A method and equipment for extracting complex aromas from herbal plants at medium and high temperatures

Abstract

This application discloses a method and equipment for extracting complex aromas from herbal plants at medium and high temperatures. The method includes: pre-treating the herbal raw materials and placing them in a CNC temperature oven or roasting furnace, heating them to 50-280℃ according to a preset heating curve program; using dehydrated inert gas to enter the oven / roasting furnace, the maximum temperature can reach 280℃ with a temperature control error of ±5℃, so that the raw materials evaporate low-temperature aromas in the medium-temperature range and decompose the precursors of high-temperature aromas in the high-temperature range to obtain the high-temperature aroma body; a servo vacuum pump is set at the end of the aroma channel to continuously pump air throughout the process, and the aromas generated in each temperature range are extracted from the heating chamber in real time to avoid the medium-temperature aromas being destroyed by subsequent high temperatures; the air enters the CNC oven or roasting furnace after two stages of dehydration, and the complex aromas generated in the CNC oven or roasting furnace enter the collection system, where the aromas are collected by any of the following methods: ultra-low temperature condensation, spray tower absorption, or solvent absorption by drainage; the exhaust gas is treated by adsorption or alkaline absorption before being discharged. This application achieves complete extraction of aromas from medium-temperature volatiles and high-temperature pyrolysis, with an aroma retention rate of over 90% and byproduct content controlled to within 5%.

Description

Technical Field

[0001] This application relates to the field of fragrance manufacturing technology, specifically to methods for extracting and separating complex aroma components from herbal plants. Background Technology

[0002] The roots, stems, leaves, and fruits of herbs such as mugwort, cloves, agarwood, mint, lavender, and tobacco are rich in complex aromatic components and precursors. These components are mostly organic compounds such as terpenes, phenols, esters, aldehydes, and ketones. Some of these volatilize at temperatures slightly above ambient (40 to 60 degrees Celsius), while others require a medium-temperature environment (60 to 100 degrees Celsius) to volatilize from the herbs. Still others are precursors to fragrances, which require higher temperatures (around 100 to 200 degrees Celsius) to decompose and extract the fragrances. Therefore, how to extract complex aromas at medium and high temperatures without destroying the aromas at medium and low temperatures has become a core technical challenge in the field of herbal fragrance extraction.

[0003] Therefore, how to achieve complete extraction of complex aromas under medium and high temperature conditions, while effectively protecting the heat-sensitive aroma components from damage, has become a core technical challenge that urgently needs to be solved in the field of herbal fragrance extraction. Summary of the Invention

[0004] This application provides a method and equipment for extracting complex aromas from herbal plants at medium and high temperatures, in order to solve the following problems existing in the prior art: low temperature control accuracy, easy degradation of heat-sensitive aroma components; insufficient conversion of aroma precursors, low raw material utilization rate; low separation efficiency, easy loss of components; large amount of by-products from general liquid phase extraction, serious waste of resources, and existing supercritical extraction processes are difficult to obtain high-temperature pyrolysis aromas.

[0005] The first aspect of this application provides a method for extracting compound aromas from herbal plants at medium and high temperatures. This method controls the temperature and time of thermal evaporation and thermal decomposition of the herbal plants to produce aromas, and extracts aromas at different temperatures caused by continuous temperature changes in real time. The method includes the following steps: placing the herbal raw material in a CNC temperature oven or furnace, heating it according to a preset heating curve with a temperature control error of ±5℃, ensuring the herbal raw material fully releases its aroma at the corresponding temperature range; installing a servo vacuum pump at the end of the aroma channel for continuous extraction throughout the process, promptly extracting the aromas generated at each temperature from the heating chamber; collecting the aromas through ultra-low temperature condensation, spray tower absorption, or solvent absorption via drainage; and discharging the exhaust gas after adsorption or alkaline absorption treatment.

[0006] Preferably, the method further includes the step of raw material pretreatment: the raw material is crushed into 60-120 mesh particles; and dried by hot air at 50-60°C or by sun drying at low temperature to remove water.

[0007] Preferably, in the method, the air entering the CNC oven / roasting oven undergoes two stages of dehydration: the first stage is low-temperature condensation dehydration at 1-5℃, and the second stage is molecular sieve adsorption dehydration, so that the moisture content of the incoming air is less than 0.1g / m³.

[0008] Preferably, the ultra-low temperature condensation temperature is -80℃ to -20℃, and the aroma flow velocity in the condensation pipe is ≤5m / s. The ultra-low temperature condensation absorption conditions are: condensation temperature -80~-20℃, and aroma velocity in the condensation pipe ≤5m / s.

