Method for recovering D-chiro-inositol mother liquor

Abstract

The invention relates to the technical field of D-chiro-inositol, in particular to a method for recovering D-chiro-inositol mother liquor, which comprises the following steps: respectively collecting D-chiro-inositol secondary crystallization mother liquor and recrystallization mother liquor, adding ethanol into the recrystallization mother liquor, cooling and crystallizing, and collecting a first solid and a first filtrate; merging the secondary crystallization mother liquor and the filtrate, concentrating, decoloring and carrying out suction filtration, concentrating the collected decoloring solution, adding ethanol, cooling, crystallizing and carrying out suction filtration, and respectively collecting a second solid and a second filtrate; mixing the first solid and the second solid, adding water, heating, dissolving, decolorizing, carrying out suction filtration, adding ethanol into the collected decolorized solution, cooling, crystallizing, carrying out suction filtration, and collecting crystals and a third filtrate; and drying the collected crystals to obtain the D-chiro-inositol product. According to the process method, the D-chiro-inositol product with high purity, high content and high yield can be obtained, and resource waste is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of D-chiro-inositol, and particularly relates to a recovery method of D-chiro-inositol mother liquor. BACKGROUND

[0002] D-chiro-inositol (DCI) is a white powder, easily soluble in water, slightly soluble in organic solvents such as ethanol and methanol, is one of nine isomers of inositol with optical activity, and is also a bioactive isomer of vitamin B8; it exists in buckwheat seeds, soybeans and some insects in a relatively high level, mostly in the form of methylation or glycosylation derivatives, is a biodegradation product of buckwheat sugar alcohol; has insulin sensitizing effect and promotes liver fat metabolism function, can significantly reduce blood sugar content, and has significant therapeutic effect on diabetes. In addition, it also has the effects of improving polycystic ovary syndrome, antioxidant, anti-aging, free radical scavenging, etc., and has good utilization value.

[0003] D-chiro-inositol can be extracted from plants such as buckwheat, but the content of D-chiro-inositol in these plants is not high, resulting in poor utilization rate of resources and high cost of separation and extraction. D-chiro-inositol can also be prepared by organic synthesis method, but due to complicated steps, it is difficult to separate by-products, and toxic substances may be left, affecting the quality of the product; in addition, a large amount of organic solvent is needed, and the environmental friendliness is poor. In addition, D-chiro-inositol can be produced by hydrolyzing D-pinitol or spring day mycin, but the price of raw material D-pinitol or spring day mycin is high, so the economy is poor. Secondary wastewater (COD>5000mg / L); long process route (average 5-7 unit operations); in recent years, with the development of production engineering technology, biological transformation synthesis of D-chiro-inositol has become a new development trend, at present, mainly through the transformation of microorganisms to convert inositol into D-chiro-inositol, then the conversion liquid is filtered, treated by resin column, and the concentrated feed liquid is collected by primary crystallization, and then the mother liquor is collected by secondary crystallization, and then the D-chiro-inositol solid obtained is recrystallized to obtain high-purity D-chiro-inositol product; but the mother liquor after secondary crystallization and the mother liquor after recrystallization contain chiro-inositol, water, ethanol and a small part of pigment; how to recover D-chiro-inositol from the secondary crystallization mother liquor and the recrystallization mother liquor has become a technical problem to be solved urgently. SUMMARY

[0004] The technical problem to be solved by the present application is that, in view of the deficiencies in the prior art, a recovery method of D-chiro-inositol mother liquor is provided, and the recovery method can obtain high-yield, high-yield and high-purity D-chiro-inositol product, and resource waste is avoided.

