WO2022155909A1

WO2022155909A1 - Production device and production method for sucrose-6-ester

Info

Publication number: WO2022155909A1
Application number: PCT/CN2021/073354
Authority: WO
Inventors: 夏家信; 姜维强; 张正颂; 李正华; 赵金刚; 张从勇; 郑学连
Original assignee: 安徽金禾实业股份有限公司
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2022-07-28
Also published as: CN112912153A

Abstract

Provided are a production device and production method for sucrose-6-ester. The device comprises separators and a reactor; each separator comprises an accommodation cavity and a condensation cavity which are provided closely and in communication with each other; a feeding port is provided at the top end of the accommodation cavity, a residual evaporation liquid outlet portion is provided at the bottom end of the accommodation cavity, and the residual evaporation liquid outlet portion is connected to the reactor by means of a conveying pipe; a condensed water outlet is provided in the condensation cavity; a film scraping apparatus is provided in the accommodation cavity, and the film scraping apparatus comprises a guide disk and several scraping plates which are arranged in the radial direction of the center axis of the guide disk and intersect with the guide disk in a penetrating manner; and the film scraping apparatus can rotate in the center axis of the guide disk, so that the scraping plates can scrape reaction liquid flowing down from the guide disk into a liquid film on the inner wall of the condensation cavity and separate the reaction liquid into residual evaporation liquid and water vapor. By mean of this, the reaction raw materials can be continuously added into the production device, and the reaction liquid separation step and the esterification reaction step are continuously performed, achieving the continuous production of sucrose-6-ester, greatly shortening the production cycle, and increasing the yield of sucrose-6-ester.

Description

Production equipment and production method of sucrose-6-ester

technical field

The invention belongs to the technical field of fine chemicals, and in particular relates to a production equipment and a production method of sucrose-6-ester.

Background of the Invention

Sucralose belongs to a new generation of sweeteners, which has the advantages of high sweetness, no calories, good stability and high safety, and has a very broad market prospect. Sucralose-6-ester is an important intermediate in the production of sucralose.

In the prior art, the process flow of the method for synthesizing sucrose-6-ester mainly includes: mixing sucrose, aprotic polar solvent and organotin esterification accelerator into a first reaction mixture; then mixing the first reaction mixture in a specific Contact with a gas or solvent vapor capable of removing water under the temperature and pressure environment and keep a certain reaction time, remove moisture from it to obtain a second reaction mixture; then add carboxylic acid anhydride to the second reactant to obtain a third reaction mixture, and use The third reaction mixture is maintained for a time sufficient to prepare the sucrose-6-ester. This method requires the use of gas or solvent vapor capable of removing water, and the existence of this link seriously affects the continuity of the production process of synthetic sucrose-6-ester, increases the production cycle, and reduces the production efficiency.

It should be noted that the statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

SUMMARY OF THE INVENTION

In view of the above-mentioned problems, the present application is made in order to provide a production apparatus and production method of sucrose-6-ester that overcome the above-mentioned problems or at least partially solve the above-mentioned problems.

According to an aspect of the present application, there is provided a production equipment of sucrose-6-ester, the equipment comprising: a separator and a reactor;

The separator includes a tightly and connected accommodating cavity and a condensing cavity, the top of the accommodating cavity is provided with a feeding port, and the bottom end is provided with an outlet for residual liquid, which is connected to the reactor through a conveying pipe; The cavity is provided with a condensed water outlet;

A film scraping device is arranged in the accommodating cavity. The film scraping device includes a guide plate and several scrapers along the radial direction of the central axis of the guide plate and intersecting with the guide plate. The film scraping device can rotate along the central axis of the guide plate to The scraper can scrape the reaction liquid flowing down from the guide plate to form a liquid film on the inner wall of the accommodating chamber and separate it into residual liquid and water vapor.

Optionally, in the above device, the outer edges of several scrapers protrude from the edge of the guide plate, and the width of the gap between the guide plate and the side wall of the accommodating cavity is 1-3 mm.

Optionally, in the above device, the guide plate is in the shape of a cone, a first heating device is arranged in the guide plate, and the included angle between the bus bar of the guide plate and the bottom surface is 1-20°.

Optionally, in the above-mentioned equipment, there are multiple separators, and the feed port of each separator and the outlet of the residual liquid are connected in turn by a conveying pipe; wherein, the guide plates of each separator have different heating power and maximum heating power. rotation rate.

Optionally, in the above-mentioned equipment, the outlet of the residual liquid is also connected to the feed port of the separator through a conveying pipe, so as to realize multiple separations of the reaction liquid.

Optionally, in the above-mentioned equipment, the bottom of the separator is also provided with a residual liquid channel, the inlet of the residual liquid channel is connected to the outlet of residual liquid, and the outlet of the residual liquid channel is connected to the reactor through a conveying pipe. There is a one-way valve in the residual liquid channel.

Optionally, in the above device, a cooling device is provided on the outer side of the conveying pipe.

Optionally, in the above equipment, the reactor is a helical reaction tube, and one end of the helical reaction tube is provided with a first feed port and a second feed port, and the other end is provided with a discharge port;

One end of the conveying pipe is connected to the first feeding port, and the other end of the conveying pipe is connected to the outlet of the residual liquid.

