Method for treating mother liquor in preparation process of D-chiro-inositol
By employing steps such as low-temperature depressurization alcohol removal, pH adjustment with glacial acetic acid, ultrasonic treatment, and macroporous adsorption resin, the problems of ethanol recovery and impurity separation in the treatment of D-chiral inositol mother liquor were solved, achieving efficient recovery and purification, and improving economic benefits and environmental friendliness.
Patent Information
- Application Number
- CN202511771901.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-02-17
AI Technical Summary
The treatment of mother liquor during the preparation of D-chiral inositol makes it difficult to recover ethanol and impurities, resulting in raw material waste and significant environmental pressure. Existing technologies are not thorough in handling these issues, affecting economic efficiency and environmental friendliness.
The process involves steps such as low-temperature depressurization alcohol removal, pH adjustment with glacial acetic acid, ultrasonic treatment, macroporous adsorption resin, and segmented crystallization. Combined with ethanol recovery and impurity separation, and through macroporous adsorption resin regeneration, the mother liquor is deeply treated and efficiently recovered.
This improved the total yield and purity of D-chiral inositol, reduced the purchase of fresh solvents and the amount of waste to be treated, lowered raw material costs, extended resin lifespan, and achieved green production and improved economic benefits.
Smart Images
Figure CN121537255A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of D-chiral inositol production technology, specifically to a method for treating the mother liquor during the preparation of D-chiral inositol. Background Technology
[0002] D-Chiro Inositol (DCI) is one of the nine isomers of inositol that exhibits optical activity. It is also the bioactive isomer of vitamin B8. It exists in relatively high levels in buckwheat seeds, soybeans, and some insects, primarily in the form of methylated or glycosylated derivatives, and is a biodegradation product of buckwheat glycosides. It possesses insulin-sensitizing properties and promotes hepatic fat metabolism, significantly lowering blood glucose levels and showing a marked therapeutic effect on diabetes. Furthermore, DCI also has effects such as improving polycystic ovary syndrome (PCOS), anti-oxidation, anti-aging, and free radical scavenging, making it of considerable practical value.
[0003] The preparation of D-chiral inositol generates a large amount of mother liquor, which contains approximately 40% ethanol, 10% D-chiral inositol, 4% inositol, 5% other impurities, and the remainder is water. Currently, ethanol is mostly recovered by distillation. However, the liquid after alcohol removal is difficult to recover due to the influence of impurities, resulting in waste of raw materials. At the same time, a large amount of wastewater is generated in the later stage, which puts great pressure on environmental protection. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a method for treating the mother liquor in the preparation of D-chiral inositol, which improves economic efficiency and is environmentally friendly, in order to address the shortcomings of the existing technology.
[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:
[0006] A method for treating the mother liquor during the preparation of D-chiral inositol, characterized by comprising the following steps:
[0007] A: The D-chiral inositol mother liquor (containing approximately 40% ethanol, 10% D-chiral inositol, 4% inositol, 5% other impurities, and the remainder being water) was subjected to de-alcoholization treatment, and the de-alcoholized liquor was collected.
[0008] B: The pH of the dealcoholized solution is adjusted to 3-4 using glacial acetic acid to obtain an acidified solution;
[0009] C: The acidified solution enters the macroporous adsorption resin to obtain the column liquid;
[0010] D: Concentrate the column chromatography solution to 50% solid content, add ethanol in stages for crystallization, and collect filter cake I and filtrate I separately by filtration;
[0011] E: Add 50% ethanol to filter cake I, heat and stir, filter and collect filter cake II and filtrate II;
[0012] F: Combine filtrate I and filtrate II, heat to 50°C, add ethanol, stir well, cool to 10-20°C, filter, and obtain crude D-chiral inositol.
[0013] Preferably, the de-alcoholization pressure in step A is -0.07 to -0.09 MPa, and the temperature is 45-55℃.