[0005] To solve the above technical problems, the technical scheme of the present application is:

[0006] A recovery method of D-chiro-inositol mother liquor, the method comprising the following steps:

[0007] (1) Take the mother liquor collected in the recrystallization, add ethanol, and after the crystals are precipitated, cool, filter, and collect the first solid and the first filtrate, respectively;

[0008] (2) Take the mother liquor collected in the secondary crystallization and combine it with the first filtrate collected in step (1), stir, concentrate to no ethanol, add activated carbon to the collected first concentrated liquid for decolorization treatment, filter after the decolorization is completed, and continue to concentrate the collected decolorized liquid to obtain the second concentrated liquid for standby;

[0009] (3) Take the second concentrated liquid in step (2), add ethanol, and after stirring for a period of time under temperature control, cool, filter, and collect the second solid and the second filtrate, respectively;

[0010] (4) Combine the first solid in step (1) and the second solid in step (3), add water and heat to dissolve, then add activated carbon for decolorization treatment, filter after the decolorization is completed, add ethanol to the collected decolorized liquid, cool and filter after the crystals are precipitated, and collect D-chiro-inositol and the third filtrate, respectively;

[0011] (5) Combine the second filtrate in step (3) and the third filtrate in step (4), and the concentrated liquid after concentration is first introduced into a cation resin column, the collected effluent is then introduced into a decolorizing resin column for decolorization treatment, the collected decolorized effluent is then introduced into an anion resin column, and the obtained desalted effluent is used in the concentrated liquid before the first crystallization.

[0012] As an improved technical solution, the ethanol in step (1) is added in an amount of 0.5-0.6 times the volume of the mother liquor, and the temperature is cooled to 25-30°C.

[0013] As an improved technical solution, the activated carbon in step (2) is added in an amount of 1-5% of the solid content of the first concentrated liquid, and the temperature of the decolorization treatment is 50-60°C, and the decolorization treatment time is 20-30 min.

[0014] As an improved technical solution, the solid content of the second concentrated liquid in step (3) is 40-50 wt%, the amount of ethanol added is 0.6-1.2 times the volume of the concentrated liquid, the temperature is controlled at 40-60°C for 1-2h, and then cooled to 25-30°C at a rate of 3-5°C / h.

[0015] As an improved technical solution, the water in step (4) is added in an amount of 1-1.5 times the weight of the combined first solid and second solid, heated to 60-80°C and stirred to dissolve; after the crystals are precipitated, cool to 25-30°C.

[0016] As an improved technical scheme, the solid content of the concentrated liquid in step (5) is 5-10wt%; the concentrated liquid enters the cation resin column at a flow rate of 1-2BV / h, and the filler in the cation resin column is macroporous strong acid cation exchange resin D001, macroporous weak acid cation exchange resin D113, macroporous strong acid styrene cation exchange resin D072 or strong acid styrene cation exchange resin 001x7.

[0017] As an improved technical scheme, the effluent in step (5) enters the decolorizing resin column at a flow rate of 2-3BV / h, and the filler in the decolorizing resin column is macroporous adsorption resin 109D, macroporous adsorption resin A-722 or macroporous adsorption resin D101.

[0018] As an improved technical scheme, the decolorizing effluent in step (5) enters the anion resin column at a flow rate of 0.5-1.0BV / h, and the filler in the anion resin column is macroporous weakly basic anion exchange resin D301, macroporous weakly basic anion exchange resin D313 or macroporous strongly basic anion exchange resin D202.

[0019] After the above technical scheme is adopted, the application has the following beneficial effects:

[0020] The D-chiro-inositol secondary crystallization mother liquor and the recrystallization mother liquor are collected respectively, and then the recrystallization mother liquor is added into ethanol for cooling crystallization, and then the first solid and the first filtrate are collected; then the secondary crystallization mother liquor and the filtrate are combined, concentrated, subjected to decolorizing treatment and suction filtration, the collected decolorizing liquid is continuously concentrated, the obtained concentrated liquid is added into ethanol for cooling crystallization and suction filtration, and the second solid and the second filtrate are collected; the first and second solids are combined, added with water, heated and stirred for dissolution, subjected to decolorizing treatment and suction filtration, the collected decolorizing liquid is added into ethanol for cooling crystallization and suction filtration, and the crystal and the third filtrate are collected; the collected crystal is dried to obtain the D-chiro-inositol product. The second filtrate and the third filtrate are combined, subjected to concentration treatment, and then enter the anion resin column, the decolorizing resin column and the cation resin column, and the obtained desalination effluent is reused in the concentrated liquid before crystallization of the next batch. The above process can obtain the D-chiro-inositol product with high purity, high content and high yield, and avoids resource waste. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the application clearer, the application will be further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the application, and are not used to limit the application.

