution to be tested contains not more than 20 mass% of ethylene glycol, or not more than 35 mass% of sodium isethionate, or not more than 10 mass% of sodium sulfate, not more than 10 mass% of ethanolamine.

In another aspect of the present invention, there is provided a method for detecting taurine content on line, characterized in that in at least one of the following steps (1) to (4), taurine content is detected by using the above method for determining taurine or its salt content in a solution, (1) the solution containing taurine is subjected to evaporation drying treatment; (2) The product after the evaporation drying treatment is subjected to neutralization treatment; (3) The solid product after the neutralization treatment is dissolved in the process of treatment; and (4) subjecting the neutralized liquid product and the dissolved product to a desalting treatment.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic structural view of an apparatus for purifying taurine according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of an apparatus for purifying taurine according to another embodiment of the present invention;

FIG. 3 is a schematic structural view of an apparatus for purifying taurine according to still another embodiment of the present invention;

FIG. 4 is a schematic diagram of the structure of a taurine production system according to one embodiment of the invention;

FIG. 5 is a simulated graph of online taurine content detection provided in accordance with an embodiment of the present invention;

FIG. 6 is a simulated graph of online taurine content detection provided in accordance with an embodiment of the present invention;

FIG. 7 is a simulated graph of on-line taurine content detection of a dissolution unit provided in accordance with an embodiment of the present invention;

FIG. 8 is a simulated graph of on-line taurine content detection of a desalination unit provided in accordance with an embodiment of the invention;

FIG. 9 is a graph comparing the on-line detection of the taurine content of a solution from an evaporation station with a titration detection according to an embodiment of the present invention;

FIG. 10 is a graph comparing the on-line detection of the taurine content of a solution from an evaporation station with a titration detection according to an embodiment of the present invention;

FIG. 11 is a graph showing the comparison of on-line detection and titration detection of taurine content by a dissolution unit refractometer provided in accordance with an embodiment of the present invention;

FIG. 12 is a graph comparing the on-line detection of the taurine content of a solution from a primary desalting station with a titration detection according to an embodiment of the present invention;

FIG. 13 is a graph comparing the on-line detection of the taurine content of a solution from a secondary desalting station with a titration detection according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

In a first aspect of the invention, the invention provides a method of determining the content of taurine or a salt thereof in a solution, the method comprising determining the refractive index of a solution to be tested, the solution to be tested containing taurine or a salt thereof and impurities including at least one selected from the group consisting of ethylene glycol, sodium isethionate, sodium sulphate, ethanolamine; and determining the content of taurine or salt thereof in the solution to be tested based on the refractive index and the standard curve. As previously mentioned, the inventors have unexpectedly found that refractive methods can accommodate a wide range of taurine content assays, e.g., 5 to 50% by weight taurine content, can be effectively distinguished and measured by refractive methods. Thus, the method can effectively detect the content of taurine in various taurine solutions with complex components. According to the embodiments of the present invention, the type of taurine-containing solution described herein is not particularly limited, and the taurine-containing solution may be either pure taurine solution free of impurities or taurine or a salt thereof in taurine solution containing a plurality of impurities may be assayed without being affected by such impurities, such as ethylene glycol, sodium isethionate, sodium sulfate, polyethylene glycol, ethanolamine, and the like. Thus, the inventors of the present invention have found that the refractive index method can use a wide range of detection of taurine content, for example, can effectively detect at least taurine content in the range of 5 to 50% by weight, and at the same time, have found that impurities generated during the production of taurine do not affect the detection of taurine content. Thus, the solution to be tested, i.e. the solution containing taurine, may be the process product of the taurine production process, i.e. may be various materials in the taurine production and purification process, such as the final product or the intermediate product to be purified. Specifically, in the purification process of taurine, the product in the neutralization process, the product in the dissolution process and the product in the desalination process can be used as a solution to be detected after evaporation drying treatment, neutralization treatment, dissolution treatment and desalination treatment, and the content of taurine or salts thereof can be measured by adopting the method.

According to an embodiment of the present invention, when the content measurement is performed by the above-described method, the solution to be measured contains not less than 5% by mass of taurine or a salt thereof. According to a preferred embodiment of the present invention, the test solution contains not less than 10% by mass of taurine or a salt thereof. According to a preferred embodiment of the present invention, the solution to be measured contains not less than 15% by mass of taurine or a salt thereof.

As described above, when the taurine or the salt thereof is measured by the above method, the impurity and the content thereof in the solution to be measured are not particularly required. According to an embodiment of the present invention, the impurities may be at least one of ethylene glycol, sodium isethionate, sodium sulfate, ethanolamine. According to an embodiment of the present invention, the solution to be tested contains not more than 20 mass% of ethylene glycol, or not more than 30 mass% of sodium isethionate, not more than 10 mass% of sodium sulfate, not more than 10 mass% of ethanolamine. According to a preferred embodiment of the present invention, the solution to be tested contains not more than 4% by mass of ethylene glycol, not more than 5% by mass of sodium isethionate, not more than 4% by mass of sodium sulfate, not more than 4% by mass of ethanolamine.