Optionally, in the above equipment, a temperature control device is provided on the outer side of the spiral reaction tube.

According to another aspect of the present application, a production method of sucrose-6-ester is provided, the method is carried out using any of the above-mentioned equipment, and the method comprises:

The reaction liquid separation step: start the film scraping device, and input the reaction liquid into the feed port of the accommodating cavity, so that the scraper scrapes the reaction liquid into a liquid film, and separates it into a residual liquid and water vapor, wherein the reaction liquid includes sucrose , aprotic polar solvent and organic tin ester accelerator; the residual liquid flows into the exit of the residual steam and enters the reactor, and the water vapor enters the condensation chamber and is condensed into condensed water and flows out from the condensed water outlet; and

The esterification reaction step: the reaction liquid entering the reactor and the carboxylic acid ester in the reactor undergo an esterification reaction under preset conditions to generate a solution containing sucrose-6-ester.

To sum up, the beneficial effect of the present application is that: a production equipment with a film scraping device is designed, and the reaction liquid is scraped into a liquid film by using the power when the film scraping device rotates, so that the moisture can evaporate and condense quickly, and the removal reaction is achieved. The purpose of water in the liquid overcomes the defect in the prior art that the first reaction mixture needs to use a large amount of gas or solvent vapor that can remove water in the process of removing water; on the other hand, without additional power, the rotating scraper The residual liquid obtained from the separation of the reaction liquid can be pushed into the reactor, so that the residual liquid reacts with the carboxylic anhydride in the reactor, saving electric energy, reducing the volume of the production equipment, saving the floor space of the production equipment, and overcoming the In the prior art, the second reaction mixture needs to be injected into another space and it takes a long time to mix with the carboxylic acid anhydride; and in the present application, the reaction raw materials can be continuously added to the production equipment, the reaction liquid separation step and the ester The chemical reaction steps are carried out uninterruptedly, so that the continuous production of sucrose-6-ester is realized, the production cycle is greatly shortened, and the production efficiency of sucrose-6-ester is improved; ester yield.

The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the description, and in order to make the above-mentioned and other purposes, features and advantages of the present application more obvious and easy to understand , and the specific embodiments of the present application are listed below.

Brief Description of Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustrating preferred embodiments only and are not to be considered limiting of the application. Also, the same components are denoted by the same reference numerals throughout the drawings. In the attached image:

Figure 1 shows a schematic perspective view of the overall external structure of a production equipment for sucrose-6-ester according to an embodiment of the present application;

FIG. 2 shows a top-view inner and outer structure perspective view of a separator of a sucrose-6-ester production equipment according to an embodiment of the present application;

3 shows a schematic perspective view of the internal and external structure of the separator of the production equipment of sucrose-6-ester according to an embodiment of the present application;

4 shows a schematic perspective view of the external structure of the separator of the production equipment for sucrose-6-ester according to another embodiment of the present application;

Figure 5 shows a schematic perspective view of the overall external structure of a production equipment for sucrose-6-ester according to another embodiment of the present application;

Fig. 6 shows the structural detail schematic diagram of the transmission device of the production equipment of sucrose-6-ester according to another embodiment of the present application;

FIG. 7 shows a schematic flowchart of a production method of sucrose-6-ester according to an embodiment of the present application.

MODES OF IMPLEMENTING THE INVENTION

Exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the application will be more thoroughly understood, and will fully convey the scope of the application to those skilled in the art.

The concept of the present application is that, in the prior art, the reaction solution for the production of sucrose-6-ester needs to first remove moisture by using steam or solvent in one reactor, then press it into another reactor, and then react with carboxylic anhydride, Sucrose-6-ester is produced. In this process, the step of removing water by steam or solvent consumes a lot of energy, and the equipment is large, covers a large area, and the degree of water removal is not thorough enough; after removing the water, the reaction hydraulic pressure needs to be put into another reactor , to carry out the esterification reaction, this process requires extra energy and time, which reduces the production efficiency of sucrose-6-ester; and this production mode of the prior art is discontinuous, and can only be carried out after each feeding reaction is completed. Another reaction also seriously affected the production efficiency of sucrose-6-ester.

FIG. 1 shows a schematic perspective view of the overall external structure of a sucrose-6-ester production equipment according to an embodiment of the present application, and FIG. 2 shows a separator of a sucrose-6-ester production equipment according to an embodiment of the present application. 3 shows a cross-sectional schematic diagram of the internal and external structures of a separator of a sucrose-6-ester production equipment according to an embodiment of the present application.

Referring to FIG. 1 , FIG. 2 , and FIG. 3 at the same time, the sucrose-6-ester production equipment 100 includes: a separator 1A and a reactor 2 .

Separator 1A (1B) includes accommodating cavity 1-1 and condensing cavity 1-2 which are tightly and communicatedly arranged. The top end of accommodating cavity 1-1 is provided with feeding port 1-1-1, and the bottom end is provided with steam residue The liquid outlet part 1-1-2 and the residual liquid outlet part 1-1-2 are connected to the reactor 2 through the conveying pipe 3; the condensation chamber 1-2 is provided with a condensed water outlet 1-2-1.

