CN111849623A

CN111849623A - Method for extracting lacquer wax by supercritical carbon dioxide fluid

Info

Publication number: CN111849623A
Application number: CN202010859566.5A
Authority: CN
Inventors: 钟帆
Original assignee: Jiaoling Futai Biotechnology Co ltd
Current assignee: Jiaoling Futai Biotechnology Co ltd
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2020-10-30

Abstract

The invention provides a method for extracting lacquer wax by supercritical carbon dioxide fluid, which comprises the following steps: (1) taking the dried sumac seeds for carrying out skin-core separation, and crushing the seed coats to 10-30 meshes; (2) putting the crushed seed coats into a supercritical carbon dioxide extraction device, setting the pressure of an extraction kettle to be 25-40 Mpa, setting the temperature to be 50-70 ℃, and extracting for 45-120 min; (3) and (3) separating by a three-stage separation kettle after extraction, setting the pressure of a first-stage separation kettle to be 9-18 MPa and the temperature to be 45-65 ℃, setting the pressure of a second-stage separation kettle to be 6-9 MPa and the temperature to be 45-55 ℃, setting the pressure of a third-stage separation kettle to be 6MPa and the temperature to be 50 ℃, and collecting extracts of the first-stage separation kettle and the second-stage separation kettle to obtain the lacquer wax/wood wax product. Compared with the traditional method, the method for extracting lacquer wax by using the supercritical carbon dioxide fluid has the advantages of environmental friendliness, high yield, good product color and appearance and the like, and can be used for industrial production.

Description

Method for extracting lacquer wax by supercritical carbon dioxide fluid

Technical Field

The invention relates to the technical field of lacquer wax extraction, in particular to a method for extracting lacquer wax by supercritical carbon dioxide fluid.

Background

A deciduous tree or a small tree of Rhus of Anacardiaceae is a special economic tree species mainly for producing wax and lacquer by collecting seeds. More than 150 varieties exist in China, wherein more than 30 varieties can produce seeds, the yield of lacquer seeds is more than 500 million tons, and the varieties are mainly distributed in Shaanxi, Guizhou, Yunnan, Sichuan and other places. The lacquer seed is lacquer tree fruit, mesocarp is wax layer, and is light yellow or grey green, and can be used for extracting lacquer wax, and the kernel is seed for squeezing lacquer oil. The lacquer wax contains more than 90% of fatty glyceride, wherein the palmitic acid content reaches about 70%, and the lacquer wax is a high-quality natural chemical raw material for preparing products such as surfactants, detergents and the like. The lacquer wax is extracted mainly in lacquer seed producing area by water boiling, mechanical squeezing, organic solvent and other methods.

The technology for extracting lacquer wax from lacquer seed coats by ultrasonic wave and analyzing physicochemical properties of the lacquer wax (Robinia, Zhangchong, Luasian, Guo Mei, grain and grease, 2011 (1): 27-30), the technology for extracting lacquer wax and chemical components thereof (Dong Yan He, Wang Cheng Chao, leaf Jianzhong, Zhonhao, Beijing university of forestry, 2010, 32 (4): 255-260), the research on extracting and decoloring lacquer wax (Vanbang, Wukukukukukuu, Yanguanyou, Jiasheng, Chinese lacquer, 2018, 37 (1): 41-43), and the technology for extracting Japanese wild lacquer wax (Liuwei, Xiebui, Yufan, Linna, economic forest research, 2008, 26 (1): 58-61) adopt petroleum ether as an extracting solvent to extract the lacquer wax, and the extraction rate is high and can reach more than 50%. However, the processes have large organic solvent consumption, certain safety problem in solvent recovery, unsuitability for industrialized production, and the product has dark appearance color and can meet the requirements only by further decolorization.

Chinese patent preparation method of fine high-quality lacquer wax (application No. 201110230852.6) adopts petroleum ether, diethyl ether, n-hexane and other reagents to extract lacquer wax, and does not consider the yield problem; chinese patent green extraction process of lacquer wax (application No. 201510476280.8) adopts dimethyl carbonate and petroleum ether to extract lacquer wax, and the yield is about 39%; the two processes have the problems of large organic reagent dosage, high toxicity, safety in use and recovery, complex production procedures, long period and low yield.

Chinese patents 'an environmental-friendly extraction method of lacquer wax' (application number 201210201113.9) and 'a method for rapidly preparing high-quality colorless lacquer wax by ultraviolet light decolorization' (application number 201010246334.9) both adopt a water boiling method to extract the lacquer wax, and the product yield can reach about 40-45%. However, the lacquer wax of the two processes is easy to dissolve or rancidity after being soaked in water and cooked at high temperature, the subsequent impurity removal difficulty is increased, the process is complex, and the lacquer wax can meet the requirement only by being decolored.

