WO2021128917A1

WO2021128917A1 - Continuous ammonolysis reaction system, preparation method for taurine alkali metal salt and taurine

Info

Publication number: WO2021128917A1
Application number: PCT/CN2020/112059
Authority: WO
Inventors: 徐淞华; 吴晓东; 何孝祥; 姚祥华; 彭俊华; 邱贵生
Original assignee: 浙江新和成药业有限公司; 上虞新和成生物化工有限公司
Priority date: 2019-12-27
Filing date: 2020-08-28
Publication date: 2021-07-01
Also published as: CN113045458A; CN113045458B

Abstract

Provided are a continuous ammonolysis reaction system, and a method for preparing taurine alkali metal salt and taurine using the continuous ammonolysis reaction system. The continuous ammonolysis reaction system comprises a high-pressure reaction device, the high-pressure reaction device comprises n ammoniating autoclaves, n≥2, the first ammoniating autoclave to the nth ammoniating autoclave are connected in series in sequence, the ammoniating autoclave is a vessel for the ammonolysis reaction, the ammonolysis reaction uses ammonia as an ammoniating agent, the first ammoniating autoclave is connected with a feeding device, the first ammoniating autoclave to the nth ammoniating autoclave are all connected with a first feed pipe, each ammoniating autoclave is connected with a second feed pipe; a buffer device, the buffer device is connected with the nth ammoniating autoclave, which is used to receive the mixed materials after the ammonolysis reaction in the first ammoniating autoclave to the nth ammoniating autoclave; a flashing device, the flashing device is connected with the buffer device, which is used to receive the mixed materials in the buffer device and obtain the ammonolysis product by means of flashing.

Description

Continuous ammonolysis reaction system, taurine alkali metal salt and preparation method of taurine

Related application

This application claims the priority of the Chinese patent application filed on December 27, 2019, the application number is 201911380161.7, and the invention title is "Continuous Ammoniolysis Reaction System, Taurine Alkali Metal Salt and Preparation Method of Taurine", The entire content is incorporated into this application by reference.

Technical field

This application relates to the technical field of taurine, in particular to a continuous ammonolysis reaction system, an alkali metal salt of taurine and a preparation method of taurine.

Background technique

Taurine, also known as β-aminoethanesulfonic acid, is a sulfur-containing non-protein amino acid. It is widely used in the fields of medicine, food additives, fluorescent whitening agents, organic synthesis, etc. The preparation methods include ethylene oxide method, cattle The ammonium sulfonate method, the monoethanolamine method and the ethanol method, etc.

Among them, the ethylene oxide method is the main method for preparing taurine at present, and among the ethylene oxide method, the ammonolysis reaction is the most studied, mainly because: first, sodium isethionate is at high temperature and high pressure. When carrying out the ammonolysis reaction in the reaction system, it is easy to produce by-products such as sodium ditaurate, which seriously affects the yield of the target product sodium taurate and the conversion rate of sodium isethionate; second, sodium ditaurate, etc. By-products and residual sodium isethionate, due to their high solubility in water, most of them remain in the mother liquor after acidification and separation. How to deal with the sodium isethionate and sodium ditaurate in the mother liquor The by-product, sodium sulfate, becomes a thorny issue.

Ammonialysis reaction equation:

Main reaction

side effects

The batch tank process is the most commonly used industrial ammonolysis operation mode at present. The method is mature and reliable in technology, stable in operation, and the reaction yield is about 77%-80%. However, its shortcomings are: 1. In order to ensure the yield and selectivity of sodium taurate, the ammonia in the reaction system should be far excessive, so that the sodium isethionate and ammonia put into the ammoniation kettle, both The molar ratio is between 1:(10-30). 2. With the progress of the amination reaction, the concentration of ammonia and sodium isethionate in the material gradually decreases, the driving force of the reaction becomes smaller, and a longer reaction time needs to be maintained, which reduces the production efficiency. 3. Intermittent kettle-type technology has low single-batch output and long production cycle. And intermittent production, high energy consumption, low efficiency, small equipment capacity, large recovery of ammonia, high ammonia consumption.

The traditional technology also transforms the production method of high-pressure reactor batch operation into pipelined continuous operation. For example, Zhu Shengdong disclosed the taurine ammoniation reaction pipeline technology in "Chemical Science and Technology" 2001, Vol. 9, No. 3, which is After 25% aqueous ammonia solution is mixed with 35% sodium hydroxysulfonate aqueous solution and a small amount of catalyst, it is pressurized from the storage tank to 18MPa-20MPa by the high-pressure corrosion-resistant pump, and then heated to 280℃ by the preheater, and then enters the tubular reaction The reactor is reacted in a tubular reactor for 30 minutes, and the reacted materials are continuously flowed out, and the pressure is reduced and flashed to obtain the ammonolysis product. Pipeline continuous operation has the characteristics of strong production capacity, short process cycle, and good stability. However, the operating conditions of this method are harsh. The equipment not only has to withstand high operating temperature, but also withstand the high pressure load of fluid, and it is also accompanied by ammonia, etc. Erosion of corrosive media. At the same time, due to the short residence time of the reaction, the pressure and temperature are too high, and the coking of the material is serious. In addition, the heat utilization rate of the system is low. In the early stage, the material should be heated to 100-200°C before the reaction. The heat released by the reaction needs to be removed.

Summary of the invention

According to various embodiments of the present application, a continuous ammonolysis reaction system, an alkali metal salt of taurine, and a preparation method of taurine are provided. The continuous ammonolysis reaction system includes:

A high-pressure reaction device, the high-pressure reaction device includes n ammoniating autoclaves, n≥2, the first ammoniating autoclave to the nth ammoniating autoclave are connected in series in sequence, and the ammoniating autoclave is A container for the ammonolysis reaction, wherein the ammonolysis reaction uses ammonia as an ammoniating agent, the first ammoniating autoclave is connected with a feeding device, the first ammoniating autoclave to the nth ammoniating The autoclaves are all connected with a first feed pipe, and each of the ammoniated autoclaves is connected with a second feed pipe;

A buffer device, which is connected to the n-th ammoniating autoclave, and is used to receive the mixture material after the ammoniation reaction in the first to the n-th ammoniating autoclaves;

A flashing device, the flashing device is connected with the buffering device, and is used to receive the mixed material in the buffering device and obtain an ammonolysis product through flashing.

In the above continuous ammonolysis reaction system, multiple ammonification autoclaves used for batch reactions are connected in series, and when multiple ammonification autoclaves are used for the ammonolysis reaction at the same time, the pressure and pressure corresponding to the kettle-type batch reaction can be ensured. The temperature and residence time can reach the capacity of pipeline continuous reaction. Moreover, in the above-mentioned continuous ammonolysis reaction system, the feeding device is used for feeding and starting the reaction, the first feeding pipe is used to supplement the ammonia consumed in the ammonolysis reaction process, and the second feeding pipe is used to provide ammonia to the ammonification autoclave. The raw materials to be reacted in the decomposition reaction, such as alkali metal isethionate, etc., so that the ammonia can be reacted with the to-be-reacted during each ammonolysis reaction through the feeding device, the first feeding pipe and the second feeding pipe. The molar ratio of the raw materials reaches a maximum value, and the occurrence of side reactions is suppressed, thereby improving the yield of the target product and the conversion rate of the raw materials.