[0022] Example 1

[0023] A D-chiro-inositol mother liquor recovery method comprises the following steps:

[0024] (1) Take 100 L mother liquor (D-chiro-inositol content is 25 g / L) collected by recrystallization, add ethanol in an amount of 0.5 times the volume of the mother liquor, and after the crystals are precipitated, cool to 30°C and filter. Collect 2000 g of first solid and 100 L of first filtrate;

[0025] (2) Take 50 L of mother liquor (D-chiro-inositol content is 15 g / L) collected by secondary crystallization and combine with the first filtrate of 100 L collected in step (1). Stir and concentrate to remove ethanol to obtain 85 L of first concentrated solution with a solid content of 5 wt%. Add activated carbon (in an amount of 1% of the solid content of the first concentrated solution) for decolorization treatment (decolorization treatment temperature is 50°C and decolorization treatment time is 20 min). After decolorization is complete, filter and continue to concentrate the collected decolorized solution to obtain 11 L of second concentrated solution with a solid content of 40 wt% for standby use;

[0026] (3) Take 11 L of second concentrated solution with a solid content of 40 wt% in step (2), add ethanol in an amount of 0.6 times the volume of the second concentrated solution, and treat at a temperature of 40°C for 1 h. Then cool to 25°C at a rate of 5°C / h and filter. Collect 510 g of second solid and 10 L of second filtrate;

[0027] (4) Combine the 2000 g of first solid in step (1) and the 510 g of second solid in step (3), and add water in an amount of 1 times the total weight of the first and second solids. Heat to 60°C, stir to dissolve, and then add activated carbon in an amount of 1% of the total weight of the first and second solids for decolorization treatment (decolorization treatment temperature is 50°C and decolorization treatment time is 30 min). After decolorization is complete, filter. Add ethanol in an amount of 0.8 times the volume of the collected 2.6 L of decolorized solution, and after the crystals precipitate, cool to 25°C and filter. Collect D-chiro-inositol and 3.4 L of third filtrate;

[0028] (5) Combine the 10.0 L of second filtrate in step (3) and the 3.4 L of third filtrate in step (4), and concentrate to obtain 9.0 L of concentrated solution with a solid content of 5 wt%. First, pass the concentrated solution into a 5 L cation resin column (filler is macroporous weak acid cation exchange resin D113) at a flow rate of 1 BV / h. Collect 20 L of effluent, and then pass the effluent into a 5 L decolorization resin column (filler is macroporous adsorption resin 109D) at a flow rate of 2 BV / h for decolorization treatment. Collect 40 L of decolorization effluent, and then pass the effluent into a 10 L anion resin column (filler is macroporous weak basic anion exchange resin D301) at a flow rate of 0.5 BV / h. Collect 55 L of desalination effluent and use it in the concentrated solution before primary crystallization.

[0029] Example 2

[0030] A method for recovering a D-chiro-inositol mother liquor, comprising the following steps:

[0031] (1) Take 100 L of the mother liquor collected in the recrystallization (D-chiro-inositol content is 25 g / L), and add ethanol in an amount of 0.52 times the volume of the mother liquor. After the crystals are precipitated, the temperature is lowered to 28.5℃, and filtration is performed. First solid 2125 g and first filtrate 110 L are collected;

[0032] (2) Take 50 L of the mother liquor collected in the secondary crystallization (D-chiro-inositol content is 15 g / L) and combine it with the first filtrate 110 L collected in step (1). Stirring and concentration are performed until there is no ethanol, and first concentrated liquid 80 L with a solid content of 6 wt% is obtained. Activated carbon is added in an amount of 2% of the solid content of the first concentrated liquid for decolorization treatment (decolorization treatment temperature is 52℃, and decolorization treatment time is 22 min). After the decolorization is completed, filtration is performed, and the collected decolorized liquid is further concentrated to obtain second concentrated liquid 11.5 L with a solid content of 42 wt% for standby use;