[0014] Preferably, in step B, the stirring speed during the acidification process is 100-150 rpm, the stirring time is 1-2 h, and ultrasonic treatment is simultaneously activated during the stirring process, with a controlled frequency of 25-30 kHz and a power of 250-350 W.
[0015] Preferably, the flow rate through the column in step C is 1-2 BV / h.
[0016] Preferably, the macroporous adsorption resin in step C is regenerated with 5% ethanol, then regenerated with 4% sodium hydroxide, and then washed with water until neutral before being fed.
[0017] Preferably, in step D, ethanol equal to 0.5 times the volume of the concentrate is added first at a temperature of 40-50℃, stirred for 0.5-1h, cooled to 30℃, and then ethanol equal to 0.5 times the volume of the concentrate is added again, and stirred for 0.5-1h.
[0018] Preferably, in step E, the amount of 50% ethanol added is 0.8-1.0 times the weight of filter cake I, and the mixture is heated to 50°C and stirred.
[0019] Preferably, the filter cake II in step E is recycled for the conversion of chiral inositol.
[0020] Preferably, in step F, the amount of ethanol added is 0.2-0.3 times the combined filtrate volume, and the stirring speed is controlled at 30-50 rpm after adding ethanol.
[0021] Preferably, the crude D-chiral inositol in step F has a content >98%, and the crude product can be further purified to obtain D-chiral inositol with a content >99.5%.
[0022] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:
[0023] 1. This invention directly targets the mother liquor rich in about 10% D-chiral inositol for deep processing, transforming materials that might otherwise be treated as waste or low-value byproducts into high-purity (>98%) crude D-chiral inositol, greatly improving the overall yield from initial raw materials to final product.
[0024] 2. In step A, approximately 40% of the ethanol in the mother liquor was recovered and reused in production through a mild vacuum deethanolation process, which significantly reduced the amount of fresh solvent purchased and the amount of waste treated in the subsequent process. In step E, inositol in the mother liquor was successfully separated and reused in the upstream chiral inositol conversion process, which not only reduced the waste of the valuable raw material inositol, but also directly reduced the raw material input cost of the main process.
[0025] 3. Step B introduces the synergistic effect of ultrasonic treatment and acidification. The cavitation effect of ultrasound can generate extremely strong local impact force and microjets, physically destroying the colloidal protective structure formed by impurities. This allows glacial acetic acid to interact more fully with impurity molecules, "breaking them down" into smaller molecular forms that are easier to process later. This innovation solves the problems of incomplete treatment and impurity encapsulation that may exist in traditional single acidification, laying a solid foundation for subsequent resin adsorption and crystallization purification.
[0026] 4. In step A, low-temperature (45-55℃) and reduced-pressure (-0.07~-0.09MPa) de-alcoholization is used. While efficiently recovering ethanol, the degradation, racemization or coking of D-chiral inositol and related substances due to heat sensitivity is avoided to the greatest extent, thus ensuring the chemical and optical purity of the final product.
[0027] 5. Step D employs a crystallization strategy combining "segmented ethanol addition" and "programmed temperature control." First, a portion of ethanol is added at a higher temperature to induce crystal nucleation; then, the remaining ethanol is added at a lower temperature to promote steady crystal growth. This method effectively controls the crystal particle size and crystal form of filter cake I, resulting in uniform, loosely packed crystals. This significantly improves the filtration speed, reduces entrained moisture in the filter cake (i.e., reduces residual product loss in the filter cake), and directly increases the yield of the target product in the filtrate.
[0028] Step 6. C clarifies the regeneration method for macroporous adsorption resin. This regeneration process is more thorough than conventional single methods, effectively washing away different types of organic impurities and ion residues, restoring the resin's adsorption capacity, significantly extending its service life, and reducing the high costs and production interruptions caused by frequent resin replacements.