In one of the embodiments, the feeding device is used to introduce an ammonia source for the ammonolysis reaction, the first feeding pipe is used to supplement the ammonia consumed in the ammonolysis reaction process, and the second feeding pipe is used to provide ammonia Decompose the raw materials to be reacted required for the reaction.

In one of the embodiments, the continuous ammonolysis reaction system further includes an ammonia recovery device, the ammonia recovery device is connected to the flash evaporation device, and the ammonia recovery device is used to recover Ammonia, get recycled ammonia.

In one of the embodiments, the ammonia recovery device is also connected to the feed device to deliver the recovered ammonia to the feed device.

In one of the embodiments, the continuous ammonolysis reaction system further includes an adjustment device, the adjustment device is connected in series with the nth ammoniating autoclave, the buffer device is connected in series with the adjustment device, and the The adjustment device is a vessel for the ammonolysis reaction.

In one of the embodiments, the adjustment device is connected with a first feed pipe.

A preparation method of taurine alkali metal salt, the preparation method adopts the above-mentioned continuous ammonolysis reaction system, and the preparation method includes the following steps:

(1) Provide ammonia water to the first ammoniating autoclave through the feeding device, so that each ammoniating autoclave connected in series is filled with ammonia water;

(2) Under the reaction temperature and reaction pressure, the feeding device is used to provide ammonia water to the first ammoniating autoclave, and the first ammoniating autoclave is supplied to the first ammoniating autoclave through the first feeding pipe. n sets of the ammoniating autoclaves provide an ammonia source, and each of the ammoniating autoclaves is provided with an isethionate alkali metal salt solution through the second feed pipe, so that each of the ammoniating autoclaves All carry out the ammonolysis reaction and make the reaction liquid enter the buffer device in a series sequence to obtain a mixed material;

(3) After the pressure of the buffer device and the n-th ammoniating autoclave is balanced, stop the feeding device to provide ammonia to the first ammoniating autoclave, and stop the first feeding pipe to supply ammonia to the first ammoniating autoclave. The first ammoniating autoclave to the nth ammoniating autoclave provide ammonia source, and the second feed pipe is stopped to provide alkali metal isethionate solution to each of the ammoniating autoclaves , And make the mixture material in the buffer device enter the flash evaporation device;

(4) After the pressures of the flashing device and the buffering device are balanced, stop the mixed material in the buffering device from entering the flashing device;

(5) Depressurizing and flashing the mixture in the flashing device to obtain an ammonolysis product, and the ammonolysis product includes an alkali metal salt of taurine.

When the continuous ammonolysis reaction system of the present application is used to prepare the alkali metal salt of taurine, the alkali metal isethionate enters the system through the second feed pipe, and the instantaneous concentration of the alkali metal isethionate in the system is low , Make the reaction molar ratio of ammonia and isethionate alkali metal salt reach the maximum value, can greatly reduce the production of by-products such as alkali metal salt of ditaurine, and make the yield of alkali metal salt of taurine reach 90 % Above, the conversion rate of alkali metal isethionate exceeds 95%. Moreover, the process is safe and stable, the product composition is stable, and the reproducibility is high.

In one of the embodiments, in step (1), the volume of ammonia in the ammoniating autoclave is 60%-90% of the volume of the ammoniating autoclave.

In one of the embodiments, in step (2), the ammonia source includes liquid ammonia.

In one of the embodiments, in step (2), the feeding device provides ammonia to the first ammoniated autoclave at a rate of 6.0m ³ /h-10.0m ³ /h, and the first inlet The feed pipe provides ammonia source from the first ammoniated autoclave to the nth ammoniated autoclave at a rate of 0.1m ³ /h-0.2m ³ /h, and the second feed pipe 1. The rate at which the ammoniated autoclave provides the alkali metal isethionate solution is 0.1m ³ /h-0.3m ³ /h.

In one of the embodiments, in step (2), the second feed pipe provides the isethionate alkali metal salt solution to each of the ammoniated autoclaves by dripping.

In one of the embodiments, in step (2), each of the ammoniated autoclaves is subjected to the ammonolysis reaction, and the reaction liquid enters the adjustment device in a series sequence, and then enters the buffer through the adjustment device. Device to obtain a mixture of materials.

In one of the embodiments, step (2) further includes providing an ammonia source to the adjusting device in a continuous or intermittent manner through the first feed pipe.

In one of the embodiments, in step (5), the ammonia after the depressurization flash vaporization is also recovered by the ammonia recovery device to obtain recovered ammonia.

In one of the embodiments, the recovered ammonia is provided to the feeding device.

In one of the embodiments, when step (5) is performed, step (2) is restarted.

A preparation method of taurine, the preparation method comprising the preparation method of the alkali metal salt of taurine, and

(6) Acidifying and separating the ammonolysis product to obtain a solid product and mother liquor;

(7) Crystallize the solid product to obtain taurine.

When the ammonolysis product prepared by the continuous ammonolysis reaction system of the present application is used to continue the preparation of taurine, the ammonolysis product is mainly taurine alkali metal salt, isethionate alkali metal salt, and ditaurine The content of the alkali metal salt and the alkali metal salt of tritaurine is extremely low. Therefore, after the mother liquor is separated, there is no need to recycle the mother liquor, which simplifies the process and makes the process safer, more stable and reliable.

In one of the embodiments, it further includes destroying the mother liquor in step (6).

Description of the drawings

In order to better describe and illustrate the embodiments and/or examples of the inventions disclosed herein, one or more drawings may be referred to. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed invention, the currently described embodiments and/or examples, and the best mode of these inventions currently understood. .

Figure 1 is a schematic diagram of the continuous ammonolysis reaction system of the application.

Figure 2 is a schematic diagram of the taurine production process of the application.

In the figure: 10, feeding device; 20, high pressure reaction device; 30, buffer device; 40, flashing device; 50, ammonia recovery device; 60, first feeding pipe; 70, second feeding pipe; 80, Acidification device; 90, separation device; 100, mother liquor recovery device; 110, incinerator; 120, crystallization device; 130, adjustment device; 200, ammoniated autoclave.

Detailed ways

The continuous ammonolysis reaction system, the alkali metal salt of taurine and the preparation method of taurine provided in the present application will be further described below.

Please refer to Figure 1, the continuous ammonolysis reaction system provided for this application, the continuous ammonolysis reaction system is used to carry out the ammonolysis reaction to generate the target product, improve the yield of the target product and the conversion rate of the raw materials to be reacted, and Improve the productivity, safety, stability and reliability of the process.

In one or more embodiments, the continuous ammonolysis reaction system includes a high-pressure reaction device 20, a buffer device 30, and a flashing device 40 connected in series in sequence.

Wherein, the high pressure reaction device 20 includes n ammoniating autoclaves 200, the first ammoniating autoclave 200 to the nth ammoniating autoclave 200 are connected in series in sequence, and the ammoniating autoclave 200 is ammonia. A vessel for the hydrolysis reaction, in which ammonia is used as the ammoniating agent in the ammonolysis reaction. Therefore, when multiple ammoniating autoclaves 200 connected in series are simultaneously used for the ammonolysis reaction, the pressure, temperature and maintenance time corresponding to the kettle-type batch reaction can be ensured, and the pipeline-type continuous reaction production capacity can be achieved. Moreover, since multiple ammoniating autoclaves 200 are connected in series to form a large-volume high-pressure reactor, the advantage of continuous reaction production capacity can prolong the residence time of the raw materials to be reacted, so that the raw materials to be reacted can fully react and reduce the reaction time. Conditional requirements.

In the high-pressure reaction device 20, two or more ammoniating autoclaves 200 can be connected in series to meet the requirements of use, that is, n≥2. Considering the production capacity of the continuous reaction, the yield of the target product and the conversion rate of the raw materials, it is preferable to use three to eight ammoniating autoclaves 200 in series, and it is more preferable to use six ammoniating autoclaves 200 in series.

In one or more embodiments, the volume of the ammoniated autoclave is 0.5 m ³ -5 ^{m 3} .

In one or more embodiments, the first ammoniating autoclave 200 is connected to the feeding device 10, and the first ammoniating autoclave 200 to the nth ammoniating autoclave 200 are all connected to The first feed pipe 60 is connected with a second feed pipe 70 to each of the ammoniated autoclaves 200.

Wherein, the feeding device 10 is used to introduce an ammonia source for the ammonolysis reaction, such as ammonia water, the first feeding pipe 60 is used to supplement the ammonia consumed in the ammonolysis reaction process, such as liquid ammonia, and the second inlet The feed pipe 70 is used to provide the raw materials to be reacted required for the ammonolysis reaction, such as alkali metal isethionate, etc., so that it can pass through the feed device 10, the first feed pipe 60 and the second feed pipe 70. Precise control makes the molar ratio of ammonia to the raw material to be reacted in each ammonolysis reaction process reach a maximum value, thereby increasing the yield of the target product and the conversion rate of the raw material to be reacted.

In one or more embodiments, the buffer device 30 is connected to the n-th ammoniating autoclave 200, and is used to receive the ammoniation reaction in the first to n-th ammoniating autoclaves 200 Mixture of materials. The pressure difference between the first ammoniating autoclave 200 and the n-th ammoniating autoclave 200 is very small. Therefore, the pressure difference between the n-th ammoniating autoclave 200 and the buffer device 30 can be used. The pressure difference caused by the reaction liquid in the ammoniated autoclave 200 flows in a series sequence and enters the buffer device 30. Therefore, the input and output of the ammonification autoclave 200 can be controlled by the buffer device 30 to improve the safety of the continuous ammonolysis reaction system, so that the continuous ammonolysis reaction system of the present application can operate continuously to realize continuous production.

Since the pressure difference between the n-th ammoniating autoclave 200 and the buffer device 30 will cause the unreacted ammonia source or the incompletely reacted reaction solution to enter the buffer device 30 in advance, the buffer device 30 There is also a discharge pipe to remove the poorly collected mixture.

In specific use, after the ammonolysis reaction in the ammonification autoclave 200 has progressed for a certain period of time or after the ammonolysis reaction has stabilized, the discharge pipe of the buffer device 30 is opened to remove the poorly collected mixture materials, and then the discharge pipe is closed Re-collection is carried out to obtain a mixture of materials.

In one or more embodiments, the flashing device 40 is connected to the buffering device 30 for receiving the mixed material in the buffering device 30 and for flashing to obtain the ammonolysis product.

In specific use, when the pressures of the buffer device 30 and the n-th ammoniating autoclave 200 are balanced, the feed valve of the buffer device 30 is closed, the discharge valve is opened, and the mixture in the buffer device 30 uses the pressure difference to enter the flash vaporizer. In the device 40, at this time, the feeding of the ammonification autoclave 200 is stopped to suspend the progress of the ammonolysis reaction. After the pressures of the buffer device 30 and the flashing device 40 are balanced, the discharge valve of the buffer device 30 is closed and the feed valve is opened. At this time, the feed of the ammoniating autoclave 200 is reopened to restart the ammonolysis reaction. Continue to circulate accordingly to achieve continuous production.

In one or more embodiments, the feed valve and the discharge valve of the buffer device 30 may be automatically controlled by an automatic shut-off valve.

When the mixed material is flashed in the flashing device 40, in addition to the ammonolysis product, an excessive amount of ammonia is also obtained. In one or more embodiments, the continuous ammonolysis reaction system further includes an ammonia recovery device 50, the ammonia recovery device 50 is connected to the flashing device 40, and the ammonia recovery device 50 is used to recover the plant. The ammonia in the flash vaporizer 40 is recovered ammonia, and the recovered ammonia may be liquid ammonia or ammonia water.

In one or more embodiments, the ammonia recovery device 50 is also connected to the feed device 10 to transport the recovered ammonia to the feed device 10 for recycling, so as to reduce the additional supplementation and liquidity of ammonia. The use of ammonia reduces production costs.

When the continuous ammonolysis reaction system of the present application is in use, the reaction time of each ammonification autoclave 200 is determined by the number, volume, and flow rate of the raw materials of the ammonification autoclave 200 connected in series. The ammonolysis reaction is continuously carried out, so that the unreacted raw materials to be reacted in the last ammoniated autoclave 200 can be completely reacted in the discharge time, until the raw materials to be reacted in the nth ammoniated autoclave 200 are completely reacted. The reaction is carried out and the material is discharged to the buffer device 30 to obtain a mixed material.

When there are unreacted raw materials to be reacted in the n-th ammoniating autoclave 200, these unreacted raw materials to be reacted cannot use the time of discharging to complete the reaction. Therefore, in order to ensure that the raw materials to be reacted in the n-th ammoniating autoclave 200 can be completely reacted, the input amount of the raw materials to be reacted in the n-th ammoniating autoclave 200 can be reduced.

Alternatively, the continuous ammonolysis reaction system further includes an adjusting device 130, which is connected in series to the n-th ammoniating autoclave 200, and the buffer device 30 is connected in series to the adjusting device 130. The adjusting device 130 is a container for the ammonolysis reaction, so that the unreacted raw materials to be reacted in the n-th ammoniating autoclave 200 are reacted in the adjusting device 130.

In order to enable the unreacted raw materials to be reacted in the n-th ammoniated autoclave 200 to complete the reaction in the adjusting device 130, the adjusting device 130 is also connected with a first feeding pipe 60 for feeding the adjusting device 130 Replenish the ammonia consumed during the ammonolysis reaction.

Please continue to refer to FIG. 1, this application also provides a method for preparing an alkali metal salt of taurine. The preparation method adopts the above-mentioned continuous ammonolysis reaction system, and the preparation method includes the following steps:

(1) Supplying ammonia water to the first ammoniating autoclave 200 through the feeding device 10, so that each ammoniating autoclave 200 connected in series is filled with ammonia water;

(2) Under the reaction temperature and reaction pressure, the feed device 10 supplies ammonia water to the first ammoniated autoclave 200, and sends ammonia water to the first ammoniated autoclave through the first feed pipe 60. The kettle 200 to the n-th ammoniating autoclave 200 provide an ammonia source, and each of the ammoniating autoclave 200 is provided with an isethionate alkali metal salt solution through the second feed pipe 70, so that each One of the ammoniated autoclaves 200 are all subjected to an ammonolysis reaction, and the reaction liquid enters the buffer device 30 in a series sequence to obtain a mixture of materials;

(3) After the pressures of the buffer device 30 and the n-th ammoniating autoclave 200 are balanced, the feeding device 10 is stopped to supply ammonia to the first ammoniating autoclave, and the first feeding is stopped. The feed pipe 60 provides an ammonia source to the first ammoniated autoclave 200 to the nth ammoniated autoclave 200, and the second feed pipe 70 is stopped to provide hydroxyl to each of the ammoniated autoclaves 200. Ethyl sulfonic acid alkali metal salt solution, and the mixture material in the buffer device 30 enters the flash device 40;

(4) After the pressures of the flashing device 40 and the buffering device 30 are balanced, stop the mixed material in the buffering device 30 from entering the flashing device 40;

(5) The mixture material in the flashing device 40 is flashed under pressure reduction to obtain an ammonolysis product, and the ammonolysis product includes an alkali metal salt of taurine.

In step (1), the ammonia water is obtained by configuring at least two of liquid ammonia, ammonia water, and water in the feeding device 10, and the mass concentration of ammonia is 25%-50%.

When n sets of the ammoniating autoclaves 200 are connected in series, the feeding device 10 provides ammonia water to the first ammoniating autoclave 200 so that each ammoniating autoclave 200 is filled with ammonia water. In one or more embodiments, the volume of ammonia in the ammoniating autoclave 200 is 60%-90% of the volume of the ammoniating autoclave 200.

In step (2), the reaction temperature is 250° C. to 290° C., the reaction pressure is 14 MPa to 24 MPa, and the rotation speed of each ammoniating autoclave 200 is 100 r/min to 500 r/min.

The ammonia source provided by the first feed pipe 60 to the first to the nth ammoniating autoclave 200 to the nth ammoniating autoclave 200 is preferably liquid ammonia. Because the alkali metal isethionate consumes ammonia during the ammonolysis, if ammonia is added to the first feed pipe 60, the reaction volume in the ammonification autoclave 200 will increase.

The isethionate alkali metal salt solution provided by the second feed pipe 70 to each ammoniating autoclave 200 includes sodium isethionate solution, potassium isethionate solution, and lithium isethionate solution. At least one is preferably a sodium isethionate solution, and the mass concentration of the alkali metal isethionate in the alkali metal isethionate solution is 30%-60%.

The feeding device 10 supplies ammonia to the first ammoniated autoclave 200 at a rate of 6.0m ³ /h-10.0m ³ /h, and the first feeding pipe 60 supplies ammonia to the first ammoniated autoclave 200. The speed at which the autoclave 200 to the n-th ammoniated autoclave 200 provides ammonia source is 0.1m ³ /h-0.2m ³ /h, and the second feed pipe 70 supplies each ammoniated autoclave The rate at which 200 provides isethionine alkali metal salt solution is 0.1m ³ /h-0.3m ³ /h.

In one or more embodiments, the second feed pipe 70 provides the alkali metal isethionate solution to each of the ammoniated autoclaves 200 by dripping, and the first feed pipe 60 The method of supplying the ammonia source to the first ammoniating autoclave 200 to the nth ammoniating autoclave 200 may also be dropwise addition.

Therefore, the preparation method can accurately control the feeding speed of the feeding device 10, the first feeding pipe 60, and the second feeding pipe 70, so that the ammonia and hydroxyethyl sulfonate in each ammoniating autoclave can be controlled accurately. The molar ratio of acid-alkali metal salt reaches a maximum value, which greatly reduces the production of by-products such as alkali metal salt of ditaurine, so that the yield of alkali metal salt of taurine can reach more than 90%. The conversion rate of the metal salt exceeds 95%. Moreover, the process is safe and stable, the product composition is stable, and the reproducibility is high.

At the same time, by controlling the number and volume of the ammoniated autoclaves 200 connected in series, as well as the feeding speed of the feeding device 10, the first feeding pipe 60 and the second feeding pipe 70, the contents of the ammoniating autoclave 200 can be adjusted. The residence time of the reaction solution.

It should be noted that the speed at which the first feed pipe 60 and the second feed pipe 70 supply liquid ammonia and the alkali metal isethionate solution to each ammoniating autoclave 200 can be the same or different of.

When the residence time of the reaction liquid in the ammoniating autoclave 200 is sufficient to completely react the alkali metal salt of isethionate, the second feed pipe 70 can be used to provide isethionate to each of the ammoniating autoclaves 200 The speed of the alkali metal salt solution remains the same.

When the residence time of the reaction liquid in the ammoniating autoclave 200 is short, in order to ensure that the alkali metal isethionate in the nth ammoniating autoclave 200 can completely react, the nth ammoniating autoclave 200 can be reduced. The amount of isethionate alkali metal salt in it. Even, starting from the first ammoniating autoclave 200, the amount of alkali metal isethionate in each ammoniating autoclave 200 can be sequentially reduced.

Or, when the continuous ammonolysis reaction system includes the adjusting device 130, the adjusting device 130 will also be filled with ammonia during the feeding process of step (1), so that each of the ammoniated components can be made in step (2). The reaction liquid in the autoclave 200 enters the adjusting device 130 in a serial sequence, so that the incompletely reacted alkali metal isethionate in the reaction liquid reacts completely in the adjusting device 130, and then passes through the adjusting device 130. 130 enters the buffer device 30 to obtain a mixture material.

At this time, in step (2), an ammonia source is also provided to the adjusting device 130 through the first feed pipe 60 in a continuous or intermittent manner to supplement the ammonia consumed by the ammonolysis reaction.

In step (2), after the ammonolysis reaction in the ammonification autoclave 200 has been carried out for a certain period of time or after the ammonolysis reaction has stabilized, it may also include opening the discharge pipe of the buffer device 30 to remove the poorly collected mixture materials, and then Close the discharge pipe for re-collection to obtain a better quality mixture.