[0033] (3) Take second concentrated liquid 11.5 L with a solid content of 42 wt% in step (2), and add ethanol in an amount of 0.7 times the volume of the second concentrated liquid. Control the temperature at 45℃ for 1.2 h, and then lower the temperature to 26.5℃ at a rate of 4.5℃ / h, and perform filtration. Second solid 530 g and second filtrate 12.7 L are collected;

[0034] (4) Combine the first solid 2125 g in step (1) and the second solid 520 g in step (3), and add water in an amount of 1.1 times the total weight of the first and second solids. Heat to 65℃, and after stirring and dissolving, add activated carbon in an amount of 2% of the total weight of the first and second solids for decolorization treatment (decolorization treatment temperature is 55℃, and decolorization treatment time is 25 min). After the decolorization is completed, filtration is performed. Add ethanol in an amount of 0.9 times the volume of the collected 2.8 L of decolorized liquid, and after the crystals are precipitated, lower the temperature to 26.5℃, and perform filtration. Collect D-chiro-inositol and third filtrate 3.8 L;

[0035] (5) Combine the second filtrate 12.7 L in step (3) and the third filtrate 3.8 L in step (4), and after concentration, obtain concentrated liquid 10.5 L with a solid content of 6.5 wt%. First, enter a 5 L cation resin column (filler is macroporous strong acid cation exchange resin D001) at a flow rate of 1.2 BV / h, and collect 20.5 L of effluent. Then, enter a 5 L decolorization resin column (filler is macroporous adsorption resin A-722) at a flow rate of 2.3 BV / h for decolorization treatment, and collect 31 L of decolorization effluent. Finally, enter a 10 L anion resin column (filler is macroporous weak alkali anion exchange resin D313) at a flow rate of 0.6 BV / h, and obtain 41 L of desalination effluent for use in the concentrated liquid before the first crystallization.

[0036] Example 3

[0037] A recovery method of D-chiro-inositol mother liquor, comprising the following steps:

[0038] (1) Take 100 L of mother liquor (D-chiro-inositol content is 25 g / L) collected by recrystallization, and add ethanol in an amount of 0.55 times the volume of the mother liquor. After the crystals are precipitated, the temperature is lowered to 26.5°C, and filtration is performed. First solid 2200 g and first filtrate 105 L are collected, respectively;

[0039] (2) Take 50 L of mother liquor (D-chiro-inositol content is 15 g / L) collected by secondary crystallization, and combine it with the first filtrate 105 L collected in step (1). Stirring and concentration are performed until there is no ethanol, and first concentrated liquid 85 L with a solid content of 6 wt% is obtained. Activated carbon is added in an amount of 3% of the solid content of the first concentrated liquid for decolorization treatment (decolorization treatment temperature is 55°C, and decolorization treatment time is 25 min). After the decolorization is completed, filtration is performed, and the collected decolorized liquid is continuously concentrated to obtain 12 L of second concentrated liquid with a solid content of 45 wt% for standby;

[0040] (3) Take 12 L of second concentrated liquid with a solid content of 45 wt% in step (2), and add ethanol in an amount of 1 times the volume of the second concentrated liquid. Control the temperature at 50°C for 1.5 h, and then lower the temperature to 27.5°C at a rate of 4°C / h, and perform filtration. Second solid 580 g and second filtrate 13.5 L are collected, respectively;

[0041] (4) Combine 2200 g of first solid in step (1) and 580 g of second solid in step (3), and add water in an amount of 1.3 times the total weight of the first and second solids. Heat to 70°C, and after stirring and dissolving, add activated carbon in an amount of 3% of the total weight of the first and second solids for decolorization treatment (decolorization treatment temperature is 60°C, and decolorization treatment time is 20 min). After the decolorization is completed, filtration is performed. Add ethanol in an amount of 1.0 times the volume of the decolorized liquid to the collected 2.8 L of decolorized liquid, and after the crystals are precipitated, the temperature is lowered to 27.5°C, and filtration is performed. D-chiro-inositol and third filtrate 4.2 L are collected, respectively;