Chinese patent 1Supercritical CO₂A process for the continuous fluid extraction of lacquer wax and lacquer oil (application No. 201010568749.8) provides a supercritical CO₂The extraction method can effectively solve the disadvantages of the organic solvent extraction method and the water boiling method. However, in the process, the pericarp and the kernel of the lacquer seed are crushed together and then extracted, the pericarp mainly contains lacquer wax, the kernel mainly contains lacquer oil, the lacquer wax and the lacquer oil are mixed and extracted together, and the lacquer wax and the lacquer oil are difficult to separate, are both fat-soluble components and are difficult to separate under the process parameters according to the principle of 'similarity and compatibility'; the extraction time is long, the product yield is low, the lacquer wax yield is 20.2-22.9%, and the lacquer oil yield is 15.2-16.3%; in addition, the pressure of the separation kettle II is difficult to realize at 4-5 MPa and 2-3 MPa, which is not beneficial to actual production.

Disclosure of Invention

In order to make up for the defects in the prior art, the invention provides a method for extracting lacquer wax by using supercritical carbon dioxide fluid, which aims to solve the problems in the background technology.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for extracting lacquer wax by supercritical carbon dioxide fluid comprises the following steps:

(1) taking the dried sumac seeds for carrying out skin-core separation, and crushing the seed coats to 10-30 meshes;

(2) putting the crushed seed coats into a supercritical carbon dioxide extraction device, setting the pressure of an extraction kettle to be 25-40 Mpa, setting the temperature to be 50-70 ℃, and extracting for 45-120 min;

(3) and (3) separating by a three-stage separation kettle after extraction, setting the pressure of a first-stage separation kettle to be 9-18 MPa and the temperature to be 45-65 ℃, setting the pressure of a second-stage separation kettle to be 6-9 MPa and the temperature to be 45-55 ℃, setting the pressure of a third-stage separation kettle to be 6MPa and the temperature to be 50 ℃, and collecting extracts of the first-stage separation kettle and the second-stage separation kettle to obtain the lacquer wax/wood wax product.

Further, in the step (1), the drying temperature of the lacquer tree seeds is not more than 50 ℃, so that the moisture content of the seed coats is lower than 5%, and then the seed coats are crushed under the conditions that the temperature is not higher than 20 ℃ and the humidity is not more than 40%.

Further, in the step (2), the flow rate of carbon dioxide in the supercritical carbon dioxide extraction device is set to be 15-25 kg/h.

Further, a method for extracting lacquer wax by supercritical carbon dioxide fluid comprises the following steps:

(1) taking the dried sumac seeds for carrying out skin-core separation, and crushing the seed coats to 20 meshes;

(2) placing the crushed seed coats into a supercritical carbon dioxide extraction device, setting the pressure of an extraction kettle at 30Mpa and the temperature at 55 ℃, and extracting for 60 min;

(3) and (3) separating by two stages of separation kettles after extraction, wherein the pressure of the first stage separation kettle is set to be 15Mpa, the temperature is set to be 55 ℃, the pressure of the second stage separation kettle is set to be 6Mpa, the temperature is set to be 50 ℃, and the extracts of the first stage separation kettle and the second stage separation kettle are collected to obtain the lacquer wax/wood wax product.

Compared with the prior art, the invention has the following beneficial technical effects:

compared with an organic solvent method, the method for extracting lacquer wax by using the supercritical carbon dioxide fluid avoids the use of a large amount of organic solvent although the product yield is slightly low, and has the advantages of no toxicity, no environmental pollution, high safety and good quality; compared with a water boiling method, the method has the advantages of simple process flow, convenient operation, short preparation period and higher product yield, and is suitable for industrial production; compared with the prior supercritical CO₂The extraction method greatly improves the product yield, shortens the extraction time and solves the problem that the pressure of the existing separation kettle is not beneficial to the actual production.

Drawings

FIG. 1 is a line graph showing the effect of extraction time on lacquer wax yield under the same extraction and separation conditions;

FIG. 2 is a line graph showing the effect of extraction pressure on lacquer wax yield under the same extraction separation conditions;

FIG. 3 is a line graph showing the effect of extraction temperature on lacquer wax yield under the same extraction separation conditions;

FIG. 4 is a line graph showing the influence of the pressure of the first stage separation kettle on the yield of lacquer wax under the same extraction and separation conditions;

FIG. 5 is a line graph showing the effect of the temperature of the first stage separation kettle on the yield of lacquer wax under the same extraction and separation conditions.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Example 1

(1) and (4) taking the dried sumac seeds for carrying out skin-core separation, and crushing the seed coats. Further, the drying temperature of the lacquer tree seeds is not more than 50 ℃, the water content of the seed coats is lower than 5%, and then the seed coats are crushed under the conditions that the temperature is not higher than 20 ℃ and the humidity is not more than 40%, and the crushing fineness is 10 meshes. In the step, the low-temperature drying can prevent the wood wax/lacquer wax in the lacquer seeds from being rancid and lost due to high temperature, and the extraction rate is improved.

