Xylitol-based glucoside compositions, and systems and methods for making same

Abstract

The present application provides a xylitol-based glucoside composition and a preparation system and method thereof. The preparation system of the xylitol-based glucoside composition comprises a micro-channel reaction device, the inside of the micro-channel reaction device is provided with a mixing tube and a heating unit, the two ends of the mixing tube are respectively communicated with the feeding port and the discharging port of the micro-channel reaction device; the heating unit is arranged outside the mixing tube; wherein the length of the mixing tube is 10-80 m, and the inner diameter of the mixing tube is 4-12 mm. By using the reaction system and the preparation method provided by the present application for preparing the xylitol-based glucoside composition, the reaction yield is close to 100%, and the desired composition ratio can be obtained by adjusting the raw material ratio.

Description

Technical Field

[0001] This invention relates to a xylitol glucoside composition, its preparation system, and its preparation method. Background Technology

[0002] Xylitol glucoside is a glycoside compound formed by the reaction of xylitol and glucose. It has high viscosity, is non-crystallizing, absorbent, and water-soluble, and can replace glycerin as a softener, plasticizer, and moisture regulator.

[0003]

[0004] Xylitol glucoside

[0005] The commonly used method for preparing xylitol glucoside in existing technologies is the direct glycosylation method. Xylitol, glucose, and an acidic catalyst undergo a glycosylation reaction at temperatures above 100°C, followed by dehydration. The water generated in the reaction is then quickly removed using vacuum and nitrogen atmospheres to obtain xylitol glucoside. The glycosylation reaction is a reversible chemical equilibrium, and water has a significant impact on the reaction; therefore, the above reaction is carried out under anhydrous conditions. However, due to the high reaction temperature, direct heating and melting of the solid easily leads to caking and carbonization, which not only affects the reaction yield but also makes it difficult to remove pigments from the product.

[0006] US8288353B2 discloses the following steps: xylitol is loaded into a glass reactor equipped with a jacket (circulating heat transfer fluid) and an effective stirring device, heated to melt, and then glucose and 96% concentrated sulfuric acid are added sequentially, reacting under a vacuum of 90 mbar to 45 mbar. To overcome the problem of uneven heating, this patent specifically uses a glass reactor equipped with a jacket (circulating heat transfer fluid) and an effective stirring device. However, during the solid melting process, solid and liquid coexist, still resulting in difficulties in stirring and severe carbonization of some raw materials, making it unsuitable for the large-scale industrial production of such products.

[0007] Therefore, there is a need for a method to prepare xylitol glucoside that is not prone to solidification and carbonization and has a high yield. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of the prior art in the preparation of xylitol glucosides, which is prone to caking and carbonization when directly heated, resulting in low yield. The present invention provides a xylitol glucoside composition, its preparation system and preparation method. The xylitol glucoside composition prepared by the preparation method of the present invention is not prone to caking and carbonization, and the yield of xylitol glucoside in the obtained xylitol glucoside composition is high.

[0009] The present invention solves the above-mentioned technical problems through the following technical solution: This invention provides a preparation system for a xylitol glucoside composition, characterized in that it includes a microchannel reaction device, wherein the microchannel reaction device is provided with a mixing tube and a heating unit inside, and the two ends of the mixing tube are respectively connected to the inlet and outlet of the microchannel reaction device; the heating unit is located on the outside of the mixing tube. The mixing tube has a length of 10-80 m and an inner diameter of 4-12 mm.

[0010] In this invention, the mixing tube may include a preheating section and a constant temperature section. The preheating section may be located near the feed inlet, and the constant temperature section may be located near the discharge outlet.

[0011] In this invention, the mixing tube is divided into a preheating section and a constant temperature section to ensure that the reaction temperature can be maintained for a period of time after it is reached, and at the same time, it is beneficial to add a temperature testing unit in it.

[0012] In some preferred embodiments of the present invention, the temperature testing unit is a first thermometer, which is disposed at the connection between the preheating section and the constant temperature section of the mixing tube.

[0013] In some preferred embodiments of the present invention, the length of the preheating section is 1 to 8 m, preferably 1.5 to 5 m, for example 1.5 m, 2 m or 5 m.

[0014] In some preferred embodiments of the present invention, the length of the constant temperature section is 8~72 m, more preferably 16.5~67 m, for example 16.5 m, 20 m, 31 m or 67 m.

[0015] In this invention, the length of the mixing tube can be 18 to 72 m, for example, 18 m, 22 m, 36 m or 72 m.

[0016] In this invention, the inner diameter of the mixing tube can be 4 to 8 mm, for example, 4 mm, 6 mm or 8 mm.

[0017] In this invention, during the preparation of the xylitol glucoside composition, the inner diameter of the mixing tube is set to 4-12 mm. This avoids the problem that the raw materials are too viscous and difficult to flow due to the inner diameter of the mixing tube being too small, and also avoids the problem that the heat transfer is slow and the reaction cannot be carried out efficiently due to the inner diameter of the mixing tube being too large.