[0029] 7. This method recovers and reuses the main components (ethanol, D-chiral inositol, and inositol) in the mother liquor, and the final waste discharged is only a small amount of impurities that have been concentrated and adsorbed, thus reducing the volume of waste liquid at the source. Through solvent recovery and material reuse, the material consumption and energy consumption of the entire production system are reduced, while the discharge of high-concentration organic waste liquid is reduced, alleviating the pressure of end-of-pipe treatment and meeting the requirements of green chemistry and clean production.
[0030] 8. This invention is not a simple aggregation of multiple processes, but rather a highly efficient, economical, and green solution for the resource recovery of mother liquor through a series of innovative steps with synergistic effects and precise process control. It not only achieves efficient recovery of D-chiral inositol and deep purification of impurities technically, but also demonstrates outstanding advantages in economic benefits and environmental sustainability, which is of great significance for promoting cost reduction, efficiency improvement, and green development in the D-chiral inositol industry. Attached Figure Description
[0031] Figure 1 This is a liquid chromatogram of crude D-chiral inositol in Example 1 of the present invention;
[0032] Figure 2 This is the liquid chromatogram of crude D-chiral inositol in Example 2 of the present invention;
[0033] Figure 3 This is a liquid chromatogram of crude D-chiral inositol in Example 3 of the present invention. Detailed Implementation
[0034] The present invention will be further illustrated below with reference to the embodiments. Example 1
[0035] 1. Take 10L of D-chiral inositol mother liquor (containing 40% ethanol, 10% D-chiral inositol, 4% inositol, 5% other impurities, and the remainder is water), first perform a de-alcoholization treatment, recover 3.8L of ethanol for reuse, control the vacuum degree to -0.07MPa, the temperature to 45℃, distill off all the ethanol, and collect 6L of de-alcoholized liquid. The temperature during the distillation process should not be too high to prevent the material from being degraded by heat.
[0036] 2. The pH of the dealcoholized solution was adjusted to 3 using glacial acetic acid, and stirred at 100 rpm for 2 hours. During the stirring process, ultrasonic treatment was started simultaneously to obtain 6.1 L of acidified solution. The ultrasonic frequency was controlled at 25 kHz and the power at 250 W, which can better destroy the colloidal structure formed by impurities in the solution and make the impurities uniformly dispersed in the system in the form of small molecules for better removal in the subsequent process.
[0037] 3. The acidified solution is adsorbed by macroporous adsorption resin to remove impurities and pigments from the feed solution. The column flow rate is 1 BV / h, and 8L of column liquid is collected. The resin is first regenerated with 5%wt ethanol, then regenerated with 4%wt sodium hydroxide, and then washed with water until neutral before being passed through the feed solution. This process can more effectively adsorb impurities in the feed solution, regenerate more thoroughly, and effectively increase the service life of the resin.
[0038] 4. Concentrate the column chromatography solution to a solid content of 50% w / w 3L. At 40℃, add 0.5 times the volume of ethanol to the concentrate and stir at 100 rpm for 1 hour. Cool down to 30℃, add another 0.5 times the volume of ethanol to the concentrate, and continue stirring for 1 hour to allow a large amount of inositol to precipitate out, thereby increasing the chiral inositol content in the filtrate. Filter and collect 600g of filter cake I and 5.5L of filtrate I separately. Gradual addition of ethanol and segmented temperature control can better control the particle size of filter cake I, improve filtration, reduce filter cake moisture content, and increase filtrate yield.
[0039] 5. Add 0.8 times the weight of 50% ethanol to filter cake I, heat to 50°C and stir to dissolve a large amount of chiral inositol into the solvent. Filter and collect 280g of filter cake II and 0.8L of filtrate II. The main component of filter cake II is inositol, which is recycled for the conversion of chiral inositol.