In addition, according to an embodiment of the present invention, the standard curve is determined based on the following steps: (1) Establishing a preliminary standard curve by using a plurality of taurine or salt solutions with known concentrations; and (2) correcting the preliminary standard curve with taurine or a salt solution thereof to which the impurities are added, so as to obtain the standard curve. According to embodiments of the present invention, the plurality of known concentrations of taurine or salt solutions thereof include 5 wt%, 10 wt%, 15 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, 40 wt%, 45 wt%, and 50 wt% taurine solutions. As described above, the inventors of the present invention have unexpectedly found that the taurine concentration has a good correlation with the refractive index in a large concentration range, for example, in the range of 5 to 50 mass%, and that the taurine concentration can be discriminated and determined by the refractive index. The inventor finds through experiments that the coincidence degree of the detection data of the refractive index and the artificial acid-base titration method reaches more than 95%.

In addition, the inventor creatively proposes a method for online detection of taurine by a refraction method, and applies the method to the industrial production process of taurine. To this end, the invention proposes a process for purifying taurine comprising: (1) Evaporating and drying the solution containing taurine; (2) Carrying out dissolution treatment on the product subjected to the evaporation drying treatment; (3) Dissolving the solid product subjected to the neutralization treatment; and (4) subjecting the neutralized liquid product and the dissolved product to a desalting treatment so as to obtain purified taurine, wherein at least one of the steps (1), (2), (3) and (4) comprises taurine content detection according to the above method. According to an embodiment of the present invention, the method of purifying taurine further comprises: the desalted product is further desalted to obtain a product of the secondary deoxidization treatment.

According to an embodiment of the present invention, in steps (1) to (4), the results of the detection are input to a server, respectively. The detection result is input to the server, so that the weight percentage concentration of taurine can be directly and conveniently output through the server, and the taurine content can be conveniently monitored.

According to an embodiment of the present invention, the server controls at least one of the evaporation drying process, the neutralization process, the dissolution process, and the desalination process based on the result of the detection. By the results output via the server, a data reference can be provided for the industrial purification process, i.e. control of at least one of the evaporation drying process, the neutralization process, the dissolution process and the desalination process is achieved by the content of taurine. In addition, these processes may be monitored and adjusted simultaneously as needed.

According to an embodiment of the present invention, in the process of performing the taurine content detection, a process temperature determination is performed, and correction of the taurine content is performed based on the process temperature. Determining solution temperatures at different stages in the whole process by combining the production and purification processes of taurine; then, correction of taurine content can be carried out under different temperature conditions according to the determined temperature, and process optimization can be carried out on the drawn standard curve. Therefore, the result of the concentration of the taurine or the salt thereof in the solution at different temperatures can be more accurately determined, and the result can be output through the server, namely the weight percent concentration of the taurine can be directly displayed and output.

The above method for determining the content of taurine or a salt thereof in a solution can be directly applied to industrial production. According to embodiments of the present invention, the test solution may be tested using equipment for purifying taurine. The provided apparatus for purifying taurine comprises: the evaporation unit comprises an evaporation tank, wherein an evaporation space is defined in the evaporation tank and is used for evaporating and drying a solution containing taurine; the neutralization unit is connected with the evaporation unit through a first pipeline, and comprises a neutralization reaction tank, wherein the neutralization reaction tank is provided with: the neutralization reaction tank comprises a neutralization reaction tank body, wherein a neutralization space is defined in the neutralization reaction tank body, and a charging port is arranged at the top of the neutralization reaction tank body and is used for adding a neutralization reagent into the neutralization space; the dissolution unit is connected with the neutralization unit and comprises a dissolution kettle, and a dissolution space is defined in the dissolution kettle; the desalting unit is respectively connected with the neutralizing unit and the dissolving unit and comprises a concentration evaporator; the refraction method concentration meter comprises at least one selected from a first refraction method concentration meter, a second refraction method concentration meter, a third refraction method concentration meter and a fourth refraction method concentration meter, wherein the first pipeline is provided with the first refraction method concentration meter for detecting the concentration of an object to be detected in the first pipeline; the second refraction method concentration meter is arranged on the neutralization reaction tank body and is used for detecting the concentration of an object to be detected in the neutralization space; the dissolution kettle is provided with a third refraction method concentration meter for detecting the concentration of an object to be detected in the dissolution kettle; and a fourth refraction method concentration meter is arranged in the concentration evaporator and used for detecting the concentration of the object to be detected in the concentration evaporator.