[0018] In this invention, the volume inside the mixing tube can be 450 mL or more, preferably 452 mL to 905 mL, for example 452 mL, 622 mL or 905 mL.

[0019] In this invention, the heating unit can be a conventional choice in the art, such as an oil bath.

[0020] In this invention, the preparation system for the xylitol glucoside composition may further include a finished product tank, which is connected to the discharge port for adjusting the pH value.

[0021] Preferably, a reaction vessel is also provided downstream of the finished product tank.

[0022] Preferably, the finished product tank and the reaction vessel are directly connected, and the inlet of the reaction vessel is equipped with a shut-off valve.

[0023] In some preferred embodiments of the present invention, the inlet of the finished product tank is directly connected to the outlet of the mixing pipe, and a second thermometer is provided at the connection point.

[0024] In this invention, the preparation system for the xylitol glucoside composition further includes a first raw material tank, a second raw material tank, and a third raw material tank. The first raw material tank is connected to the inlet via a first feed pipe, the second raw material tank is connected to the inlet via a second feed pipe, and the third raw material tank is connected to the inlet via a third feed pipe.

[0025] In some preferred embodiments of the present invention, a first pump is provided on the first feed pipe, and the first pump is preferably a peristaltic pump.

[0026] In some preferred embodiments of the present invention, a first flow meter is provided on the first feed pipe.

[0027] In some preferred embodiments of the present invention, a second pump is provided on the second feed pipe, and the second pump is preferably a peristaltic pump.

[0028] In some preferred embodiments of the present invention, a second flow meter is provided on the second feed pipe.

[0029] In some preferred embodiments of the present invention, a third pump is provided on the third feed pipe, and the third pump is preferably a peristaltic pump.

[0030] In some preferred embodiments of the present invention, a third flow meter is provided on the third feed pipe.

[0031] Secondly, the present invention also provides a method for preparing a xylitol glucoside composition, which uses the xylitol glucoside composition preparation system as described above, and includes the following steps: The raw material mixture is fed into the mixing tube through the feed inlet to react and obtain reactants. The raw material mixture includes a first raw material, a second raw material, and a third raw material. The first raw material includes xylitol slurry, the second raw material includes glucose slurry, and the third raw material includes sulfuric acid. The sum of the water content in the first raw material and the second raw material is less than 10% and not 0. The glucose syrup comprises glucose and water, wherein the water accounts for 10% to 35% of the glucose by mass; the preparation method of the first raw material includes the following steps: The mixture containing xylitol and water is first heated; The temperature of the first heating is 110~120℃; The preparation method of the second raw material includes the following steps: The mixture containing glucose and water is subjected to a second heating; The second heating temperature is 110~120℃; the reaction time is 20 minutes or more.

[0032] In this invention, the water content in the raw material means the percentage of the mass of water in the raw material. For example, the water content of the first raw material being less than 10% means that the mass of water in the first raw material is less than 10% of the mass of the first raw material.

[0033] In this invention, the first raw material can be introduced into the mixing pipe through the first raw material tank, the second raw material can be introduced into the mixing pipe through the second raw material tank, and the third raw material can be introduced into the mixing pipe through the third raw material tank.

[0034] In this invention, the xylitol slurry may include xylitol and water.

[0035] In some preferred embodiments of the present invention, the water accounts for 1%-10% of the mass percentage of the xylitol.

[0036] In this invention, the preparation method of the first raw material may further include the following steps: Stirring is performed during the heating process.

[0037] In this invention, the heating time is not limited. The heating time depends on the amount of the first raw material. The first heating can be stopped when the water accounts for less than 1% of the mass percentage of the xylitol.

[0038] In this invention, the temperature of the first heating is, for example, 110~115℃ or 115~120℃.

[0039] In some preferred embodiments of the present invention, the water accounts for 25% to 35% of the glucose by mass.

[0040] In this invention, the preparation method of the second raw material may further include the following steps: Stirring is performed during the heating process.

[0041] In this invention, the second heating time is not limited. The heating time depends on the amount of the second raw material. The second heating can be stopped when the water accounts for less than 10% of the glucose by mass.

[0042] In this invention, the temperature of the second heating is, for example, 110~115℃ or 115~120℃.

[0043] In this invention, after the reaction, the intermediate product obtained from the reaction may be subjected to vacuum heating treatment in sequence.

[0044] In some preferred embodiments of the present invention, the intermediate product has a pH value of 6.5 to 7.

[0045] More preferably, the pH is adjusted by an alkali.

[0046] The pH value of the intermediate product is adjusted using an alkaline compound, preferably in the form of an aqueous solution, such as an aqueous solution of sodium hydroxide. In some preferred embodiments of the present invention, the aqueous solution of sodium hydroxide is a 10 wt.% aqueous solution of sodium hydroxide, wherein wt.% is the mass percentage of NaOH in the aqueous solution of sodium hydroxide.

[0047] In some preferred embodiments of the present invention, the vacuum degree of the vacuum heating is 0.02 MPa; In some preferred embodiments of the present invention, the temperature of the vacuum heating is 50~80°C.