[0042] (5) Combine the 13.5 L of the second filtrate from step (3) and the 4.2 L of the third filtrate from step (4), and concentrate to obtain a concentrated solution of 7.5 wt% solid content, 12 L. First, pass the concentrated solution into a 5 L cation resin column (the filler is macroporous strong acid cation exchange resin D001) at a flow rate of 1.5 BV / h, collect the 22 L effluent, and then pass the effluent into a 5 L decolorizing resin column (the filler is macroporous adsorbing resin 109D) at a flow rate of 2.5 BV / h for decolorizing treatment, collect the 32 L decolorized effluent, and then pass the effluent into a 10 L anion resin column (the filler is macroporous weak alkali anion exchange resin D301) at a flow rate of 0.8 BV / h, and obtain the desalted effluent of 42 L, which is used in the concentrated solution before the first crystallization.

[0043] Example 4

[0044] A recovery method of a D-chiro-inositol mother liquor, comprising the following steps:

[0045] (1) Take 100 L of the mother liquor (D-chiro-inositol content is 25 g / L) collected by recrystallization, and add ethanol in an amount of 0.58 times the volume of the mother liquor. After the crystals are precipitated, cool to 28.5 °C, and filter, collect the first solid of 2150 g and the first filtrate of 130 L, respectively;

[0046] (2) Take 50 L of the mother liquor (D-chiro-inositol content is 15 g / L) collected by secondary crystallization, and combine with the first filtrate of 130 L collected in step (1). Stir, and concentrate to remove ethanol, to obtain a first concentrated solution of 80 L with a solid content of 6 wt%. Add activated carbon (in an amount of 4% of the solid content of the first concentrated solution) for decolorizing treatment (the temperature of the decolorizing treatment is 58 °C, and the time of the decolorizing treatment is 28 min). After the decolorizing treatment is completed, filter, and continue to concentrate the decolorized solution to obtain a second concentrated solution of 10 L with a solid content of 48 wt% for standby use;

[0047] (3) Take the second concentrated solution of 10 L with a solid content of 48 wt% from step (2), and add ethanol in an amount of 1.1 times the volume of the second concentrated solution. Treat at a temperature of 55 °C for 1.8 h, then cool to 28.5 °C at a rate of 3.5 °C / h, and filter, collect the second solid of 510 g and the second filtrate of 14.5 L, respectively;

[0048] (4) Combine 2150 g of the first solid from step (1) and 510 g of the second solid from step (3), add water in an amount of 1.4 times the total weight of the first and second solids, heat to 75°C, and after dissolving with stirring, add activated carbon in an amount of 4% of the total weight of the first and second solids to perform decolorization treatment (the temperature of the decolorization treatment is 55°C, and the time of the decolorization treatment is 30 minutes), after the decolorization treatment is complete, perform suction filtration, and in the 2.7 L of decolorized solution collected, add ethanol in an amount of 0.7 times the volume of the decolorized solution, and after the crystals precipitate, perform suction filtration at a temperature of 28.5°C, and collect D-chiro- inositol and the third filtrate, 4.5 L;

[0049] (5) Combine the 14.5 L of the second filtrate from step (3) and the 4.5 L of the third filtrate from step (4), concentrate to obtain 8 L of a concentrated solution having a solid content of 8.5 wt%, first pass through a 5 L cation resin column (the filler is macroporous strong acid styrene cation exchange resin D072) at a flow rate of 1.8 BV / h, collect 18 L of effluent, then pass the collected effluent through a 5 L decolorization resin column (the filler is macroporous adsorption resin A-722) at a flow rate of 2.8 BV / h to perform decolorization treatment, collect 30 L of decolorized effluent, and then pass the collected decolorized effluent through a 10 L anion resin column (the filler is macroporous weak base anion exchange resin D313) at a flow rate of 0.9 BV / h to obtain desalted effluent, and use the obtained desalted effluent, 40 L, in the concentrated solution before the first crystallization.