[0009] Preferably, the absorption conditions of the spray tower are: absorbent temperature 10–20℃, gas-liquid ratio 10:1 to 30:1, gas velocity 0.5–1m / s, and packing height 0.5–1.2m.

[0010] Preferably, the solvent absorption conditions for the water displacement method are: solvent temperature 0–10℃, gas-liquid contact time 2–5s, and solvent water content ≤0.05%.

[0011] Preferably, the exhaust gas treatment uses activated carbon, molecular sieves, macroporous resins or low-concentration caustic soda solution for adsorption, and the exhaust gas flow rate is ≤5m / s.

[0012] This application also includes an apparatus comprising: a numerically controlled temperature oven or roasting oven for programmed temperature heating of herbal raw materials for aroma production; an air intake dehydration device, including a low-temperature condensation dehydration device and a molecular sieve dehydration device, for two-stage dehydration of the air entering the oven / roasting oven; a servo vacuum pump, located at the rear end of the aroma channel, for creating a negative pressure environment inside the oven and extracting the aroma in real time; an aroma collection device, including at least one of an ultra-low temperature condensation device, a spray tower absorption device, or a drainage solvent absorption device; and a tail gas recovery device for adsorption or alkaline absorption treatment of the tail gas; the devices are connected in sequence to form a complete dehydration-aroma production-extraction-collection-tail gas treatment system.

[0013] Preferably, the servo vacuum pump works in conjunction with the CNC oven to create a negative pressure environment inside the oven; the servo vacuum pump is located at the end of the aroma channel to prevent high-temperature aroma from directly damaging the pumping equipment; the temperature control range of the CNC oven or baking oven is 50~280℃ and the temperature control accuracy is ±5℃.

[0014] It should be understood that the description in this section is not intended to identify key or important features of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0015] The accompanying drawings exemplify embodiments and form part of the specification, working together with the textual description to explain exemplary implementations of the embodiments. The drawings shown are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0016] Figure 1 This is a schematic diagram of a method for extracting complex aromas from herbal plants at medium and high temperatures, as described in this application. Figure 2 This is a schematic diagram of Example 1 of a medium-high temperature compound aroma extraction device for herbal plants according to this application.

[0017] Figure 3 This is a schematic diagram of Example 2 of a medium-high temperature compound aroma extraction device for herbal plants according to this application.

[0018] Figure 4 This is a schematic diagram of Example 3 of a medium-high temperature compound aroma extraction device for herbal plants according to this application. Detailed Implementation

[0019] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "multiple" means two or more, unless otherwise explicitly specified. The term "comprising" indicates the presence of the described feature, whole, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. The term "and / or" describes the relationship between related objects, indicating that three relationships may exist. For example, A and / or B may include three cases: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0022] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art; the terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification, claims and foregoing description of the drawings of this application are intended to cover non-exclusive inclusion.

[0023] Furthermore, terms such as "exemplary," "for example," and "optional" are used to indicate illustrative purposes. Any technical solution described by the above terms in the embodiments of this application should not be construed as being more preferred or advantageous than other technical solutions. Specifically, these terms are intended to present the relevant technical concepts in terms of specific implementation methods.

[0024] Please refer to the present invention, which is a high-temperature complex aroma extraction device with highly coupled method and equipment. The specific technical solution is as follows: This invention aims to overcome the technical limitations of existing fragrance extraction methods and provides a high-temperature complex aroma extraction method and equipment. Through an integrated design of controllable temperature thermodynamic precise regulation, molecular sieve adsorption for impurity removal, multi-mode protection and separation of heat-sensitive components, and adsorption-type closed-loop tail gas recovery, it achieves: 1. High-efficiency protection of heat-sensitive aroma components throughout the process under high-temperature conditions, solving the problems of low temperature control accuracy and easy degradation of components in existing technologies; 2. Precise staged release of aroma components with different boiling points, while simultaneously achieving effective conversion of high-temperature pyrolysis aroma precursors; 3. High-efficiency separation and high-purity collection of aroma components, solving the problems of low separation efficiency and easy loss of components in existing technologies; 4. Low-loss recovery of method byproducts and closed-loop gas circulation, controlling the amount of byproducts to within 5%, significantly improving raw material utilization. To achieve the above-mentioned objectives, this invention provides a high-temperature complex aroma extraction method that can achieve protection of heat-sensitive aroma components and staged aroma release. The method includes the following steps: Please see Figure 1 This is a schematic diagram of a method for extracting complex aromas from herbal plants at medium and high temperatures, as described in this application. The method includes the following steps: 1. Raw material pretreatment The herbal raw materials are pulverized into 60-120 mesh particles to ensure more even heating and fuller aroma release. They are then dried with hot air at 50-60℃ or sun-dried at low temperature to remove free moisture from the raw materials and prevent high-temperature moisture from interfering with the incense-making process.

