Treatment method of sucralose-6-ethyl ester-containing mother liquor and application of sucralose-6-ethyl ester-containing mother liquor

Abstract

The invention belongs to the technical field of sucralose production, and relates to a treatment method and application of a sucralose-6-ethyl ester-containing mother solution. The treatment method comprises the following steps: S1, concentrating the sucralose-6-ethyl ester-containing mother solution to obtain a concentrated solution; s2, washing the concentrated solution with water to remove impurities so as to obtain a mother solution 1; s3, layering the mother solution 1 to obtain an ester phase, and decolorizing to obtain a decolorized solution; s4, recrystallizing the decolored solution, and carrying out solid-liquid separation to obtain sucralose-6-ethyl ester; the concentration temperature in the step S1 is 40-45 DEG C; the relative density of the concentrated solution is 1.08 to 1.15. Compared with the prior art, the sucralose-6-ethyl ester has the advantages that the yield and the purity of the sucralose-6-ethyl ester are higher, the sucralose-6-ethyl ester crystalline substance obtained by the method is put into production, the production yield and the yield of sucralose can be increased, and the cost is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of sucralose production, and in particular relates to a method for treating a mother liquor containing sucralose-6-ethyl ester and an application thereof. Background Art

[0002] Sucralose is a high-intensity sweetener made from sucrose through a chlorination reaction. It was jointly developed and patented by Tate & Lyle and the University of London in 1976, and was put on the market in 1988. The chemical name of sucralose is 4,1',6'-trichloro-4,1',6'-trideoxygalactosucrose, with a molecular formula of C12H19O8Cl3 and a molecular weight of 397.64.

[0003] Sucralose is widely used in a variety of foods, such as carbonated beverages, still beverages, alcoholic beverages, sweets, canned fruits and vegetables, pickled foods, sauces, jams, baked foods, ice cream, dairy products, etc. The prior art generally uses sucrose as a raw material, and sequentially undergoes tinization, esterification, and chlorination to obtain sucralose-6-acetate, which is then deacylated to obtain sucralose.

[0004] In the traditional process, the crude product mother liquor is concentrated and then crystallized and filtered. However, due to the large number of impurities in the system, the material often does not crystallize, or the crystallinity is poor, and very little sugar is produced. The crude product is also subjected to oxidative hydrolysis due to the large number of impurities. During the hydrolysis process, the temperature is often difficult to control, resulting in high temperatures and overflow of materials from the kettle, which poses a great threat to the environment and safety. DMF and some water-soluble impurities seriously affect the crystallinity, yield and purity of sucralose-6-ethyl ester, and also affect the separation of sucralose-6-ethyl ester from impurities. Therefore, there is an urgent need for a method to improve the yield and purity of sucralose-6-ethyl ester. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for treating a mother liquor containing sucralose-6-ethyl ester and application thereof.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In one aspect, the present invention provides a method for treating a mother liquor containing sucralose-6-ethyl ester, comprising the following steps:

[0008] S1, concentrating the mother liquor containing sucralose-6-ethyl ester to obtain a concentrated solution;

[0009] S2, washing the concentrated liquid with water to remove impurities, and obtaining mother liquor 1;

[0010] S3, separating the mother liquor 1 into layers to obtain an ester phase, and decolorizing to obtain a decolorized liquid;

[0011] S4, recrystallizing the decolorized liquid and separating the solid from the liquid to obtain sucralose-6-ethyl ester.

[0012] Preferably, the concentration temperature in step S1 is 40-45°C.

[0013] Preferably, the relative density of the concentrated solution in step S1 is 1.08-1.15; preferably 1.1-1.12.

[0014] The present invention can ensure that no abnormal situation occurs in the subsequent oxidation and hydrolysis reaction stage by controlling the relative density of the concentrated liquid.

[0015] Preferably, the water washing pressure in step S2 is 145-155 KPa; more preferably, it is 148-152 KPa; and even more preferably, it is 150 KPa.

[0016] Preferably, the mass ratio of the concentrate to water in step S2 is 1-3:1, preferably 1.5-2.5:1, and more preferably 2:1.

[0017] The present invention can effectively remove impurities such as DMF, sucralose and tetrachlorosucrose by controlling the ratio of the concentrate to water and the pressure during the water washing process.

[0018] Preferably, the decolorization in step S3 is performed by adding a physical adsorbent. The material adsorbent includes but is not limited to activated carbon, molecular sieve

[0019] Preferably, the recrystallization in step S4 is cooling crystallization.

[0020] Specifically, the recrystallization is: crystallization at 3-9°C for 15-20h; preferably crystallization at 4-6°C for 15-20h.

[0021] Preferably, the solid-liquid separation in step S4 includes centrifugation, suction filtration or filter pressing, and filter pressing is more preferred.

[0022] In another aspect, the present invention provides application of the above treatment method in the production of sucralose.

[0023] The mother liquor containing sucralose-6-ethyl ester described in the present invention is the mother liquor after crude mother liquor filtration, comprising sucralose-6-ethyl ester, sucralose, DMF, polychlorinated ester, dichlorinated ester and ethyl acetate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention can ensure that no abnormal situation will occur in the subsequent oxidation and hydrolysis reaction stage by controlling the relative density of the concentrated liquid, which is beneficial to reducing the generation of subsequent impurities.

[0026] (2) The present invention washes the concentrated liquid with water, which, on the one hand, helps to reduce impurities in the ester phase of sucralose-6-ethyl ester and improves the yield and crystallinity of solid sugar blocks with a relatively high content of sucralose-6-ethyl ester; on the other hand, it can control the decomposition reaction temperature of hydrogen peroxide in the subsequent oxidative hydrolysis reaction, eliminate certain safety hazards, and is beneficial to the repeatability of the overall reaction.

[0027] (3) Compared with the prior art, the yield and purity of sucralose-6-ethyl ester of the present invention are higher. The crystalline sucralose-6-ethyl ester obtained by the present invention can be put into production to improve the production yield and output of sucralose and save costs.

[0028] (4) The process of the present invention is simple, can be produced continuously, and is suitable for large-scale production. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention in conjunction with specific examples. Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention.

[0030] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0031] Example 1 Treatment method of mother liquor containing sucralose-6-ethyl ester

[0032] The mother liquor containing sucralose-6-ethyl ester was concentrated by a single-effect evaporator at a concentration temperature of 42° C., so that the relative density of the concentrated liquid in the bottom material of the single-effect evaporator was controlled between 1.1 and 1.12.

[0033] The concentrated liquid is transported to a water washing tower, and is washed with water to remove impurities (DMF, sucralose and tetrachlorosucrose) in a mass ratio of 2:1 between the concentrated liquid and water. The bottom pressure of the tower is 150 Kpa during the water washing.

[0034] The mother liquor 1 after water washing is conveyed into an automatic stratification tank to obtain an ester phase, and the ester phase is conveyed into a decolorization kettle, and activated carbon is added for stirring and decolorization treatment.

[0035] The decolorized liquid is transported into the crystallization kettle for cooling and crystallization. The crystallization temperature is 5°C and the crystallization time is 15-20h.

[0036] The crystals are separated from the mother liquor by filtering through a filter press, and the filter residue is sucralose-6-ethyl ester.

[0037] Example 2 Treatment method of mother liquor containing sucralose-6-ethyl ester

[0038] The mother liquor containing sucralose-6-ethyl ester was concentrated by a single-effect evaporator at a concentration temperature of 40° C., so that the relative density of the concentrated liquid in the bottom material of the single-effect evaporator was controlled between 1.12 and 1.15.

[0039] The concentrated liquid is transported to a water washing tower, and is washed to remove impurities (DMF, sucralose and tetrachlorosucrose) at a mass ratio of 1.5:1 between the concentrated liquid and water. The tower bottom pressure during the water washing is 145 Kpa.

[0040] The mother liquor 1 after water washing is conveyed into an automatic stratification tank to obtain an ester phase, and the ester phase is conveyed into a decolorization kettle, and activated carbon is added for stirring and decolorization treatment.

[0041] The decolorized liquid is transported into the crystallization kettle for cooling and crystallization. The crystallization temperature is 3°C and the crystallization time is 15-20h.

[0042] The crystals are separated from the mother liquor by filtering through a filter press, and the filter residue is sucralose-6-ethyl ester.

[0043] Example 3 Treatment method of mother liquor containing sucralose-6-ethyl ester

[0044] The mother liquor containing sucralose-6-ethyl ester is concentrated by a single-effect evaporator at a concentration temperature of 45° C., so that the relative density of the concentrated liquid in the bottom material of the single-effect evaporator is controlled between 1.08 and 1.13.

[0045] The concentrated liquid is transported to a water washing tower, and is washed to remove impurities (DMF, sucralose and tetrachlorosucrose) at a mass ratio of 2.5:1 between the concentrated liquid and water. The tower bottom pressure during the water washing is 155 Kpa.

[0046] The mother liquor 1 after water washing is conveyed into an automatic stratification tank to obtain an ester phase, and the ester phase is conveyed into a decolorization kettle, and activated carbon is added for stirring and decolorization treatment.

[0047] The decolorized liquid is transported into the crystallization kettle for cooling and crystallization. The crystallization temperature is 9°C and the crystallization time is 15-20h.

[0048] The crystals are separated from the mother liquor by filtering through a filter press, and the filter residue is sucralose-6-ethyl ester.

[0049] Comparative Example 1 Treatment Method of Mother Liquor Containing Sucralose-6-Ethyl Ester The difference between this comparative example and the embodiment lies in that the concentration parameters, water washing parameters and recrystallization parameters are different.

[0050] Specifically:

[0051] The mother liquor containing sucralose-6-ethyl ester was concentrated by a single-effect evaporator at a concentration temperature of 42° C., so that the relative density of the concentrated liquid in the bottom material of the single-effect evaporator was controlled between 1.20 and 1.25.

[0052] The concentrated liquid is transported to a water washing tower, and is washed to remove impurities (DMF, sucralose and tetrachlorosucrose) at a mass ratio of 0.5:1 between the concentrated liquid and water. The tower bottom pressure during the water washing is 140 Kpa.

[0053] The mother liquor 1 after water washing is conveyed into an automatic stratification tank to obtain an ester phase, and the ester phase is conveyed into a decolorization kettle, and activated carbon is added for stirring and decolorization treatment.

[0054] The decolorized liquid is transported into the crystallization kettle for cooling and crystallization. The crystallization temperature is 0°C and the crystallization time is 15-20h.

[0055] The crystals are separated from the mother liquor by filtering through a filter press, and the filter residue is sucralose-6-ethyl ester.

[0056] Comparative Example 2 Treatment Method of Mother Liquor Containing Sucralose-6-Ethyl Ester The difference between this comparative example and the embodiment lies in that the concentration parameters, water washing parameters and recrystallization parameters are different.

[0057] Specifically:

[0058] The mother liquor containing sucralose-6-ethyl ester was concentrated by a single-effect evaporator at a concentration temperature of 42° C., so that the relative density of the concentrated liquid in the bottom material of the single-effect evaporator was controlled between 1.01 and 1.03.

[0059] The concentrated liquid is transported to a water washing tower, and is washed with water to remove impurities (DMF, sucralose and tetrachlorosucrose) at a mass ratio of 4:1 between the concentrated liquid and water. The tower bottom pressure during the water washing is 160Kpa.

[0060] The mother liquor 1 after water washing is conveyed into an automatic stratification tank to obtain an ester phase, and the ester phase is conveyed into a decolorization kettle, and activated carbon is added for stirring and decolorization treatment.

[0061] The decolorized liquid is transported into the crystallization kettle for cooling and crystallization. The crystallization temperature is 10°C and the crystallization time is 15-20h.

[0062] The crystals are separated from the mother liquor by filtering through a filter press, and the filter residue is sucralose-6-ethyl ester.

[0063] The yields of sucralose-6-ethyl ester and the purity of sucralose-6-ethyl ester of Examples 1-3 and Comparative Examples 1-2 are shown in Table 1.

[0064] Table 1

[0065]

[0066] Meanwhile, subsequent production was carried out using the sucralose-6-ethyl ester prepared in the example and the comparative example as raw materials, and it was found that the sugar content in the comparative example was significantly lower than that in the example.

[0067] It should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in the field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for treating a mother liquor containing sucralose-6-ethyl ester, characterized in that: The steps include: S1, concentrating the mother liquor containing sucralose-6-ethyl ester to obtain a concentrated solution; S2, washing the concentrated liquid with water to remove impurities, and obtaining mother liquor 1; S3, separating the mother liquor 1 into layers to obtain an ester phase, and decolorizing to obtain a decolorized liquid; S4, recrystallizing the decolorized liquid and separating the solid from the liquid to obtain sucralose-6-ethyl ester; The concentration temperature in step S1 is 40-45° C.; the relative density of the concentrated solution is 1.08-1.

15.

2. The processing method according to claim 1, characterized in that: The relative density of the concentrated liquid is 1.1-1.

12.

3. The processing method according to claim 1, characterized in that: The water washing pressure in step S2 is 145-155 KPa.

4. The processing method according to claim 1, characterized in that: The water washing pressure in step S2 is 148-152 KPa.

5. The processing method according to claim 1, characterized in that: The mass ratio of the concentrate to water in step S2 is 1-3:1, preferably 1.5-2.5:1, and more preferably 2:

1.

6. The processing method according to claim 1, characterized in that: The recrystallization in step S4 is cooling crystallization.

7. The processing method according to claim 6, characterized in that: The recrystallization is as follows: crystallization at 3-9°C for 15-20h.

8. The processing method according to claim 7, characterized in that: The recrystallization is as follows: crystallization at 4-6°C for 15-20h.

9. The processing method according to claim 5, characterized in that: The solid-liquid separation in step S4 includes centrifugation, suction filtration or filter pressing.

10. Use of the treatment method according to any one of claims 1 to 9 in the production of sucralose.

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