CN102504955B - Processing for extracting and purifying eucalyptus oil - Google Patents

Abstract

The invention discloses a process for extracting and purifying eucalyptus oil, which uses auxiliary agents to assist vacuum batch rectification to extract high-purity eucalyptus oil; without greatly changing the traditional rectification process, the eucalyptus leaves are changed by adding auxiliary agents The thermodynamic properties of the oil system improve the separation efficiency. By adjusting the reflux ratio and the temperature of the tower kettle, high-purity eucalyptol and by-product α-pinene are extracted; the content of the extracted eucalyptol is greater than 90%, and the highest can reach 96.50%. , the yield is more than 75%, the production cycle is within 6 hours, the process operation is simple, the production process is stable, and the by-product containing about 80% α-pinene is obtained at the same time, which increases the added value of eucalyptus crude oil.

Description

A kind of process of extracting and purifying eucalyptus oil

technical field

The present invention relates to the separation technology of the high-purity products of natural spice oils, more specifically, relates to a kind of eucalyptus

Process of extracting and purifying leaf oil.

Background technique

Eucalyptus oil is an aromatic essential oil secreted by eucalyptus leaf oil gland cells, which is a mixture of various organic components. Eucalyptus oil can be divided into three categories according to its main components and uses: medicine, fragrance and industrial oil. The most important of these is the medical eucalyptus oil, whose main component is 1,8-cineole.

Crude eucalyptus oil, a natural product, has many impurities, among which α-pinene is the main one, and a small amount of β-pinene, myrcene, α-phellandrene, limonene, p-pinene, γ-terpinene , Linalool, etc. A variety of impurities are isomers or molecular structures and molecular weights are very close to 1,8-cineole, and have similar physical and chemical properties, which brings great difficulty to the purification of eucalyptol. Literature research shows that there are many methods for separating eucalyptol, such as supercritical extraction, silica gel column chromatography, chemical reaction, catalytic distillation, low temperature crystallization, falling film crystallization, etc.

Due to the simple process and mature industrial production process, the rectification method has become the main means of purifying natural products such as eucalyptol. Chinese patent (CN1181415) discloses a double-tower continuous refining method for eucalyptus oil. In this method, eucalyptus oil is pretreated at high temperature (100-250°C) and high pressure (2-10kg/cm2) for 1-5 hours. Then the pretreated eucalyptus oil is rectified through a continuous rectification tower, wherein the still raffinate of the first tower is used as the raw material of the second tower for rectification, and finally eucalyptol is collected from the light components of the second tower Eucalyptus oil with a content of 70~83%. Although it is a continuous rectification with two towers, it still belongs to batch rectification. Compared with batch rectification, one more tower is added, and the pretreatment steps of gas stripping and pre-distillation are required in the early stage, which increases the production cost and generates unnecessary energy. Consumption makes the production cycle longer and the cost increases, and the products produced are all with a eucalyptol content below 80%, and the yield is on the low side.

Chinese patent (101899361A) uses a single-tower continuous distillation method for eucalyptus oil, using Eucalyptus eucalyptus oil with a eucalyptol content of 62.5% as raw material, and adopts continuous feeding and discharging. Materials such as light components, eucalyptol, and still residues are continuously extracted at different product outlets. According to the content of the extracted material, the eucalyptus oil with different eucalyptus oil content is extracted by adjusting the reflux ratio and controlling the distillation temperature. The content of eucalyptol collected can reach up to 92%, the daily processing capacity of raw materials is 10 tons/day, the production loss is less than or equal to 1%, and the yield of 80% eucalyptus oil is over 75%. This method has large daily processing capacity, stable production quality, less production loss and simple operation. But the main product of this method is 80% eucalyptol, although it can reach the highest content of 92%, but in the case of limited tower height, single tower continuous distillation cannot produce higher purity products, and the product yield is partial Low, it cannot be produced on a large scale, and if the tower height is increased, excessive energy consumption will be generated. Moreover, in the continuous rectification process, the product purity is controlled by adjusting the reflux ratio and distillation temperature, which will inevitably cause the entire continuous instability and complicate the rectification operation process.

Chinese patent (CN101307058A) and Chinese patent (CN201276512Y) invented a new type of fractionation tower, in the case of maintaining the original process conditions, by setting the heat exchange area between the decondenser of the fractionation tower and the top of the fractionation tower to be 50~70% condensate return channel. That is, the heat exchange tube bundles that are consistent with the gas flow direction of the tower are evenly arranged on the tube plate tray. The pipe layout area of the tube bundle is 35% of the tray area. To reduce the volatilization of γ-terpinene and p-cymene. Expanded the relative volatility of each component in eucalyptus oil. The content of primary fractionated eucalyptol reaches 80%, and the process conditions are stable. However, the content of the products produced by this device is mostly between 80% and 83%, which is not suitable for the production of high-purity eucalyptol.

Contents of the invention

The present invention overcomes the deficiencies of the prior art and aims to provide a process for extracting and purifying eucalyptus oil, which can change the thermodynamic properties of the system by means of the synergistic effect of additives without greatly changing the traditional rectification process. Thereby making the production process simple and easy, shortening the preparation cycle, reducing production loss, and obtaining 1,8-cineole with high purity and high yield; collecting the by-product α-pinene in the rectification process to increase the crude oil of eucalyptus added value.

The present invention adopts following technical scheme to realize:

(1) Evenly mix the eucalyptus oil stock solution and additives in a certain ratio;

(2) Add a well-proportioned solution into the tower kettle, turn on the vacuum pump and the tower top condensing device, so that the vacuum degree of the rectification system meets the process requirements and is stable;

(3) When the temperature of the set tower kettle meets the process requirements, perform total reflux operation;

(4) Eucalyptus oil collection, first collect the light components mainly composed of α-pinene in the eucalyptus oil system with a large reflux ratio, after the light components are collected completely, increase the temperature of the tower kettle, reduce the reflux ratio and collect 1 , 8-cineole, when the content of 1,8-cineole is lower than the process requirements, then increase the reflux ratio to collect 1,8-cineole, until the product content cannot meet the process requirements, then stop collecting, and finally Combine the collected solutions containing 1,8-cineole to obtain eucalyptus oil.

The eucalyptus oil stock solution described in the present invention has a 1,8-cineole content of 58% to 63% (mass percentage,

The same below) for eucalyptus oil, the additives are C ₂ -C ₄ alcohols, and the amount of additives accounts for 5-10% of the stock solution of eucalyptus oil.

The vacuum degree of the rectification system in the present invention is 1.0-4.0KPa.

The heating method of the tower kettle in the present invention is electric heating or steam indirect heating, the temperature of the tower kettle is 50° C. to 65° C., and the total reflux is 30 minutes.

In the collection of eucalyptus oil described in the present invention, the light components mainly composed of α-pinene in the eucalyptus oil system are collected by using a large reflux ratio. The content of α-pinene is less than 5%; then raise the temperature of the tower kettle to 65°C-80°C, reduce the reflux ratio to 10-15, collect 1,8-cineole, and the collected 1,8-cineole oil The cineole content should not be lower than 90.00%. After collecting for 60-90 minutes, take samples for analysis every 15 minutes. When the 1,8-cineole content in the sample is lower than 90.00%, increase the reflux ratio to 15-20 and collect 1,8-cineole, and the content of 1,8-cineole in the collection liquid is not less than 90.00%; stop collecting until the content of 1,8-cineole in the collected products cannot reach more than 90.00%, Finally, the collected liquids containing 1,8-cineole were combined.

The invention adopts the method of auxiliary vacuum batch rectification to purify 1,8-cineole from eucalyptus oil. Eucalyptus oil has strong heat sensitivity, and vacuum distillation can reduce the boiling point of the eucalyptus oil system to ensure that the raw material liquid does not polymerize. The batch distillation process is simple and flexible, and it is suitable for the situation where the separation requirements of the mixed liquid are high and the type or composition of the feed liquid changes frequently. The addition of additives changes the relative volatility between the eucalyptus oil systems and improves the separation efficiency; and the operation of variable reflux ratio is adopted in the process to ensure the high purity and high yield of the product.

Advantages and technical effects of the present invention relative to the prior art:

1. The invention only needs a single tower, and the raw material liquid does not need to be pretreated, which saves production and equipment operation costs. The process is simple, the operation is stable, and the product purity and yield are much higher than that of double-tower continuous distillation.

2. The present invention changes the thermodynamic properties of the separated system by adding additives, and improves the mass transfer efficiency by changing the reflux ratio operation and controlling the kettle temperature, and obtains a 1,8-cineole content of 90 More than 96.50% of the eucalyptus oil, the product quality is stable, the yield is high, the highest can reach 96.50%, and the yield reaches more than 75%.

3. The present invention directly changes the relative volatility between eucalyptus oil systems by adding additives, without adding equipment, reduces production capacity consumption, and can obtain high-purity products.

4. Eucalyptus oil has strong heat sensitivity. Vacuum distillation can make the eucalyptus oil separation process run at low temperature, which not only ensures that the raw material liquid does not polymerize, but also has strong temperature controllability.

5. The batch distillation process adopted is simple and flexible in operation. At the same time, the by-product α-pinene in the eucalyptus oil system can be collected, and the by-product containing about 80% α-pinene can be obtained, which increases the yield of eucalyptus crude oil. Added value, and adopt variable reflux ratio operation in the process to ensure the high purity and high yield of the product.

