Method for producing high-purity arabinose crystals

Abstract

The present invention relates to a method for producing high-purity arabinose crystals, which comprises sequential steps of dissolving, blending, ion exchange, decolorization filtration, microfiltration, evaporation concentration, crystallization, centrifugation, drying, etc. During the production of arabinose crystals, the pH of the material is controlled to 4.3-7.5 and the temperature to 70°C or lower, thereby avoiding a decrease in purity due to the promotion of conversion of arabinose to miscellaneous sugars at high temperatures, and improving the purity of the produced arabinose crystals.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of sugar alcohol production, and particularly relates to a method for producing high-purity arabinose crystals. [Background technology]

[0002] Arabinose is widely used in fields such as medicine and health food. Low-purity arabinose crystal products cannot meet customer demand and are therefore cheap, while high-purity arabinose crystal products are sold at a relatively high price due to the complex process and high production difficulty. However, they can meet the process prescription needs of some special customers and have great market potential.

[0003] In conventional production processes, L-arabinose is affected by high temperature and low pH conditions, and undergoes reactions to be converted into other substances, such as isomerization to convert it into xylose, decomposition to break down into small molecules with five carbons or less, and polymerization to produce maltotriose. As a result, the content of L-arabinose constantly decreases during the arabinose production process, especially during the decolorization, evaporation, and chromatographic separation processes, and the purity of the produced crystalline arabinose rarely reaches 99.5% or more.

[0004] The patent with publication number CN112079886A discloses a method for increasing the purity of xylose and arabinose by chromatographic separation, but does not take into account the problem that high temperature and low pH in processes such as decolorization and chromatographic separation reduce the conversion rate of arabinose. Summary of the Invention [Problem to be solved by the invention]

[0005] The technical problem to be solved by the present invention is to provide a method for producing high-purity arabinose crystals, which improves the purity of arabinose crystals by controlling the pH and temperature during the production process to prevent isomerization, decomposition, and polymerization reactions. [Means for solving the problem]

[0006] The present invention is achieved as follows: A method for producing high-purity arabinose crystals, comprising the steps of: Step 1: dissolving low-content arabinose crystals to obtain a dissolved sugar solution, in which a temperature sensor and an automatic control valve are installed in the dissolving tank system, and the temperature during dissolving of the materials is monitored by a Siemens DCS automatic temperature control system, ensuring that the temperature of the dissolving solution during dissolving is 55-60°C, and the arabinose content of the low-purity arabinose crystals is 96-97%; Blending: Using an electromagnetic flowmeter, an automatic control valve, and a Siemens intelligent control system, the dissolved sugar solution is fed into a blending tank through a tube, and the arabinose centrifuged mother liquor from step 8 is added to the blending tank and blended to obtain a blended sugar solution with a pH value of 4.3-5.0, a dry base concentration of 50-60%, and an arabinose content of 94±0.5% after blending; Step 3: Ion exchange: The prepared sugar solution is subjected to ion exchange to obtain an ion-exchanged sugar solution, and the temperature of the material is controlled at 45-50°C by an ion exchange feed heat exchanger, and the pH of the ion-exchanged sugar solution is stabilized at 5.5-6.5; Step 4: Decolorization and filtration: The ion-exchanged sugar solution is fed into a decolorization tank through a tube, and the decolorization temperature is controlled to 60-65°C and the pH is controlled to 5.5-7.5 to decolorize and filter the solution to obtain a decolorized sugar solution; Step 5: using a microfiltration membrane with a pore size of 0.45 μm, microfiltrating the decolorized sugar solution while controlling the temperature at 50 to 65 ° C and the pH value at 5.0 to 7.5 during the microfiltration process to obtain a microfiltrated sugar solution; Step 6: Evaporation and concentration: The microfiltrated sugar solution is placed in an MVR evaporator, and evaporated and concentrated at a temperature of 65-70°C and a pH value of 5.0-7.5 to obtain a concentrated sugar solution; Step 7: crystallization: the concentrated sugar solution is placed in a vacuum sugar boiling system and crystallized at a temperature of 63-65°C and a vacuum of 70-90mbar; Step 8: centrifuging the material treated in step 7 in a centrifuge to separate solid arabinose from arabinose centrifuged mother liquor, and introducing the arabinose centrifuged mother liquor with an arabinose content of 89-91% into a blending tank through a tube for use in step 2; and Step 9: drying the solid arabinose with hot air at 80°C to obtain high-purity arabinose crystals having an arabinose content of 99.8% or more.

[0007] The temperature of the liquid material processing stage is strictly controlled at 70°C to avoid loss of purity due to accelerated conversion of arabinose to miscellaneous sugars at higher temperatures. [Effects of the Invention]

[0008] Compared with the prior art, the method for producing high-purity arabinose crystals of the present invention has the following features: (1) By installing a blending process before purification, the stability of the raw material liquid is ensured. (2) By setting the ratio of cations to anions in the ion exchange resin to 7:10 and stabilizing the pH of the discharged material from the ion exchange at 5.5 to 6.5, it is possible to avoid the problem of isomerization of the raw material liquid caused by local over-alkalinization during the pH adjustment operation of the raw material liquid by adding alkali, which would affect the production efficiency and product quality of the subsequent production process. (3) By dissolving, purifying, and concentrating arabinose crystals with a high miscellaneous sugar content to obtain arabinose crystals with a purity of 99.8% or more, the yield of the finished crystal product can be improved by more than 3.5% compared to conventional production processes. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the flow of steps in the method for producing high-purity arabinose crystals of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] In order to make the technical problems, technical solutions and beneficial effects of the present invention clearer and more obvious, the present invention will be described in more detail below with reference to examples and drawings. It should be understood that the specific examples described in this specification are only used to explain the present invention and are not used to limit the present invention.

[0011] A preferred embodiment of the method for producing high-purity arabinose crystals of the present invention is shown in Figure 1. The arrows in the figure indicate the direction of material flow or the direction of process progression. The production method includes the following steps:

[0012] Step 1 Dissolution: Low-content arabinose crystals are dissolved to obtain a dissolved sugar solution. The dissolution tank system is equipped with a temperature sensor and an automatic adjustment valve, and the temperature during dissolution is monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution is maintained at 55-60°C, and the arabinose content of the low-purity arabinose crystals is 96-97%, ensuring the stability of the raw material solution.

[0013] Step 2 Blending: The dissolved sugar solution is fed into the blending tank via a tube using an electromagnetic flowmeter, an automatic control valve, and a Siemens intelligent control system, and the arabinose centrifuged mother liquor from step 8 is added to the blending tank and blended to obtain a blended sugar solution with a pH value of 4.3 to 5.0, a dry base concentration of 50 to 60%, and an arabinose content of 94±0.5% after blending.

[0014] Step 3 Ion exchange: The prepared sugar solution is subjected to ion exchange to obtain an ion-exchanged sugar solution. The temperature of the material is controlled at 45-50°C using an ion exchange feed heat exchanger, and the pH of the ion-exchanged sugar solution is stabilized at 5.5-6.5. An ion exchange column is used for the ion exchange process, and the ratio of cationic resin to anionic resin in the ion exchange column is 7:10. By adjusting the ratio of cations to anions in the ion exchange resin to 7:10, the pH of the material discharged from the ion exchange is stabilized at 5.5-6.5, thereby preventing arabinose from being converted to other miscellaneous sugars when the pH is too low.

[0015] Step 4 Decolorization and filtration: The ion-exchanged sugar solution is placed in a decolorization tank via a tube, and the temperature is controlled to 60-65°C and the pH to 5.5-7.5, followed by decolorization and filtration to obtain a decolorized sugar solution. The decolorization and filtration process involves adding activated carbon for decolorization to the decolorization tank at 1.2-1.4 kg / ton dry basis, stirring at 110 rpm for 30-45 minutes to decolorize, and then filtering the solution using a plate-frame filter press to remove the activated carbon.

[0016] Step 5 Microfiltration: The decolorized sugar solution is microfiltered using a microfiltration membrane with a pore size of 0.45 μm, while controlling the temperature at 50 to 65° C. and the pH value at 5.0 to 7.5, to obtain a microfiltered sugar solution.

[0017] Step 6 Evaporation and concentration: The microfiltrated sugar solution is placed in an MVR evaporator, and evaporated and concentrated at a temperature of 65-70°C and a pH of 5.0-7.5 to obtain a concentrated sugar solution.

[0018] Step 7 Crystallization: The concentrated sugar solution is placed in a vacuum sugar boiling system and crystallized at a temperature of 63-65°C and a vacuum of 70-90 mbar. When the supersaturation of the concentrated sugar solution reaches 1.01-1.02, arabinose seed crystals of 300-400 mesh are added at a ratio of 2 / 10000 of the dry basis, followed by vacuum evaporation, followed by crystallization for 8 hours with a stirring speed of 80 rpm.

[0019] Step 8 Centrifugation: The material treated in step 7 is centrifuged in a centrifuge to separate the solid arabinose from the arabinose centrifugation mother liquor, and the arabinose centrifugation mother liquor with an arabinose content of 89-91% is introduced into a blending tank via a tube for the operation in step 2. The centrifugation treatment further includes controlling the water washing time to 10 seconds and the water temperature to 55-60°C.

[0020] Step 9 Drying: The solid arabinose is dried with hot air at 80°C to obtain high-purity arabinose crystals with an arabinose content of 99.8% or more. The drying process controls the moisture content to 0.15-0.3%, and once the desired moisture content is reached, the product is cooled to 20-24°C with clean cold air at 12-15°C.

[0021] The temperature of the liquid material processing stage is strictly controlled at 70°C to avoid loss of purity due to accelerated conversion of arabinose to miscellaneous sugars at higher temperatures.

[0022] The method for producing high purity arabinose crystals of the present invention is further illustrated below by specific examples.

[0023] Example 1: Determining the effect of temperature and pH on arabinose content

[0024] This embodiment includes the following steps.

[0025] Water was added to 100 g of L-arabinose sample to prepare a solution with a refractive index of 60%, and the pH was adjusted to 2.7 and 4.3. The solution was then heated at 60°C, 65°C, and 70°C for 48 hours. Samples were then taken and detected at 24 hours and 48 hours, respectively. The results are shown in Table 1 below.

[0026] [Table 1]

[0027] The results showed that the lower the pH and the higher the heating temperature during the arabinose production process, the faster the arabinose content decreased over time. A comparison of the trends in arabinose under various conditions revealed that pH is the main factor in reducing arabinose content. When the pH was 4.3 or higher, the content decreased by only 2.31% when the material was heated at 75°C for 48 hours. However, when the material was heated at pH 2.7 for 48 hours at 75°C, the arabinose content decreased by 8.9%, three times as much as when the material was heated at pH 4.3.

[0028] From the above, ensuring that the pH of the arabinose sugar solution is adjusted to 4.3 or higher reduces the impact of high temperatures on the arabinose content and avoids a decrease in production efficiency that would occur if the processing temperature were lowered due to the content of the ingredients. Example 2

[0029] A first embodiment of the method for producing high purity arabinose crystals of the present invention comprises the following steps.

[0030] Step 11 Dissolution: The purchased low-purity arabinose crystals were dissolved. The dissolution tank system was equipped with a temperature sensor and an automatic adjustment valve, and the temperature during dissolution was monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was maintained at 55-60°C, and the arabinose content in the low-purity arabinose crystals was 96%.

[0031] Step 12 Blending: Using an electromagnetic flow meter, an automatic control valve, and a Siemens intelligent control system, the sugar solution from step 11 was fed into the blending tank via a tube, and the arabinose centrifuged mother liquor from step 18 was added to the blending tank and blended, with the resulting pH value being 5.0, the dry base concentration being 50%, and the arabinose content being 93.84%.

[0032] Step 13 Ion exchange: The sugar solution prepared in step 12 was subjected to an ion exchange process. The temperature of the sugar solution was controlled at 45-50°C using an ion exchange feed heat exchanger, the ratio of cationic resin to anionic resin in the ion exchange system was adjusted to 7:10, and the pH of the solution after ion exchange was stabilized at 6.5.

[0033] Step 14 Decolorization and filtration: The sugar solution after ion exchange was placed in a decolorization tank via a tube, and activated carbon for decolorization was added to the decolorization tank at an amount of approximately 1.2 kg / ton dry basis. The temperature for decolorization was controlled at 60°C, the pH at 5.0 to 7.5, and the mixture was stirred at 110 rpm for 30 minutes to decolorize. The mixture was then filtered using a plate-frame filter press to remove the activated carbon.

[0034] Step 15 Microfiltration: Using a microfiltration membrane with a pore size of 0.45 μm, the temperature was controlled to 50 to 65° C. and the pH value to 5.0 to 7.5 during the microfiltration process, and the decolorized sugar solution was microfiltered in step 14.

[0035] Step 16 Evaporation concentration: The sugar solution treated in step 15 was placed in an MVR evaporator and concentrated by controlling the temperature at 68°C and the pH value at 5.0 to 7.5.

[0036] Step 17 Crystallization: The sugar solution processed in step 16 was placed in a vacuum sugar reduction system, and the temperature was controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution reached 1.01-1.02, 300-400 mesh seed crystals were added at a rate of 2 / 10000 of the dry basis, followed by vacuum evaporation. The crystallization period was 8 hours, and the stirring speed was controlled at 80 rpm to crystallize the sugar solution.

[0037] Step 18 Centrifugation: The material treated in step 17 was centrifuged in a centrifuge, the water washing time was 10 seconds, and the water temperature was controlled at 55-60°C to separate the solid arabinose from the arabinose centrifuged mother liquor. The solid arabinose was subjected to the operation in step 19, and the arabinose centrifuged mother liquor with an arabinose content of 89% was introduced into the blending tank through a tube and subjected to the operation in step 12.

[0038] Step 19 Drying and packaging: The solid arabinose processed in step 18 was dried with hot air at 80°C to control the moisture content to 0.15-0.3%. Once the desired moisture content was reached, the finished product was cooled to 20-24°C with clean cold air at 12-15°C to obtain high-purity arabinose crystals with an arabinose content of 99.8% or more. The processed arabinose crystals were packaged in a packaging machine. Example 3

[0039] A second embodiment of the method for producing high purity arabinose crystals of the present invention comprises the following steps.

[0040] Step 21 Dissolution: The purchased low-purity arabinose crystals were dissolved. The dissolution tank system was equipped with a temperature sensor and an automatic adjustment valve. The temperature during dissolution was monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was maintained at 55-60°C, and the arabinose content in the low-purity arabinose crystals was 97%.

[0041] Step 22 Blending: Using an electromagnetic flowmeter, an automatic control valve, and a Siemens intelligent control system, the sugar solution was fed into the blending tank via the sugar solution tube in step 21, and the arabinose centrifuged mother liquor in step 28 was added to the blending tank and blended, with the pH value after blending being within the range of 4.3 to 5.0, the dry base concentration being 60%, and the arabinose content being 94.57%.

[0042] Step 23 Ion exchange: The sugar solution prepared in step 22 was subjected to an ion exchange process, and the temperature of the sugar solution was controlled at 45 to 50°C using an ion exchange feed heat exchanger. The ratio of cationic resin to anionic resin in the ion exchange system was adjusted to 7:10, and the pH of the solution after ion exchange was stabilized at 6.0.

[0043] Step 24 Decolorization and filtration: The sugar solution after ion exchange was placed into a decolorization tank via a tube, and activated carbon for decolorization was added to the decolorization tank at 1.4 kg / ton dry basis. The temperature for decolorization was controlled at 62°C, the pH at 5.5 to 7.5, and the mixture was stirred at 110 rpm for 35 minutes to decolorize. The mixture was then filtered using a plate-frame filter press to remove the activated carbon.

[0044] Step 25 Microfiltration: Using a microfiltration membrane with a pore size of 0.45 μm, the temperature was controlled to 50 to 65° C. and the pH value to 5.0 to 7.5 during the microfiltration process, and the decolorized sugar solution was microfiltered in step 24.

[0045] Step 26 Evaporation concentration: The sugar solution treated in step 25 was placed in an MVR evaporator and concentrated by controlling the temperature at 68°C and the pH value at 5.0 to 7.5.

[0046] Step 27 Crystallization: The sugar solution processed in step 26 was placed in a vacuum sugar boiling system, and the temperature was controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution reached 1.01-1.02, 300-400 mesh seed crystals were added at a rate of 2 / 10000 of the dry basis, followed by vacuum evaporation. The crystallization period was 8 hours, and the stirring speed was controlled at 80 rpm to crystallize the sugar solution.

[0047] Step 28 Centrifugation: The material treated in step 27 was centrifuged in a centrifuge, the water washing time was 10 seconds, and the water temperature was controlled at 55-60°C to separate the solid arabinose from the arabinose centrifuged mother liquor. The solid arabinose was subjected to the operation in step 29, and the arabinose centrifuged mother liquor with an arabinose content of 91% was introduced into the blending tank through a tube and subjected to the operation in step 22.

[0048] Step 29 Drying and packaging: The solid arabinose processed in step 28 was dried with hot air at 80°C to control the moisture content to 0.15-0.3%. Once the desired moisture content was reached, the finished product was cooled to 20-24°C with clean cold air at 12-15°C to obtain high-purity arabinose crystals with an arabinose content of 99.8% or more. The processed arabinose crystals were packaged in a packaging machine. Example 4

[0049] A third embodiment of the method for producing high purity arabinose crystals of the present invention comprises the following steps.

[0050] Step 31 Dissolution: The purchased low-purity arabinose crystals were dissolved. The dissolution tank system was equipped with a temperature sensor and an automatic adjustment valve. The temperature during dissolution was monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was maintained at 55-60°C, and the arabinose content in the low-purity arabinose crystals was 96.5%.

[0051] Step 32 Blending: Using an electromagnetic flowmeter, an automatic control valve, and a Siemens intelligent control system, the sugar solution was fed into the blending tank via the sugar solution tube in step 31, and the arabinose centrifuged mother liquor in step 38 was added to the blending tank and blended, with the pH value after blending being within the range of 4.3 to 5.0, the dry base concentration being 55%, and the arabinose content being 94.50%.

[0052] Step 33 Ion exchange: The sugar solution prepared in step 32 was subjected to an ion exchange process. The temperature of the sugar solution was controlled at 45-50°C using an ion exchange feed heat exchanger, the ratio of cationic resin to anionic resin in the ion exchange system was adjusted to 7:10, and the pH of the solution after ion exchange was stabilized at 5.5.

[0053] Step 34 Decolorization and filtration: The sugar solution after ion exchange was placed in a decolorization tank via a tube, and activated carbon for decolorization was added to the decolorization tank at 1.25 kg / ton dry basis. The temperature for decolorization was 65°C, the pH was controlled at 5.5 to 7.5, and the decolorization was carried out for 45 minutes by stirring at 110 rpm. The solution was then filtered using a plate-frame filter press to remove the activated carbon.

[0054] Step 35 Microfiltration: Using a microfiltration membrane with a pore size of 0.45 μm, the temperature was controlled to 50 to 65° C. and the pH value to 5.0 to 7.5 during the microfiltration process, and the decolorized sugar solution was microfiltered in step 34.

[0055] Step 36 Evaporation concentration: The sugar solution treated in step 35 was placed in an MVR evaporator and concentrated by controlling the temperature at 70°C and the pH value at 5.0 to 7.5.

[0056] Step 37 Crystallization: The sugar solution processed in step 36 was placed in a vacuum sugar reduction system, and the temperature was controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution reached 1.01-1.02, 300-400 mesh seed crystals were added at a rate of 2 / 10000 of the dry basis, followed by vacuum evaporation. The crystallization period was 8 hours, and the stirring speed was controlled at 80 rpm to crystallize the sugar solution.

[0057] Step 38 Centrifugation: The material treated in step 37 was centrifuged in a centrifuge, the water washing time was 10 seconds, and the water temperature was controlled at 55-60°C to separate the solid arabinose from the arabinose centrifuged mother liquor. The solid arabinose was subjected to the operation in step 39, and the arabinose centrifuged mother liquor with an arabinose content of 90.3% was introduced into the blending tank through a tube and subjected to the operation in step 32.

[0058] Step 39 Drying and packaging: The solid arabinose processed in step 38 was dried with hot air at 80°C to control the moisture content to 0.15-0.3%. Once the desired moisture content was reached, the finished product was cooled to 20-24°C with clean cold air at 12-15°C to obtain high-purity arabinose crystals with an arabinose content of 99.8% or more. The processed arabinose crystals were packaged in a packaging machine. Example 5

[0059] A fourth embodiment of the method for producing high purity arabinose crystals of the present invention comprises the following steps.

[0060] Step 41 Dissolution: The purchased low-purity arabinose crystals were dissolved. The dissolution tank system was equipped with a temperature sensor and an automatic adjustment valve, and the temperature during dissolution was monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was maintained at 55-60°C, and the arabinose content in the low-purity arabinose crystals was 96.9%.

[0061] Step 42 Blending: Using an electromagnetic flowmeter, an automatic control valve, and a Siemens intelligent control system, the sugar solution was fed into the blending tank via the sugar solution tube in step 41, and the arabinose centrifuged mother liquor in step 48 was added to the blending tank and blended, with the pH value after blending being within the range of 4.3 to 5.0, the dry base concentration being 60%, and the arabinose content being 94.43%.

[0062] Step 43 Ion exchange: The sugar solution prepared in step 42 was subjected to an ion exchange process, and the temperature of the sugar solution was controlled at 45 to 50°C using an ion exchange feed heat exchanger. The ratio of cationic resin to anionic resin in the ion exchange system was adjusted to 7:10, and the pH of the solution after ion exchange was stabilized at 6.2.

[0063] Step 44 Decolorization and filtration: The sugar solution after ion exchange was placed into a decolorization tank via a tube, and activated carbon for decolorization was added to the decolorization tank at 1.38 kg / ton dry basis. The temperature for decolorization was controlled at 60°C, the pH at 5.5 to 7.5, and the mixture was stirred at 110 rpm for 40 minutes to decolorize. The mixture was then filtered using a plate-frame filter press to remove the activated carbon.

[0064] Step 45 Microfiltration: Using a microfiltration membrane with a pore size of 0.45 μm, the temperature was controlled to 50 to 65° C. and the pH value to 5.0 to 7.5 during the microfiltration process, and the decolorized sugar solution was microfiltered in step 44.

[0065] Step 46 Evaporation concentration: The sugar solution treated in step 45 was placed in an MVR evaporator and concentrated by controlling the temperature at 65°C and the pH value at 5.0 to 7.5.

[0066] Step 47 Crystallization: The sugar solution processed in step 46 was placed in a vacuum sugar boiling system, and the temperature was controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution reached 1.01-1.02, 300-400 mesh seed crystals were added at a rate of 2 / 10000 of the dry basis, followed by vacuum evaporation. The crystallization period was 8 hours, and the stirring speed was controlled at 80 rpm to crystallize the sugar solution.

[0067] Step 48 Centrifugation: The material treated in step 47 was centrifuged in a centrifuge, the water washing time was 10 seconds, and the water temperature was controlled at 55-60°C to separate the solid arabinose from the arabinose centrifuged mother liquor. The solid arabinose was subjected to the operation in step 49, and the arabinose centrifuged mother liquor with an arabinose content of 89.8% was introduced into the blending tank through a tube and subjected to the operation in step 42.

[0068] Step 49 Drying and packaging: The solid arabinose processed in step 48 was dried with hot air at 80°C to control the moisture content to 0.15-0.3%. Once the desired moisture content was reached, the finished product was cooled to 20-24°C with clean cold air at 12-15°C to obtain high-purity arabinose crystals with an arabinose content of 99.8% or more. The processed arabinose crystals were packaged in a packaging machine.

[0069] The technical effects of the method for producing high-purity arabinose crystals of the present invention will be further explained below by way of comparative examples. Comparative Example

[0070] A conventional manufacturing process was employed, with the ratio of anionic resin to cationic resin in the ion exchange step being 1:1.

[0071] Step 51 Dissolution: The purchased low-purity arabinose crystals were dissolved. The dissolution tank system was equipped with a temperature sensor and an automatic adjustment valve, and the temperature during dissolution was monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was maintained at 55-60°C, and the arabinose content of the low-purity arabinose crystals was 97%, the dry base concentration was 55%, and the pH value was in the range of 3.5-5.0.

[0072] Step 52 Ion exchange: The sugar solution obtained in step 51 was subjected to an ion exchange process, and the temperature of the sugar solution was controlled at 45 to 50°C using an ion exchange feed heat exchanger. The ratio of cationic resin to anionic resin in the ion exchange system was adjusted to 1:1, and the pH of the solution after ion exchange was stabilized at 3.5 to 4.0.

[0073] Step 53 Decolorization and filtration: The sugar solution after ion exchange was placed into a decolorization tank via a tube, and activated carbon for decolorization was added to the decolorization tank at 1.4 kg / ton dry basis. The temperature for decolorization was controlled at 75-80°C, the pH at 3.5-4.5, and the mixture was stirred at 110 rpm for 45 minutes to decolorize. The mixture was then filtered using a plate-frame filter press to remove the activated carbon.

[0074] Step 54 Microfiltration: Using a microfiltration membrane with a pore size of 0.45 μm, the temperature was controlled to 50 to 65° C. and the pH value to 3.5 to 4.5 during the microfiltration process, and the decolorized sugar solution was microfiltered in step 53 .

[0075] Step 55 Evaporation concentration: The sugar solution treated in step 54 was placed in a falling film evaporator and concentrated at a temperature of 65 to 98°C and a pH value of 3.5 to 4.5.

[0076] Step 56 Crystallization: The sugar solution processed in step 55 was placed in a vacuum sugar boiling system, and the temperature was controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution reached 1.01-1.02, 300-400 mesh seed crystals were added at a rate of 2 / 10000 of the dry basis, followed by vacuum evaporation. The crystallization period was 8 hours, and the stirring speed was controlled at 80 rpm to crystallize the sugar solution.

[0077] Step 57 Centrifugation: The material treated in step 56 was centrifuged in a centrifuge, the water washing time was 10 s, and the water temperature was controlled at 55-60°C to separate the solid arabinose from the arabinose centrifuged mother liquor. The solid arabinose was subjected to the operation in step 58, and the arabinose centrifuged mother liquor was recovered through a tube and returned to step 51 for reuse.

[0078] Step 58 Drying and packaging: The solid arabinose treated in step 57 was dried with hot air at 80°C to control the moisture content to 0.15-0.3%. When the desired moisture content was reached, the finished product was cooled to 20-24°C with clean cold air at 12-15°C to obtain arabinose crystals, which were then packaged in a packaging machine.

[0079] [Table 2]

[0080] From Table 2, it is clear that the arabinose crystals produced in each example had an arabinose content greater than 99.8% and a yield of the finished product greater than 96%, both of which were superior to the arabinose crystals produced in the comparative examples, and that the desired effects were achieved.

[0081] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for producing high-purity arabinose crystals, comprising: Step 1: dissolving low-content arabinose crystals to obtain a dissolved sugar solution, in which a temperature sensor and an automatic control valve are provided in the dissolving tank system, and the temperature during dissolving of the materials is monitored by an automatic temperature control system to ensure that the temperature of the dissolving solution during dissolution is 55-60°C, and the arabinose content in the low-purity arabinose crystals is 96-97%; Step 2: blending: the dissolved sugar solution is placed in a blending tank through a tube, and the arabinose centrifuged mother liquor from Step 8 is added to the blending tank and blended to obtain a blended sugar solution having a pH value of 4.3 to 5.0, a dry base concentration of 50 to 60%, and an arabinose content of 94±0.5% after blending; Step 3: ion exchange: the prepared sugar solution is subjected to ion exchange to obtain an ion-exchanged sugar solution, and the temperature of the material is controlled at 45-50°C by an ion exchange feed heat exchanger, and the pH of the ion-exchanged sugar solution is stabilized at 5.5-6.5; Step 4: Decolorization and filtration: The ion-exchanged sugar solution is fed into a decolorization tank through a tube, and the decolorization temperature is controlled to 60-65°C and the pH to 5.5-7.5, followed by decolorization and filtration to obtain a decolorized sugar solution; Step 5: microfiltration using a microfiltration membrane with a pore size of 0.45 μm, controlling the temperature during the microfiltration process to 50 to 65° C. and the pH value to 5.0 to 7.5 to microfilter the decolorized sugar solution to obtain a microfiltered sugar solution; Step 6: Evaporation and concentration: The microfiltrated sugar solution is placed in an MVR evaporator, and evaporated and concentrated at a temperature of 65-70°C and a pH value of 5.0-7.5 to obtain a concentrated sugar solution; Step 7: crystallization: the concentrated sugar solution is placed in a vacuum sugar boiling system and crystallized at a temperature of 63-65°C and a vacuum of 70-90mbar; Step 8: centrifuging the material treated in step 7 in a centrifuge to separate solid arabinose from arabinose centrifuged mother liquor, and introducing the arabinose centrifuged mother liquor with an arabinose content of 89-91% into a blending tank through a tube for the operation of step 2; and step 9: drying the solid arabinose with hot air at 80°C to obtain high-purity arabinose crystals having an arabinose content of 99.8% or more.

2. The method for producing high-purity arabinose crystals described in claim 1, characterized in that in step 3, an ion exchange column is used for the ion exchange treatment, and the ratio of cationic resin to anionic resin in the ion exchange column is 7:

10.

3. 2. The method for producing high-purity arabinose crystals according to claim 1, wherein in step 4, the decolorization and filtration treatment comprises adding activated carbon for decolorization to a decolorization tank at a dry basis of 1.2 to 1.4 kg / ton, stirring at 110 rpm for 30 to 45 minutes to decolorize the mixture, and then filtering the mixture using a plate-frame filter press to remove the activated carbon.

4. 2. The method for producing high-purity arabinose crystals according to claim 1, wherein in step 7, the crystallization treatment comprises adding 300 to 400 mesh arabinose seed crystals at a ratio of 2 / 10000 of the dry basis when the degree of supersaturation of the concentrated sugar solution reaches between 1.01 and 1.02, evaporating under vacuum, and crystallizing the concentrated sugar solution with a crystallization period of 8 hours and a stirring rotation speed controlled at 80 rpm.

5. The method for producing high-purity arabinose crystals according to claim 1, wherein in step 8, the centrifugation treatment further comprises controlling the water washing time to 10 seconds and the water temperature to 55 to 60°C.

6. The method for producing high-purity arabinose crystals according to claim 1, wherein in step 9, the drying treatment further comprises controlling the moisture content to 0.15-0.3%, and cooling the finished product to 20-24°C with clean cold air at 12-15°C once the desired moisture content is reached.

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