[0025] 2. Two-stage deep water removal at the air intake The air entering the CNC oven / grill undergoes a two-stage dehumidification process: The first stage involves low-temperature condensation at 1-5℃ to remove a large amount of free water. The second stage employs molecular sieve adsorption for deep dehydration, ensuring that the moisture content of the air entering the furnace is below 0.1g / m³. This air intake dehydration process improves the stability and purity of the incense-making process.

[0026] 3. Incense making using medium-temperature evaporation and high-temperature pyrolysis A CNC temperature oven or CNC roasting oven is used as the main incense-making device. Based on the medium-temperature evaporation and high-temperature decomposition characteristics of herbal raw materials, a preset temperature rise curve is implemented in the control system. The temperature is gradually increased to 50-280℃ according to the program. When the oven / roasting oven is protected with dehydrated inert gas, the maximum temperature can reach 280℃, with a temperature control accuracy of ±5℃. The CNC system strictly controls temperature fluctuations within ±5℃, ensuring stable aroma extraction of the raw materials within the corresponding temperature range, while avoiding overheating that could damage the heat-sensitive aroma.

[0027] 4. Servo negative pressure real-time air extraction A servo vacuum pump is installed at the rear end of the aroma channel, operating synchronously and continuously with the CNC oven to create a stable negative pressure environment inside the oven. As soon as the aroma produced at each temperature range is released, it is immediately extracted from the heating chamber by the negative pressure airflow, no longer remaining in the high-temperature environment. This completely avoids the destruction, oxidation, and decomposition of the aroma at medium temperatures by subsequent heating, achieving "fragrance extracted immediately, high temperature without damage".

[0028] 5. Aroma separation and collection The primary method is cryogenic coagulation and collection, but depending on the aroma characteristics, either spray tower absorption or water-based solvent absorption can be selected. Ultra-low temperature condensation absorption: condensation temperature -80℃~-20℃, aroma flow rate in condensation pipe ≤5m / s, causing the complex aroma to condense into a gel or liquid mixture for collection; Spray tower absorption: absorbent temperature 10~20℃, gas-liquid ratio 10:1~30:1, gas flow rate 0.5~1m / s, packing height 0.5~1.2m; Drainage solvent absorption: solvent temperature 0~10℃, gas-liquid contact time 2~5s, solvent water content ≤0.05%.

[0029] 6. Exhaust gas treatment The exhaust gas contains a small amount of low-boiling-point non-polar molecules and incompletely absorbed aroma components. Activated carbon, molecular sieves, macroporous resins, or low-concentration caustic soda solutions are used for adsorption treatment. The exhaust gas flow rate is controlled to ≤5m / s to ensure that the emitted gas meets environmental protection requirements.

[0030] Please see Figures 2-4 A second aspect of this application provides an apparatus for implementing the above method, comprising: Air intake dehydration device 1; including low temperature condensation dehydration device 11 and molecular sieve dehydration device 12, used to perform two-stage dehydration on the air entering the oven / roasting oven, so that the air intake moisture content is less than 0.1g / m³.

[0031] 2. Numerical control temperature oven or roaster; used for programmed heating of herbal raw materials for incense making, with a temperature control range of 50 to 280°C. When inert gas after dehydration is introduced into the oven / roaster, the maximum temperature can reach 280°C. The temperature control accuracy is ±5°C.

[0032] Servo vacuum pump 3; located at the rear end of the aroma channel, working in conjunction with the CNC oven to create a negative pressure environment inside the oven, so that the aroma is extracted in time and enters the aroma collection device 4.

[0033] Aroma collection device 4; including ultra-low temperature condensation device 41 (see Figure 2 Example 1), Spray tower absorption device 42 (see Figure 3 Example 2) or water displacement solvent absorption device 43 (see Figure 4 At least one of the following in Example 3) is used for efficient aroma collection.

[0034] The exhaust gas recovery device 5 includes an adsorption column and a return pipe, used for adsorption treatment of exhaust gas and recovery of residual aroma components.

[0035] The devices are connected in sequence to form a complete system for water removal, incense making, gas extraction, collection, and exhaust gas treatment.