(2) Placing the crushed seed coat into a supercritical carbon dioxide extraction device, setting the flow of carbon dioxide at 15kg/h, setting the pressure of an extraction kettle at 25Mpa and the temperature at 50 ℃, and extracting for 120 min.

(3) And (3) separating by two stages of separation kettles after extraction, wherein the pressure of the first stage separation kettle is set to be 9Mpa, the temperature is set to be 45 ℃, the pressure of the second stage separation kettle is set to be 6Mpa, the temperature is set to be 45 ℃, and the extracts of the first stage separation kettle and the second stage separation kettle are collected to obtain the lacquer wax/wood wax product.

According to the steps, 3500g of raw materials are taken for three batches of tests each time, and the extraction yield of the lacquer wax is as follows:

TABLE 1 three batches of sample extraction yield tables

And (3) performing physical and chemical index tests on the three batches of lacquer wax respectively to obtain the physical and chemical indexes as shown in the following table:

TABLE 2 three batches of physical and chemical index tables

The main components of the wood wax product prepared by the embodiment are palmitic acid, linoleic acid, oleic acid, stearic acid and the like, and the relative percentage content of the palmitic acid is more than 75%, the oleic acid is more than 7%, and the stearic acid is more than 4%. The product is yellow oil or extract in appearance, and the difficulty of refining subsequent products can be reduced.

Example 2

(1) and (4) taking the dried sumac seeds for carrying out skin-core separation, and crushing the seed coats. Further, the drying temperature of the lacquer tree seeds is not more than 50 ℃, the water content of the seed coats is lower than 5%, and then the seed coats are crushed under the conditions that the temperature is not higher than 20 ℃ and the humidity is not more than 40%, and the crushing fineness is 20 meshes. In the step, the low-temperature drying can prevent the wood wax/lacquer wax in the lacquer seeds from being rancid and lost due to high temperature, and the extraction rate is improved.

(2) Placing the crushed seed coat into a supercritical carbon dioxide extraction device, setting the flow of carbon dioxide at 20kg/h, setting the pressure of an extraction kettle at 30MPa and the temperature at 55 ℃, and extracting for 60 min.

TABLE 3 three-batch sample extraction yield table

TABLE 4 table of physical and chemical indexes of three batches of samples

Example 3

(1) and (4) taking the dried sumac seeds for carrying out skin-core separation, and crushing the seed coats. Further, the drying temperature of the lacquer tree seeds is not more than 50 ℃, the water content of the seed coats is lower than 5%, and then the seed coats are crushed under the conditions that the temperature is not higher than 20 ℃ and the humidity is not more than 40%, and the crushing fineness is 30 meshes. In the step, the low-temperature drying can prevent the wood wax/lacquer wax in the lacquer seeds from being rancid and lost due to high temperature, and the extraction rate is improved.

(2) Placing the crushed seed coat into a supercritical carbon dioxide extraction device, setting the flow of carbon dioxide at 25kg/h, setting the pressure of an extraction kettle at 40Mpa, setting the temperature at 70 ℃, and extracting for 45 min.

(3) And (3) separating by two stages of separation kettles after extraction, wherein the pressure of the first stage separation kettle is set to be 18Mpa, the temperature is set to be 65 ℃, the pressure of the second stage separation kettle is set to be 9Mpa, the temperature is set to be 55 ℃, and the extracts of the first stage separation kettle and the second stage separation kettle are collected to obtain the lacquer wax/wood wax product.

TABLE 5 three-batch sample extraction yield table

TABLE 6 table of physical and chemical indexes of three batches of samples

Comparing the above three examples, it can be seen that the optimum extraction process conditions are those of example 2, and the following is an analysis of the effect of various process parameters on the extraction yield of wood wax:

1. time of extraction

Under the extraction pressure of 30MPa, the extraction temperature of 55 ℃ and the same separation conditions (the pressure of a first-stage separation kettle is 15MPa, the temperature of 55 ℃, the pressure of a second-stage separation kettle is 6MPa, and the temperature of 50 ℃), the extraction yield is correspondingly increased along with the extension of the extraction time. As shown in fig. 1, the extraction yield increased rapidly within 45 minutes before the start of extraction, and after 45 minutes of extraction, the yield increased gradually and slowly, and after 60 minutes, the yield was almost completely extracted.

In addition, the effect of extraction time on yield is also associated with CO₂Relative to the flow of CO, increasing CO₂The flow can increase the extraction times of the fluid on the raw materials, and the mass transfer effect in the extraction process is enhanced, so that the extraction time is shortened. However, supercritical CO₂Increased fluid flow, reduced residence time of solvent in the feedstock, CO₂The solute content of the fluid is also reduced.