The refractometer is an instrument for testing the concentration of liquid by utilizing light, and mainly comprises a detection probe, an optical prism, a prism reflecting mirror, a lens, a processor and the like, wherein the processor contains electronic elements. When the refractometer is used for measuring taurine in the solution, the refractometer can be adaptively improved, and the content of the taurine can be measured more accurately. According to the embodiment of the invention, the heat insulation section is arranged between the electronic component of the refractometer and the detection probe, so that the candidate electronic component is prevented from being overheated and aged or even affecting measurement due to high temperature. According to an embodiment of the invention, the refractometer light source employs a sodium-D line light emitting diode. The diode has strong anti-interference capability, and the measurement result is less interfered by crystals, bubbles and colors in the liquid. According to the embodiment of the invention, the optical prism of the refractometer is made of diamond, preferably, artificially synthesized diamond added with boron. The diamond added with the boron element has stronger weather resistance and good anti-interference capability. According to an embodiment of the present invention, a self-cleaning device is provided around the optical prism, so that particles adhering to the surface of the optical prism can be removed. According to the embodiment of the invention, the electronic element adopts a 3D digital measurement means, no signal drift exists, and the measurement result can be corrected through standard curve, so that the interference of crystals, bubbles, colors and the like in the liquid is reduced again.

According to an embodiment of the present invention, the detection of taurine content using an apparatus for purifying taurine comprises: (1) Inputting the taurine-containing solution into an evaporation unit, wherein the evaporation unit comprises an evaporation tank, and an evaporation space is defined in the evaporation tank and is used for evaporating and drying the taurine-containing solution; (2) Inputting the product subjected to the evaporation drying treatment into a neutralization unit, wherein the neutralization unit is connected with the evaporation unit through a first pipeline, a first refraction method concentration meter is arranged on the first pipeline and used for detecting the concentration of an object to be detected in the first pipeline, and the neutralization unit comprises a neutralization reaction tank, and the neutralization reaction tank is provided with a first light-splitting device; the neutralization reaction tank comprises a neutralization reaction tank body, a charging port and a second refraction method concentration meter, wherein a neutralization space is defined in the neutralization reaction tank body, the charging port is arranged at the top of the neutralization reaction tank body and used for adding a neutralization reagent into the neutralization space, and the second refraction method concentration meter is arranged on the neutralization reaction tank body and used for detecting the concentration of an object to be detected in the neutralization space; (3) Inputting the solid product processed by the neutralization unit into a dissolution unit, wherein the dissolution unit is connected with the neutralization unit, the dissolution unit comprises a dissolution kettle, a dissolution space is defined in the dissolution kettle, and the dissolution kettle is provided with a third refraction method concentration meter for detecting the concentration of an object to be detected in the dissolution kettle; (4) The liquid product treated by the neutralization unit and the product treated by the dissolution unit are input into a desalination unit, the desalination unit is respectively connected with the neutralization unit and the dissolution unit, the desalination unit comprises a concentration evaporator, and a fourth refraction method concentration meter is arranged in the concentration evaporator and is used for detecting the concentration of an object to be detected in the concentration evaporator. It can be understood by those skilled in the art that the above-mentioned device for purifying taurine can effectively realize real-time monitoring of concentration of taurine in solution through refractive index of solution by adopting refractive concentration meter, thereby saving a great deal of cost of manpower and material resources, reducing cost of producing taurine, improving efficiency, adapting to large-scale industrial production requirement, and being used in the process of automatic production. When the method is applied, the person skilled in the art can also be provided with the refraction method concentration meters on one link or one unit according to the needs, and the plurality of refraction method concentration meters can be arranged on the same link or the same unit according to the needs, so that the number and the arrangement positions of the refraction method concentration meters are not particularly required.

For ease of understanding, the apparatus for purifying taurine that can be used to carry out the above method is described in detail below with reference to fig. 1 to 3, and according to an embodiment of the present invention, the apparatus for purifying taurine includes: an evaporation unit 100, a neutralization unit 200, a dissolution unit 300, and a desalination unit 400. And the refractometry concentration meter and the position thereof shown in fig. 2 and 3 are only referred to, and a person skilled in the art can set only one of the refractometry concentration meters according to the need, or can additionally set the refractometry concentration meter according to the need.

The evaporation unit 100 includes an evaporation tank 110, an evaporation space 120 is defined in the evaporation tank 110, and a solution containing taurine is evaporated and dried in the evaporation space 120. According to the embodiments of the present invention, the type of taurine-containing solution described herein is not particularly limited, and the inventors of the present invention have found that the refractive index method can use a wide range of detection of taurine content, for example, can effectively detect at least taurine content in the range of 5 to 50% by weight, while the inventors have found that impurities generated during the production of taurine do not affect the detection of taurine content.

According to an embodiment of the present invention, the neutralization unit 200 is connected to the evaporation unit 300 through the first pipe 130, and a first refraction concentration meter 140 for detecting the concentration of the analyte in the first pipe 130 may be disposed on the first pipe 130. Thus, the material leaving the evaporation unit and entering the neutralization unit 200 can be detected by the first refraction concentration meter. In addition, the neutralization unit 200 includes a neutralization reaction tank having a neutralization reaction tank body 210 and a charging port 230 defined in the neutralization reaction tank body 210, the charging port 230 being disposed at the top of the neutralization reaction tank body 210 for adding a neutralization reagent to the neutralization space 220. In addition, a second refraction method concentration meter 240 is further disposed on the neutralization reaction tank body 210 for detecting the concentration of the analyte in the neutralization space 220. Thus, real-time monitoring of the material in the neutralization space 220 can be achieved, and the content of the detectable component can be selected as desired.