In step (5), the ammonia recovery device 50 is also used to recover the reduced-pressure flashed ammonia to obtain recovered ammonia. The recovered ammonia may be ammonia or liquid ammonia. Considering the cost, one or more In the embodiment, water circulation is used to recover the ammonia after the depressurization and flash evaporation to obtain ammonia water.

In one or more embodiments, the recovered ammonia is provided to the feeding device 10 for recycling, so as to reduce the use of liquid ammonia in the feeding device 10 and reduce production costs.

Since the feeding device 10 is supplemented with ammonia in step (2) and the first feeding pipe 60 is supplemented with liquid ammonia in step (2), it is possible to maintain each ammoniating autoclave 200 during the ammonolysis reaction. The volume of the reaction solution in the process. Therefore, referring to the specific use of the continuous ammonolysis reaction system, when step (5) is performed, step (2) can be restarted and cycled in order to realize the continuous production of the alkali metal salt of taurine.

Please refer to Figure 2, this application also provides a method for preparing taurine, including the method for preparing the alkali metal salt of taurine, and

(7) Crystallize the solid product to obtain taurine.

In step (6), specifically, sulfuric acid, hydrochloric acid, etc. may be used to acidify the ammonolysis product in the acidification device 80 to obtain a solid-liquid acidification product, which is separated by the separation device 90 to obtain a solid product and mother liquor.

Since the ammonolysis products prepared by the continuous ammonolysis reaction system of the present application are mainly taurine alkali metal salt, isethionate alkali metal salt, ditaurine alkali metal salt and tritaurine alkali metal salt The salt content is extremely low. Therefore, after the solid product is separated, the mother liquor described in step (6) can be directly destroyed without recycling the mother liquor. This not only simplifies the process, but also avoids the stability problems and safety caused by the mother liquor. Hidden dangers make the production process safer, more stable and reliable.

Further, there are many ways to destroy the mother liquor. In one or more embodiments, the mother liquor recovery device 100 is used to recover the mother liquor separated by the separation device 90 and transported to the incinerator 110 for incineration.

In step (7), the solid product can be specifically cooled and crystallized in the crystallization device 120 to obtain a crude taurine, and the crude taurine is purified to obtain a pure taurine.

Hereinafter, the continuous ammonolysis reaction system, the alkali metal salt of taurine, and the preparation method of taurine will be further described through the following specific examples.

The continuous ammonolysis reaction systems of the following examples all use 6 sets of 5.0m ³ ammonification autoclaves connected in series. The ammonification autoclaves in series are all in the form of upper feeding and bottom discharging of the bottom pipe, and high-pressure pipes are used. Connect to each other. Use a high-pressure pump and a feeding device to press ammonia into the first ammoniated autoclave, use the first feed pipe to drop liquid ammonia into the first to sixth ammoniated autoclaves, and use the high-pressure pump and the second inlet The feed pipe drips sodium isethionate aqueous solution into the first to sixth ammoniated autoclaves. The pressure difference between the first to the sixth ammoniating autoclave in series is very small. The pressure difference generated by the discharge of the sixth ammoniating autoclave is used to buffer the reaction liquid in the ammoniating autoclave in the sequence of the series. The device flows.

Example 1

Liquid ammonia and water are used to prepare a 40% aqueous ammonia solution, and sodium isethionate solid and water are used to prepare a 40% sodium isethionate aqueous solution.

The prepared ammonia water with a concentration of 40% is pressed into the first ammoniating autoclave through the high-pressure pump and the feeding device, so that the ammonia water in the first to sixth ammoniating autoclaves in series reaches the volume of the ammoniation autoclave. When 80% of the feed is reached, stop feeding.

Turn on the stirring device to make the speed of the first to sixth ammoniating autoclaves reach 250r/min, start to heat up the first to sixth ammoniating autoclaves, and use the discharge valve to control the ammoniating autoclave in the system pressure. When the temperature of the first to sixth ammoniating autoclaves rises to 250°C and the pressure reaches 14.5MPa, 40% ammonia water is added to the first ammoniating autoclave through the high-pressure pump and the feeding device, and the high-pressure pump and The second feed pipe drips 40% sodium isethionate aqueous solution into the 1st to 6th ammoniated autoclaves to carry out the ammonolysis reaction, and at the same time passes the first feed pipe to the 1st to 6th ammonia Liquid ammonia is added dropwise to the autoclave to supplement the ammonia consumed in the reaction process. The flow rate of ammonia water in the feeding device is 10.0m ³ /h, and the flow rate of liquid ammonia in the first feeding pipe is 0.10m ³ /h. The flow rate of the sodium isethionate aqueous solution in the second feed pipe is 0.22m ³ /h.

With the progress of the ammonolysis reaction, the reaction liquid in the first to the sixth ammoniated autoclave flows in series, passes through the feed valve of the buffer device and enters the buffer device, and the buffer device collects the mixed material. When the pressure of the buffer device reaches 14.5MPa, it balances with the pressure of the sixth ammoniating autoclave, close the feed valve of the buffer device, open the discharge valve of the buffer device, and pressure the mixture into the flash vaporizer. When the pressure of the buffer device and the flashing device is balanced, close the discharge valve of the buffer device, open the feed valve of the buffer device, and make the feeding device, the first feeding pipe and the second feeding pipe into the ammoniating autoclave Re-feeding is carried out, and the cycle continues accordingly.

The mixture material in the flashing device is flashed by pressure reduction to obtain an ammonolysis product, and the excess ammonia in it is recycled to the ammonia recovery device using water recycling, and the formed ammonia water is recycled to the feeding device for continued use. After the system has been running continuously for 8 hours, samples are taken for analysis and calculations. The results are shown in Table 1.

Table 1

物料materials	百分比percentage
牛磺酸钠含量Sodium taurate content	87.07％87.07%
二牛磺酸钠含量Sodium ditaurate content	7.79％7.79%
三牛磺酸钠含量Sodium Tritaurate Content	0.53％0.53%

羟乙基磺酸钠含量Sodium isethionate content	4.61％4.61%
牛磺酸钠收率Yield of Sodium Taurate	90.72％90.72%
羟乙基磺酸钠转化率Conversion rate of sodium isethionate	95.23％95.23%

The flashed ammonolysis product is transferred to the acidification device, and concentrated H ₂ SO ₄ is added dropwise for acidification, until the pH=5.6, the dropwise addition of concentrated H ₂ SO _{4 is} stopped to obtain a solid-liquid acidification product. After the acidification product is separated by a separation device, the solid product is transferred to a crystallization device, and the temperature is lowered and crystallized to obtain a crude taurine. The crude taurine is purified to obtain a pure taurine. The mother liquor is recovered by the mother liquor recovery device and then enters the incineration plant for incineration treatment, and the mother liquor is not reused.

Finally, the pure taurine product is analyzed, and the taurine content in the pure taurine product is 99.96%, the content of sodium isethionate is 0.02%, sodium ditaurate and sodium tritaurate Not detected, the content of other impurities is 0.02%.