[0040] 6. Combine filtrate I and filtrate II, heat to 50°C, add ethanol at 0.2 times the volume of the combined filtrate, control the stirring speed at 30 rpm, cool to 20°C, filter, and obtain 656 g of crude D-chiral inositol, with a yield of 65.6% and a purity of 98.27%. Example 2
[0041] 1. Take 10L of D-chiral inositol mother liquor (containing 40% ethanol, 10% D-chiral inositol, 4% inositol, 5% other impurities, and the remainder is water), first perform a de-alcoholization treatment, recover 3.9L of ethanol for reuse, control the vacuum degree to -0.08MPa, the temperature to 50℃, distill off all the ethanol, and collect 5.9L of de-alcoholized liquid. The temperature during the distillation process should not be too high to prevent the material from being degraded by heat.
[0042] 2. The pH of the dealcoholized solution was adjusted to 3 using glacial acetic acid, and stirred at 120 rpm for 1.5 h. During the stirring process, ultrasonic treatment was started simultaneously to obtain 6 L of acidified solution. The ultrasonic frequency was controlled at 28 kHz and the power at 300 W, which can better destroy the colloidal structure formed by impurities in the solution and make the impurities uniformly dispersed in the system in the form of small molecules for better removal in the subsequent process.
[0043] 3. The acidified solution is adsorbed by macroporous adsorption resin to remove impurities and pigments from the feed solution. The column flow rate is 1.5 BV / h, and 8.2 L of column liquid is collected. The resin is first regenerated with 5% wt ethanol, then regenerated with 4% wt sodium hydroxide, and then washed with water until neutral before being passed through the feed solution. This process can more effectively adsorb impurities in the feed solution, regenerate more thoroughly, and effectively increase the service life of the resin.
[0044] 4. Concentrate the column chromatography solution to a solid content of 50% w / w (3.1 L). At 45°C, add 0.5 times the volume of ethanol to the concentrate and stir at 120 rpm for 0.8 h. Cool to 30°C, then add another 0.5 times the volume of ethanol to the concentrate and continue stirring for 0.8 h to allow a large amount of inositol to precipitate, thereby increasing the chiral inositol content in the filtrate. Filter and collect 590 g of filter cake I and 5.7 L of filtrate I separately. Gradual addition of ethanol and segmented temperature control can better control the particle size of filter cake I, improve filtration, reduce filter cake moisture content, and increase filtrate yield.
[0045] 5. Add 0.9 times the weight of 50% ethanol to filter cake I, heat to 50°C and stir to dissolve a large amount of chiral inositol into the solvent. Filter and collect 240g of filter cake II and 0.9L of filtrate II. The main component of filter cake II is inositol, which is recycled for the conversion of chiral inositol.
[0046] 6. Combine filtrate I and filtrate II, heat to 50°C, add 0.25 times the volume of the combined filtrate with ethanol, control the stirring speed at 40 rpm, cool to 15°C, filter, and obtain 685 g of crude D-chiral inositol, with a yield of 68.5% and a purity of 98.58%. Example 3
[0047] 1. Take 10L of D-chiral inositol mother liquor (containing 40% ethanol, 10% D-chiral inositol, 4% inositol, 5% other impurities, and the remainder is water) and first perform a de-alcoholization treatment. Recover 4L of ethanol for reuse. Control the vacuum degree to -0.09MPa and the temperature to 55℃. Distill off all the ethanol and collect 5.8L of de-alcoholized liquid. The temperature during the distillation process should not be too high to prevent the material from being degraded by heat.
[0048] 2. The pH of the dealcoholized solution was adjusted to 4 using glacial acetic acid, and stirred at 150 rpm for 1 hour. During the stirring process, ultrasonic treatment was started simultaneously to obtain 5.9 L of acidified solution. The ultrasonic frequency was controlled at 30 kHz and the power at 350 W, which can better destroy the colloidal structure formed by impurities in the solution and make the impurities uniformly dispersed in the system in the form of small molecules for better removal in the subsequent process.