Detailed ways

Embodiment 1: the technology of this eucalyptus oil extraction and purification is that the blue eucalyptus eucalyptus crude oil 1000g that contains 63% 1,8-cineole is mixed with ethanol 60g and then packed into the rectification tower kettle, wherein the amount of auxiliary agent Accounting for 6% of the original liquid volume; turn on the vacuum pump and condensed water, the vacuum degree is 1.0KPa, after the vacuum degree is stable, turn on the heater switch, heat to 50°C, after 30 minutes of full reflux, set the reflux ratio to 20, and start collecting For light components mainly composed of α-pinene, this process lasts for 60 minutes. When the content of α-pinene in the tower still liquid is less than 5%, stop collecting light components; adjust the temperature of the tower still to 65°C, and the reflux ratio is 10 , collect 1,8-cineole, the process continues for 70 minutes, increase the reflux ratio to 16, collect 1,8-cineole, this process continues for 140 minutes, stop collecting, and obtain 1,8-cineole Leaf oil 96.50% product, the total yield is 75.35%.

Embodiment 2: the technology of this eucalyptus oil extraction and purification is to mix the straight rod eucalyptus eucalyptus crude oil 1000g containing 60% 1,8-cineole with 80g of ethanol and then pack into the rectification tower kettle, wherein the auxiliary agent The volume accounts for 8% of the original liquid volume; turn on the vacuum pump and condensate water, the vacuum degree is 2.0KPa, after the vacuum degree is stable, turn on the heater switch, heat to 55°C, after 30 minutes of full reflux, set the reflux ratio to 25, start Collect light components mainly composed of α-pinene. This process lasts for 80 minutes. When the content of α-pinene in the tower still liquid is less than 5%, stop collecting light components; adjust the temperature of the tower still to 70°C and the reflux ratio to 12 , collect 1,8-cineole, the process continues for 70 minutes, raise the reflux ratio to 18, collect 1,8-cineole, this process continues for 150 minutes, stop collecting; The product of 93.12% olein, the total yield is 76.75%.

Embodiment 3: the technology of this eucalyptus oil extraction and purification is to mix the blue eucalyptus eucalyptus crude oil 1000g and ethanol 100g containing 58% 1,8-cineole into the rectification tower still, wherein the amount of auxiliary agent Account for 10% of the original liquid volume; turn on the vacuum pump and condensate water, the vacuum degree is 4.0KPa, after the vacuum degree is stable, turn on the heater switch, heat to 65°C, after 30 minutes of full reflux, set the reflux ratio to 30, and start collecting For light components mainly composed of α-pinene, this process lasts for 90 minutes. When the content of α-pinene in the tower liquid is less than 5%, stop collecting light components; adjust the temperature of the tower to 80°C and the reflux ratio to 15 , collect 1,8-cineole, the process continues for 90 minutes, increase the reflux ratio to 20, collect 1,8-cineole, this process continues for 150 minutes, stop collecting; obtain 1,8-cineole Leaf oil 94.34% product, the total yield is 75.85%.

Embodiment 4: the technology of this eucalyptus oil extraction and purification is that the crude oil 1000g of eucalyptus eucalyptus straight bar containing 63% 1,8-cineole and 50g of isopropanol are mixed uniformly and loaded into the rectification tower kettle, wherein The amount of the agent accounts for 5% of the original liquid; turn on the vacuum pump and condensed water, and the vacuum degree is 3.0KPa. After the vacuum degree is stable, turn on the heater switch, heat to 60°C, and after 30 minutes of full reflux, set the reflux ratio to 20 , start to collect light components mainly composed of α-pinene, and this process lasts for 60 minutes. When the content of α-pinene in the tower still liquid is less than 5%, stop collecting light components; adjust the temperature of the tower still to 75°C, and reflux Ratio is 10, collects 1,8-cineole, and this process continues 70 minutes, and raising reflux ratio is 15, collects 1,8-cineole, and this process continues 150 minutes, stops to collect; Obtain containing 1, 8-cineole 93.34% product, the total yield is 76.05%.

Embodiment 5: The technology of this eucalyptus oil extraction and purification is to mix eucalyptus blue eucalyptus crude oil 1000g containing 60% 1,8-cineole and isopropanol 70g and then pack into the rectification tower kettle, wherein the auxiliary agent The amount accounts for 7% of the original liquid; turn on the vacuum pump and condensed water, the vacuum degree is 1.0KPa, after the vacuum degree is stable, turn on the heater switch, heat to 50°C, after 30 minutes of full reflux, set the reflux ratio to 25, start Collect light components based on α-pinene, and this process continues for 80 minutes. When the content of α-pinene in the tower still liquid is less than 5%, stop collecting light components; adjust the temperature of the tower still to 65 ° C, and the reflux ratio is 12. Collect 1,8-cineole. This process lasts for 80 minutes. Increase the reflux ratio to 17. Collect 1,8-cineole. This process lasts for 160 minutes. Stop collecting to obtain 1,8- The product of 94.50% eucalyptol has a total yield of 75.75%.

