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 in particular 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, so they are cheap. High-purity arabinose crystal products have a complicated process and are difficult to produce, so the selling price is relatively high. However, they can meet the process prescription needs of some special customers, so the market has great potential.

[0003] In the production process of conventional technology, due to the characteristics of L-arabinose being affected by high temperature and low pH conditions, it undergoes reactions to be converted into other substances, such as isomerization to convert it into xylose, decomposition to decompose it into small molecules with five carbons or less, and polymerization to produce maltotriose. Therefore, during the arabinose production process, especially the decolorization, evaporation, and chromatographic separation processes, its content constantly decreases, and the purity of the produced crystalline arabinose is difficult to reach 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 steps 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 value and temperature during the production process to prevent the occurrence of isomerization reactions, decomposition reactions, and polymerization reactions. [Means for solving the problem]

[0006] The present invention is accomplished as follows: A method for producing high-purity arabinose crystals, comprising: Dissolving: a step of 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 material dissolution is monitored by a Siemens DCS automatic temperature control system, ensuring 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: by 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 into the blending tank to blend, and a blended sugar solution is obtained with a blended pH value in the range of 4.3-5.0, a dry base concentration of 50-60%, and an arabinose content of 94±0.5%; ion exchange: the blended sugar liquid is ion-exchanged to obtain an ion-exchanged sugar liquid, 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 liquid 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 to decolorize and filter the sugar solution to obtain a decolorized sugar solution; Step 5: using a microfiltration membrane with a pore size of 0.45 μm, the temperature is controlled to 50 to 65 ° C and the pH value is controlled to 5.0 to 7.5 during the microfiltration process to microfilter the decolorized sugar solution to obtain a microfiltered sugar solution; Step 6: Evaporation and concentration: The microfiltered sugar solution is put into an MVR evaporator, and the temperature is controlled to 65-70°C and the pH value is controlled to 5.0-7.5 to evaporate and concentrate to obtain a concentrated sugar solution; Step 7: crystallization: the concentrated sugar solution is put into a vacuum sugar boiling system and crystallized by controlling the temperature at 63-65°C and the vacuum at 70-90mbar; Step 8: centrifuging the material treated in step 7 by a centrifuge to separate solid arabinose and 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 of drying: 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. Effect 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 making the ratio of cations and anions in the ion exchange resin 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 liquid caused by localized over-alkalinization of the raw liquid during the pH adjustment operation of the raw liquid by adding alkali, which can affect the production efficiency and product quality of the subsequent production process. (3) By dissolving arabinose crystals with a high miscellaneous sugar content, refining and concentrating them to obtain arabinose crystals with a purity of 99.8% or more, the yield of the finished crystal product can be improved by 3.5% or more compared to conventional production processes. [Brief description 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 PREFERRED EMBODIMENTS

[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 the embodiments and drawings. It should be understood that the specific embodiments 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 direction of the arrow in the figure indicates the direction of flow of materials or the direction of progress of the process. 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 control valve, the temperature during material dissolution is monitored by a Siemens DCS automatic temperature control system, the temperature of the dissolution solution during dissolution is kept at 55-60°C, and the arabinose content in the low purity arabinose crystals is 96-97%, and the stability of the raw material solution is ensured.

[0013] Step 2 Blending: The dissolved sugar solution is fed into the blending tank through a tube by means of an electromagnetic flowmeter, an automatic control valve, and a Siemens intelligent control system, and the arabinose centrifuged mother liquor from step 8 is added into the blending tank for blending 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.

[0014] Step 3 Ion exchange: The blended sugar solution is ion-exchanged to obtain an ion-exchanged sugar solution, and the temperature of the material is controlled to 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. 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 discharged material from the ion exchange is stabilized at 5.5-6.5, thereby preventing arabinose from being converted to other miscellaneous sugars under conditions of too low pH.

[0015] Step 4 Decolorization 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. The decolorization 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 using a plate-frame filter press to remove the activated carbon.

