CN107435084A - It is a kind of that cane molasses are carried out with refined technique using multistage membrane filtration - Google Patents

Abstract

The invention relates to a process for refining sugarcane molasses by multi-stage membrane filtration, which comprises the following steps: first, decolorize and clarify the diluted and centrifuged molasses by using an ultrafiltration membrane; The filtered permeate is further decolorized and desalinated by ion exchange resin and enters the nanofiltration membrane system. After being concentrated and removed by the nanofiltration membrane, the nanofiltration concentrated solution continues to circulate and apply crystallization to produce sugar, and the nanofiltration permeate is concentrated by the reverse osmosis membrane. Finally, the reverse osmosis concentrate is used to prepare functional sugar drinks, and the reverse osmosis permeate is used for dilution and diafiltration of molasses during ultrafiltration membrane treatment. The process provided by the invention can realize the recycling and high-value utilization of molasses, has simple equipment, is easy for continuous and automatic production, has no chemical additives, and can avoid the generation of waste molasses.

Description

A process for refining sugarcane molasses by multi-stage membrane filtration

technical field

The invention belongs to the technical field of refined molasses, and in particular relates to a process for refining sugarcane molasses by using multistage membrane filtration.

Background technique

Cane sugar molasses is a dark brown, viscous by-product produced by a sugar factory using sugar cane as raw material after pressing, clarification and purification of cane juice, filtration, evaporation and concentration, and crystallization of sugar. It is commonly known as orange water. The yield of sucrose molasses is 2.5-3.0% of the raw material sugar cane, containing water, sugar, pigment, inorganic salt and other components, the total sugar content is about 50%, and the sugar hammer is greater than 60%. The sugars are mainly sucrose, glucose and fructose.

Sucrose molasses is a widely used raw material, which can be used in chemical industry, light industry, food, medicine and building materials and other industries. Most of them are processed into various fermented products (alcohol, monosodium glutamate, organic acids, etc.), are also used to produce caramel pigment, and can also be directly used as feed additives, but these applications have low added value and are prone to secondary pollution. question. In order to improve the economic benefits of sugar factories and solve environmental pollution problems, the high-value utilization of sugarcane molasses resources has been paid more and more attention.

CN102020870A discloses a process of using sucrose molasses as raw material to produce caramel by high-temperature chemical catalysis; CN102634545A discloses a method for producing L-malic acid by fermenting sucrose molasses; CN105063124A discloses a method of using sucrose molasses as raw material, A method for obtaining raffinose by fermentation, centrifugation, membrane separation, resin adsorption, concentration, crystallization and dry extraction; CN105154226A discloses a method for preparing tobacco flavor by dilute acidolysis of sugarcane molasses and Maillard reaction. The techniques adopted in the above-mentioned methods are relatively complicated, and it is difficult to popularize them locally in sugar factories, and the utilization of each component of molasses is not sufficient. In addition, the preservation and transportation of molasses will greatly increase its processing cost.

Molasses is mainly produced by the accumulation and formation of impurities such as pigments, reducing sugars and inorganic salts during the evaporation and crystallization of sugarcane clear juice. The removal of pigments, reducing sugars and inorganic salts in molasses can realize the recycling of molasses, which will greatly reduce the generation of waste molasses. CN105063247A uses ultrafiltration and nanofiltration membranes to decolorize sugarcane mixed juice and remove reducing sugar to reduce the color value of sugarcane mixed juice and improve its purity, reducing the generation of molasses; there are also activated carbon, microfiltration membranes or ion exchange resins for molasses To clarify the reports of decolorization and refining, however, due to the complex composition of molasses, the removal and utilization of reducing sugar in molasses cannot be achieved.

Therefore, how to realize the recycling and high-value utilization of molasses with a simpler process and easier continuous and automated production has become a hot research topic at present.

Contents of the invention

Based on the above problems, the present invention provides a process for refining sugarcane molasses by multi-stage membrane filtration, which realizes the recycling and high-value utilization of molasses. chemical additives.

For reaching this purpose, the present invention adopts following technical scheme:

The invention provides a process for refining sugarcane molasses by multistage membrane filtration, which comprises the following steps:

(1) Ultrafiltration membrane treatment: the ultrafiltration membrane is used to decolorize and clarify the diluted and centrifuged molasses, and the ultrafiltration concentrated solution is used for natural pigment extraction;

(2) Nanofiltration membrane treatment: After the ultrafiltration permeate is decolorized and desalinated by ion exchange resin, it is concentrated and removed by nanofiltration membrane, and the nanofiltration concentrated solution is recycled for crystallization to produce sugar;

(3) Reverse osmosis membrane treatment: After the nanofiltration permeate is concentrated by the reverse osmosis membrane, the reverse osmosis concentrate is used to prepare functional sugar beverages, and the reverse osmosis permeate is used for the dilution of molasses in step (1) ultrafiltration membrane treatment and diafiltration.

In the present invention, the ultrafiltration membrane is used to decolorize and clarify the molasses after dilution and centrifugation. The ultrafiltration concentrated liquid can be used for the extraction of natural pigments after being washed and filtered by adding water. Membrane system: after concentration and removal of impurities through the nanofiltration membrane, the nanofiltration concentrated solution can continue to circulate and apply crystallization to produce sugar due to the removal of some small molecular impurities such as reducing sugars, amino acids, and inorganic salts, and the nanofiltration permeate enters the reverse osmosis membrane system; after reverse osmosis concentration, the reverse osmosis concentrate contains a large amount of sugar, amino acids and monovalent inorganic salts, which can be used to prepare functional sugar drinks; the reverse osmosis permeate is pure water, which can be used for dilution and washing of molasses in the ultrafiltration process filter.

The process for refining sugarcane molasses by using multi-stage membrane filtration provided by the present invention adopts the multi-stage membrane integrated filtration technology of ultrafiltration-nanofiltration-reverse osmosis to realize the removal and utilization of reducing sugar in molasses, so that the molasses can be obtained Recycling and high-value utilization are eliminated.

According to the present invention, the process of diluting and centrifuging described in step (1) is: first add pure water to the molasses for dilution, and then adjust the pH value of the diluted molasses to 6.8-7.5, for example, it can be 6.8, 6.9, 7, 7.1, 7.2 , 7.3, 7.4 or 7.5, preferably 7.2, then remove suspended matter in the molasses by a high-speed centrifuge.

According to the present invention, the mass ratio of molasses and pure water in step (1) is 1:1-1:6, such as 1:1, 1:2, 1:3, 1:4, 1:5 or 1 :6, preferably 1:2-1:6.

According to the present invention, the temperature of the ultrafiltration membrane treatment in step (1) is 50-95°C, such as 50°C, 52°C, 55°C, 60°C, 62°C, 65°C, 68°C, 72°C, 77°C ℃, 80℃, 90℃ or 95℃, preferably 50-65℃; the operating pressure is 0.5-2.0MPa, such as 0.5MPa, 0.8MPa, 1.0MPa, 1.2MPa, 1.3MPa, 1.5MPa, 1.8MPa or 2.0MPa, preferably 1.0-1.5MPa.

According to the present invention, the molecular weight cut-off of the ultrafiltration membrane in step (1) is 1000-5000Da, such as 1000Da, 1200Da, 1500Da, 2000Da, 2500Da, 3000Da, 3500Da, 4000Da or 5000Da, preferably 1200-4800Da.

According to the present invention, the ultrafiltration membrane in step (1) is any one or a combination of at least two of roll-type modules, tube-type modules, flat-type modules or hollow-fiber modules.

According to the present invention, the material of the ultrafiltration membrane in step (1) is any one or at least two of regenerated cellulose, polyamide, polysulfone, polyethersulfone, sulfonated polyethersulfone or polyvinylidene fluoride combination.

According to the present invention, the decolorization and desalination of the ion exchange resin in step (2) is to remove the residual pigment, calcium ion, magnesium ion, sulfate ion and phosphate ion in the ultrafiltration permeate.

Exemplarily, the decolorization and desalination in step (2) adopt the following process, but not limited thereto.

Pass the ultrafiltration permeate through a mixed bed of anion and cation exchange resins to remove a small amount of pigment, calcium, magnesium, sulfate and phosphate ions.

According to the present invention, the ion exchange resin is a combination of anion exchange resin and cation exchange resin, and the present invention does not specifically limit the types of the anion exchange resin and cation exchange resin.

According to the present invention, the temperature of the nanofiltration membrane treatment in step (2) is 50-95°C, such as 50°C, 52°C, 55°C, 60°C, 62°C, 65°C, 68°C, 72°C, 77°C ℃, 80℃, 90℃ or 95℃, preferably 50-65℃; the operating pressure is 2.0-4.1MPa, such as 2MPa, 2.2MPa, 2.5MPa, 3MPa, 3.2MPa, 3.5MPa, 3.8MPa or 4.1MPa , preferably 2.0-3.5MPa.

According to the present invention, the molecular weight cut-off of the nanofiltration membrane in step (2) is 150-400Da, such as 150Da, 180Da, 200Da, 220Da, 250Da, 300Da, 350Da or 400Da, preferably 200Da.

According to the present invention, the nanofiltration membrane in step (2) is a roll-type assembly.

According to the present invention, the material of the nanofiltration membrane in step (2) is sulfonated polyethersulfone and/or polyamide.

According to the present invention, the temperature of the reverse osmosis membrane treatment in step (3) is 25-45°C, such as 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40°C, 42°C or 45°C. °C, preferably 28-35 °C; operating pressure 3.0-6.0MPa, for example, 3.0MPa, 3.2MPa, 3.5MPa, 4.0MPa, 4.2MPa, 4.5MPa, 5.0MPa or 6.0MPa, preferably 3.5-5.0MPa.

According to the present invention, the reverse osmosis membrane described in step (3) is a roll-type module.

According to the present invention, the material of the reverse osmosis membrane in step (3) is polyamide and/or cellulose acetate.

According to the present invention, the standard desalination rate of sodium chloride by the reverse osmosis membrane in step (3) is 99.0-99.8%.

The ultrafiltration concentrated liquid described in the present invention, its concentration ratio is 2-7 times, for example 2 times, 3 times, 4 times, 6 times or 7 times etc., add pure water washing and filtering constantly after concentrating, control the rate of adding water and The permeation flux of the ultrafiltration membrane is equal, and the volume of pure water added is 1-5 times that of the ultrafiltration concentrate.

The concentration ratio of the nanofiltration concentrated liquid described in the present invention is 2-5 times; the concentration ratio of the reverse osmosis described in the present invention is 4-8 times.

Exemplarily, the process for refining sugarcane molasses by multi-stage membrane filtration according to the present invention comprises the following steps:

(1) Ultrafiltration membrane treatment: Under the conditions of temperature 50-95℃ and pressure 0.5-2.0MPa, ultrafiltration membrane is used to decolorize and clarify the diluted and centrifuged molasses, and the ultrafiltration concentrate is used for natural pigment extraction ;

(2) Nanofiltration membrane treatment: Under the conditions of temperature 50-95°C and pressure 2.0-4.1MPa, the ultrafiltration permeate is decolorized and desalinated by ion exchange resin, and then concentrated and removed by nanofiltration membrane. The nanofiltration concentrated solution continues to circulate and apply crystallization to produce sugar;

(3) Reverse osmosis membrane treatment: Under the conditions of temperature 25-45°C and pressure 3.0-6.0MPa, after the nanofiltration permeate is concentrated through the reverse osmosis membrane, the reverse osmosis concentrate is used to prepare functional sugar beverages. The permeate permeate is used for dilution and diafiltration of molasses in step (1) ultrafiltration membrane treatment process.

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) The present invention uses ultrafiltration-nanofiltration-reverse osmosis multi-stage membrane integrated filtration technology to refine sugarcane molasses, and realizes high-value utilization of sugarcane molasses. This process can not only avoid the generation of molasses and Accumulate, improve the sugar production rate and product quality, and also obtain natural raw materials for extracting natural pigments and preparing sugar beverages, realize high-value utilization of non-sucrose substances in molasses, and reduce the production cost of sucrose;

(2) The present invention uses ultrafiltration-nanofiltration-reverse osmosis multi-stage membrane integrated filtration technology to refine sugarcane molasses, realizes the grading and full utilization of molasses, and improves the added value of comprehensive utilization of molasses; the nanofiltration concentrated solution is recycled Sugar production by crystallization can increase the yield of sucrose by more than 20%; reverse osmosis effluent is used to dilute molasses and ultrafiltration washing water, which can save water by more than 40%;

(3) The refining process provided by the present invention has the advantages of simple and safe operation, no chemical additives, and easy continuous production.

Description of drawings

Figure 1 is a schematic diagram of the process flow for refining sugarcane molasses by multi-stage membrane filtration.

detailed description

The device used in the process of refining sugarcane molasses by multi-stage membrane filtration in the present invention typically but not limitedly can include the following components: buffer tank, evaporation crystallization tank, centrifuge, anion and cation exchange resin, ultrafiltration, nanofiltration and reverse The permeable membrane module and the connecting pipeline; the inlet of the centrifuge is connected with the buffer tank through the pipeline, the inlet of the ultrafiltration membrane module is connected with the outlet of the centrifuge through the pipeline, and the retention side of the ultrafiltration membrane module The discharge port is connected to the natural pigment extraction system through pipelines, the discharge port on the permeation side of the ultrafiltration membrane module is connected to the feed port of the anion-cation exchange resin mixed bed through pipelines, and the discharge port of the anion-cation exchange mixed bed is The mouth is connected with the inlet of the nanofiltration membrane module, the outlet of the intercepted side of the nanofiltration membrane module is connected with the inlet of the evaporation crystallization tank through the pipeline, and the outlet of the side of the nanofiltration membrane module is connected with the reverse osmosis through the pipeline. The feed port of the membrane module is connected, the discharge port of the intercepted side of the reverse osmosis membrane module is connected with the sugar beverage preparation system through the pipeline, and the discharge port of the permeation side of the reverse osmosis membrane module is connected with the feed port of the ultrafiltration membrane module through the pipeline Pass.

Concrete utilize multi-stage membrane filtration to carry out the technological process of refining sugarcane molasses as shown in Figure 1, and it comprises the following steps:

(1) Ultrafiltration membrane treatment: the ultrafiltration membrane is used to decolorize and clarify the diluted and centrifuged molasses, and the ultrafiltration concentrated solution is used for natural pigment extraction;

(2) Nanofiltration membrane treatment: After the ultrafiltration permeate is decolorized and desalinated by ion exchange resin, it is concentrated and removed by nanofiltration membrane, and the nanofiltration concentrated solution continues to circulate and apply crystallization to produce sugar;

(3) Reverse osmosis membrane treatment: After the nanofiltration permeate is concentrated by the reverse osmosis membrane, the reverse osmosis concentrate is used to prepare functional sugar beverages, and the reverse osmosis permeate is used for dilution and diafiltration of molasses during ultrafiltration membrane treatment .

The present invention will be further described below in conjunction with the embodiments, and the protection scope of the subject matter involved in the present invention is not limited to these embodiments.

Example 1

First pump 100kg of waste molasses into the buffer tank, add 100kg of pure water, heat and mix well, add food-grade sodium hydroxide to adjust the pH to 7.2, and then remove the suspended solids through a high-speed centrifuge and enter the ultrafiltration decolorization system. The ultrafiltration membrane module is Polyamide/polysulfone spiral membrane module, molecular weight cut-off is 1000Da, operating temperature is 65°C, pressure is 1.5MPa, after concentrating twice, continue to add 500kg of washing water to the ultrafiltration membrane module to obtain 600kg of decolorized and clarified ultrafiltration The permeate enters the anion-cation exchange resin mixed bed to continue decolorization and desalination. The diluted molasses after decolorization and desalination enters the nanofiltration membrane module for concentration. 65°C, pressure 3MPa, concentrated 2 times to get 300kg of nanofiltration concentrated liquid into the crystallization tank, 300kg of nanofiltration permeate into the reverse osmosis membrane module for concentration, the reverse osmosis membrane module is a polyamide roll-type membrane module, for sodium chloride The standard desalination rate is 99.5%, the operating temperature is 45°C, and the pressure is 5Mpa. After being concentrated 8 times, 37.5kg of reverse osmosis concentrate enters the sugar beverage preparation system, and 262.5kg of reverse osmosis permeate is used for ultrafiltration and washing water.

Table 1 shows the sucrose, reducing sugar, color value, turbidity and conductivity in the above-mentioned feed liquids at all levels. The concentrated nanofiltration solution is used continuously as refined molasses. Compared with the stock solution of molasses, the concentration ratio of sucrose and reducing sugar in refined molasses increases by 84.6%, the color value decreases by 99.8%, the turbidity decreases by 99.9%, and the conductivity decreases by 99.9%.

Table 1

Example 2

First, pump 100kg of molasses into the buffer tank, add 300kg of pure water, heat and mix, add food grade sodium hydroxide to adjust the pH to 7.2, and then remove the suspended solids through a high-speed centrifuge and enter the ultrafiltration decolorization system. Chemicalized polyethersulfone roll-type membrane module with a molecular weight cut-off of 2000Da, an operating temperature of 60°C and a pressure of 1MPa. After concentrating for 4 times, continue to add 300kg of wash water to the ultrafiltration membrane module to obtain 600kg of decolorized ultrafiltration permeate Enter the anion-cation exchange resin mixed bed to continue decolorization and desalination. The diluted molasses after decolorization and desalination enters the nanofiltration membrane module for concentration. Pressure 4MPa, concentrated 3 times to get 200kg of nanofiltration concentrated liquid into the crystallization tank, 400kg of nanofiltration permeate into the reverse osmosis membrane module for concentration, the reverse osmosis membrane module is a polyamide roll-type membrane module, the standard desalination of sodium chloride The rate is 99.0%, the operating temperature is 25°C, and the pressure is 6MPa. After being concentrated 4 times, 100kg of reverse osmosis concentrate enters the sugar beverage preparation system, and 300kg of reverse osmosis permeate is used for ultrafiltration and diafiltration water.

The concentrated nanofiltration solution is used continuously as refined molasses. Compared with the stock solution of molasses, the concentration ratio of sucrose and reducing sugar in refined molasses increases by 143%, the color value decreases by 99.7%, the turbidity decreases by 99.9%, and the conductivity decreases by 99.9%.

Example 3

First, pump 100kg of molasses into the buffer tank, add 600kg of pure water, heat and mix well, add food-grade sodium hydroxide to adjust the pH to 7.2, and then remove the suspended solids through a high-speed centrifuge and enter the ultrafiltration decolorization system. Chemicalized polyethersulfone roll-type membrane module, with a molecular weight cut-off of 5000Da, an operating temperature of 50°C, and a pressure of 1MPa. After concentration of 7 times, 600kg of decolorized ultrafiltration permeate is obtained and enters an anion-cation exchange resin mixed bed for further decolorization and desalination. The diluted molasses after decolorization and desalination enters the nanofiltration membrane module for concentration. The nanofiltration membrane module is a polyamide roll-type membrane module with a molecular weight cut-off of 400Da, an operating temperature of 65°C, and a pressure of 4MPa. After concentration of 4 times, 150kg of nanofiltration concentrate is obtained. After entering the crystallization tank, 450kg of nanofiltration permeate enters the reverse osmosis membrane module for concentration. The reverse osmosis membrane module is a polyamide roll-type membrane module. The standard desalination rate of sodium chloride is 99.0%. The operating temperature is 40°C and the pressure is 6MPa. After being concentrated 3 times, 150kg of reverse osmosis concentrate enters the sugar beverage preparation system, and 300kg of reverse osmosis permeate is used for molasses dilution water.

The concentrated nanofiltration solution is used continuously as refined molasses. Compared with the stock solution of molasses, the concentration ratio of sucrose and reducing sugar in refined molasses increases by 185%, the color value decreases by 99.5%, the turbidity decreases by 99.9%, and the conductivity decreases by 99.9%.

Comparative example 1

Compared with Example 1, except that without the ultrafiltration membrane module, others are the same as Example 1, and the concrete steps are:

First, pump 100kg of molasses into the buffer tank, add 100kg of pure water, heat and mix well, add food-grade sodium hydroxide to adjust the pH to 7.2, remove the suspended solids in a high-speed centrifuge, mix with 400kg of pure water, and enter the anion and cation exchange resin Mixed bed decolorization and desalination, the diluted molasses after decolorization and desalination enters the nanofiltration membrane module for concentration. The nanofiltration membrane module is a polyamide roll-type membrane module with a molecular weight cut-off of 150Da, an operating temperature of 65°C, a pressure of 3MPa, and after being concentrated twice The obtained 300kg nanofiltration concentrate enters the crystallization tank, and the 300kg nanofiltration permeate enters the reverse osmosis membrane module for concentration. The reverse osmosis membrane module is a polyamide roll-type membrane module. 45°C, pressure 5MPa, concentrated 8 times, 37.5kg reverse osmosis concentrate enters the sugar beverage preparation system, 262.5kg reverse osmosis permeate is used for molasses dilution. The comparison of comparative example 1 and embodiment 1 result is as shown in table 2:

Table 2

Comparative example 2

Compared with Example 1, except that only ultrafiltration membrane modules are used, the others are the same as Example 1. The comparison of comparative example 2 and embodiment 1 result is as shown in table 3:

table 3

Comparative example 3

Compared with Example 1, except that only the nanofiltration membrane module is used, the others are the same as in Example 1, and the nanofiltration permeate directly enters the sugar beverage preparation system. The comparison between the results of Comparative Example 3 and Example 1 is shown in Table 4. In addition, compared with Example 1, the water consumption of Comparative Example 3 increased by 77.8%.

Table 4

It can be seen from the comparison that the present invention refines sugarcane molasses by adopting the multi-stage membrane integrated filtration technology of ultrafiltration-nanofiltration-reverse osmosis, and realizes the high-value utilization of sugarcane molasses. The generation and accumulation of molasses can improve the sugar yield and product quality, and can also obtain natural raw materials for extracting natural pigments and preparing sugar beverages, realizing high-value utilization of non-sucrose substances in molasses, and reducing the production of sucrose cost.

The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of selected components in the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (10)

1. a kind of carry out refined technique to cane molasses using multistage membrane filtration, it is characterised in that comprises the following steps：

(1) ultrafiltration membrane treatment：Molasses after being centrifuged using milipore filter to dilution carry out decolouring clarifying treatment, and liquid is concentrated by ultrafiltration and is used for Nature strength；

(2) nanofiltration membrane treatment：Ultrafiltration permeate is after ion-exchange resin decolorization and desalination, at NF membrane concentrating and impurity removing Reason, nanofiltration concentrate recycled crystallization production sugar；

(3) reverse osmosis membrane processing：After reverse osmosis membrane concentrates, reverse osmosis concentrated liquid is used to prepare functional sugar drink nanofiltration permeate liquid Material, counter-infiltration permeate are used for the dilution of molasses and filter wash in step (1) ultrafiltration membrane treatment.

2. technique according to claim 1, it is characterised in that step (1) it is described dilution centrifugation process be：First to sugar Pure water is added in honey to be diluted, and is then 6.8-7.5 by dilution molasses adjustment pH value, preferably 7.2, then pass through high speed centrifugation Machine removes the suspension in molasses；

Preferably, the mass ratio of the molasses and pure water is 1:1-1:6, preferably 1:2-1:6.

3. technique according to claim 1 or 2, it is characterised in that the temperature of step (1) described ultrafiltration membrane treatment is 50- 95 DEG C, preferably 50-65 DEG C；Operating pressure is 0.5-2.0MPa, preferably 1.0-1.5MPa.

4. according to the technique described in one of claim 1-3, it is characterised in that the molecular cut off of step (1) described milipore filter For 1000-5000Da, preferably 1200-4800Da；

Preferably, the milipore filter is any one in wound module, tubular module, flat plate module or hollow fiber form component Kind or at least two combination；

Preferably, the material of the milipore filter is regenerated cellulose, polyamide, polysulfones, polyether sulfone, sulfonated polyether sulfone or gathers inclined fluorine In ethene any one or at least two combination.

5. according to the technique described in one of claim 1-4, it is characterised in that step (2) ion-exchange resin decolorization and Desalination is to be removed the remaining pigment and inorganic salts in ultrafiltration permeate；

Preferably, the ion exchange resin is any combination of anion exchange resin and cationic ion-exchange resin；

Preferably, the desalination is by the Ca in molasses²⁺、Mg²⁺、SO₄ ^2-And PO₄ ^2-It is removed.

6. according to the technique described in one of claim 1-5, it is characterised in that the temperature of step (2) described nanofiltration membrane treatment is 50-95 DEG C, preferably 50-65 DEG C；Operating pressure is 2.0-4.1MPa, preferably 2.0-3.5MPa.

7. according to the technique described in one of claim 1-6, it is characterised in that the molecular cut off of step (2) described NF membrane For 150-400Da, preferably 200Da；

Preferably, the NF membrane is wound module；

Preferably, the material of the NF membrane is sulfonated polyether sulfone and/or polyamide.

8. according to the technique described in one of claim 1-7, it is characterised in that the temperature of step (3) described reverse osmosis membrane processing For 25-45 DEG C, preferably 28-35 DEG C；Operating pressure 3.0-6.0MPa, preferably 3.5-5.0MPa.

9. according to the technique described in one of claim 1-8, it is characterised in that step (3) described reverse osmosis membrane is wound module；

Preferably, the material of the reverse osmosis membrane is polyamide and/or cellulose acetate；

Preferably, the reverse osmosis membrane is 99.0-99.8% to the standard salt rejection rate of sodium chloride.

10. according to the technique described in one of claim 1-9, it is characterised in that comprise the following steps：

(1) ultrafiltration membrane treatment：Temperature be 50-95 DEG C, pressure be 0.5-2.0MPa under conditions of, using milipore filter to dilution from Molasses after the heart carry out decolouring clarifying treatment, and liquid is concentrated by ultrafiltration and is used for nature strength；

(2) nanofiltration membrane treatment：It it is 50-95 DEG C in temperature, under conditions of pressure is 2.0-4.1MPa, ultrafiltration permeate is handed over through ion After changing resin decolorization and desalination, handled by NF membrane concentrating and impurity removing, nanofiltration concentrate, which continues cycling through, applies mechanically crystallization production sugar；

(3) reverse osmosis membrane processing：It it is 25-45 DEG C in temperature, under conditions of pressure is 3.0-6.0MPa, nanofiltration permeate liquid is by anti- After permeable membrane concentration, reverse osmosis concentrated liquid is used to prepare function sugar beverage, and counter-infiltration permeate is used for step (1) ultrafiltration membrane treatment The dilution of middle molasses and filter wash.