A wiper device 1-3 is arranged in the accommodating cavity 1-1. The wiper device 1-3 includes a guide plate 1-3-1 and a guide plate 1-3-1-1 radially along the central axis of the guide plate 1-3-1-1 and connected to the guide plate. The disk 1-3-1 runs through several scrapers 1-3-2 that intersect, and the scraping device 1-3 can rotate along the central axis 1-3-1-1 of the guide disk 1-3-1, so that the scraper 1 -3-2 The reaction liquid flowing down from the guide plate can be scraped to form a liquid film on the inner wall of the accommodating chamber 1-1 and separated into residual liquid and water vapor. In some embodiments of the present application, the central shaft 1-3-1-1 can be connected to an external motor or has a built-in motor to provide power for the rotation of the film scraping device 1-3.

Taking the above-mentioned equipment with one separator as an example, the process of producing sucrose-6-ester can be briefly described as follows. Start the film scraping device 1-3, so that the guide plate 1-3-1 drives the scraper 1-3-2 along the guide plate 1-3-2. The central axis 1-3-1-1 of the disk 1-3-1 rotates, and the reaction liquid is input to the feed port of the first separator 1A, and the reaction liquid is distributed on the upper surface of the guide disk 1-3-1 and guided by gravity The centrifugal force caused by the rotation of the disk 1-3-1 gradually flows down from top to bottom along the inner wall of the accommodating chamber 1-1, and the rotating scraper 1-3-2 scrapes the reaction liquid into a liquid film. During the process, the water in the reaction liquid will evaporate into water vapor, enter the condensation chamber 1-2, and condense into liquid water droplets on the side wall 1-2-2 of the condensation chamber 1-2, along the side wall 1-2- 2 Flow down to the condensed water outlet 1-2-1 of the condensation chamber 1-2 for discharge. The reaction liquid after the evaporation of water is called the residual liquid. The residual liquid is driven by the rotating scraper 1-3-2, flows upward in the conveying pipe 3 and enters the reactor 2 along the conveying pipe 3, and is added to the reactor 2. The carboxylic acid anhydride reacts to form sucrose-6-ester.

In some embodiments of the present application, the accommodating chamber 1-1 and the condensing chamber 1-2 of the separator 1A (1B) are formed by an integral tank shell separated by a liquid separator 1-4, please refer to FIG. 2 3, the box shell is divided into a semi-cylindrical shell and a cuboid shell, the semi-cylindrical shell is the accommodating cavity 1-1, and the cuboid shell is the condensation cavity 1-2, in order to The setting cavity 1-1 is communicated with the condensation cavity 1-2, and the height of the liquid separator 1-4 should be lower than the height of the tank shell.

In some embodiments of the present application, the shape of the accommodating cavity 1-1 is a semi-cylindrical body cut along the diameter connected to a rectangle with the diameter of the semi-cylindrical body as the length of one side, the upper end may not be closed and the interior is hollow, and the upper end An additional top cover with inlet 1-1-1 can be added.

The film scraping device 1-3 is arranged in the accommodating cavity 1-1. In some embodiments of the present application, the guide disk 1-3-1 of the film scraping device 1-3 is in the shape of a cone, and the guide disk 1-3- The diameter of 1 is slightly smaller than the inner diameter of the accommodating cavity 1-1, the outer edges of several scrapers 1-3-2 protrude from the edge of the guide plate 1-3-1, the guide plate 1-3-1 and the accommodating cavity 1 The width of the gap between the inner walls of the -1 can be, but not limited to, 1-3 mm, so that the reaction liquid can pass from the gap between the guide plate 1-3-1 and the inner wall of the accommodating cavity 1-1 along the accommodating cavity 1- The inner wall of 1 flows down.

Please refer to Figures 2 and 3. It can be seen from Figures 2 and 3 that the scraper 1-3-2 runs through the guide plate 1-3-1 and is connected to the central axis 1 of the guide plate 1-3-1. - Radial alignment of 3-1-1. That is to say, the upper surface of the guide plate 1-3-1 is divided into several sub-regions by several scrapers 1-3-2. After the reaction liquid enters from the feed port, since the guide plate rotates, the In the case of uniform rotation, the reaction solution can evenly enter each sub-region, so as to achieve uniform distribution of the reaction solution.

The shape of the condensing cavity 1-2 is that the upper end of the condensing cavity is not closed and the interior is hollow, wherein the side wall 1-2-2 away from the accommodating cavity 1-1 is the place where the condensate water condenses, and the side wall 1-2-2 can be Contact with the external refrigerant for heat exchange to accelerate the condensation of water vapor. The liquid separator 1-4 can be set to be parallel to the side wall 1-2-2. When the film scraping device 1-3 rotates, the scraper 1-3-2 is just not in contact with the liquid separator 1-4 for separating Steam residue and condensate.

In some embodiments of the present application, in order to make the reaction liquid flow down the guide plate smoothly, the guide plate can be set in the shape of a cone, and its apex angle can also be cut off for better use. The surface is divided into a plurality of fan-shaped conical surfaces by a plurality of scrapers. Theoretically speaking, the larger the angle between the busbar of the guide plate and the bottom surface, the faster the reaction liquid will flow down, but in practical applications, it is hoped that the reaction liquid will flow down at a suitable speed range. The entire scraping and separation process is made too fast, and the evaporation of water is insufficient; if the flow rate is too slow, the overall reaction time is prolonged, which is not conducive to the rapid production of sucrose-6-ester. In some embodiments of the present application, the guide plate The included angle between the bus bar and the bottom surface can be set but not limited to 1-20°. It should be noted that the flow rate of the reaction liquid is related to many factors, such as the temperature of the reaction liquid, the viscosity of the reaction liquid, the rotation speed of the guide plate, etc. Only the influence of the angle between the bus bar of the guide plate and the bottom surface is discussed here.

In some embodiments of the present application, in order to accelerate the evaporation of water in the reaction liquid, a heating device may be provided in the guide plate, which is referred to as the first heating device, and the heating medium in the heating device may be, but not limited to, water, oil or Resistance wires, etc., in order to make the heating uniform, the above heating medium needs to be evenly distributed in the guide plate.

In some embodiments, a plurality of separators may be provided, and the feed port of each separator and the outlet of the residual liquid are connected in sequence through a conveying pipe, please refer to FIG. 1 , this embodiment includes two separators, which are denoted as The first separator 1A and the second separator 1B, the internal structures of the first separator 1A and the second separator 1B are completely the same, and the residual liquid outlet of the second separator 1B is separated from the first separator 1B through a conveying pipe The feed port of the device 1A is connected. The reaction liquid for producing sucrose-6-ester enters from the feed port of the second separator 1B, and the residual liquid after being separated by the second separator 1B enters from the feed port of the first separator 1A, and is separated by the first separator 1B. 1A is separated again, and the obtained distilled liquid enters into the reactor 2 to carry out the esterification reaction, thus realizing the multiple dewatering of the reaction liquid for producing sucrose-6-ester, so as to achieve the purpose of improving the degree of water separation. Further, the guide discs of each separator can have different heating power and maximum rotation speed to meet the needs of practical applications.

For the same reason, reference can be made to FIG. 4, which shows a schematic perspective view of the external structure of the separator of the production equipment for sucrose-6-ester according to another embodiment of the present application. In this embodiment, the first separator 1A, the first separator 1A, the The second separator 1B and the third separator 1C are connected in series in sequence, so as to realize the multiple dewatering of the reaction liquid for producing sucrose-6-ester, so as to achieve the purpose of improving the degree of water separation.

Fig. 5 shows a schematic perspective view of the overall external structure of the production equipment of sucrose-6-ester according to another embodiment of the present application; Fig. 6 shows the transmission device of the production equipment of sucrose-6-ester according to another embodiment of the present application Schematic diagram of the structural details.

In some embodiments of the present application, the above-mentioned generating device also has a motor 5 and a transmission device 6. The specific setting method, taking FIG. 5 and FIG. 6 as examples, the motor 5 is fixedly arranged on the upper end of the separator 1B, and the motor 5 The shaft is connected to the transmission device 6, and the structure of the transmission device 6 is not unique. It is only necessary to make the rotation speed of the separator 1A greater than the rotation speed of the separator 1B. In this embodiment, it can pass between the gear, sprocket, chain and the fixed shaft. The main shaft 1-3-1-2 of the separator 1 extends upward and is connected with the transmission device 6, and the transmission device 6 also has a fixed shaft 6-1, and the fixed shaft 6-1 is fixedly arranged on the separator 1A The upper end of the upper end is used to support the transmission device 6, and the reaction liquid to be evaporated is evaporated through the separator 1B and the separator 1A in turn to remove moisture to achieve purification, and the purified reaction liquid will be passed into the reactor 2. Take sucrose-6-ester.

In other embodiments of the present application, another technical means is also provided to realize the multiple separation and water removal of the reaction liquid for producing sucrose-6-ester. In the case of only one separator, the distillation of the separator The outlet of the residual liquid can also be connected to the feed port of the separator through a conveying pipe to realize multiple separations of the reaction liquid. Add function valve.

Please refer to FIG. 1 , FIG. 2 and FIG. 3 at the same time. In some embodiments of the present application, in order to make the residual liquid gather to the exit of the residual liquid more quickly and enter the conveying pipe, at the bottom of the accommodating cavity of the separator The residual liquid channel 1-5 can be added, and the shape of the residual liquid channel 1-5 can be set as a rectangular parallelepiped. The conveying pipe 3 is connected with the reactor 2, and a one-way valve (not shown in the figure) is provided in the residual liquid passages 1-5. As can be seen from the figure, the inlets of the residual liquid passages 1-5 are relatively large, which can well collect the residual liquid, wherein the one-way valve can prevent the residual liquid from flowing back into the separator 1A.

Referring to FIG. 1, in some embodiments of the present application, a cooling device 3-1 is provided on the outer side of the conveying pipe 3, and the cooling device 3-1 may be an air cooling device or a water cooling device, and the cooling device can convey the The tube 3 is surrounded, which is not limited in this application. The temperature at which the reaction liquid is heated in the separator may be higher than the temperature at which it carries out the esterification reaction with the carboxylic acid anhydride. The residual liquid quickly reaches the preset reaction temperature of the esterification reaction.

In some embodiments of the present application, the type of the reactor is not limited, any reactor that can complete the esterification reaction can be used. In other embodiments, the reactor 2 is a helical reaction tube. One end is provided with the first feeding port 2-1 and the second feeding port 2-1, and the other end is provided with the discharging port 2-3; one end of the conveying pipe 3 is connected with the first feeding port 2-1, and the conveying pipe The other end of 3 is connected to the outlet part 1-1-2 of the residual liquid.