[0016] Step 5 Microfiltration: Using a microfiltration membrane with a pore size of 0.45 μm, the decolorized sugar solution is microfiltered 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 microfiltered sugar solution is placed in an MVR evaporator, and evaporated and concentrated at a temperature of 65-70℃ and a pH value of 5.0-7.5 to obtain a concentrated sugar solution.

[0018] Step 7 Crystallization: The concentrated sugar solution is put into a vacuum sugar boiling system, and crystallized by controlling the temperature at 63-65°C and the vacuum at 70-90mbar. The crystallization process includes adding 300-400 mesh arabinose seed crystals at a ratio of 2 / 10000 of the dry basis when the concentrated sugar solution has a supersaturation degree of 1.01-1.02, evaporating under vacuum, and crystallizing with a crystallization period of 8 hours and agitation speed of 80rpm.

[0019] Step 8 Centrifugation: The material treated in step 7 is centrifuged in a centrifuge to separate solid arabinose from arabinose centrifugal mother liquor, and the arabinose centrifugal mother liquor with an arabinose content of 89-91% is introduced into a blending tank through a tube for the operation of step 2. The centrifugation treatment further includes controlling the water washing time to 10s 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 further includes 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 when the desired moisture content is reached.

[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 process for producing high purity arabinose crystals of the present invention is further illustrated below by specific examples.

[0023] Example 1: Determination of 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, then heated at 60°C, 65°C, and 70°C for 48 hours, and samples were taken and detected at 24 hours and 48 hours, respectively, and the results are shown in Table 1 below.

[0026] [Table 1]

[0027] As a result of the comparison, the lower the pH and the higher the heating temperature during the arabinose production process, the faster the arabinose content decreases over time. As a result of comparing the change trends of arabinose under various conditions, it was found that pH is the main factor that reduces the arabinose content, and when the pH is 4.3 or higher, the content only decreases by 2.31% when the material is heated at 75°C for 48 hours, but when the material is heated at 75°C for 48 hours under the condition of pH 2.7, the arabinose content decreases by 8.9%, which is three times that of 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 effect of high temperatures on the arabinose content and avoids a decrease in production efficiency that would result from lowering the processing temperature due to the material content. Example 2

[0029] A first embodiment of the method for producing high purity arabinose crystals of the present invention includes 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. The temperature during material dissolution was monitored by Siemens' DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was kept at 55-60°C, and the arabinose content in the low-purity arabinose crystals was 96%.

[0031] Step 12 Blending: Using an electromagnetic flowmeter, automatic control valve, and Siemens intelligent control system, the sugar solution from step 11 is fed into the blending tank through a tube, and the arabinose centrifuged mother liquor from step 18 is added into the blending tank for blending. After blending, the pH value is 5.0, the dry base concentration is 50%, and the arabinose content is 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 into a decolorization tank through 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 decolorization temperature was controlled at 60°C, the pH at 5.0-7.5, and the mixture was decolorized by stirring at 110 rpm for 30 minutes. Thereafter, the mixture was filtered through 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 was controlled 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 5.0-7.5.

[0036] Step 17 Crystallization: The sugar solution treated in step 16 is put into a vacuum sugar boiling system, and the temperature is controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution is between 1.01-1.02, 300-400 mesh seed crystals are added at a ratio of 2 / 10000 of the dry basis, and the mixture is evaporated under vacuum. The crystallization period is 8 hours, and the stirring speed is controlled at 80rpm to crystallize the mixture.

[0037] Step 18 Centrifugation: The material treated in step 17 was centrifuged in a centrifuge, the water washing time was controlled to 10 s, and the water temperature was controlled to 55-60°C to separate solid arabinose and arabinose centrifugal mother liquor, the solid arabinose was subjected to the operation in step 19, and the arabinose centrifugal 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 treated in step 18 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 high-purity arabinose crystals with an arabinose content of 99.8% or more. The treated arabinose crystals were packaged using 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 material dissolution was monitored by Siemens' DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was kept 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 through the sugar solution tube in step 21, and the arabinose centrifuged mother liquor in step 28 was added into the blending tank for blending. After blending, the pH value was within the range of 4.3 to 5.0, the dry base concentration was 60%, and the arabinose content was 94.57%.

[0042] Step 23 Ion exchange: The sugar solution prepared in step 22 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 6.0.

[0043] Step 24 Decolorization and filtration: The sugar solution after ion exchange was placed in a decolorization tank through 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 5.5-7.5, and the mixture was stirred at 110 rpm for 35 minutes to decolorize. The mixture was then filtered through 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 was controlled 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 treated in step 26 is put into a vacuum sugar reduction system, and the temperature is controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution is between 1.01-1.02, 300-400 mesh seed crystals are added at a ratio of 2 / 10000 of the dry basis, and the mixture is evaporated under vacuum. The crystallization period is 8 hours, and the stirring speed is controlled at 80rpm to crystallize the mixture.

[0047] Step 28 Centrifugation: The material treated in step 27 was centrifuged in a centrifuge, the water washing time was controlled to 10 s, and the water temperature was controlled to 55-60°C to separate solid arabinose and arabinose centrifugal mother liquor, the solid arabinose was subjected to the operation in step 29, and the arabinose centrifugal 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 treated in step 28 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 high-purity arabinose crystals with an arabinose content of 99.8% or more. The treated arabinose crystals were packaged using a packaging machine. Example 4

[0049] A third embodiment of the method for producing high purity arabinose crystals of the present invention includes 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 material dissolution was monitored by Siemens' DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was kept at 55-60°C, and the arabinose content in the low-purity arabinose crystals was 96.5%.

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

[0052] Step 33 Ion exchange: The sugar solution prepared in step 32 was subjected to an ion exchange process, in which 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 into a decolorization tank through a tube, and activated carbon for decolorization was added to the decolorization tank at 1.25 kg / ton dry basis. The decolorization temperature was controlled at 65°C, the pH at 5.5-7.5, and decolorization was carried out for 45 minutes by stirring at 110 rpm. After that, the solution was filtered through 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 was controlled 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 treated in step 36 is put into a vacuum sugar reduction system, and the temperature is controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution is between 1.01-1.02, 300-400 mesh seed crystals are added at a ratio of 2 / 10000 of the dry basis, and the mixture is evaporated under vacuum. The crystallization period is 8 hours, and the stirring speed is controlled at 80rpm to crystallize.

[0057] Step 38 Centrifugation: The material treated in step 37 was centrifuged in a centrifuge, the water washing time was controlled to 10 s, and the water temperature was controlled to 55-60°C to separate solid arabinose and arabinose centrifugal mother liquor, the solid arabinose was subjected to the operation in step 39, and the arabinose centrifugal 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 treated in step 38 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 high-purity arabinose crystals with an arabinose content of 99.8% or more. The treated 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. The temperature during material dissolution was monitored by Siemens' DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was kept 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 is fed into the blending tank through the sugar solution tube in step 41, and the arabinose centrifuged mother liquor in step 48 is added into the blending tank for blending. After blending, the pH value is within the range of 4.3 to 5.0, the dry base concentration is 60%, and the arabinose content is 94.43%.

[0062] Step 43 Ion exchange: The sugar solution prepared in step 42 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 6.2.

[0063] Step 44 Decolorization and filtration: The sugar solution after ion exchange was placed into a decolorization tank through 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 5.5-7.5, and the mixture was stirred at 110 rpm for 40 minutes to decolorize. The mixture was then filtered through 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 was controlled 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 treated in step 46 is put into a vacuum sugar boiling system, and the temperature is controlled at 63-65°C and the vacuum is controlled at 70-90mbar. When the degree of supersaturation of the sugar solution is between 1.01-1.02, 300-400 mesh seed crystals are added at a ratio of 2 / 10000 of the dry basis, and the mixture is evaporated under vacuum. The crystallization period is 8 hours and the stirring speed is controlled at 80rpm to crystallize the mixture.

[0067] Step 48 Centrifugation: The material treated in step 47 was centrifuged in a centrifuge, the water washing time was controlled to 10 s, and the water temperature was controlled to 55-60°C to separate solid arabinose and arabinose centrifugal mother liquor, the solid arabinose was subjected to the operation in step 49, and the arabinose centrifugal 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 treated in step 48 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 high-purity arabinose crystals with an arabinose content of 99.8% or more. The treated 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 illustrated below by comparative examples. Comparative Example

[0070] A conventional manufacturing process was adopted, and the ratio of anionic resin to cationic resin in the ion exchange step was 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. The temperature during material dissolution was monitored by a Siemens DCS automatic temperature control system. The temperature of the dissolution solution during dissolution was kept at 55-60°C, and the arabinose content in the low-purity arabinose crystals was set to 97%, the dry base concentration to 55%, and the pH value to 3.5-5.0.

[0072] Step 52 Ion exchange: The sugar solution obtained in step 51 was subjected to an ion exchange process, 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 in a decolorization tank through 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 through 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 was controlled 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 by controlling the temperature at 65-98°C and the pH value at 3.5-4.5.

[0076] Step 56 Crystallization: The sugar solution treated in step 55 is put into a vacuum sugar boiling system, and the temperature is controlled at 63-65°C and the vacuum at 70-90mbar. When the degree of supersaturation of the sugar solution is between 1.01-1.02, 300-400 mesh seed crystals are added at a ratio of 2 / 10000 of the dry basis, and the mixture is evaporated under vacuum. The crystallization period is 8 hours, and the stirring speed is controlled at 80rpm to crystallize the mixture.

[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 solid arabinose and arabinose centrifugal mother liquor, the solid arabinose was subjected to the operation in step 58, and the arabinose centrifugal mother liquor was recovered through a tube and reused in step 51.

[0078] Step 58 Drying and packaging: The solid arabinose treated in step 57 is dried with hot air at 80°C to control the moisture content to 0.15-0.3%. When the desired moisture content is reached, the finished product is cooled to 20-24°C with clean cold air at 12-15°C to obtain arabinose crystals. The treated arabinose crystals are 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 finished product yield greater than 96%, both of which were superior to the arabinose crystals produced in the comparative example, and 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 the 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 the material dissolution is monitored by a Siemens DCS 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: put the dissolved sugar solution into a blending tank through a tube, add the arabinose centrifuged mother liquor of step 8 into the blending tank and blend 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; ion exchange: the blended sugar liquid is ion-exchanged to obtain an ion-exchanged sugar liquid, 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 liquid 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 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 by 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 microfiltered sugar solution; Step 6: Evaporation and concentration: The microfiltered sugar solution is put into 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 of the concentrated sugar solution by placing it in a vacuum sugar reduction system and controlling the temperature at 63-65°C and the vacuum at 70-90mbar; Step 8: centrifuging the material treated in step 7 with a centrifuge to separate solid arabinose from arabinose centrifuge mother liquor, and introducing the arabinose centrifuge 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: 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 as 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. The method for producing high-purity arabinose crystals according to claim 1, characterized in that in step 4, the decolorization and filtration treatment includes adding activated carbon for decolorization to a decolorization tank at 1.2 to 1.4 kg / ton dry basis, stirring at 110 rpm for 30 to 45 minutes to decolorize, and then filtering using a plate-frame filter press to remove the activated carbon.

4. The method for producing high purity arabinose crystals according to claim 1, characterized in that in step 7, the crystallization treatment includes adding 300 to 400 mesh arabinose seed crystals at a ratio of two ten-thousandths of the dry basis when the degree of supersaturation of the concentrated sugar liquid is between 1.01 and 1.02, evaporating under vacuum, and crystallizing the crystals by controlling the crystallization period to 8 hours and the stirring speed to 80 rpm.

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

6. The method for producing high purity arabinose crystals according to claim 1, characterized in that in step 9, the drying process 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 when the desired moisture content is reached.

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