Method for obtaining convallaria majalis pyrane by acidifying and hydrolyzing rectification base material
By using a microreactor continuous acidification and hydrolysis process to convert distillation feedstock, the problem of resource waste in lily of the valley pyran production has been solved, and efficient recovery and purification of lily of the valley pyran products has been achieved, improving resource utilization and product quality.
Patent Information
- Application Number
- CN202511406064.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2026-01-02
AI Technical Summary
The distillation residue generated during the existing lily of the valley pyran production process is considered hazardous waste, resulting in resource waste and additional treatment costs, and failing to effectively utilize its usable components.
A microreactor continuous acidification and hydrolysis process was adopted. By controlling the feed rate and temperature, the uncyclized precursors and oligomers in the distillation bottom material were converted into lily of the valley pyran. The oil and water density difference was used for separation, and the product was purified by a vacuum distillation column to obtain high-purity lily of the valley pyran.
It significantly improves raw material utilization, reduces resource waste and processing costs, and enhances the total recovery rate and purity of lily of the valley pyran, meeting both environmental and economic requirements.
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Figure CN121248552A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lily of the valley pyran production technology, specifically a method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation feedstock. Background Technology
[0002] Lily of the valley pyran, a high-value synthetic fragrance with a fresh lily of the valley aroma, occupies an irreplaceable position in high-end perfumes, skin care cosmetics, and functional food flavor formulations due to its long-lasting aroma and strong chemical stability. The production process of lily of the valley pyran must undergo precise distillation and purification, and trace isomers and residual raw materials must be removed through multiple fractionation. This step directly determines the sensory quality and market value of the product.
[0003] While distillation can achieve high-purity separation, it inevitably generates a large amount of residual material. On average, each ton of lily of the valley pyran produced generates approximately 150-200 kg of distillation residue, accounting for 10%-15% of the total raw material input. This residue is complex in composition, mainly containing three types of usable substances: first, incompletely cyclized precursor compounds (such as the condensation intermediate of isopentenol and isopentanal, accounting for 30%-40%), whose molecular structure has the potential to be converted into lily of the valley pyran through acid-catalyzed rearrangement; second, oligomeric impurities (accounting for 20%-25%), formed by intermolecular dehydration polymerization of precursor molecules, which can be depolymerized into monomers through hydrolysis; and third, trace amounts of lily of the valley pyran (5%-8%), which are retained due to their boiling points being close to those of impurities. However, in traditional production, this residue is often treated as hazardous waste and directly incinerated or landfilled, resulting in the waste of thousands of tons of usable resources annually and incurring additional hazardous waste treatment costs, creating a significant economic and environmental burden. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation bottom material. This method solves the problem that existing distillation processes generate 10%-15% residual bottom material, which contains uncyclized precursors, oligomer impurities, and trace amounts of lily of the valley pyran and other usable substances. However, this material is treated as hazardous waste and incinerated or landfilled by traditional processes, resulting in resource waste and additional treatment costs.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate, comprising the following steps: S1. Raw material ratio and reaction start-up: The lily of the valley pyran distillation bottom material and the acid catalyst solution are pumped into the microreactor through two feed channels at a mass ratio of 1.0:0.7-1.0. S2, Continuous feeding: During step S1, when the lily of the valley pyran distillation bottom material and the acid catalyst solution are pumped into the microreactor through two feed channels, the feed rate is controlled separately and mixed in the microreactor to obtain a mixture; S3. Oil phase separation: After obtaining the mixture in step S2, a micro separation module is used for real-time separation. The oil phase and water phase are separated by the density difference between oil and water. The separated oil phase is sampled and then detected by gas chromatography. When the purity of lily of the valley pyran is 55-71%, it meets the standard and proceeds to the next step. S4. Refining and Purification: The oil phase liquid obtained in step S3 is transferred to a refining tank and washed with 5% sodium carbonate solution to neutralize residual acid. Then, it is washed 2-3 times with deionized water to remove salt impurities, resulting in a neutral oil phase liquid. The neutral oil phase is then sent to a vacuum distillation column and distilled under conditions of vacuum degree above -0.095MPa, reflux ratio of 3-5:1, and column top temperature of 80-95℃. The main fraction is collected to obtain high-purity lily of the valley pyran product, and the purity of the high-purity lily of the valley pyran product after refining is ≥99%.