The first feed port 2-1 is used to connect the outlet of the residual liquid 1-1-2 of the separator. The residual liquid enters the spiral reaction tube through the first feed port 2-1, and the carboxylic anhydride can be passed through the second feed port 2-1. The feed port 2-1 is added to the spiral reaction tube, mixed with the residual liquid, and undergoes an esterification reaction under preset conditions to generate a mixed solution whose main product is sucrose-6-ester, and is passed through the discharge port 2- 3 is discharged and enters the next process link of sucralose generation.

Further, the spiral reaction tube is provided with a temperature control device, including but not limited to a heating device formed by a heating medium such as water, oil, and resistance wire, which can surround the outside of the spiral reaction tube.

Fig. 7 shows the schematic flow sheet of the production method of sucrose-6-ester according to an embodiment of the present application, the method is carried out by adopting any of the above-mentioned equipment, and the method comprises at least the following steps S710 to S720:

The reaction liquid separation step S710: start the film scraping device, and input the reaction liquid into the feed port of the accommodating cavity, so that the scraper scrapes the reaction liquid into a liquid film, and separates it into residual liquid and water vapor, wherein the reaction liquid includes Sucrose, aprotic polar solvent and organic tin ester accelerator; the residual liquid flows into the exit of the residual steam and enters the reactor, and the water vapor enters the condensation chamber and is condensed into condensed water and flows out from the condensed water outlet.

Step S720 of esterification reaction: the reaction liquid entering the reactor and the carboxylic acid ester in the reactor undergo an esterification reaction under preset conditions to generate a solution containing sucrose-6-ester.

In the above method, the rotation speed of the film scraping device is not limited in the present application, and in some embodiments of the present application, it may be set to 40 rpm to 100 rpm. If the rotation speed of the film scraping device is less than 40 rpm, the speed of the reaction liquid flowing down is too fast, which will make the whole scraping and separation process too fast, and the water evaporation will be insufficient; If it is too slow, the overall reaction time is prolonged, which is not conducive to the rapid production of sucrose-6-ester.

In the above method, the reaction raw materials and preset conditions of the esterification reaction are not limited, and the prior art can be referred to, and the following recommended technical solutions can also be adopted.

In this application, the types of organotin ester accelerators are not limited, and single-tin organic compounds or double-tin organic compounds may be used, in some embodiments, 1,3-dihydrocarbyloxy-1,1 ,3,3-tetra-(hydrocarbyl)distannoxane, bis(hydrocarbyl)tin oxide, 1,3-diacyloxy-1,1,3,3-tetra-(hydrocarbyl)distannoxane, and 1 - any one or more of diacyloxy-1,1,3,3-tetra-(hydrocarbyl)distannoxane, in other embodiments 1,3-diacyloxy-1, 1,3,3-tetra-(hydrocarbyl)distannoxane, in yet other embodiments 1,3-diacetoxy-1,1,3,3-tetrabutyldistannoxane; wherein, The alkoxy group can be selected from alkoxy group or phenoxy group, and in some embodiments, the alkoxy group can be selected from methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentoxy group or n-hexyl group Oxygen, in other embodiments, is methoxy; in some embodiments, hydrocarbyl can be optionally alkyl, cycloalkyl, aryl or aralkyl, in other embodiments, is alkyl, In yet other embodiments, n-butyl.

The application does not limit the types of aprotic polar solvents, in some embodiments, selected from acetonitrile, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl ketone, nitromethane, nitroethane , any one or more of cyclohexanone, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylacetamide, hexamethylphosphoramide and N,N-dimethylformamide, In other embodiments, it is acetonitrile.

The application does not limit the amount of the aprotic polar solvent. In some embodiments, based on the mass of sucrose, the ratio of the mass amount of the solvent to the mass amount of the sucrose is 2 to 20, and in other embodiments, it is 3 ~10, and in further embodiments 4-8.

In the present application, the heating temperature for the evaporation of the reaction solution is not limited, in some embodiments, it can be 65-150°C, and in other embodiments, it can be 85-120°C.

In this application, the types of carboxylic acid anhydrides are not limited, and can be selected from any one of acetic anhydride, butyric anhydride, benzoic anhydride, stearic anhydride, and lauric anhydride, preferably acetic anhydride, according to the types of the above-mentioned organic acid anhydrides , the corresponding sucrose-6-carboxylates obtained are sucrose-6-acetate, sucrose-6-butyrate, sucrose-6-benzoate, sucrose-6-fatty acid ester, sucrose-6 - Lauric acid ester. Sucrose-6-acetate and sucrose-6-benzoate can be used as raw materials for the synthesis of other types of sucrose-6-carboxylate and intermediates for the synthesis of the sweetener sucralose, while other types of sucrose- 6-Carboxylic acid esters can be used as synthetic intermediates for food additives, chemical products and other reactions.

In this application, the amount of carboxylic anhydride is not limited. In some embodiments, the mass amount of carboxylic acid anhydride and the mass amount of sucrose are 0.6 to 3.0 based on the mass of sucrose. In other embodiments , is 0.8 to 1.0.