[0036] Example 1 I. Raw material pretreatment Select 500g of mugwort leaves and pulverize them into 80-mesh particles using a grinder. Place the pulverized material in a hot air drying oven and dry it at 55℃ for 2 hours until the moisture content of the material drops below 5%.

[0037] II. Air intake water removal Turn on the low-temperature condensation and dehydration device and set the condensation temperature to 3℃ to perform the first stage of dehydration on the air entering the oven. After the first stage of dehydration, the air enters the molecular sieve dehydration device for the second stage of deep dehydration, reducing the moisture content of the incoming air to 0.08g / m³.

[0038] III. Incense Making by Procedural Heating The pretreated raw material is evenly spread in a CNC temperature oven to a thickness of 10mm. The heating program is set as follows: heat to 70℃ at a rate of 2℃ / min and hold for 30min; then heat to 90℃ at a rate of 1℃ / min and hold for 20min.

[0039] During the heating process, the medium-temperature aroma components (such as monoterpenols and monoterpenoid esters) in the raw materials gradually volatilize in the temperature range of 50 to 80°C; the high-temperature aroma components (such as sesquiterpenes) and aroma precursors decompose and release in the temperature range of 80 to 100°C.

[0040] IV. Real-time air extraction The servo vacuum pump starts synchronously with the oven, creating a stable negative pressure environment (-0.02 to -0.05 MPa) inside the oven. Once the aromas produced at each temperature range are released, they are immediately extracted by the negative pressure airflow and enter the subsequent collection system.

[0041] V. Ultra-low temperature condensation collection The aromatic gas entered an ultra-low temperature condenser, with the condensation temperature set at -40℃. The aroma flowed at a speed of 3 m / s within the condensation pipe, undergoing a phase change condensation to form a pale yellow gel-like substance. Approximately 12.5 g of Artemisia argyi complex aroma extract was collected, with an aroma retention rate of 92%.

[0042] VI. Exhaust Gas Treatment Incompletely condensed exhaust gas enters the exhaust gas recovery device and is treated by an activated carbon adsorption column to meet emission standards. After the activated carbon becomes saturated, residual aroma components can be recovered by desorption through heating.

[0043] Example 2 I. Raw material pretreatment Select 300g of clove buds and crush them into 100-mesh particles. Dehydrate them by sun-drying until the moisture content of the raw material drops to 4%.

[0044] II. Air intake water removal Using the same two-stage dehydration process as in Example 1, the moisture content of the intake air was reduced to 0.06 g / m³.

[0045] III. Incense Making by Procedural Heating Place the raw materials in a CNC oven and set the heating program: heat to 65°C at a rate of 3°C / min and hold for 25 minutes; then heat to 85°C at a rate of 1.5°C / min and hold for 15 minutes.

[0046] IV. Real-time air extraction The servo vacuum pump creates a negative pressure environment of -0.03MPa inside the oven, extracting the aroma in real time.

[0047] V. Spray tower absorption and collection The aromatic gas entered the absorption unit of the spray tower, using a food-grade ethanol-water solution at 15℃ as the absorbent, with a gas-liquid ratio of 20:1, a gas flow rate of 0.8 m / s, and a packing height of 1.0 m. Approximately 9.2 g of clove complex aroma extract was collected, with an aroma retention rate of 91%.

[0048] VI. Exhaust Gas Treatment The exhaust gas is treated by macroporous resin adsorption and then discharged in compliance with standards.

[0049] Example 3 I. Raw material pretreatment Select 400g of agarwood chips and pulverize them into 60-mesh particles. Dry them with hot air at 50℃ for 3 hours until the moisture content of the raw material drops to 3%.

[0050] II. Air intake water removal Using the same two-stage dehydration process as in Example 1, the moisture content of the intake air was reduced to 0.05 g / m³.

[0051] III. Incense Making by Procedural Heating Place the raw materials in a CNC oven and set the heating program: heat to 80°C at a rate of 2°C / min and hold for 40 minutes; then heat to 95°C at a rate of 1°C / min and hold for 25 minutes.

[0052] IV. Real-time air extraction The servo vacuum pump creates a negative pressure environment of -0.04MPa inside the oven, extracting the aroma in real time.

[0053] V. Solvent Absorption and Collection by Water Displacement Method The aromatic gas was introduced into a water displacement solvent absorption device, using ethyl acetate at 5°C as the absorption solvent. The gas-liquid contact time was 3 seconds, and the solvent water content was 0.03%. Approximately 18.6 g of agarwood complex aroma extract was collected, with an aroma retention rate of 93%.