[0048] In this invention, the sum of the mass of water in the xylitol slurry and the mass of water in the glucose slurry accounts for less than 10% of the sum of the mass of the xylitol slurry and the glucose slurry, for example, 7.24% or 5.69%.

[0049] In this invention, the sum of the water content of the first raw material and the second raw material is controlled to be less than 10% and not 0. On the one hand, this ensures that the glucose syrup of the second raw material can remain in a fluid state at 110-120℃. On the other hand, it avoids the problem of the reaction deteriorating due to the total water content being too high.

[0050] In this invention, the mass ratio of xylitol to water in the mixture of xylitol and water can be 10:(1~2), preferably 10:(1~1.5), for example 30:3.4; In this invention, after the first heating, a dehydration operation is also included.

[0051] In some preferred embodiments of the invention, the dehydration operation is performed under vacuum.

[0052] The vacuum level can be a conventionally selected one in the art, preferably above 0.02 MPa, for example 0.02 MPa.

[0053] In some preferred embodiments of the present invention, the temperature of the dehydration operation is 115°C to 125°C, for example, 115°C or 120°C.

[0054] In this invention, water accounts for 3.36% of the mass of xylitol in the xylitol slurry.

[0055] In this invention, the mass ratio of glucose to water in the mixture of glucose and water is (2~5):1, preferably (2.5~5):1, for example 13.8:5 or 9.2:3.3.

[0056] In this invention, after the second heating, a dehydration operation is also included.

[0057] In some preferred embodiments of the invention, the dehydration operation is performed under vacuum.

[0058] The vacuum level can be a conventionally selected one in the art, preferably above 0.02 MPa, for example 0.02 MPa.

[0059] In some preferred embodiments of the present invention, the temperature of the dehydration operation is 115°C to 125°C, for example, 115°C or 120°C.

[0060] In this invention, in the second raw material, the glucose syrup, the water content of the glucose can be 31.1% or 28.9% by mass.

[0061] In this invention, during the feeding process, the flow rate ratio of the first raw material, the second raw material, and the third raw material can be (8~12):(3~7):(0.1~0.2), preferably (8~11):(3~6):(0.1~0.2), for example 10.4:5.9:0.2, 8:4.5:0.1, or 10.4:3.9:0.2.

[0062] In this invention, during the introduction process, the sum of the flow rates of the first raw material, the second raw material, and the third raw material can be 10 mL / min to 18 mL / min, preferably 10 mL / min to 16.5 mL / min, for example 12.6 mL / min, 14.5 mL / min, or 16.5 mL / min.

[0063] In this invention, the residence time of the reaction can be 20 min to 80 min, preferably 20 min to 60 min, for example 27.4 min, 31.2 min, 49.4 min or 54.8 min.

[0064] In this invention, the reaction temperature can be 110°C to 125°C, preferably 110°C to 120°C, for example 115°C or 120°C.

[0065] In this invention, the sulfuric acid in the third raw material can have a mass concentration of 10 wt.% to 25 wt.%, for example, 20 wt.%.

[0066] Thirdly, the present invention also provides a xylitol glucoside composition, which is prepared according to the preparation method of the xylitol glucoside composition as described above.

[0067] In this invention, the mass percentage of the xylitol glucoside in the xylitol glucoside composition can be more than 40%, preferably 40% to 60%, for example 44.8%, 58.1%, 58.6%, 59.0% or 59.13%.

[0068] In this invention, the mass percentage of the dehydrated xylitol in the xylitol glucoside composition can be 20% to 50%, preferably 20% to 44.2%, for example 24.8%, 26.4%, 26.6%, 34.13% or 44.2%.

[0069] In this invention, the mass percentage of xylitol in the xylitol glucoside composition may be less than 20%, preferably 6-17%, for example 6.74%, 11.0%, 14.6%, 15.3% or 16.6%.

[0070] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0071] The reagents and raw materials used in this invention are all commercially available. The positive and progressive effects of this invention are as follows: This invention employs a specific xylitol glucoside composition preparation system, which overcomes the problems caused by the inherent characteristics of xylitol slurry and glucose slurry (such as excessive viscosity), solves the problem of easy caking and carbonization when solids are directly heated and melted during the preparation process, and also achieves excellent yield and content of xylitol glucoside. Attached Figure Description

[0072] Figure 1 This is a schematic diagram of the preparation system for the xylitol glucoside composition used in the embodiments of the present invention.

[0073] Figure 2 This is a schematic diagram of the microchannel reactor in the preparation system of the xylitol glucoside composition used in the embodiments of the present invention.

[0074] The attached diagram is labeled as follows: 001-First raw material tank, 11-First feed pipe, 101-First peristaltic pump, 201-First flow meter, 002-Second raw material tank, 12-Second feed pipe, 102-Second peristaltic pump, 202-Second flow meter, 003-Third raw material tank, 13-Third feed pipe, 103-Third peristaltic pump, 203-Third flow meter, 30-Mixing point, 300-Inlet, 301-Preheating section of mixing tube, 302-Oil bath, 303-First thermometer, 304-Constant temperature section of mixing tube, 305-Second thermometer, 306-Microchannel reactor, 307-Mixing tube, 40-Outlet, 401-Finished product tank, 501-Reaction vessel. Detailed Implementation

[0075] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0076] In this invention, residence time refers to the time required for the liquid to flow from one end of the reaction tube to the other, that is, the time it takes for the material to pass through the pipe.

[0077] The following are the calculation methods for the parameters in various embodiments of the present invention: Flow rate = Flow velocity × π × (Pipe inner diameter / 2) 2 ; Residence time = pipe length / flow velocity = pipe volume / flow rate; Yield = Product Quality Xylitol glucoside content / theoretical yield of xylitol glucoside; Theoretical yield of xylitol glucoside = glucose mass / glucose molecular weight molecular weight of xylitol glucoside.

[0078] In this invention, the boiling water is at a temperature of 100°C and boils under normal pressure.

[0079] The raw materials used in this invention are sourced from the following sources:

[0080] Example 1

[0081] A schematic diagram of the preparation system for the xylitol glucoside composition is shown below. Figure 1 As shown, it includes a first raw material tank 001, a second raw material tank 002, and a third raw material tank 003 in sequence; The first raw material tank 001 is connected to the first peristaltic pump 101 through the first feed pipe 11. The first peristaltic pump 101 is used to pump the first raw material out of the first raw material tank. The first raw material flows into the mixing point 30 through the first feed pipe 11 and merges with the second raw material and the third raw material. A first flow meter 201 is provided between the mixing point 30 and the first peristaltic pump 101. The second raw material tank 002 is connected to the second feed pipe 12 and the second peristaltic pump 102. The second peristaltic pump 102 is used to pump the second raw material out of the second raw material tank. The second raw material flows into the mixing point 30 through the second feed pipe 12 and merges with the first raw material and the third raw material. A second flow meter 202 is provided between the mixing point 30 and the second peristaltic pump 102. The third raw material tank 003 is connected to the third peristaltic pump 103 through the third feed pipe 13. The third peristaltic pump 103 is used to pump the third raw material out of the third raw material tank. The third raw material flows into the mixing point 30 through the third feed pipe 13 and merges with the first raw material and the third raw material. A third flow meter 203 is provided between the mixing point 30 and the third peristaltic pump 103. At mixing point 30, the first, second, and third raw materials are mixed to form a raw material mixture. This raw material mixture reacts in the microchannel reactor 306 and flows into the mixing tube preheating section 301 through the inlet 300. The outlet of the mixing tube preheating section 301 is directly connected to the inlet of the mixing tube constant temperature section 304. The mixing tube 307 is formed by the combination of the mixing tube preheating section 301 and the mixing tube constant temperature section 304. Figure 2 As shown. A first thermometer 303 is installed at the connection between the outlet of the preheating section 301 and the inlet of the constant temperature section 304 of the mixing tube. An oil bath 302 is installed outside the preheating section and the constant temperature section of the mixing tube. The mixing tube 307 is immersed in the oil bath 302. The outlet of the constant temperature section 304 of the mixing tube is connected to the discharge port 40. The oil bath 302 is used to heat the mixing tube 307 to maintain the temperature of the raw material mixture in the mixing tube 307 within the temperature range required for the reaction. A second thermometer 305 is also installed at the connection between the outlet of the constant temperature section 304 of the mixing tube and the discharge port 40. The second thermometer 305 is used to measure the temperature of the liquid flowing out of the constant temperature section 304 of the mixing tube. The raw material mixture reacts in the preheating section 301 and the constant temperature section 304 of the mixing tube. The product obtained from the reaction is connected to the inlet of the finished product tank 401 through the outlet 40. The finished product tank 401 is also equipped with a finished product tank feeding port 402 and a finished product tank sampling port 403. The finished product tank 401 is equipped with a stirring device and is used to adjust the pH of the product obtained from the reaction. The outlet of the finished product tank 401 is connected to the inlet of the reaction vessel 501. The reaction vessel 501 is used to perform final vacuum dehydration treatment on the product in the finished product tank 401 that has been adjusted to a suitable pH. The reaction vessel 501 is also equipped with a shut-off valve to control whether liquid flows into the finished product tank 401. When the shut-off valve is opened, the liquid in the finished product tank 401 will flow into the reaction vessel 501.

[0082] Each of the raw material tanks 001, 002, and 003 is equipped with a stirring device for holding the first raw material, the second raw material, and the third material. Each of the raw material tanks 001, 002, and 003 is equipped with a jacket, and heat transfer oil is circulated inside the jacket to keep the materials inside the raw material tanks warm.

[0083] Raw material tanks 001, 002 and 003 are also equipped with vacuum devices for vacuum dehydration of the raw materials.

[0084] In this embodiment, the length of the mixing tube is 36 m, of which the length of the preheating section of the mixing tube is 5 m, the length of the constant temperature section of the mixing tube is 31 m, the inner diameter of the mixing tube is 4 mm, and the internal volume of the mixing tube is 452 mL.

[0085] The method for preparing the xylitol glucosidase composition includes the following steps: (1) Prepare the first raw material, the second raw material and the third raw material. First ingredient: Place 30kg xylitol and 3.4L boiling water (i.e., 3.4kg boiling water) in the first ingredient tank and heat to 110-115℃. Turn on the stirring and control the stirring speed at 500 rpm.

[0086] After the materials in the first raw material tank are mixed evenly, the vacuum is turned on and the vacuum degree is controlled at 0.02MPa to carry out the dehydration operation. The temperature in the first raw material tank is controlled at 115℃. After 2.9L of condensate flows out, the vacuum is stopped, and the remaining 20.4L of xylitol slurry is retained as the first raw material and stirred continuously. The first raw material has a very light yellow color. In the first raw material, water accounts for 3.36% of the mass of xylitol.

[0087] Second ingredient: Place 13.80 kg of glucose and 5.0 L of boiling water (i.e., 5.0 kg of boiling water) in the second ingredient tank and heat to 110-115°C. Turn on the stirring and control the stirring speed at 500 rpm.

[0088] After the materials in the second raw material tank are mixed evenly, the vacuum is turned on and the vacuum degree is controlled at 0.02MPa to carry out the dehydration operation. The temperature in the second raw material tank is controlled at 115℃. After 2.4 L of condensate flows out, the vacuum is stopped, and the remaining 11.6 L of glucose syrup is retained as the second raw material and stirred continuously. The second raw material has a very light yellow color. In the second raw material, water accounts for 31.3% of the glucose by mass.

[0089] The third material is a dilute sulfuric acid with a mass of 0.438 kg, a volume of 0.39 L, and a concentration of 20 wt.%. This third material is colorless and transparent.

[0090] The first and second raw materials contain a total of 3.42 kg of water, and the total mass of the first and second raw materials is 47.22 kg. Therefore, the mass of water in the xylitol slurry and glucose slurry accounts for 7.23% of the total mass of the xylitol slurry and glucose slurry.

[0091] (2) Set the flow rates of the first peristaltic pump, the second peristaltic pump and the third peristaltic pump to 10.4 mL / min, 5.9 mL / min and 0.2 mL / min respectively; the ratio of the flow rates of the first peristaltic pump, the second peristaltic pump and the third peristaltic pump is 10.4:5.9:0.2, and the sum of the flow rates of the first peristaltic pump, the second peristaltic pump and the third peristaltic pump is 16.5 mL / min.

[0092] In this embodiment, the dwell time is 27.4 minutes.

[0093] (3) Turn on the oil bath heating. After the oil bath temperature stabilizes at 115℃, turn on each pump. The first, second, and third raw materials from the first, second, and third raw material tanks are introduced into the mixing point through the first, second, and third feed pipes, respectively. After passing through the mixing point, the first, second, and third raw materials form a raw material mixture, which flows into the preheating section of the mixing tube through the feed inlet. The temperature of the raw material mixture is measured to be 115℃ at the first thermometer. The raw material mixture continues to flow through the constant temperature section of the mixing tube until it reaches the outlet of the constant temperature section. The reaction is considered to be complete at the outlet of the constant temperature section of the mixing tube. The temperature of the liquid is measured to be 115℃ by the second thermometer. The liquid continues to flow and flows into the finished product tank through the discharge port.

[0094] (4) Prepare 25 L of water at 80℃ in advance in the finished product tank. After the liquid obtained in (3) has completely flowed into the finished product tank, turn on the stirring device in the finished product tank at 500 rpm. Add 10% NaOH solution by mass through the feed port of the finished product tank to adjust the pH of the liquid. Take a sample from the sampling port of the finished product tank at a frequency of 5 min to test the pH until the pH of the liquid in the finished product tank is measured to be 6.5-7. Stop adding NaOH solution and open the shut-off valve to let the liquid in the finished product tank flow into the reactor.

[0095] (5) After the liquid in the finished product tank has completely flowed into the reactor, turn on the vacuum device of the reactor and set the vacuum degree to 0.02 MPa. Heat the liquid to 80°C to concentrate it, and the product mass is 45.5 kg with a volume of about 33.2 L. The product is light yellow. The yield of xylitol glucoside is 99.23% based on glucose.

[0096] After dehydration, the final product contains 59.0% xylitol glucoside, 26.4% dehydrated xylitol, and 14.6% xylitol.

[0097] Example 2

[0098] In this embodiment, the preparation system for the xylitol glucoside composition differs from that in Example 1 only in that the length of the mixing tube is 18 m, with the preheating section being 1.5 m long and the isothermal section being 16.5 m long; the inner diameter of the mixing tube is 8 mm; and the internal volume of the mixing tube is 905 mL. In Example 2, the preparation method differs from that in Example 1 as shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0099] In Example 2, the product characterization is shown in Table 3.

[0100] Example 3

[0101] In this embodiment, the preparation system for the xylitol glucoside composition differs from that in Example 1 only in that the length of the mixing tube is 22 m, wherein the length of the preheating section of the mixing tube is 2 m, the length of the constant temperature section of the mixing tube is 20 m, the inner diameter of the mixing tube is 6 mm, and the inner volume of the mixing tube is 622 mL.