According to an embodiment of the present invention, the dissolution unit 300 is connected to the neutralization unit 200, and the solid product obtained through the neutralization unit 200 directly enters the dissolution unit, and the liquid product obtained through the neutralization unit 200 directly enters the desalination unit. The dissolution unit 300 includes a dissolution vessel 310, a dissolution space 320 is defined in the dissolution vessel 310, and the dissolution vessel 310 is provided with a third refraction method concentration meter 340 for detecting the concentration of the analyte in the dissolution vessel 310. The desalination unit 400 is connected to the neutralization unit 200 and the dissolution unit 300, respectively, and the desalination unit 400 includes a concentration evaporator 410, and a fourth refraction method concentration meter 440 is disposed in the concentration evaporator 400, for detecting the concentration of the analyte in the concentration evaporator 410.

By adopting the equipment, the solution containing taurine can be sequentially evaporated, neutralized, dissolved and concentrated, and finally the taurine product with higher purity is obtained, meanwhile, in the process of the working procedures, the detection of materials can be carried out through the first refraction method concentration meter 140, the second refraction method concentration meter 240, the third refraction method concentration meter 340 and the fourth refraction method concentration meter 440, and the detection is carried out on line, so that a large amount of manpower and material resources are saved, manual sampling is not needed, and a large amount of time cost is not needed to be consumed, thereby effectively improving the efficiency of purifying the taurine and reducing the cost of purifying the taurine.

In addition, for the implementation and specific device structure and constitution of the functions of the respective processing units, such as the evaporation unit 100, the neutralization unit 200, the dissolution unit 300 and the desalination unit 400, common or well-known technical means in the art may be adopted, and will not be described herein. It should be noted that, as required, a person skilled in the art may detect different material components by using the first refraction method concentration meter 140, the second refraction method concentration meter 240, the third refraction method concentration meter 340 and the fourth refraction method concentration meter 440, and may detect taurine or specific impurities in the taurine solution. According to an embodiment of the present invention, the first refractive method concentration meter 140, the second refractive method concentration meter 240, the third refractive method concentration meter 340 and the fourth refractive method concentration meter 440 are each independently used to detect at least one of taurine and sodium bezoar. The inventors of the present invention found that for the detection of taurine or sodium taurine, good discrimination in a wide range, for example, in the range of 5 to 50%, can be achieved, and thus detection of taurine or sodium taurine at each section can be adapted.

According to an embodiment of the present invention, since the first, second, third, and

fourth refraction concentrators

140, 240, 340, and 440 may acquire component information of a material in real time, and the information may be converted into digital signals, the digital signals may be transmitted to the server 500 through a communication device, and the server 500 may be connected to at least one of the first, second, third, and

fourth refraction concentrators

140, 240, 340, and 440, respectively, for acquiring detection results of the first, second, third, and

fourth refraction concentrators

140, 240, 340, and 440, respectively, referring to fig. 3. The first refraction method concentration meter 140, the second refraction method concentration meter 240, the third refraction method concentration meter 340 and the fourth refraction method concentration meter 440 are connected, and the first refraction method concentration meter 140, the second refraction method concentration meter 240, the third refraction method concentration meter 340 and the fourth refraction method concentration meter 440 are used for obtaining the concentration of taurine or sodium taurine in the corresponding working section, which can directly transmit the converted concentration information of taurine to the server 500, or transmit the collected refractive index information to the server 500, and the server 500 calculates the concentration of taurine or sodium taurine in the corresponding working section. To this end, according to an embodiment of the present invention, a standard curve established based on a plurality of taurine solutions of known concentrations is stored in advance in the server 500. According to embodiments of the present invention, the plurality of taurine solutions of known concentrations includes 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 22 wt.%, 24 wt.%, 26 wt.%, 28 wt.%, 30 wt.%, 32 wt.%, 34 wt.%, 36 wt.%, 38 wt.%, 40 wt.%, 45 wt.%, and 50 wt.% taurine solutions. As previously described, the inventors of the present invention have unexpectedly found that taurine concentration has a good correlation with refractive index in a large concentration range, for example, in the range of 5 to 50%, and that taurine concentration can be discriminated and determined by using refractive index. The inventor finds through experiments that the coincidence degree of the detection data of the refractive index and the artificial acid-base titration method reaches more than 95%.

According to an embodiment of the present invention, the server 500 may be connected to at least one of the first refractive method concentration meter 140, the second refractive method concentration meter 240, the third refractive method concentration meter 340 and the fourth refractive method concentration meter 440 through wireless or wired communication, and specifically, the wireless communication may be wifi communication with a reverse monitoring design or 5G-based communication. Thereby ensuring the safety of data transmission. According to an embodiment of the present invention, when the server 500 acquires the corresponding detection information, the taurine production process may also be controlled based on the information. Specifically, the evaporation unit 100 according to an embodiment of the present invention includes a first heater, the neutralization unit 200 is provided with a neutralizing agent flow controller, the dissolution unit 300 is provided with a solvent flow controller, and the desalination unit 400 is provided with a second heater, so that the first heater, the neutralizing agent flow controller, the solvent flow controller, and the second heater can be regulated and controlled based on the detection results of the first refraction concentration meter 140, the second refraction concentration meter 240, the third refraction concentration meter 340, and the fourth refraction concentration meter 440 by connecting the server 500 to the first heater, the neutralizing agent flow controller, the solvent flow controller, and the second heater, respectively. Thus, the automatic control of taurine production can be realized. In addition, in order to facilitate remote control, the first heater according to the present invention includes a plurality of heating loads symmetrically disposed on the evaporation tank, and the server 500 symmetrically turns on or off at least a portion of the heating loads. Thus, temperature unevenness due to control of the heater can be avoided.

Of course, it will be appreciated by those skilled in the art that the process of purifying taurine may be combined with the process of preparing taurine. As previously described, the inventors of the present invention have unexpectedly found that taurine concentration has a good correlation with refractive index in a large concentration range, for example, in the range of 5 to 50%, and that taurine concentration can be discriminated and determined by using refractive index. And by adopting remote control equipment, the production process can be regulated and controlled. For example, referring to fig. 4, the taurine production system of the present invention can aggregate data of relevant taurine contents of a plurality of factories (factory 1, factory 2, factory 3, and factory 4, for example) and perform feedback and remote control by providing a cloud server.

In addition, the apparatus for synthesizing taurine according to the embodiment of the present invention is not particularly limited, and for example, an apparatus suitable for producing taurine from nitromethane as a raw material according to the embodiment of the present invention may be employed. The inventors found that common impurities in taurine solutions obtained by this apparatus do not interfere with the determination of taurine content by refractive index. Therefore, the method can be effectively applied to monitoring and automatic control of the concentration of taurine in the production process.

Other configurations, etc. and operations of the apparatus for preparing taurine according to the embodiments of the present invention are known to those of ordinary skill in the art, and will not be described in detail herein.

In connection with the industrial production of taurine, the scheme of the present invention will be explained below with reference to examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the present invention and should not be construed as limiting the scope of the invention. The examples are not to be construed as limiting the specific techniques or conditions described in the literature in this field or as per the specifications of the product. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

In the industrial production of taurine, it is generally involved that taurine is obtained by an addition reaction, an ammonolysis reaction, and the desired taurine is obtained by a purification process including an evaporation drying process, a neutralization process, a dissolution process, and a desalting process. In the addition reaction, by-product glycol and polyethylene glycol are generated, and the by-product glycol can accumulate in a reaction system after addition; during the ammonolysis reaction, by-product ethanolamine, polyethanolamine and sodium isethionate which are not reacted are generated, and the by-product ethanolamine, polymers and derivatives thereof and the sodium isethionate are accumulated in a system after the ammonolysis reaction; in the evaporation drying treatment process, the byproducts are glycol and derivatives and polymers thereof, ethanolamine and polymers and derivatives thereof and sodium isethionate in addition reaction and ammonolysis reaction; the neutralization treatment can generate sodium sulfate as a byproduct, and the content of the sodium sulfate as a byproduct in the mother solution can be reduced along with the increase of desalination times; generating glycol and polymer and derivative thereof, ethanolamine and polymer and derivative thereof, sodium isethionate, sodium sulfate and the like after desalination treatment; the main impurity after dissolution treatment is sodium sulfate (content is about 5%). The examples presented demonstrate the solution provided by the present invention by modeling the composition of the solution in industrial production, and combining the composition of the solution in actual industrial production.

Example 1

Example 1 a preliminary standard curve was prepared using taurine comprising the steps of:

weighing 40g taurine and 60g ultrapure water accurately by a balance, preparing the weighed sodium taurine and ultrapure water into a 250ml beaker, stirring uniformly, preparing a pure taurine solution with the mass concentration percentage of 40w percent, dividing the solution into 20 parts, wherein each part is 5g by mass and is respectively numbered as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20, and deionized water 47.5g, 45g, 42.5g, 40g, 37.5g, 35g, 32.5g, 30g, 27.5g, 25g, 22.5g, 20g, respectively in pure taurine solutions numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 17.5g, 15g, 12.5g, 10g, 7.5g, 5g, 2.5g diluting taurine solution by 10.5 accompany, 10 accompany, 9.5 accompany, 9 accompany, 8.5 accompany, 8 accompany, 7.5 accompany, 7 accompany, 6.5 accompany, 6 accompany, 5.5 accompany, 5 times, 4.5 accompany, 4 times, 3.5 accompany, 3 times, 2.5 accompany, 2 times, 1.5 accompany, the content of taurine solution is 3.9%, 4%, 4.2%, 4.4%, 4.7%, 5%, 5.3%, 5.7%, 6.2%, 6.7%, 7.3%, 8%, 8.9%, 10%, 11.4%, 13.3%, 16%, 20%, 26.7%, respectively, and a standard curve of pure taurine solution is established according to the concentration of pure taurine solution and the corresponding refractive index value, thus obtaining a preliminary standard curve.