[0006] Preferably, in step S1, the lily of the valley pyran distillation substrate is specifically: the residual substrate after lily of the valley pyran distillation, containing incompletely converted precursors and byproducts; The acid catalyst solution is specifically an organic or inorganic acid solution with a mass fraction of 35%-70%, used to promote the acidification and hydrolysis reaction of the precursor in the substrate.
[0007] Preferably, in step S2, the respective controls include: The rates of pumping lily of the valley pyran distillation feedstock into the microreactor, the rate of pumping the acid catalyst solution into the microreactor, and the rate of mixing within the microreactor are: The feed rate of the lily of the valley pyran distillation substrate is specifically 4-8 ml / min; The acid catalyst solution is pumped into the microreactor at a rate of 3-5 ml / min. The mixture is transported at a rate of 7-13 ml / min within the microreactor.
[0008] Preferably, in step S2, the microreactor parameters include: the microreactor temperature is controlled at 50-85℃, and the reactor pressure is maintained at 0.05-1.0 MPa, providing a suitable thermodynamic environment for the hydrolysis reaction.
[0009] Preferably, in step S3, the gas chromatography method includes: The chromatographic column was a DB-5 capillary column (30m × 0.25mm × 0.25μm). The temperature program was initially 60℃ and held for 2 min, then increased to 200℃ at a rate of 15℃ / min and held for 5 min. The detector was an FID.
[0010] Preferably, in step S3, the micro-separation module includes a centrifugal separator, the parameters of which include: rotation speed of 8000-10000 r / min, separation chamber diameter of 20 mm, and time of 3-5 minutes.
[0011] Preferably, in step S4, the volume ratio of the oil phase liquid to the sodium carbonate solution is 1:1.
[0012] This invention provides a method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation feedstock. It has the following beneficial effects: 1. This invention uses an acidification and hydrolysis process to directionally convert uncyclized precursors, oligomers and other usable components in distillation feedstock, transforming feedstock that is treated as hazardous waste in traditional processes into lily of the valley pyran product, significantly improving the overall utilization rate of raw materials and reducing the waste of thousands of tons of resources each year; at the same time, it saves the cost of hazardous waste incineration or landfill, further reducing the economic burden. Attached Figure Description
[0013] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation
[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0015] Please see the appendix Figure 1 This invention provides a method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate, comprising the following steps: S1. Raw material ratio and reaction start-up: The lily of the valley pyran distillation bottom material and the acid catalyst solution are pumped into the microreactor through two feed channels at a mass ratio of 1.0:0.7-1.0. The lily of the valley pyran distillation substrate is specifically the residual substrate after lily of the valley pyran distillation, containing incompletely converted precursors and byproducts. The acid catalyst solution is specifically an organic or inorganic acid solution with a mass fraction of 35%-70%, used to promote the acidification and hydrolysis reaction of the precursor in the substrate; S2. Continuous Feeding: During step S1, when the lily-of-the-valley pyran distillation substrate and the acid catalyst solution are pumped into the microreactor through two feed channels, the feed rate is controlled separately, and the mixture is then carried out in the microreactor to obtain a mixture. The separate control includes: The pumping rates of lily of the valley pyran distillation substrate into the microreactor, the pumping rates of acid catalyst solution into the microreactor, and the velocity of the mixture within the microreactor; The feed rate of the lily of the valley pyran distillation substrate is specifically 4-8 ml / min; The acid catalyst solution is pumped into the microreactor at a rate of 3-5 ml / min. The mixture is transported at a rate of 7-13 ml / min within the microreactor; The microreactor parameters include: the microreactor temperature is controlled at 50-85℃, and the reactor pressure is maintained at 0.05-1.0 MPa, providing a suitable thermodynamic environment for the hydrolysis reaction; S3. Oil phase separation: After obtaining the mixture in step S2, a micro separation module is used for real-time separation. The oil phase and water phase are separated by the density difference between oil and water. The separated oil phase is sampled and then detected by gas chromatography. When the purity of lily of the valley pyran is 55-71%, it meets the standard and proceeds to the next step. The gas chromatography method includes: The chromatographic column was a DB-5 capillary column (30m×0.25mm×0.25μm), the temperature was programmed (initially 60℃ and held for 2 min, then increased to 200℃ at 15℃ / min and held for 5 min), and the detector was FID; The micro-separation module includes, but is not limited to, a centrifugal separator, the parameters of which include: rotation speed of 8000-10000 r / min, separation chamber diameter of 20 mm, and time; S4. Refining and Purification: The oil phase liquid obtained in step S3 is transferred to a refining tank and washed with 5% sodium carbonate solution to neutralize residual acid. Then, it is washed 2-3 times with deionized water to remove salt impurities, resulting in a neutral oil phase liquid. The neutral oil phase is then sent to a vacuum distillation column and distilled under conditions of vacuum degree above -0.095MPa, reflux ratio of 3-5:1, and column top temperature of 80-95℃. The main fraction is collected to obtain high-purity lily of the valley pyran product, and the purity of the high-purity lily of the valley pyran product after refining is ≥99%. The volume ratio of the oil phase liquid to the sodium carbonate solution is 1:1. Comparative experiment: I. Experimental Objective The effects of the "microreactor continuous acidification and hydrolysis process" of this invention and the traditional "batch reactor hydrolysis process" in the recovery of lily of the valley pyran from distillation bottom materials were compared, with a focus on verifying the differences in raw material utilization, product purity, processing efficiency and environmental friendliness.
[0016] II. Experimental Materials and Equipment Raw materials: Lily of the valley pyran distillation bottom material from the same batch (tested to contain 35% uncyclized precursor, 22% oligomer, trace amount of lily of the valley pyran, the remainder being impurities); 30% sulfuric acid solution (analytical grade, conforming to GB / T625-2007); 5% sodium carbonate solution (conforming to GB / T639-2008); deionized water.
[0017] equipment: Experimental group: microreactor (channel diameter 300μm), centrifugal separator (8000r / min), vacuum distillation column (-0.095MPa), gas chromatograph (equipped with DB-5 capillary column, conforming to GB / T22731-2008 requirements).
[0018] Control group: 5L batch reactor (with stirring device), separatory funnel, vacuum distillation column (same as experimental group), gas chromatograph of the same model.
[0019] III. Experimental Procedure Experimental group (method of this invention) Raw material ratio: Take 1000g of distillation bottom material and 800g of 30% sulfuric acid solution at a mass ratio of 1.0:0.8 and put them into a double feed tank respectively.
[0020] Continuous reaction: The feed rate of the base material is 6 ml / min, the feed rate of the sulfuric acid solution is 4 ml / min, and the total flow rate is 10 ml / min. The microreactor was set at a temperature of 70℃, a pressure of 0.3MPa, and a material residence time of 1min.
[0021] Oil phase separation: The reaction mixture enters a centrifugal separator (8000r / min, separation chamber diameter 20mm), separates for 3min, and collects the oil phase.
[0022] Refining and purification: The oil phase was washed with 5% sodium carbonate solution at a volume ratio of 1:1 for 10 min, and then washed twice with deionized water (5 min each time). Vacuum distillation (-0.095 MPa, reflux ratio 4:1, top temperature 85 °C) was performed to collect the main fraction.
[0023] Testing: Purity of the finished product was determined by gas chromatography according to GB / T22731-2008 (chromatographic conditions: DB-5 column 30m×0.25mm×0.25μm, temperature program 60℃→200℃, FID detector).
[0024] Control group (traditional intermittent process) Raw material ratio: Take 1000g of the same batch of distillation bottom material and 1200g of 30% sulfuric acid solution (50% excess catalyst in traditional process) and add them to a 5L reactor.
[0025] Batch reaction: stirring speed 300 r / min, temperature 70℃, atmospheric pressure reaction for 4 h (traditional processes require longer time to ensure conversion).