[0049] 3. The acidified solution is adsorbed by macroporous adsorption resin to remove impurities and pigments from the feed solution. The column flow rate is 2 BV / h, and 8.5L of column liquid is collected. The resin is first regenerated with 5%wt ethanol, then regenerated with 4%wt sodium hydroxide, and then washed with water until neutral before being passed through the feed solution. This process can more effectively adsorb impurities in the feed solution, regenerate more thoroughly, and effectively increase the service life of the resin.
[0050] 4. Concentrate the column chromatography solution to a solid content of 50% w / w (3.05 L). At 50°C, add 0.5 times the volume of ethanol to the concentrate and stir at 150 rpm for 0.5 h. Cool to 30°C, then add another 0.5 times the volume of ethanol to the concentrate and continue stirring for 0.5 h to allow a large amount of inositol to precipitate, thereby increasing the chiral inositol content in the filtrate. Filter and collect 586 g of filter cake I and 5.5 L of filtrate I separately. Gradual addition of ethanol and segmented temperature control can better control the particle size of filter cake I, improve filtration, reduce filter cake moisture content, and increase filtrate yield.
[0051] 5. Add 50% ethanol at 1.0 times the weight of the filter cake to filter cake I, heat to 50°C and stir to dissolve a large amount of chiral inositol into the solvent. Filter and collect 228g of filter cake II and 0.96L of filtrate II. The main component of filter cake II is inositol, which is recycled for the conversion of chiral inositol.
[0052] 6. Combine filtrate I and filtrate II, heat to 50°C, add ethanol at 0.3 times the volume of the combined filtrate, control the stirring speed at 50 rpm, cool to 10°C, filter, and obtain 702 g of crude D-chiral inositol, with a yield of 70.2% and a purity of 98.74%.
[0053] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.
Claims
1. A method for treating the mother liquor during the preparation of D-chiral inositol, characterized in that... Includes the following steps: A: The D-chiral inositol mother liquor was subjected to de-alcoholization treatment, and the de-alcoholized liquid was collected; B: The pH of the dealcoholized solution is adjusted to 3-4 using glacial acetic acid to obtain an acidified solution; C: The acidified solution enters the macroporous adsorption resin to obtain the column liquid; D: Concentrate the column chromatography solution to 50% solid content, add ethanol in stages for crystallization, and collect filter cake I and filtrate I separately by filtration; E: Add 50% ethanol to filter cake I, heat and stir, filter and collect filter cake II and filtrate II; F: Combine filtrate I and filtrate II, heat to 50°C, add ethanol, stir well, cool to 10-20°C, filter, and obtain crude D-chiral inositol.
2. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: The de-alcoholization pressure in step A is -0.07 to -0.09 MPa, and the temperature is 45-55℃.
3. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: In step B, the stirring speed during the acidification process is 100-150 rpm, the stirring time is 1-2 hours, and ultrasonic treatment is simultaneously activated during the stirring process, with a controlled frequency of 25-30 kHz and a power of 250-350 W.
4. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: The flow rate through the column in step C is 1-2 BV / h.
5. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: Before use, the macroporous adsorption resin in step C is regenerated with 5% ethanol, then with 4% sodium hydroxide, and then washed with water until neutral before being fed.
6. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: In step D, at a temperature of 40-50℃, first add 0.5 times the volume of the concentrated liquid of ethanol, stir at 100-150 rpm for 0.5-1 h, cool down to 30℃, then add another 0.5 times the volume of the concentrated liquid of ethanol, and continue stirring for 0.5-1 h.
7. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: In step E, the amount of 50% ethanol added is 0.8-1.0 times the weight of filter cake I, and the mixture is heated to 50°C and stirred at a speed of 100-150 rpm.
8. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: The filter cake II in step E is recycled for the conversion of chiral inositol.
9. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: In step F, the amount of ethanol added is 0.2-0.3 times the combined filtrate volume, and the stirring speed is controlled at 30-50 rpm after adding ethanol.
10. The method for treating the mother liquor during the preparation of D-chiral inositol as described in claim 1, characterized in that: The content of crude D-chiroinositol in step F is >98%.