[0102] The differences between the preparation method in Example 3 and Example 1 are shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0103] In Example 3, the product characterization is shown in Table 3.

[0104] Example 4

[0105] In this embodiment, the preparation system for the xylitol glucoside composition differs from that in Example 1 only in that the length of the mixing tube is 72 m, wherein the length of the preheating section of the mixing tube is 5 m, the length of the constant temperature section of the mixing tube is 67 m, the inner diameter of the mixing tube is 4 mm, and the volume inside the mixing tube is 905 mL.

[0106] In Example 4, the preparation method differs from that in Example 1 as shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0107] In Example 4, the product characterization is shown in Table 3.

[0108] Example 5

[0109] In this embodiment, the preparation system for the xylitol glucoside composition differs from that in Example 1 only in that the length of the mixing tube is 36 m, of which the length of the preheating section of the mixing tube is 5 m, the length of the constant temperature section of the mixing tube is 31 m, the inner diameter of the mixing tube is 4 mm, and the inner volume of the mixing tube is 452 mL.

[0110] In Example 5, the preparation method differs from that in Example 1 as shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0111] In Example 5, the product characterization is shown in Table 3.

[0112] Comparative Example 1

[0113] In Comparative Example 1, the preparation system for the xylitol glucoside composition differed from that in Example 1 only in that the total length of the mixing tube was 10m, the mixing tube preheating section and the mixing tube constant temperature section were not set, the inner diameter of the tube was set to 2mm, and the inner volume of the mixing tube was 31.4 mL.

[0114] Comparative Example 1 is used to verify the situation where, when the inner diameter is smaller than the protection range of the present invention and the length is shorter than the protection range of the present invention, the residence time is less than the protection range of the present invention, resulting in the reactants failing to react completely.

[0115] In Comparative Example 1, the differences in preparation method compared to Example 1 are shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0116] In Comparative Example 1, the product characterization is shown in Table 3.

[0117] Comparative Example 2

[0118] Comparative Example 2 was used to verify the situation where the first heating temperature and the second heating temperature are higher than the range defined in this invention, resulting in increased side reactions, increased carbonization, and decreased target product content.

[0119] In Comparative Example 2, the differences in preparation method compared to Example 1 are shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0120] In Comparative Example 2, the product characterization is shown in Table 3.

[0121] Comparative Example 3

[0122] Comparative Example 3 was used to verify the situation where the first heating temperature and the second heating temperature were lower than the range defined in this invention, resulting in incomplete reaction and a large amount of unreacted raw material residue.

[0123] In Comparative Example 3, the differences in preparation method compared to Example 1 are shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0124] In Comparative Example 3, the product characterization is shown in Table 3.

[0125] Comparative Example 4

[0126] Comparative Example 4 was used to verify the adverse effects of high water content in the reaction system on the condensation reaction equilibrium and reaction efficiency.

[0127] In Comparative Example 4, the differences in preparation method compared to Example 1 are shown in Tables 1 and 2. All other steps and parameters are the same as in Example 1.

[0128] In Comparative Example 4, the product characterization is shown in Table 3.

[0129] Comparative Example 5

[0130] Comparative Example 5 was used to verify the situation where the reaction process could not proceed normally when the properties of the raw materials were not suitable for delivery in the microchannel reaction tube.

[0131] In Comparative Example 5, the differences between the preparation method and Example 1 are shown in Tables 1 and 2. In Example 5, the water content of the second raw material is too low, resulting in the second raw material being too viscous and unable to flow smoothly through the microchannel reaction tube, thus preventing subsequent reactions from taking place.

[0132] In Comparative Example 5, the product characterization is shown in Table 3.

[0133] Table 1. Parameters showing differences between the first and second raw materials and those in step (1) of Examples 1-5 and Comparative Examples 1-5 and Example 1.

[0134] The first raw material dehydration temperature (°C) in Table 1 corresponds to the temperature in the first raw material tank during the dehydration operation in step (1) of Example 1.

[0135] The dehydration temperature (°C) of the second raw material in Table 1 corresponds to the temperature in the second raw material tank during the dehydration operation in step (1) of Example 1.

[0136] Table 2. Relevant method parameters in steps (2) and (3) of Examples 1-5 and Comparative Examples 1-5

[0137] Table 3. Product characterization of Examples 1-5 and Comparative Examples 1-5

[0138] Based on the parameter differences and product yield and content results recorded in Tables 1-3, it can be seen that, from the perspective of reaction temperature, the results show that temperature has a significant impact on the formation of xylitol glucoside. When the reaction temperature is at the conditions used in Example 1, the xylitol glucoside content reaches 59.0%, the yield is 99.23%, the proportion of by-products is low, and the product color is uniform. However, when the reaction temperature is increased to the conditions shown in Comparative Example 2, the content of the target product decreases significantly to 37.2%, and the proportion of dehydrated xylitol increases significantly, indicating that high temperature conditions are unfavorable for the product system required by this invention. When the reaction temperature is decreased to the conditions shown in Comparative Example 3, the residual proportions of xylitol and glucose increase significantly, and the xylitol glucoside content decreases to 22.2%, indicating that the reaction is insufficient under low temperature conditions. The above results indicate that when the reaction temperature deviates from the limits defined in this invention, it is not conducive to the efficient formation of the target product.