[0026] Oil phase separation: The reaction solution is allowed to stand for 30 minutes to separate into layers (traditional separation method), and the upper oil phase is taken.
[0027] Purification and refining: Same washing and distillation steps as the experimental group (ensuring that the only variable is the reaction and separation method).
[0028] Detection: Same as the experimental group.
[0029] IV. Experimental Results and Comparative Analysis (n=3 parallel experiments, average value taken) V. Conclusion The process of this invention, while complying with the GB / T22731-2008 standard, significantly improves the recovery rate of distillation bottom material (+20.6%) and shortens the processing time (-58.8%) compared with the traditional batch process, while reducing acid consumption and wastewater discharge, making it more suitable for green and intensive production needs.
[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate, characterized in that, Includes the following steps: S1. Raw material ratio and reaction start-up: The lily of the valley pyran distillation bottom material and the acid catalyst solution are pumped into the microreactor through two feed channels at a mass ratio of 1.0:0.7-1.
0. S2, Continuous feeding: During step S1, when the lily of the valley pyran distillation bottom material and the acid catalyst solution are pumped into the microreactor through two feed channels, the feed rate is controlled separately and mixed in the microreactor to obtain a mixture; S3. Oil phase separation: After obtaining the mixture in step S2, a micro separation module is used for real-time separation. The oil phase and water phase are separated by the density difference between oil and water. The separated oil phase is sampled and then detected by gas chromatography. When the purity of lily of the valley pyran is 55-71%, it meets the standard and proceeds to the next step. S4. Refining and Purification: The oil phase liquid obtained in step S3 is transferred to a refining tank and washed with 5% sodium carbonate solution to neutralize residual acid. Then, it is washed 2-3 times with deionized water to remove salt impurities, resulting in a neutral oil phase liquid. The neutral oil phase is then sent to a vacuum distillation column and distilled under conditions of vacuum degree above -0.095MPa, reflux ratio of 3-5:1, and column top temperature of 80-95℃. The main fraction is collected to obtain high-purity lily of the valley pyran product, and the purity of the high-purity lily of the valley pyran product after refining is ≥99%.
2. The method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate according to claim 1, characterized in that, In step S1, the lily of the valley pyran distillation substrate specifically refers to the residual substrate after lily of the valley pyran distillation, containing incompletely converted precursors and byproducts. The acid catalyst solution is specifically an organic or inorganic acid solution with a mass fraction of 35%-70%, used to promote the acidification and hydrolysis reaction of the precursor in the substrate.
3. The method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate according to claim 1, characterized in that, In step S2, the respective controls include: The rates of pumping lily of the valley pyran distillation feedstock into the microreactor, the rate of pumping the acid catalyst solution into the microreactor, and the rate of mixing within the microreactor are: The feed rate of the lily of the valley pyran distillation substrate is specifically 4-8 ml / min; The acid catalyst solution is pumped into the microreactor at a rate of 3-5 ml / min. The mixture is transported at a rate of 7-13 ml / min within the microreactor.
4. The method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate according to claim 1, characterized in that, In step S2, the microreactor parameters include: the microreactor temperature is controlled at 50-85℃, and the reactor pressure is maintained at 0.05-1.0 MPa, providing a suitable thermodynamic environment for the hydrolysis reaction.
5. The method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate according to claim 1, characterized in that, In step S3, the gas chromatography method includes: The chromatographic column was a DB-5 capillary column (30m × 0.25mm × 0.25μm). The temperature program was initially 60℃ and held for 2 min, then increased to 200℃ at a rate of 15℃ / min and held for 5 min. The detector was an FID.
6. The method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate according to claim 1, characterized in that, In step S3, the micro-separation module includes a centrifugal separator, the parameters of which include: rotation speed of 8000-10000 r / min, separation chamber diameter of 20 mm, and time of 3-5 minutes.
7. The method for obtaining lily of the valley pyran by acidification and hydrolysis of distillation substrate according to claim 1, characterized in that, In step S4, the volume ratio of the oil phase liquid to the sodium carbonate solution is 1:1.