In this application, the reaction conditions of the esterification reaction are not limited. In some embodiments, the reaction temperature of the esterification reaction can be 0-50°C, and in other embodiments, it can be 1-20°C; In some embodiments, the reaction time of the esterification reaction is 10 min to 24 h, and in other embodiments, 30 min to 4 h.

It should be noted that for the reaction conditions not described above, reference may be made to the prior art.

Taking the separators as two examples below, the above-mentioned production method of sucrose-6-ester is briefly described:

First, the wiper device of the second separator 1B is activated to start heating and rotating, the reaction liquid is fed into the feed port of the second separator 1B, and the reaction liquid is heated and guided on the guide plate of the second separator 1B It flows down from the inner wall of its accommodating chamber from top to bottom, the rotating scraper scrapes the reaction liquid into a liquid film to speed up the evaporation, and the residual liquid flows down in the second separator 1B, and the residual liquid is driven by the rotating scraper to flow into the steam In the residual liquid channel, the evaporated water vapor is condensed from the side wall of the condensation chamber into water and flows out from the condensed water outlet 14 .

Then, start the scraping device of the first separator 1A, and the residual liquid produced by the second separator 1B flows into the first separator 1A through the conveying pipe for the second evaporative separation. The wiped film device is set to a different heating power and rotation speed from the wiped film device of the second separator 1B, so as to realize the secondary evaporation of the residual liquid produced in the second separator 1B to remove the first evaporation. Unexhausted moisture.

Finally, when the residual liquid after the second evaporation is about to flow into the reactor 1-5 after being cooled by the cooling device 3-1 in the conveying pipe 3, the carboxylic acid anhydride is continuously fed into the reactor 1-5, and the carboxylic acid anhydride is in the Reactors 1-5 are mixed with the residual liquid, and the esterification reaction occurs in the process of flowing out of the reactors 1-5, and the reaction product can be continuously obtained at the outlet of the reactors 1-5.

Test means involved in this application

High performance liquid chromatography (for testing the content of sucrose, sucrose-6-ester and other substances in the reaction product)

Shimadzu high performance liquid chromatograph, equipped with RID-10A differential refractive index detection, LC-10ADVP high pressure pump, CTO-10ASVP incubator; chromatographic column: Agilent XDB C18 column (250mm×4.6mm, 5μm); mobile phase: methanol- 0.125% dipotassium hydrogen phosphate aqueous solution (4:6); column temperature: 30°C; flow rate: 1.0 mL/min. Among them, methanol (chromatographic grade), dipotassium hydrogen phosphate (analytical grade), ultrapure water, sucralose standard (purity 99.9%) are required, and the content is measured by external standard method.

Test method for moisture

The determination of water content uses Karl Fischer method, please refer to the prior art, and will not be repeated in each embodiment.

Example 1

Taking the above equipment as an example with a separator, sucrose-6-ester is produced.

According to the mass ratio of sucrose, organotin ester accelerator (1,1,3-diacetoxy-1,1,3,3-tetrabutyldistannoxane), and aprotic polar solvent (DMF), it is 1 :2:10 is configured into a 300 kg reaction solution.

Start the scraping device and turn on all the heating and condensing devices of the separator, so that the scraping device rotates at a speed of 40rpm (about 10rad/min), so that the guide plate drives the scraper to rotate along the central axis of the guide plate. The feed port of the separator 1A was fed with the reaction liquid at a rate of 4 m ³ /h. At the same time, the heating temperature of the guide plate was set to 80°C, so that the reaction liquid gradually flowed down from the guide plate and was scraped into a liquid film.

The temperature control device of the reactor is set at a temperature of less than 10 ° C, and acetic anhydride is blown into the reactor according to the ratio of the mass ratio of sucrose and the mass ratio of acetic anhydride to 1:1.1 to carry out acylation reaction. From the beginning, the final flow out from the reaction product outlet is about 1 hour, and the product containing sucrose-6-ester flowing out from the reaction product outlet is collected.

Before the distilled liquid does not flow into the reactor, a sample can be taken to test the water content in it. In this embodiment, the water content is less than 450 ppm.

Quench the reaction with water with a volume ratio of 0.25:1 to the total volume of the reaction system, and extract the organotin ester accelerator with hexane with a volume ratio of 1:1 to the total volume of the reaction system, the obtained sucrose-6-ethyl Ester solution, and analyze the content of each substance by high performance liquid chromatography, the following and the normalization in the following examples refer to the use of high performance liquid chromatography for the separation and determination of mixed substances. All substances are artificially specified The amount is 100%, and the percentage of each substance in all substances is determined according to the peak area, and the product distribution is as follows:

a. Sucrose-6-acetate 85.50% (normalized);

b. Diacetate 3.68% (normalized);

c. Sucrose 1.77% (normalized).

Example 2

Taking the above equipment with two separators as an example, sucrose-6-ester is produced.

Start the wiper device of the first separator, and turn on all the heating and condensation devices of the first separator, so that the wiper device rotates at a speed of 40rpm (about 10rad/min), so that the guide plate drives the scraper along the guide plate. The central axis was rotated, and the reaction solution was fed into the feed port of the first separator 1A at a rate of 4 m ³ /h. At the same time, the heating temperature of the guide plate of the first separator was set to 80° C., so that the reaction liquid gradually flowed down from the guide plate and was scraped into a liquid film.

Start the scraping film device of the second separator, and turn on all the heating and condensing devices of the first separator, set the heating temperature of the guide plate of the second separator to 60°C, and enter the residual liquid from the first separator process. The second separator, and after evaporation, enters the reactor.

The temperature control device of the reactor is set at a temperature of less than 20 ° C, and acetic anhydride is blown into the reactor according to the ratio of the mass ratio of sucrose and the mass ratio of acetic anhydride to 1:1.1 to carry out acylation reaction. From the beginning, the final flow out from the reaction product outlet is about 1 hour, and the product containing sucrose-6-ester flowing out from the reaction product outlet is collected.

Before the distilled liquid does not flow into the reactor, a sample can be taken to test the water content in it. In this embodiment, the water content is less than 350 ppm.

a. Sucrose-6-acetate 89.70% (normalized);

b. Diacetate 2.85% (normalized);

c. Sucrose 0.86% (normalized).

Example 3

Taking the above equipment with three separators as an example, sucrose-6-ester is produced.

Start the wiper device of the first separator, and turn on all the heating and condensation devices of the first separator, so that the wiper device rotates at a speed of 40rpm (about 10rad/min), so that the guide plate drives the scraper along the guide plate. The central axis was rotated, and the reaction solution was fed into the feed port of the first separator 1A at a rate of 4 m ³ /h. At the same time, the heating temperature of the guide plate of the first separator is set to 80°C, so that the reaction liquid gradually flows down from the guide plate and is scraped into a liquid film. The residual liquid discharged from the first separator is called the first residual liquid. .

Start the wiper device of the second separator and turn on all the heating and condensation devices of the second separator, make the wiper device rotate at 60rpm, set the heating temperature of the guide plate of the second separator to 60°C, from The first residual liquid in the process of the first separator enters the second separator, and the residual liquid discharged from the second separator is called the second residual liquid.

Start the wiper device of the third separator, and turn on all the heating and condensation devices of the third separator, make the wiper device rotate at 80rpm, set the heating temperature of the guide plate of the third separator to 50°C, from The second residual liquid of the second separator process enters the third separator, and after being evaporated, enters the reactor.

The temperature control device of the reactor is set at a temperature of less than 15 ° C, and acetic anhydride is blown into the reactor according to the ratio of the mass ratio of sucrose to the mass of acetic anhydride of 1:1.1 to carry out acylation reaction. From the beginning, the final flow out from the reaction product outlet is about 1 hour, and the product containing sucrose-6-ester flowing out from the reaction product outlet is collected.

Before the distilled liquid does not flow into the reactor, a sample can be taken to test the water content. In this embodiment, the water content is less than 250 ppm.

a. Sucrose-6-acetate 90.35% (normalized);

b. Diacetate 2.12% (normalized);

c. Sucrose 0.22% (normalized).

Comparative Example 1

According to the mass ratio of sucrose, organotin ester accelerator (1,1,3-diacetoxy-1,1,3,3-tetrabutyldistannoxane), and aprotic polar solvent (DMF), it is 1 :2:10 is configured into a 300 kg reaction solution, heated at 90°C to dissolve into a reaction mixture solution.

The dehydration is carried out by the method of falling liquid in the packed tower. The diameter of the packed tower is 40 mm, 3×8 glass spring packing, and the packing height is 1 meter, which is equivalent to a 10-stage tray.

The reaction mixture solution prepared above was placed at the inlet of the top of the packed column, and the negative pressure was kept at 0.5 kPa, and at the same time, cyclohexane vapor (100° C., 4 atm) was fed to the gas inlet of the flask at the bottom of the packed column. The reaction mixture solution is reacted with cyclohexane vapor in countercurrent contact, and the vapor containing cyclohexane, water and DMF in the top distillate of the packed column is condensed and collected, and can be recycled after being dried and anhydrous.

A liquid sample was collected in the bottom flask of the packed column and the resulting product was clear, light amber in color. The residence time of the reaction liquid in the gas-liquid exchange reactor is about 1 min.

The obtained solution is calculated to contain 10% sucrose, and the obtained solution is pressed into another reaction kettle, and acetic anhydride is added dropwise at a temperature lower than 10 ° C according to the mass ratio of sucrose and acetic anhydride to be 1:1.1. The acylation reaction was quenched with 0.25:1 water after continuing the reaction for 2 hours at a temperature below 10°C. Extract the organotin compound with 1:1 cyclohexane, the obtained sucrose-6-ethyl ester solution is analyzed by high performance liquid chromatography, and the product is as follows:

a. Sucrose-6-acetate 72.05% (normalized);

b. Diacetate 4.36% (normalized);

c. Sucrose 22.76% (normalized).

As can be seen from Examples 1 to 3 and Comparative Example 1, the production equipment provided by the present application is compared with the filler liquid drop production equipment in Comparative Example 1, the yield of the sucrose-6-carboxylate prepared by the present application is high, The probability of side reactions is low, and the sucrose reaction is complete. It can be seen from the yield of sucrose-6-ethyl ester that some examples in the present application can reach 90.35% (normalized), while the yield of sucrose-6-acetate in Comparative Example 1 is only 72.05% (normalized). In other words, the output of sucrose-6-carboxylate in the application is significantly higher than the prior art; Similarly, it can be seen from the content of diacetate and sucrose in the reaction product that the probability of occurrence of side reactions in the application Significantly lower, the sucrose conversion is more complete. And when sucrose-6-ester is prepared by the method of Comparative Example 1, chemical reagents such as polar aprotic solvents are used when removing water from sucrose, and chemical reagents for water removal will be mixed with sucrose after water removal in this way. , resulting in impure reactants, and the use of chemical reagents to remove water from sucrose makes the production cost of sucrose-6-ester higher.