[0050] Example 5

[0051] A method for recovering a D-chiro-inositol mother liquor, comprising the following steps:

[0052] (1) Take 100 L of the mother liquor collected in the recrystallization (the D-chiro-inositol content is 25 g / L), add ethanol in an amount of 0.6 times the volume of the mother liquor, and after the crystals precipitate, perform suction filtration at a temperature of 30°C, and collect a first solid, 2100 g, and a first filtrate, 155 L;

[0053] (2) Combine 50 L of the mother liquor collected in the second crystallization (the D-chiro-inositol content is 15 g / L) and the first filtrate, 155 L, collected in step (1), stir and concentrate to remove the ethanol, obtain 80 L of a first concentrated solution having a solid content of 6 wt%, add activated carbon (in an amount of 5% of the solid content of the first concentrated solution), and perform decolorization treatment (the temperature of the decolorization treatment is 60°C, and the time of the decolorization treatment is 30 minutes), after the decolorization treatment is complete, perform suction filtration, continue to concentrate the collected decolorized solution, and obtain 9.0 L of a second concentrated solution having a solid content of 50 wt% for use;

[0054] (3) Take 9.0L of the second concentrated solution with a solid content of 50wt% in step (2), add ethanol with a volume of 1.2 times that of the second concentrated solution, and treat at 60℃ for 2h, then cool to 30℃ at a rate of 3℃ / h, and filter. Collect 510g of the second solid and 16.0L of the second filtrate, respectively;

[0055] (4) Combine 2100g of the first solid in step (1) and 510g of the second solid in step (3), add water with a volume of 1.5 times that of the total weight of the first and second solids, heat to 80℃, and stir to dissolve. Then add activated carbon with a weight of 5% of the total weight of the first and second solids to perform decolorization treatment (the temperature of the decolorization treatment is 55℃, and the time of the decolorization treatment is 25min). After the decolorization is completed, filter. Add ethanol with a volume of 0.7 times that of the decolorization liquid to 2.7L of the collected decolorization liquid. After the crystals precipitate, cool to 30℃, and filter. Collect D-chiro-inositol and 5.0L of the third filtrate, respectively;

[0056] (5) Combine 16L of the second filtrate in step (3) and 5.0L of the third filtrate in step (4), and concentrate to obtain a concentrated solution with a solid content of 10wt% of 7.0L. First, pass it into a 5L cation resin column (the filler is strong acid styrene cation exchange resin 001×7) at a flow rate of 2BV / h. Collect 17L of the effluent. Then, pass it into a 5L decolorization resin column (the filler is macroporous adsorption resin D101) at a flow rate of 3BV / h to perform decolorization treatment. Collect 27L of the decolorization effluent. Then, pass it into a 10L anion resin column (the filler is macroporous strong alkaline anion exchange resin D202) at a flow rate of 1.0BV / h. The obtained desalination effluent 37L is used in the concentrated solution before the first crystallization.

[0057] Example 6

[0058] It should be noted that in this example, the desalination effluent 42L collected in step (5) of Example 3 is used in the concentrated solution before the first crystallization. The mother liquor after recrystallization is 90L, and the second crystallization collects 45L;

[0059] A method for recovering D-chiro-inositol mother liquor, comprising the following steps:

[0060] (1) Take 90L of the mother liquor collected after recrystallization (D-chiro-inositol content is 20g / L), and add ethanol with a volume of 0.55 times that of the liquid. After the crystals precipitate, cool to 27.5℃, and filter. Collect 1620g of the first solid and 100L of the first filtrate, respectively;