Example 2

Example 2 the preliminary standard curve obtained in example 1 was corrected in connection with the composition of the solution passing through the evaporation unit, comprising:

according to the impurity content components of the evaporation station, accurately weighing 24g of glycol, 30 ethanolamine, 60g of isethionic acid, 10g of sodium sulfate, 105g of taurine and 71g of ultrapure water by a balance, preparing the weighed sodium taurine and ultrapure water into a 500ml beaker, uniformly stirring, preparing an aqueous solution of ethylene glycol with the percentage content of 8%, 10% of ethanolamine, 20% of sodium isethionate, 10% of sodium sulfate and 35% of taurine, equally dividing the solution into 15 parts, wherein the mass of each part is 20g, and the parts are respectively marked as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15, and diluting the solution by multiple, namely adding 155g, 96.7g, 67.5g, 50.0g, 38.3g, 30g, 23.8g, 18.9g, 15g, 11.8g, 9.2g, 6.9g, 5.4g, 3.4g and 1.9g of ultrapure water into the solution with the marks of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 respectively, so that the taurine content in the solution is diluted to 4%, 6%, 8%, 10%, 12, 14, 16, 18, 20%, 22%, 24%, 26%, 28, 30 and 32 respectively, measuring the refractive index value of the solution with the simulated evaporation positions and known by using a refractometer, and drawing a standard curve; the standard curve of the refractometer under the condition of the simulated evaporation station containing impurities was corrected by combining the standard curve of the pure sodium taurine solution prepared in the example 1, and the corrected standard curve was obtained.

Example 3

Example 3 provides an on-site taurine content on-line detection simulation experiment, comprising the following steps:

as shown in table 1 below, weighing taurine, ethylene glycol, sodium isethionate, sodium sulfate and ethanolamine by a balance, adding into deionized water, dissolving, stirring uniformly, preparing taurine solution with known mass concentration, measuring by adopting two different methods of titration and refractometer detection, establishing an online simulation experiment, checking the accuracy of instrument measurement, simulating a concentration curve, and obtaining the results shown in table 1 below and fig. 5:

table 1 on-line taurine content simulation experiment record table and measurement results

As can be readily seen from Table 1 and FIG. 5, accurate results were obtained by examining the taurine solution containing the impurities by the refraction method. And the R value of the refraction method can reach 0.95 through calculation, almost no accidental error exists, the R value detected by titration is about 0.90, and the accidental error is larger.

Example 4

Example 4 provides an on-site sodium taurate content on-line detection simulation experiment in combination with evaporation station solution components, comprising the following steps:

as shown in table 2 below, weighing and metering sodium taurate, ethylene glycol, sodium isethionate, sodium sulfate and ethanolamine by a balance, adding into a certain amount of deionized water, dissolving, stirring uniformly, simulating the content change of each impurity in an evaporation station, preparing taurine solution with known mass concentration, measuring by adopting a titration method and a refractometer by two different methods, establishing an online simulation experiment, checking the measurement accuracy of the instrument, simulating the taurine content change curve, and recording the results shown in table 2 and fig. 6 below:

Table 2 simulation experiment record table for on-line detecting sodium taurine content

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As can be readily seen from Table 2 and FIG. 6, accurate results were obtained by examining the sodium taurate solution containing impurities by the refraction method. And the R value of the refraction method can reach 0.95 through calculation, almost no accidental error exists, the R value detected by titration is about 0.90, and the accidental error is larger.

Example 5

Example 5 provides an on-site taurine content on-line detection simulation experiment in combination with components of a dissolution station solution, comprising the following steps:

as shown in table 3 below, weighing taurine, ethylene glycol, sodium isethionate, sodium sulfate and ethanolamine by a balance, adding into the measured deionized water, dissolving, stirring uniformly, simulating the impurity content change of the site dissolving station, preparing taurine solution with known content, measuring the taurine solution by adopting a titration method and a refractometer by two different methods, establishing an online simulation experiment, checking the measurement accuracy of the instrument, simulating the taurine content change curve, and recording the results shown in table 3 below and fig. 7:

table 3 on-line taurine content simulation experiment record table

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As can be readily seen from Table 3 and FIG. 7, accurate results were obtained by examining the taurine solution containing the impurities by the refraction method. The R value of the refraction method can reach 0.95 through calculation, almost no accidental error exists, the R value detected by titration is about 0.90, and the accidental error is larger.

Example 6

Example 6 in combination with the components of the desalination station solution, an on-site taurine content on-line detection simulation experiment is provided, comprising the following steps:

as shown in table 4 below, the above-mentioned materials are added into water to dissolve, and uniformly stirred, so that a solution with known taurine content is prepared, and two different methods of titration and refractometer detection are adopted to measure the taurine content, an on-line simulation experiment is established, the accuracy of instrument measurement is checked, and a concentration curve is simulated, and the recorded results are shown in table 4 below and fig. 8:

table 4 on-line taurine content simulation experiment record table

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As can be seen from Table 4 and FIG. 8, the detection of the above-mentioned taurine solution containing impurities by the refraction method can obtain accurate results. The R value of the refraction method can reach 0.95 through calculation, almost no accidental error exists, the R value detected by titration is about 0.90, and the accidental error is larger.

Example 7

For different batches of solution from the evaporation station during taurine purification, example 7 provides an on-line detection method for taurine content of the solution by using a refractometer, and titration analysis is performed.

Installing a calibrated online taurine content detection refractometer at an evaporation station, recording concentration change values on the refraction meter, arranging different QC analysts at the evaporation station, sampling on site for titration analysis, and recording, calculating and finishing data. And comparative analysis of the data simulated curves as shown in table 5 and fig. 9 below:

table 5 recording table for on-line detection and titration detection of taurine content of different batches by evaporation station refractometer

/>

As can be seen from Table 5 and FIG. 9, accurate results were obtained by examining taurine-containing solutions from the evaporation sites by refraction.

Example 8

For solutions from different times of evaporation during taurine purification, example 8 provides an on-line method for detecting taurine content of the solution by using a refractometer, and titration analysis is performed.

Installing the calibrated on-line concentration detection refractometer at an evaporation station, recording concentration change values on the refractometer, arranging different QC analysts at the evaporation station, sampling on site for titration analysis, and recording, calculating and finishing data. And comparative analysis of the data simulated curves as shown in table 6 and fig. 10:

TABLE 6 Evaporation station evaporator inline continuous detection and titration analysis content recording Table

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As can be seen from Table 6 and FIG. 10, accurate results were obtained by examining taurine-containing solutions from the above evaporation stations at different times by refraction.

Example 9

For different batches of solution from the dissolution station during taurine purification, example 9 provides an on-line method for detecting taurine content of the solution by using a refractometer, and titration analysis is performed.

Installing a calibrated on-line content detection refractometer at a dissolution station, recording content variation values on the refractometer, arranging different QC analysts at the dissolution station, sampling, performing taurine content titration analysis, and recording, calculating and finishing data. And comparative analysis of the data simulated curves as shown in table 7 and fig. 11 below:

table 7 recording table for on-line detection and titration detection of taurine content by dissolution station refractometer

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As can be seen from Table 7 and FIG. 11, the above taurine-containing solutions from the dissolution stations were examined by refraction method, and accurate results were obtained.

Example 10

Example 10 provides an on-line method for detecting taurine content of a solution by using a refractometer for different batches of the solution from a desalting station in the taurine purification process, and simultaneously performing titration analysis.

Installing the calibrated on-line concentration detection refractometer at one desalting station, recording concentration change values on the refractometer, arranging different QC analysts at the desalting station, sampling in time for titration analysis, and recording, calculating and arranging data. And a comparative analysis was performed on the data simulation curves, as shown in table 8 below and in fig. 12:

table 8 on-line detection and titration detection table for taurine sodium content by primary desalination position refractometer

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As can be seen from Table 8 and FIG. 12, the above-mentioned taurine solution from the primary desalting station was examined by the refraction method, and accurate results were obtained.

Example 11

For different batches of solution from the secondary desalting station during taurine purification, example 11 provides an on-line method for detecting taurine content of the solution by using a refractometer, and titration analysis is performed.

And installing the calibrated on-line concentration detection refractometer at a secondary desalting station, recording concentration change values on the refractometer in real time in the production process, arranging different QC analysts at the desalting station, sampling in time for titration analysis, recording calculation data and arranging data. And comparative analysis was performed on the data simulation curves as shown in table 9 below and in fig. 13:

Table 9 recording table for on-line detection and titration detection of taurine content by secondary desalination station refractometer

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As can be seen from Table 9 and FIG. 13, the detection of the taurine solution from the secondary desalting station by the refraction method can obtain accurate results.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method of purifying taurine comprising:

(1) Neutralizing a solution containing taurine or a salt thereof, and carrying out solid-liquid separation, wherein the solution containing taurine or a salt thereof is prepared by an ethanolamine or ethylene oxide method;

(2) Dissolving the obtained solid product; and

(3) Desalting the neutralized liquid product and/or the solubilized product to obtain purified taurine,

at least one of the step (1), the step (2) and the step (3) comprises taurine content detection, the adopted solution to be detected consists of taurine or salts thereof and a background solution, and the taurine content detection method comprises the following steps:

1) Preparing a simulation solution capable of simulating the refractive index of the background solution, adding different amounts of taurine into the simulation solution, respectively measuring the refractive index of the simulation solution, and establishing a standard curve of the taurine content relative to the refractive index based on the refractive index of the simulation solution and the refractive index of the simulation solution added with different amounts of taurine;

2) Measuring the refractive index of the solution to be measured, and obtaining the content of taurine or the salt thereof corresponding to the refractive index from the standard curve;

The solution to be tested contains ethylene glycol, sodium isethionate, sodium sulfate and ethanolamine, and contains no more than 20 mass percent of ethylene glycol, or no more than 35 mass percent of sodium isethionate, or no more than 10 mass percent of sodium sulfate, and no more than 10 mass percent of ethanolamine;

the refractometer is provided with a probe with an optical prism;

the optical prism is made of diamond containing boron element;

and a self-cleaning device is arranged around the optical prism.