Example 2

Liquid ammonia and water are used to prepare 40% ammonia water, and sodium isethionate solid and water are used to prepare 50% sodium isethionate aqueous solution.

Turn on the stirring device to make the first to sixth ammoniating autoclaves reach 300r/min, start to heat up the first to sixth ammoniating autoclaves, and use the discharge valve to control the ammoniated autoclave in the system pressure. When the temperature of the first to sixth ammoniating autoclaves rise to 265°C and the pressure to 18.3MPa, 40% ammonia water is added to the first ammoniating autoclave through the high-pressure pump and the feeding device, and the high-pressure pump and The second feed pipe drips 50% sodium isethionate aqueous solution into the first to sixth ammoniated autoclaves to carry out the ammonolysis reaction, and at the same time passes the first feed pipe to the first to sixth ammonia Liquid ammonia was added dropwise to the autoclave to supplement the ammonia consumed in the reaction process. The flow rate of ammonia in the feeding device was 8.0m ³ /h, and the flow rate of liquid ammonia in the first feeding pipe was 0.1m ³ /h. The flow rate of the sodium isethionate aqueous solution in the second feed pipe is 0.11 m ³ /h.

With the progress of the ammonolysis reaction, the reaction liquid in the first to the sixth ammoniated autoclave flows in a series sequence, passes through the feed valve of the buffer device and enters the buffer device, and the buffer device collects the mixed material. When the pressure of the buffer device reaches 18.3 MPa, it balances with the pressure of the sixth ammoniating autoclave, close the feed valve of the buffer device, open the discharge valve of the buffer device, and pressure the mixture into the flash vaporizer. When the pressure of the buffer device and the flashing device is balanced, close the discharge valve of the buffer device, open the feed valve of the buffer device, and make the feeding device, the first feeding pipe and the second feeding pipe into the ammoniating autoclave Re-feeding is carried out, and the cycle continues accordingly.

The mixture material in the flashing device is flashed by pressure reduction to obtain the ammonolysis product, and the excess ammonia in it is recovered by water recycling to the ammonia recovery device, and the formed ammonia water is recycled to the feeding device for continued use. After the system has been running continuously for 8 hours, samples are taken for analysis and calculations. The results are shown in Table 2.

Table 2

物料materials	百分比percentage
牛磺酸钠含量Sodium taurate content	93.57％93.57%
二牛磺酸钠含量Sodium ditaurate content	4.24％4.24%
三牛磺酸钠含量Sodium Tritaurate Content	0.43％0.43%
羟乙基磺酸钠含量Sodium isethionate content	1.76％1.76%
牛磺酸钠收率Yield of Sodium Taurate	95.75％95.75%
羟乙基磺酸钠转化率Conversion rate of sodium isethionate	98.21％98.21%

The flashed ammonolysis product is transferred to the acidification device, and concentrated H ₂ SO ₄ is added dropwise for acidification, until the pH=7.1, the dropwise addition of concentrated H ₂ SO _{4 is} stopped to obtain a solid-liquid acidification product. After the acidification product is separated by a separation device, the solid product is transferred to a crystallization device, and the temperature is lowered and crystallized to obtain a crude taurine. The crude taurine is purified to obtain a pure taurine. The mother liquor is recovered by the mother liquor recovery device and then enters the incineration plant for incineration treatment, and the mother liquor is not reused.

Finally, the pure taurine product was analyzed, and the content of taurine in the pure taurine product was 99.91%, the content of sodium isethionate was 0.02%, sodium ditaurate and sodium tritaurate Not detected, the content of other impurities is 0.07%.

Example 3

Liquid ammonia and water are used to prepare 50% ammonia water, and sodium isethionate solid and water are used to prepare 50% sodium isethionate aqueous solution.

The prepared ammonia water with a concentration of 50% is pressed into the first ammoniating autoclave through the high-pressure pump and the feeding device, so that the ammonia water in the first to sixth ammoniating autoclaves in series reaches the volume of the ammoniated autoclave. When 80% of the feed is reached, stop feeding.

Turn on the stirring device to make the first to sixth ammoniating autoclaves reach 300r/min, start to heat up the first to sixth ammoniating autoclaves, and use the discharge valve to control the ammoniated autoclave in the system pressure. When the temperature of the first to sixth ammoniating autoclaves rises to 280°C and the pressure reaches 18.6MPa, 50% ammonia water is added to the first ammoniating autoclave through the high-pressure pump and feeding device, and the high-pressure pump and The second feed pipe adds 50% sodium isethionate aqueous solution dropwise to the first to fifth ammoniated autoclaves to carry out the ammonolysis reaction, and at the same time to the first to sixth ammonia via the first feed pipe Liquid ammonia was added dropwise to the autoclave to supplement the ammonia consumed in the reaction process. Among them, the flow rate of ammonia in the feeding device was 9.0m ³ /h, and the flow rate of liquid ammonia in the first feeding pipe was 0.1m ³ /h. The flow rate of the sodium isethionate aqueous solution in the second feed pipe is 0.11 m ³ /h.

With the progress of the ammonolysis reaction, the reaction liquid in the first to the sixth ammoniated autoclave flows in series, passes through the feed valve of the buffer device and enters the buffer device, and the buffer device collects the mixed material. When the pressure of the buffer device reaches 18.6MPa, it balances with the pressure of the sixth ammoniating autoclave, close the feed valve of the buffer device, open the discharge valve of the buffer device, and pressure the mixture into the flashing device. When the pressure of the buffer device and the flashing device is balanced, close the discharge valve of the buffer device, open the feed valve of the buffer device, and make the feeding device, the first feeding pipe and the second feeding pipe into the ammoniating autoclave Re-feeding is carried out, and the cycle continues accordingly.

The mixture material in the flashing device is flashed by pressure reduction to obtain an ammonolysis product, and the excess ammonia in it is recycled to the ammonia recovery device using water recycling, and the formed ammonia water is recycled to the feeding device for continued use. After the system has been running continuously for 8 hours, samples are taken for analysis and calculations. The results are shown in Table 3.

table 3

物料materials	百分比percentage
牛磺酸钠含量Sodium taurate content	95.53％95.53%
二牛磺酸钠含量Sodium ditaurate content	3.00％3.00%
三牛磺酸钠含量Sodium Tritaurate Content	0.27％0.27%
羟乙基磺酸钠含量Sodium isethionate content	1.19％1.19%
牛磺酸钠收率Yield of Sodium Taurate	97.08％97.08%
羟乙基磺酸钠转化率Conversion rate of sodium isethionate	98.80％98.80%

The flashed ammonolysis product is transferred to an acidification device, and concentrated H ₂ SO ₄ is added dropwise for acidification, until the pH is 7.0, the dropwise addition of concentrated H ₂ SO _{4 is} stopped, and a solid-liquid acidification product is obtained. After the acidification product is separated by a separation device, the solid product is transferred to a crystallization device, and the temperature is lowered and crystallized to obtain a crude taurine. The crude taurine is purified to obtain a pure taurine. The mother liquor is recovered by the mother liquor recovery device and then enters the incineration plant for incineration treatment, and the mother liquor is not reused.

Finally, the pure taurine product was analyzed, and the content of taurine in the pure taurine product was 99.92%, the content of sodium isethionate was 0.02%, sodium ditaurate and sodium tritaurate Not detected, the content of other impurities is 0.06%.

Example 4

Liquid ammonia and water are used to prepare 50% ammonia water, and sodium isethionate solid and water are used to prepare 45% sodium isethionate aqueous solution.

Turn on the stirring device to make the first to sixth ammoniating autoclaves reach 300r/min, start to heat up the first to sixth ammoniating autoclaves, and use the discharge valve to control the ammoniated autoclave in the system pressure. When the temperature of the first to sixth ammoniating autoclaves rises to 280°C and the pressure reaches 19.2MPa, 50% ammonia water is added to the first ammoniating autoclave through the high-pressure pump and feeding device, and the high-pressure pump and The second feed pipe drips 45% sodium isethionate aqueous solution into the first to fifth ammoniated autoclaves to carry out the ammonolysis reaction, and at the same time passes the first feed pipe to the first to sixth ammonia Liquid ammonia is added dropwise to the autoclave to supplement the ammonia consumed in the reaction process. Among them, the flow rate of ammonia in the feeding device is 8.0m ³ /h, and the flow rate of liquid ammonia in the first feeding pipe is 0.1m ³ /h. The flow rate of the sodium isethionate aqueous solution in the second feed pipe is 0.18 m ³ /h.

With the progress of the ammonolysis reaction, the reaction liquid in the first to the sixth ammoniated autoclave flows in series, passes through the feed valve of the buffer device and enters the buffer device, and the buffer device collects the mixed material. When the pressure of the buffer device reaches 19.2MPa, it balances with the pressure of the sixth ammoniating autoclave, close the feed valve of the buffer device, open the discharge valve of the buffer device, and pressure the mixture into the flashing device. When the pressure of the buffer device and the flashing device is balanced, close the discharge valve of the buffer device, open the feed valve of the buffer device, and make the feeding device, the first feeding pipe and the second feeding pipe into the ammoniating autoclave Re-feeding is carried out, and the cycle continues accordingly.

The mixture material in the flashing device is flashed by pressure reduction to obtain an ammonolysis product, and the excess ammonia in it is recycled to the ammonia recovery device using water recycling, and the formed ammonia water is recycled to the feeding device for continued use. After the system has been running continuously for 8 hours, samples are taken for analysis and calculations. The results are shown in Table 4.

Table 4

物料materials	百分比percentage
牛磺酸钠含量Sodium taurate content	93.13％93.13%
二牛磺酸钠含量Sodium ditaurate content	3.78％3.78%
三牛磺酸钠含量Sodium Tritaurate Content	0.38％0.38%
羟乙基磺酸钠含量Sodium isethionate content	2.70％2.70%
牛磺酸钠收率Yield of Sodium Taurate	95.07％95.07%
羟乙基磺酸钠转化率Conversion rate of sodium isethionate	97.26％97.26%

The flashed ammonolysis product is transferred to an acidification device, and concentrated H ₂ SO ₄ is added dropwise for acidification, until the pH is 7.0, the dropwise addition of concentrated H ₂ SO _{4 is} stopped, and a solid-liquid acidification product is obtained. After the acidified product is separated by a separation device, the solid product is transferred to a crystallization device, and the temperature is lowered and crystallized to obtain a crude taurine, and the crude taurine is purified to obtain a pure taurine. The mother liquor is recovered by the mother liquor recovery device and then enters the incineration plant for incineration treatment, and the mother liquor is not reused.

Finally, the pure taurine product is analyzed, and the taurine content in the pure taurine product is 99.90%, the content of sodium isethionate is 0.02%, sodium ditaurate and sodium tritaurate Not detected, the content of other impurities is 0.08%.

Example 5

Turn on the stirring device to make the first to sixth ammoniating autoclaves reach 300r/min, start to heat up the first to sixth ammoniating autoclaves, and use the discharge valve to control the ammoniated autoclave in the system pressure. When the temperature of the first to sixth ammoniating autoclaves rise to 280°C and the pressure to 18.4 MPa, 50% ammonia water is added to the first ammoniating autoclave through the high-pressure pump and feeding device, and the high-pressure pump and The second feed pipe drips 45% sodium isethionate aqueous solution into the first to fifth ammoniated autoclaves for the ammonolysis reaction, and at the same time passes the first feed pipe to the first to sixth ammonia Liquid ammonia was added dropwise to the autoclave to supplement the ammonia consumed in the reaction process. The flow rate of ammonia in the feeding device was 8.0m ³ /h, and the flow rate of liquid ammonia in the first feeding pipe was 0.1m ³ /h. two feed conduit a flow rate of an aqueous solution of sodium isethionate were ^{^{^{^{0.22m 3 /h,0.20m 3 /h,0.18m 3 /h,0.16m 3}}}} /h,0.14m 3 / h.

With the progress of the ammonolysis reaction, the reaction liquid in the first to the sixth ammoniated autoclave flows in series, passes through the feed valve of the buffer device and enters the buffer device, and the buffer device collects the mixed material. When the pressure of the buffer device reaches 18.4MPa, it balances with the pressure of the sixth ammoniating autoclave, close the feed valve of the buffer device, open the discharge valve of the buffer device, and pressure the mixture into the flashing device. When the pressure of the buffer device and the flashing device is balanced, close the discharge valve of the buffer device, open the feed valve of the buffer device, and make the feeding device, the first feeding pipe and the second feeding pipe into the ammoniating autoclave Re-feeding is carried out, and the cycle continues accordingly.

The mixture material in the flashing device is flashed by pressure reduction to obtain an ammonolysis product, and the excess ammonia in it is recycled to the ammonia recovery device using water recycling, and the formed ammonia water is recycled to the feeding device for continued use. After the system has been running continuously for 8 hours, samples are taken for analysis and calculations. The results are shown in Table 5.

table 5

物料materials	百分比percentage
牛磺酸钠含量Sodium taurate content	93.58％93.58%
二牛磺酸钠含量Sodium ditaurate content	3.62％3.62%
三牛磺酸钠含量Sodium Tritaurate Content	0.38％0.38%

羟乙基磺酸钠含量Sodium isethionate content	2.42％2.42%
牛磺酸钠收率Yield of Sodium Taurate	95.45％95.45%
羟乙基磺酸钠转化率Conversion rate of sodium isethionate	97.55％97.55%

Comparison

Use autoclave for batch ammoniation reaction

According to the conventional batch-tank ammonolysis reaction process, the metered sodium isethionate solid is dissolved in an autoclave containing a certain concentration of ammonia water (25%-50%), and reacted at 250℃-290℃, 14MPa-25MPa Under the conditions, the ammoniating reaction is carried out for 1 hour to 3 hours to obtain an aqueous solution of sodium taurate. According to calculation, the yield of sodium taurate is 77%-80% on average.