[0054] VI. Exhaust Gas Treatment The exhaust gas is treated by molecular sieve adsorption and then discharged in compliance with standards.

[0055] This application offers the following advantages: Significant protection of heat-sensitive aroma components; through a quadruple design of precise temperature control (±5℃), real-time negative pressure extraction, two-stage air intake for water removal, and low-temperature collection, heat-sensitive aroma components are effectively protected from high-temperature damage, increasing aroma retention to over 90%. Full-spectrum extraction of complex aroma components is achieved; while protecting heat-sensitive components, a programmed temperature increase of 50–100℃ enables the release of high-boiling-point aroma components and the high-temperature conversion of aroma precursors, increasing raw material utilization to over 95%. High aroma purity with no secondary pollution; the multi-mode separation device employs physical separation + low-temperature protection design, achieving an extracted fragrance purity of over 98%, meeting the safety requirements of food, daily chemicals, and pharmaceutical industries. Significantly reduced by-products, environmentally friendly and energy-saving; the closed-loop exhaust gas recovery system controls by-products to below 5%, reducing by over 60% compared to existing technologies (by-products exceeding 15%); energy consumption is reduced by over 30%, meeting the requirements of green and environmentally friendly industrial production.

[0056] The above embodiments are only used to illustrate the present application and are not intended to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A method for extracting complex aromas from herbal plants at medium and high temperatures, characterized in that: Controlling the temperature and time of herbal plant thermal evaporation and thermal decomposition for fragrance production, and extracting the aroma at different temperatures caused by continuous temperature changes in real time, includes the following steps: Place the herbal raw materials in a CNC temperature oven or roasting oven, and heat them according to a preset temperature rise curve with a temperature control error of ±5℃, so that the herbal raw materials can fully release their aroma in the corresponding temperature range; A servo vacuum pump is installed at the end of the aroma channel to continuously extract the aroma generated at each temperature from the heating chamber in a timely manner. The aroma is collected by any of the following methods: ultra-low temperature condensation, absorption by a spray tower, or solvent absorption by drainage. The exhaust gas is discharged after being treated by adsorption or alkaline absorption.

2. The method according to claim 1 further includes the step of raw material pretreatment: crushing the raw material into 60-120 mesh particles; and drying it with hot air at 50-60℃ or sun-drying it at low temperature to remove moisture.

3. According to the method of claim 1, the air entering the CNC oven / roasting oven undergoes two stages of dehydration: the first stage is low-temperature condensation dehydration at 1-5℃, and the second stage is molecular sieve adsorption dehydration, so that the moisture content of the incoming air is less than 0.1g / m³.

4. The method according to claim 1, characterized in that, The ultra-low temperature condensation temperature is -80℃ to -20℃, and the aroma flow rate in the condensation pipe is ≤5m / s.

5. The method according to claim 1, characterized in that, The absorption conditions of the spray tower are: absorption liquid temperature 10–20℃, gas-liquid ratio 10:1~30:1, gas flow rate 0.5–1m / s, and packing height 0.5–1.2m.

6. The method according to claim 1, characterized in that, The solvent absorption conditions for the water displacement method are: solvent temperature 0–10℃, gas-liquid contact time 2–5s, and solvent water content ≤0.05%.

7. The method according to claim 1, characterized in that, The exhaust gas is treated by adsorption using activated carbon, molecular sieves, macroporous resins, or low-concentration caustic soda solution, with an exhaust gas flow rate ≤5m / s.

8. An apparatus for implementing the method according to any one of claims 1 to 7, characterized in that, include: Numerical control temperature oven or roasting oven is used to program the temperature of herbal raw materials for incense making; The air intake dehydration device, including a low-temperature condensation dehydration device and a molecular sieve dehydration device, is used to perform two-stage dehydration on the air entering the oven / roasting oven. A servo vacuum pump, located at the rear end of the aroma channel, is used to create a negative pressure environment inside the oven and extract the aroma in real time. Aroma collection device, including at least one of ultra-low temperature condensation device, spray tower absorption device or water drainage solvent absorption device; The exhaust gas recovery device is used to treat exhaust gas by adsorption or alkaline absorption. The devices are connected in sequence to form a complete system for water removal, incense making, gas extraction, collection, and exhaust gas treatment.

9. The device according to claim 8, characterized in that: The servo vacuum pump works in conjunction with the CNC oven to create a negative pressure environment inside the oven; the servo vacuum pump is located at the end of the aroma channel to prevent high-temperature aroma from directly damaging the pumping equipment; the temperature control range of the CNC oven or baking oven is 50 to 280°C.

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