[0139] Regarding the impact of raw material moisture content, the results of Comparative Example 4 further demonstrate that the degree of pre-dehydration of the raw materials has a significant effect on the reaction equilibrium. In Comparative Example 4, due to the high moisture content of the first material, the residual proportions of xylitol and glucose in the system reached 46.0% and 17.8%, respectively, while the xylitol glucoside content was only 18.4%, resulting in a significant decrease in yield. Unlike the reaction caused by "insufficient kinetics" in Comparative Example 3, this result reflects that the presence of moisture directly inhibits the condensation reaction from proceeding towards the target product, causing the reaction equilibrium to shift significantly towards the reactant side. This further verifies the necessity of controlling the degree of dehydration of the raw materials within the scope of this invention.

[0140] Furthermore, the results shown in Comparative Example 5 indicate that when excessive dehydration of the second material leads to a significant increase in system viscosity, the reaction process itself cannot proceed smoothly, resulting in reaction tube blockage and failure to obtain characterizable final product data. This result demonstrates that, in addition to reaction temperature and moisture content, material properties also have lower limits on feasibility. In summary, the results of the above examples and comparative examples show that only when the reaction temperature, the degree of raw material dehydration, and the synergistic effect of material properties are within the limits defined by this invention can a high yield and high content of xylitol glucoside be achieved while ensuring process feasibility.

[0141] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A system for preparing a xylitol glucoside composition, characterized in that, It includes a microchannel reaction device, the inside of which is provided with a mixing tube and a heating unit. The two ends of the mixing tube are respectively connected to the inlet and outlet of the microchannel reaction device; the heating unit is located on the outside of the mixing tube. The mixing tube has a length of 10-80 m and an inner diameter of 4-12 mm.

2. The preparation system for the xylitol glucoside composition according to claim 1, characterized in that, It meets one or more of the following conditions: (1) The mixing tube includes a preheating section and a constant temperature section, wherein the preheating section is located near the feed inlet and the constant temperature section is located near the discharge outlet; Preferably, the length of the preheating section is 1 to 8 m, more preferably 1.5 to 5 m, for example 1.5 m, 2 m or 5 m; Preferably, the length of the constant temperature section is 8~72 m, more preferably 16.5~67 m, for example 16.5 m, 20 m, 31 m or 67 m; (2) The length of the mixing tube is 18~72 m, for example, 18 m, 22 m, 36 m or 72 m; (3) The inner diameter of the mixing tube is 4 to 8 mm, for example, 4 mm, 6 mm or 8 mm; (4) The volume of the mixing tube is 450 mL or more, preferably 452 mL to 905 mL, for example 452 mL, 622 mL or 905 mL; (5) The heating unit is, for example, an oil bath; (6) The preparation system of the xylitol glucoside composition further includes a finished product tank, which is connected to the discharge port for adjusting the pH value; Preferably, a reaction vessel is also provided downstream of the finished product tank; Preferably, the finished product tank and the reaction vessel are directly connected, and the inlet of the reaction vessel is equipped with a shut-off valve.

3. The preparation system for the xylitol glucoside composition according to claim 1, characterized in that, It also includes a first raw material tank, a second raw material tank and a third raw material tank. The first raw material tank is connected to the inlet through a first feed pipe, the second raw material tank is connected to the inlet through a second feed pipe, and the third raw material tank is connected to the inlet through a third feed pipe. Preferably, the first feed pipe is equipped with a first pump, which is preferably a peristaltic pump; Preferably, a first flow meter is provided on the first feed pipe; Preferably, a second pump is provided on the second feed pipe, and the second pump is preferably a peristaltic pump; Preferably, a second flow meter is provided on the second feed pipe; Preferably, the third feed pipe is equipped with a third pump, which is preferably a peristaltic pump; Preferably, the third feed pipe is equipped with a third flow meter.

4. A method for preparing a xylitol glucoside composition, characterized in that, The preparation system for the xylitol glucoside composition as described in any one of claims 1 to 3 includes the following steps: The raw material mixture is fed into the mixing tube through the feed inlet to react and obtain reactants. The raw material mixture includes a first raw material, a second raw material, and a third raw material. The first raw material includes xylitol slurry, the second raw material includes glucose slurry, and the third raw material includes sulfuric acid. The sum of the water content of the first raw material and the second raw material is less than 10% and not 0. The glucose slurry includes glucose and water, and the water accounts for 10% to 35% of the mass percentage of the glucose. The preparation method of the first raw material includes the following steps: The mixture containing xylitol and water is first heated; The temperature of the first heating is 110~120℃; The preparation method of the second raw material includes the following steps: The mixture containing glucose and water is subjected to a second heating; The temperature of the second heating is 110~120℃; The reaction residence time is 20 minutes or more.

5. The method for preparing the xylitol glucoside composition according to claim 4, characterized in that, It satisfies one or more of the following conditions (1) to (7): (1) The first raw material is introduced into the mixing pipe through the first raw material tank, the second raw material is introduced into the mixing pipe through the second raw material tank, and the third raw material is introduced into the mixing pipe through the third raw material tank; (2) The xylitol slurry comprises xylitol and water, wherein, preferably, the water accounts for 1%-10% of the mass percentage of the xylitol; (3) The preparation method of the first raw material further includes the following steps: Stirring is performed during the first heating process; The temperature of the first heating is, for example, 110-115°C or 115-120°C; (4) In the glucose syrup, the water accounts for 25% to 35% of the glucose by mass; (5) The preparation method of the second raw material further includes the following steps: Stirring is performed during the second heating process; The second heating temperature is, for example, 110-115°C or 115-120°C; (6) The reaction is followed by a step of subjecting the intermediate product obtained from the reaction to vacuum heating treatment; Preferably, the pH value of the intermediate product is 6.5-7; more preferably, the pH value of the intermediate product is adjusted by an alkaline compound, which is preferably in the form of an aqueous solution, such as an aqueous solution of sodium hydroxide. Preferably, the vacuum degree of the vacuum heating is 0.02 MPa; Preferably, the temperature of the vacuum heating is 50-80°C; (7) The sum of the mass of water in the xylitol slurry and the mass of water in the glucose slurry is less than 10% of the sum of the mass of the xylitol slurry and the glucose slurry, for example, 7.24% or 5.69%.

6. The method for preparing the xylitol glucoside composition according to claim 5, characterized in that, The first raw material satisfies one or more of the following conditions (1) to (3): (1) In the mixture of xylitol and water, the mass ratio of xylitol to water is 10:(1~2), preferably 10:(1~1.5), for example 30:3.4; (2) After the first heating, a dehydration operation is also included. Preferably, the dehydration operation is performed in a vacuum environment. Preferably, the vacuum level of the vacuum environment is 0.02 MPa or higher, for example, 0.02 MPa; The temperature of the dehydration operation is preferably 115°C to 125°C, for example, 115°C or 120°C; (3) In the xylitol slurry, the water accounts for 3.36% of the mass of the xylitol.

7. The method for preparing the xylitol glucoside composition according to claim 5, characterized in that, The second raw material satisfies one or more of the following conditions (1) to (3): (1) In the mixture of glucose and water, the mass ratio of glucose to water is (2~5):1, preferably (2.5~5):1, for example 13.8:5 or 9.2:3.3; (2) After the second heating, a dehydration operation is also included. Preferably, the dehydration operation is performed in a vacuum environment. Preferably, the vacuum level of the vacuum environment is 0.02 MPa or higher, for example, 0.02 MPa; The temperature of the dehydration operation is preferably 115°C to 125°C, for example, 115°C or 120°C; (3) In the glucose syrup, the water accounts for 31.1% or 28.9% of the glucose by mass.

8. The method for preparing the xylitol glucoside composition according to claim 4, characterized in that, It satisfies one or more of the following conditions (1) to (5): (1) During the feeding process, the flow ratio of the first raw material, the second raw material and the third raw material is (8~12):(3~7):(0.1~0.2), preferably (8~11):(3~6):(0.1~0.2), for example 10.4:5.9:0.2, 8:4.5:0.1, 10.4:3.9:0.2; (2) During the process of introducing the raw material, the sum of the flow rates of the first raw material, the second raw material and the third raw material is 10 mL / min to 18 mL / min, preferably 10 mL / min to 16.5 mL / min, for example 12.6 mL / min, 14.5 mL / min or 16.5 mL / min; (3) The residence time of the reaction is 20 min to 80 min, preferably 20 min to 60 min, for example 27.4 min, 31.2 min, 49.4 min, 54.8 min; (4) The reaction temperature is 110℃~125℃, preferably 110℃~120℃, for example 115℃ or 120℃; (5) In the third raw material, the mass concentration of sulfuric acid is 10 wt.% to 25 wt.%, for example, 20 wt.%.

9. A xylitol glucoside composition, characterized in that, It is prepared by the method according to any one of claims 4 to 8.

10. The xylitol glucoside composition according to claim 9, characterized in that, The xylitol glucoside composition comprises xylitol glucoside, dehydrated xylitol, and xylitol, preferably satisfying one or more of the following conditions (1) to (4): (1) The xylitol glucoside accounts for more than 40% of the mass percentage of the xylitol glucoside composition, preferably 40% to 60%, for example 44.8%, 58.1%, 58.6%, 59.0% or 59.13%; (2) The mass percentage of the dehydrated xylitol in the xylitol glucoside composition is 20% to 50%, preferably 20% to 44.2%, for example 24.8%, 26.4%, 26.6%, 34.13% or 44.2%; (3) The mass percentage of xylitol in the xylitol glucoside composition is less than 20%, preferably 6-17%, for example 6.74%, 11.0%, 14.6%, 15.3% or 16.6%; (4) The xylitol glucoside composition does not contain glucose.

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