[0061] (2) Take 45L mother liquor (D-chiro-inositol content is 10g / L) collected by secondary crystallization and 100L first filtrate collected in step (1), stir, concentrate to be free of ethanol, to obtain first concentrated solution 70L with solid content of 6wt%, add activated carbon (add according to 3% of solid content of the first concentrated solution) to carry out decolorization treatment (decolorization treatment temperature is 55℃, decolorization treatment time is 25min), after decolorization is completed, extract filtration, continue to concentrate the collected decolorization solution, to obtain second concentrated solution 9.0L with solid content of 45wt% for standby;

[0062] (3) Take second concentrated solution 9.0L with solid content of 45wt% in step (2), add ethanol with volume of second concentrated solution, control temperature at 50℃ for 1.5h, then reduce temperature to 27.5℃ at a rate of 4℃ / h, extract filtration, collect second solid 600g and second filtrate 8.0L respectively;

[0063] (4) Combine first solid 1620g in step (1) and second solid 600g in step (3), add water with amount of 1.3 times of total weight of first and second solid, heat to 70℃, after stirring and dissolving, add activated carbon with amount of 3% of total weight of first and second solid to carry out decolorization treatment (decolorization treatment temperature is 60℃, decolorization treatment time is 20min), after decolorization is completed, extract filtration, add ethanol with volume of 0.8 times of the decolorization solution to the collected 1.9L decolorization solution, after crystals precipitate, reduce temperature to 27.5℃, extract filtration, collect D-chiro-inositol and third filtrate 2.8L respectively;

[0064] (5) Combine second filtrate 8.0L in step (3) and third filtrate 2.8L in step (4), concentrate to obtain concentrated solution 5.0L with solid content of 7.5wt%, first enter 5L cation resin column (filler is macroporous strong acid cation exchange resin D001) at a flow rate of 1.5BV / h, collect 15L effluent, then enter 5L decolorization resin column (filler is macroporous adsorption resin 109D) at a flow rate of 2.5BV / h to carry out decolorization treatment, collect 25L decolorization effluent, then enter 10L anion resin column (filler is macroporous weak alkali anion exchange resin D301) at a flow rate of 0.8BV / h, obtain desalination effluent 35L which is used in concentrated solution before primary crystallization.

[0065] In order to better prove that the process method of the present application can obtain high yield, high yield and high purity D-chiro-inositol product, the following comparative examples are given with reference to example 3, the yield, yield and purity of D-chiro-inositol in examples 1-5 and comparative examples are shown in table 1.

[0066] Comparative example 1

[0067] Different from Example 3, the temperature was lowered to 22°C after the crystals were precipitated in step (1), and the rest of the operations were the same.

[0068] Comparative Example 2

[0069] Different from Example 3, the temperature was lowered to 32°C after the crystals were precipitated in step (1), and the rest of the operations were the same.

[0070] Comparative Example 3

[0071] Different from Example 3, the first concentrated solution collected in step (2) was not subjected to decolorization treatment, and the rest of the operations were the same.

[0072] Comparative Example 4

[0073] Different from Example 3, the amount of ethanol added in step (3) was 0.3 times the volume of the concentrated solution, and the rest of the operations were the same.

[0074] Comparative Example 5

[0075] Different from Example 3, the amount of ethanol added in step (3) was 1.5 times the volume of the concentrated solution, and the rest of the operations were the same.

[0076] Comparative Example 6

[0077] Different from Example 3, the temperature was lowered to 27.5°C at a rate of 2°C / h in step (3), and the rest of the operations were the same.

[0078] Comparative Example 7

[0079] Different from Example 3, the temperature was lowered to 27.5°C at a rate of 6°C / h in step (3), and the rest of the operations were the same.

[0080] Comparative Example 8

[0081] Different from Example 3, after the second filtrate and the third filtrate were combined in step (5), they were not subjected to treatment with a cation resin column, but were directly applied to the concentrated solution before the first crystallization; the rest of the operations were the same.

[0082] Comparative Example 9

[0083] After the second filtrate and the third filtrate were combined in step (5), they were not subjected to treatment with a decolorization resin column, but were directly applied to the concentrated solution before the first crystallization; the rest of the operations were the same.