To sum up, the beneficial effect of the present application is that: a production equipment with a film scraping device is designed, and the reaction liquid is scraped into a liquid film by using the power when the film scraping device rotates, so that the moisture can evaporate and condense quickly, and the removal reaction is achieved. The purpose of water in the liquid overcomes the defect in the prior art that the first reaction mixture needs to use a large amount of gas or solvent vapor that can remove water in the process of removing water; on the other hand, without additional power, the rotating scraper The residual liquid obtained by the separation of the reaction liquid can be pushed into the reactor, so that the residual liquid can react with the carboxylic anhydride in the reactor, which saves electric energy, reduces the volume of the production equipment, saves the floor space of the production equipment, and overcomes the In the prior art, the second reaction mixture needs to be injected into another space and it takes a long time to mix with the carboxylic acid anhydride; and in the present application, the reaction raw materials can be continuously added to the production equipment, the reaction liquid separation step and the ester The chemical reaction steps are carried out uninterruptedly, so that the continuous production of sucrose-6-ester is realized, the production cycle is greatly shortened, and the production efficiency of sucrose-6-ester is improved; ester yield.

The above descriptions are only specific implementations of the present application, and those skilled in the art can make other improvements or modifications on the basis of the above-mentioned embodiments under the above teachings of the present application. Those skilled in the art should understand that the above-mentioned specific description is only to better explain the purpose of the present application, and the protection scope of the present application should be subject to the protection scope of the claims.

Furthermore, those skilled in the art will appreciate that although some of the embodiments described herein include certain features, but not others, included in other embodiments, that combinations of features of different embodiments are intended to be within the scope of the present application within and form different embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination.

Claims

A production equipment of sucrose-6-ester, comprising: a separator and a reactor;

The separator includes a tightly and connected accommodating cavity and a condensing cavity, the top of the accommodating cavity is provided with a feeding port, and the bottom end is provided with a residual liquid outlet, which passes through a conveying pipe. connected with the reactor; the condensation chamber is provided with a condensed water outlet;

A film scraping device is provided in the accommodating cavity, and the scraping device includes a guide plate and a plurality of scrapers along the radial direction of the central axis of the guide plate and intersecting with the guide plate. It can be rotated along the central axis of the guide plate, so that the scraper can scrape the reaction liquid flowing down from the guide plate to form a liquid film on the inner wall of the accommodating cavity and separate it into residual liquid and water vapor .
The device according to claim 1, wherein the outer edges of the scrapers protrude from the edge of the guide plate, and the width of the gap between the guide plate and the side wall of the accommodating cavity is 1-3mm.
The device according to claim 1, wherein the guide plate is in the shape of a cone, a first heating device is arranged in the guide plate, and the included angle between the bus bar and the bottom surface of the guide plate is 1-20 °.
The device according to claim 1, wherein the separator is provided with a plurality of separators, and the feed port and the residual liquid outlet of each separator are sequentially connected through a conveying pipe;

Therein, the guide discs of each of the separators have different heating powers and maximum rotation rates.
The device according to claim 1, characterized in that, the outlet of the residual liquid is also connected to the feed port of the separator through a conveying pipe, so as to realize multiple separations of the reaction liquid.
The apparatus according to claim 1, wherein the bottom of the separator is further provided with a residual liquid channel, the inlet of the residual liquid channel is connected to the outlet of the residual liquid, and the residual liquid channel is The outlet of the reactor is connected with the reactor through a conveying pipe, and a one-way valve is arranged in the residual liquid channel.
The apparatus according to claim 1, wherein a cooling device is provided on the outer side of the conveying pipe.
The device according to claim 1, wherein the reactor is a helical reaction tube, one end of the helical reaction tube is provided with a first feed port and a second feed port, and the other end is provided with an outlet material mouth;

One end of the conveying pipe is connected to the first feed port, and the other end of the conveying pipe is connected to the outlet of the residual liquid.
The apparatus according to claim 8, wherein a temperature control device is provided on the outer side of the spiral reaction tube.
A method for producing sucrose-6-ester, characterized in that the method is carried out using the equipment described in any one of claims 1 to 9, comprising:

The reaction liquid separation step: start the film scraping device, and input the reaction liquid into the feed port of the accommodating cavity, so that the scraper scrapes the reaction liquid into a liquid film, and separates it into residual liquid and water vapor, Wherein, the reaction solution includes sucrose, aprotic polar solvent and organotin ester accelerator; the residual liquid flows into the exit of the residual steam and enters the reactor, and the water vapor enters the condensation chamber and is condensed into condensed water from the out of the condensate outlet; and

The esterification reaction step: the reaction liquid entering the reactor and the carboxylic acid ester in the reactor undergo an esterification reaction under preset conditions to generate a solution containing the sucrose-6-ester.