Embodiment 6: The technology of this eucalyptus oil extraction and purification is to mix 1000g of straight bar eucalyptus eucalyptus crude oil containing 59% 1,8-cineole and 90g of n-butanol and then pack it into the rectification tower kettle, wherein the auxiliary agent The amount accounts for 9% of the original liquid; turn on the vacuum pump and condensate, the vacuum degree is 2.0KPa, after the vacuum degree is stable, turn on the heater switch, heat to 55°C, and after 30 minutes of full reflux, set the reflux ratio to 25, Start to collect light components mainly composed of α-pinene, and this process lasts for 70 minutes. When the content of α-pinene in the tower still liquid is less than 5%, stop collecting light components; adjust the temperature of the tower still to 70°C, and the reflux ratio 15. Collect 1,8-cineole, the process lasts for 90 minutes, increase the reflux ratio to 20, collect 1,8-cineole, this process lasts for 160 minutes, stop collecting; get 1,8-cineole Leaf oil 93.12% product, the total yield is 76.75%.

Embodiment 7: the technology of this eucalyptus oil extraction and purification is to mix the eucalyptus blue eucalyptus crude oil 1000g containing 63% 1,8-cineole and n-butanol 60g and then pack into the rectification tower kettle, wherein the auxiliary agent The volume accounts for 6% of the original liquid volume; turn on the vacuum pump and condensed water, the vacuum degree is 3.0KPa, after the vacuum degree is stable, the steam is heated indirectly to 60°C, after 30 minutes of full reflux, the reflux ratio is set to 20, and the collection starts For light components mainly composed of α-pinene, this process lasts for 60 minutes. When the content of α-pinene in the tower liquid is less than 5%, stop collecting light components; adjust the temperature of the tower to 75°C and the reflux ratio to 12 , collect 1,8-cineole, the process continues for 80 minutes, increase the reflux ratio to 18, collect 1,8-cineole, this process continues for 150 minutes, stop collecting; obtain 1,8-cineole Leaf oil 94.54% product, the total yield is 75.25%.

Claims (1)

1. eucalyptus oil extracts a technique for purifying, it is characterized in that carrying out as follows:

(1) eucalyptus oil stoste and auxiliary agent are evenly mixed by certain ratio;

(2) in tower reactor, add the mixing stoste that proportioning is good, open vacuum pump and overhead condensation device, make the vacuum tightness of distillation system reach processing requirement stable;

(3) to tower reactor heating, when tower reactor temperature reaches processing requirement, carry out total reflux operation;

(4) eucalyptus oil is collected, and first adopts large reflux ratio to collect in eucalyptus oil system and take α-pinene as main light constituent, after light constituent is collected completely, rising tower reactor temperature, reduces reflux ratio and collects 1,8-eucalyptol, treat 1,8-eucalyptol content is during lower than processing requirement, then improves reflux ratio and collect 1,8-eucalyptol, until cannot reaching processing requirement, product content stops gathering, finally merge containing 1,8-eucalyptol and collect liquid, obtain eucalyptus oil;

Wherein said eucalyptus oil stoste is the eucalyptus oil containing mass percent 58%～63% 1,8-eucalyptol, and auxiliary agent is C ₂～C ₄alcohols, the addition of auxiliary agent accounts for 5～10% of the former liquid measure of eucalyptus oil;

The vacuum tightness of described distillation system is 1.0～3.0KPa;

Described tower reactor type of heating is electrically heated or steam indirect heating, and tower reactor temperature is 50 ℃～60 ℃, total reflux 30 minutes;

Described first employing in large reflux ratio collection eucalyptus oil system be take α-pinene as main light constituent, reflux ratio is 20～30, when in tower bottoms, α-pinene content is less than 5%, light constituent has been collected, then the tower reactor that raises temperature to 65 ℃～80 ℃, reducing reflux ratio is 10～15, collect 1, 8-eucalyptol, and in collection liquid 1, 8-eucalyptol content is not less than 90.00%, every 15 minutes sampling analysis, gather after 60～90 minutes, treat 1 in sample, 8-eucalyptol content is lower than 90.00% time, improving reflux ratio is 15～20, collect 1, 8-eucalyptol, and in collection liquid 1, 8-eucalyptol content is not less than 90.00%, until in the product of collecting 1, 8-eucalyptol content cannot reach 90.00% to be stopped when above gathering, finally merge 1 of collection, 8-eucalyptol liquid.