2. The method of claim 1, wherein the simulated solution has a refractive index deviation from the background solution of no more than 10%.

3. The method of claim 1, wherein the simulated solution has a refractive index deviation from the background solution of no more than 5%.

4. The method of claim 1, wherein the simulated solution has a refractive index deviation of no more than 2% from the background solution.

5. The method of claim 1, wherein the simulated solution is prepared from all solutes in the background solution that are present in an amount of at least 10% by weight or more dissolved in a solvent used in the background solution.

6. The method of claim 1, wherein the simulated solution is prepared from all solutes in the background solution that are present in an amount of at least 5% by weight or more dissolved in a solvent used in the background solution.

7. The method of claim 1, wherein the simulated solution is prepared from all solutes in the background solution that are present in an amount of at least 2% by weight or more dissolved in a solvent used in the background solution.

8. The method of claim 1, wherein the simulated solution is prepared from a solvent used in the background solution in which at least 1% by weight of all solutes in the background solution are dissolved.

9. The method of claim 1, wherein the specific step of determining the refractive index of the standard or test taurine solution comprises:

placing a probe with an optical prism on a refractometer into the taurine solution;

detecting a critical angle of an incident light source;

and determining the refractive index of the taurine solution according to the critical angle.

10. The method of claim 1, wherein the refractometer has electronic components mounted thereon with computing capabilities.

11. The method according to claim 1, wherein the solution to be tested contains not less than 10 mass% of the taurine or a salt thereof.

12. The method according to claim 1, wherein the solution to be tested contains not less than 5% by mass of the taurine or a salt thereof.

13. The method according to claim 11, wherein, before the step (1), a solution containing taurine or a salt thereof is subjected to an evaporation drying treatment, and a product subjected to the evaporation drying treatment is subjected to a neutralization treatment.

14. A method for on-line detection of taurine content, characterized in that the taurine content detection is performed in at least one of the following steps (1) to (4),

(1) In the evaporation drying treatment process of the taurine-containing solution, wherein the taurine-containing solution is prepared by an ethanolamine or ethylene oxide method;

(2) The product after the evaporation drying treatment is subjected to neutralization treatment;

(3) The solid product after the neutralization treatment is dissolved in the process of treatment; and

(4) The liquid product after the neutralization treatment and the product after the dissolution treatment are subjected to a desalination treatment process;

the adopted solution to be detected consists of taurine or salts thereof and background solution, and the taurine content detection method comprises the following steps:

2) Measuring the refractive index of the solution to be measured, and obtaining the content of taurine or the salt thereof corresponding to the refractive index from the standard curve; the end point of each production step and the running condition of each production step are judged through the detection result;

the refractometer is provided with a probe with an optical prism;

the optical prism is made of diamond containing boron element;

and a self-cleaning device is arranged around the optical prism.

15. The method of claim 14, wherein the simulated solution has a refractive index deviation from the background solution of no more than 10%.

16. The method of claim 14, wherein the simulated solution has a refractive index deviation from the background solution of no more than 5%.

17. The method of claim 14, wherein the simulated solution has a refractive index deviation of no more than 2% from the background solution.

18. The method of claim 14, wherein the simulated solution is prepared from all solutes in the background solution that are present in an amount of at least 10% by weight or more dissolved in a solvent used in the background solution.

19. The method of claim 14, wherein the simulated solution is prepared from all solutes in the background solution that are present in an amount of at least 5% by weight or more dissolved in a solvent used in the background solution.

20. The method of claim 14, wherein the simulated solution is prepared from all solutes in the background solution that are present in an amount of at least 2% by weight or more dissolved in a solvent used in the background solution.

21. The method of claim 14, wherein the simulated solution is prepared from a solvent used in the background solution having at least 1% by weight of all solutes in the background solution dissolved therein.

22. The method of claim 14, wherein the specific step of determining the refractive index of the standard or test taurine solution comprises:

detecting a critical angle of an incident light source;

23. The method of claim 14, wherein the refractometer has electronic components mounted thereon with computing capabilities.

24. The method according to claim 14, wherein the solution to be tested contains not less than 10 mass% of the taurine or a salt thereof.

25. The method according to claim 14, wherein the solution to be tested contains not less than 5% by mass of the taurine or a salt thereof.

26. The method according to claim 14, wherein in the steps (1) to (4), the results of the detection are input to a server, respectively, and the server controls at least one of the evaporation drying process, the neutralization process, the dissolution process, and the desalination process based on the results of the detection.

27. The method according to claim 14, wherein in the process of performing the taurine content detection, a process temperature determination is performed, and correction of taurine content is performed based on the process temperature.