It can be seen from the foregoing examples and comparative examples that the yield of sodium taurate in the preparation method of the present application is about 95%, which is far greater than the 77%-80% yield of the batch kettle type. It can be seen that in the preparation process of taurine, firstly, the content of sodium isethionate, sodium ditaurate and sodium tritaurate is less, which is beneficial to acidification, crystallization and purification in the later stage, and the obtained cattle The sulfonic acid content is close to 100%. Secondly, it can avoid the complicated mother liquor application process, simplify the production process, and improve the safety, stability and reliability of the production process.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several implementation manners of the present application, and their description is relatively specific and detailed, but they should not be interpreted as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can be made, and these all fall within the protection scope of this application. Therefore, the scope of protection of the patent of this application shall be subject to the appended claims.

Claims

A continuous ammonolysis reaction system, characterized in that it comprises:

A high-pressure reaction device, the high-pressure reaction device includes n ammoniating autoclaves, n≥2, the first ammoniating autoclave to the nth ammoniating autoclave are connected in series in sequence, and the ammoniating autoclave is A container for the ammonolysis reaction, wherein the ammonolysis reaction uses ammonia as an ammoniating agent, the first ammoniating autoclave is connected with a feeding device, the first ammoniating autoclave to the nth ammoniating The autoclaves are all connected with a first feed pipe, and each of the ammoniated autoclaves is connected with a second feed pipe;

A buffer device, which is connected to the n-th ammoniating autoclave, and is used to receive the mixture material after the ammoniation reaction in the first to the n-th ammoniating autoclaves;

A flashing device, the flashing device is connected with the buffering device, and is used to receive the mixed material in the buffering device and obtain an ammonolysis product through flashing.
The continuous ammonolysis reaction system according to claim 1, wherein the feeding device is used to introduce an ammonia source for the ammonolysis reaction, and the first feeding pipe is used to supplement the ammonia consumed in the ammonolysis reaction process. , The second feed pipe is used to provide raw materials to be reacted required for the ammonolysis reaction.
The continuous ammonolysis reaction system according to claim 1, wherein the continuous ammonolysis reaction system further comprises an ammonia recovery device, the ammonia recovery device is connected to the flashing device, and the ammonia recovery The device is used to recover the ammonia in the flash evaporation device to obtain recovered ammonia.
The continuous ammonolysis reaction system according to claim 3, wherein the ammonia recovery device is also connected to the feeding device to deliver the recovered ammonia to the feeding device.
The continuous ammonolysis reaction system according to claim 1, wherein the continuous ammonolysis reaction system further comprises an adjusting device, and the adjusting device is connected in series with the nth ammoniating autoclave, and The buffer device is connected in series with the adjustment device, and the adjustment device is a vessel for the ammonolysis reaction.
The continuous ammonolysis reaction system according to claim 5, wherein the adjusting device is connected with a first feed pipe.
A preparation method of taurine alkali metal salt, characterized in that the preparation method adopts the continuous ammonolysis reaction system according to any one of claims 1 to 6, and the preparation method comprises the following steps:

(1) Provide ammonia water to the first ammoniating autoclave through the feeding device, so that each ammoniating autoclave connected in series is filled with ammonia water;

(2) Under the reaction temperature and reaction pressure, the feeding device is used to provide ammonia water to the first ammoniating autoclave, and the first ammoniating autoclave is supplied to the first ammoniating autoclave through the first feeding pipe. n sets of the ammoniating autoclaves provide an ammonia source, and each of the ammoniating autoclaves is provided with an isethionate alkali metal salt solution through the second feed pipe, so that each of the ammoniating autoclaves All carry out the ammonolysis reaction and make the reaction liquid enter the buffer device in a series sequence to obtain a mixed material;

(3) After the pressure of the buffer device and the n-th ammoniating autoclave is balanced, stop the feeding device to provide ammonia to the first ammoniating autoclave, and stop the first feeding pipe to supply ammonia to the first ammoniating autoclave. The first ammoniating autoclave to the nth ammoniating autoclave provide ammonia source, and the second feed pipe is stopped to provide alkali metal isethionate solution to each of the ammoniating autoclaves , And make the mixture material in the buffer device enter the flash evaporation device;

(4) After the pressures of the flashing device and the buffering device are balanced, stop the mixed material in the buffering device from entering the flashing device;

(5) Depressurizing and flashing the mixture in the flashing device to obtain an ammonolysis product, and the ammonolysis product includes an alkali metal salt of taurine.
The method for preparing an alkali metal salt of taurine according to claim 7, wherein in step (1), the volume of ammonia in the ammoniated autoclave is 60% to the volume of the ammoniated autoclave. 90%.
The method for preparing an alkali metal salt of taurine according to claim 7, wherein in step (2), the ammonia source comprises liquid ammonia.
The method for preparing an alkali metal salt of taurine according to claim 7, wherein in step (2), the feeding device provides ammonia to the first ammoniating autoclave at a rate of 6.0 m 3 /h-10.0m 3 /h, the rate at which the first feed pipe provides ammonia source from the first ammoniating autoclave to the nth ammoniating autoclave is 0.1m 3 /h-0.2 m 3 / h, the second feed pipe provided isethionate alkali metal salt solution to each of the amides are autoclave speed 0.1m 3 /h-0.3m 3 / h.
The method for preparing an alkali metal salt of taurine according to claim 7, characterized in that, in step (2), the second feed pipe provides alkali isethionate to each of the ammoniated autoclaves The method of the metal salt solution is dropwise addition.
The method for preparing an alkali metal salt of taurine according to claim 7, characterized in that, in step (2), each of the ammoniated autoclaves is subjected to an ammonolysis reaction and the reaction liquid enters the plant in series. The adjusting device then enters the buffering device through the adjusting device to obtain the mixed material.
The method for preparing an alkali metal salt of taurine according to claim 12, characterized in that, in step (2), it further comprises feeding the adjusting device in a continuous or intermittent manner through the first feed pipe Provide ammonia source.
The method for preparing an alkali metal salt of taurine according to claim 7, characterized in that, in step (5), the ammonia after depressurization and flashing is also recovered by the ammonia recovery device to obtain recovered ammonia.
The method for preparing an alkali metal salt of taurine according to claim 14, wherein the recovered ammonia is supplied to the feeding device.
The method for preparing an alkali metal salt of taurine according to claim 7, wherein when step (5) is performed, step (2) is restarted.
A preparation method of taurine, characterized in that the preparation method comprises the preparation method of the alkali metal salt of taurine according to any one of claims 7-16, and

(6) Acidifying and separating the ammonolysis product to obtain a solid product and mother liquor;

(7) Crystallize the solid product to obtain taurine.
The method for preparing taurine according to claim 17, characterized in that it further comprises destroying the mother liquor in step (6).