[0084] Comparative Example 10

[0085] After the second filtrate and the third filtrate were combined in step (5), they were not subjected to treatment with an anion resin column, but were directly applied to the concentrated solution before the first crystallization; the rest of the operations were the same.

[0086] Table 1

[0087]

[0088]

[0089] It can be found from the data in Table 1 that the yield, the recovery rate and the purity of the D-chiro-inositol product obtained by the process of Example 3 of the present application are superior to those of other examples and comparative examples. It can also be found from the comparison between Comparative Examples 8-10 and Example 6 that the yield, the recovery rate and the purity of the D-chiro-inositol product obtained by Example 6 are superior to those of Comparative Examples 8-10.

[0090] The above description is merely preferred embodiments of the present application but not to confine the present application. Any modification, equivalent replacement and improvement made in the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for recovering a D-chiro-inositol mother liquor, characterized in that, The method comprises the following steps: (1) Take the mother liquor collected in the recrystallization, add ethanol, and after the crystals are precipitated, cool, filter, and collect the first solid and the first filtrate, respectively; (2) Take the mother liquor collected in the secondary crystallization and combine with the first filtrate collected in step (1), stir, concentrate to no ethanol, add activated carbon to the collected first concentrated liquid for decolorization treatment, after the decolorization is completed, filter, and continue to concentrate the collected decolorized liquid, and the obtained second concentrated liquid is reserved; (3) Take the second concentrated liquid in step (2), add ethanol, and after stirring for a period of time under temperature control, cool, filter, and collect the second solid and the second filtrate, respectively; (4) Combine the first solid in step (1) and the second solid in step (3), add water and heat to dissolve, then add activated carbon for decolorization treatment, after the decolorization is completed, filter, add ethanol to the collected decolorized liquid, and after the crystals are precipitated, cool, filter, and collect D-chiro-inositol and the third filtrate, respectively; (5) Combine the second filtrate in step (3) and the third filtrate in step (4), and the concentrated liquid after concentration is first introduced into a cation resin column, the collected effluent is then introduced into a decolorization resin column for decolorization treatment, the collected decolorized effluent is then introduced into an anion resin column, and the obtained desalination effluent is used in the concentrated liquid before the first crystallization.

2. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (1), the ethanol is added in an amount of 0.5-0.6 times the volume of the mother liquor, and the temperature is cooled to 25-30°C.

3. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (2), the activated carbon is added in an amount of 1-5% of the solid content of the first concentrated liquid, and the temperature of the decolorization treatment is 50-60°C, and the decolorization treatment time is 20-30 min.

4. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (3), the solid content of the second concentrated liquid is 40-50 wt%, the added amount of ethanol is 0.6-1.2 times the volume of the concentrated liquid, and the temperature is controlled at 40-60°C for 1-2 h, and then the temperature is cooled to 25-30°C at a rate of 3-5°C / h.

5. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (4), the water is added in an amount of 1-1.5 times the weight of the combined first solid and second solid, heated to 60-80°C and stirred to dissolve; after the crystals are precipitated, the temperature is cooled to 25-30°C.

6. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (5), the solid content of the concentrated liquid is 5-10 wt%, and the concentrated liquid is introduced into the cation resin column at a flow rate of 1-2 BV / h, and the filler in the cation resin column is macroporous strong acid cation exchange resin D001, macroporous weak acid cation exchange resin D113, macroporous strong acid styrene cation exchange resin D072, or strong acid styrene cation exchange resin 001×7.

7. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (5), the effluent is introduced into the decolorization resin column at a flow rate of 2-3 BV / h, and the filler in the decolorization resin column is macroporous adsorption resin 109D, macroporous adsorption resin A-722, or macroporous adsorption resin D101.

8. The method of claim 1, wherein the D-chiro-inositol mother liquor is recovered by, In step (5), the decolorized effluent is introduced into the anion resin column at a flow rate of 0.5-1.0 BV / h, and the filler in the anion resin column is macroporous weak base anion exchange resin D301, macroporous weak base anion exchange resin D313, or macroporous strong base anion exchange resin D202.

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