2. Pressure of extraction

The extraction pressure has a more significant effect on lacquer wax extraction, and generally the extraction yield increases with increasing extraction pressure, since increasing extraction pressure causes supercritical CO₂The density of the fluid increases and the solvent power to the material increases, so that more components are extracted. However, when the extraction pressure is increased to a certain extent, the yield increases slowly, and the increase of the extraction pressure increases the extraction cost and the content of impurities in the extract, which is not the desired target component, adversely affects the quality of the product.

As shown in FIG. 2, the effect of the extraction pressure on the lacquer wax yield was examined at an extraction temperature of 55 ℃ and an extraction time of 45min under the same separation conditions (15 MPa in the first stage separation vessel, 55 ℃ in the second stage separation vessel, 6MPa in the second stage separation vessel, and 50 ℃ in the first stage separation vessel), and the highest extraction yield was achieved at an extraction pressure of 30 MPa.

3. Temperature of extraction

The extraction temperature is supercritical CO₂An important influence factor of extraction has two aspects: on one hand, the extraction temperature is increased, the density of the supercritical fluid is reduced, the dissolving capacity is reduced, and the extraction rate is reduced; on the other hand, the increase of the extraction temperature increases the volatility of the extraction target component, increases the diffusion coefficient, increases the concentration of the extraction substance in the fluid, and is beneficial to extraction. This may be responsible for the variation of the extraction yield with temperature. But after the temperature reaches a certain level, the lacquer wax is in CO₂Solubility in (C) increases with CO₂The yield is reduced by circulating the extraction process.

As shown in FIG. 3, the effect of extraction temperature on lacquer wax yield was examined under the same separation conditions (first stage separation tank pressure of 15MPa, temperature of 55 ℃ C., second stage separation tank pressure of 6MPa, temperature of 50 ℃ C.) at an extraction pressure of 30MPa and extraction time of 45min, and the highest extraction yield was achieved at an extraction temperature of 55 ℃.

4. Pressure and temperature of the separation vessel

The pressure and temperature of the separation kettle are also important factors influencing the extraction yield of the lacquer wax. As shown in FIG. 4, under the same extraction and separation conditions (extraction pressure 30MPa, temperature 55 ℃, first stage separation kettle temperature 55 ℃, second stage separation kettle pressure 6MPa, temperature 50 ℃), the effect of different first stage separation kettle pressures on the yield was examined, and the highest extraction yield was achieved when the first stage separation kettle pressure was 15 MPa.

As shown in FIG. 5, under the same extraction and separation conditions (extraction pressure 30MPa, temperature 55 ℃, first stage separation kettle pressure 15MPa, second stage separation kettle pressure 6MPa, temperature 50 ℃), the effect of different first stage separation kettle temperatures on the yield was examined, and the highest extraction yield was achieved when the first stage separation kettle temperature was 55 ℃.

Comparative example 1

10.0536g of the seed coat of the wood wax used in the invention is weighed and placed in a Soxhlet extractor, 20 times of petroleum ether is added, reflux extraction is carried out for 2h at 80 ℃, after the extraction is finished, the petroleum ether is recovered to obtain 4.9501g of extract, the yield is 49.23%, and the color is gray.

Comparative example 2

(1) Firstly, taking 200g of screened and impurity-removed lacquer seeds, and crushing the lacquer seeds to 50 meshes;

(2) secondly, placing the crushed lacquer seeds in supercritical CO₂Heating to 45 deg.C in extraction tank, and pressurizing to 35 Mpa; opening of CO₂Flow control valve for controlling CO₂The flow is 10L/h, the lacquer wax is separated by the separation kettle I and the separation kettle II respectively after 100min of extraction, and the extraction yield of the lacquer wax is 23.2 percent. The pressure of the separation kettle I is 6Mpa, and the separation temperature is controlled at 50 ℃; the pressure of the separation kettle II is 5Mpa, and the separation temperature is controlled at 45 ℃.

Although the present invention has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.

Claims

1. A method for extracting lacquer wax by supercritical carbon dioxide fluid is characterized by comprising the following steps:

2. The method of claim 1, wherein the supercritical carbon dioxide fluid is used to extract lacquer wax: in the step (1), the drying temperature of the lacquer tree seeds is not more than 50 ℃, so that the water content of the seed coat is lower than 5%, and then the seed coat is crushed under the conditions that the temperature is not higher than 20 ℃ and the humidity is not more than 40%.

3. The method for extracting lacquer wax by using supercritical carbon dioxide fluid as claimed in claim 2, wherein: in the step (2), the flow rate of carbon dioxide in the supercritical carbon dioxide extraction device is set to be 15-25 kg/h.

4. A method of supercritical carbon dioxide fluid extraction of lacquer wax according to any of claims 1-3, characterized by the following steps: