Method for extracting vegetable wax from wood sterol by-product through catalytic conversion

Abstract

The invention discloses a method for extracting vegetable wax from a wood sterol byproduct through catalytic conversion, which comprises the following steps: S1, mixing the wood sterol byproduct with an alcohol substance at a first temperature to obtain a first mixed solution; s2, mixing the first mixed solution with a catalyst, and carrying out a reaction at a second temperature to obtain a reacted mixed solution; and S3, purifying the reacted mixed solution by adopting column chromatography to obtain the refined vegetable wax. According to the method, the vegetable wax can be effectively extracted from the lignin sterol by-product, the method is suitable for industrial production and application, meanwhile, the crude wax is purified and refined through column chromatography, the product purity can be further improved, and the application range can be further expanded.

Description

Technical Field

[0001] The present application relates to the field of chemical separation technology, and in particular to a method for extracting plant wax from lignin sterol byproducts through catalytic conversion. Background Art

[0002] Plant wax refers to wax extracted from plants. Its main components are esters formed by higher fatty acids and higher alcohols, usually including candelilla wax, rice bran wax, carnauba wax, sunflower wax and lacquer wax. Plant wax has a wide range of uses and is an important industrial resource. It can be used to produce polishes, protective agents and emulsifiers for fiber. Some refined plant waxes can not only be used as food additives and preservatives for edible fruits and vegetables, but also be used in the pharmaceutical field. Plant wax has the advantage of being renewable. The processing of common plant waxes such as sunflower seed wax, rice bran wax, soybean wax, flax wax and rapeseed wax has gradually become a hot topic in the research field. In addition, plant wax is a renewable energy source, most of which also contains a variety of essential fatty acids for the human body. It is a green, environmentally friendly and healthy natural resource. With the improvement of people's living standards and the increasing attention to environmental protection, the call for strengthening the use of new renewable energy such as plant wax has become stronger.

[0003] At present, most of the research on plant wax at home and abroad is about the preparation, refining and application of rice bran wax, while there are fewer studies on wood wax. Plant wax can be extracted from the production process of plant sterols. For lignin sterols, the pinewood ointment raw material can effectively separate and remove fatty acids and other substances through molecular distillation process, and at the same time, the bound sterols can be converted into free sterols, and more than 98% of lignin sterols can be extracted, and plant wax is produced as a by-product. Although the existing high-efficiency separation and purification technology can effectively improve the extraction rate and purity of lignin sterols, the complex and variable composition of pinewood ointment raw materials will increase the difficulty of separating by-product plant wax from impurities and the level of comprehensive utilization of by-products will be low.

[0004] The main methods for preparing crude wax in China include bag filtration, saponification, solvent extraction, etc. Bag filtration is now less used due to its low production efficiency, large footprint, poor feasibility and other disadvantages. The saponification method is not often used due to the large amount of wastewater discharged and the great impact on the environment. At the same time, the yield is low, the labor intensity is high, and the oil loss rate is also high. The solvent crystallization method has many production processes, long processes, and is discontinuous, which is easy to cause waste of resources. In recent years, some related domestic studies have also used supercritical CO2 leaching, ultrasound-assisted, and enzyme-ultrasound dual-assisted extraction of plant waxes, but these methods have only remained in the laboratory research stage and have not yet been promoted and applied.

[0005] Therefore, as the production of lignanol increases, in order to make full use of pine wood raw materials and plant wax, it is urgent to develop a method for extracting plant wax from lignanol molecular distillation waste with high conversion rate and yield, simple process, low cost, energy saving and environmental protection. Summary of the invention

[0006] In view of the above problems in the prior art, the present application provides a method for extracting plant wax from lignin sterol byproducts by catalytic conversion.

[0007] In a first aspect, the present application provides a method for extracting plant wax from lignin sterol byproducts by catalytic conversion, which comprises the following steps:

[0008] S1: mixing the lignin sterol byproduct and the alcohol substance at a first temperature to obtain a first mixed solution;

[0009] S2: mixing the first mixed solution with the catalyst and reacting them at a second temperature to obtain a reacted mixed solution;

[0010] S3: Purifying the mixed solution after the reaction by column chromatography to obtain refined vegetable wax.

[0011] The presence of a large number of higher fatty acids in the byproducts of lignin sterol (waste from molecular distillation of lignin sterol) can be converted by catalytic conversion, that is, the fatty acids and fatty alcohols are subjected to esterification reaction under the action of a catalyst to synthesize ester waxes, or the higher alkanes are first oxidized into acids and then esterified to imitate natural ester waxes. The traditional catalytic conversion method generally needs to be carried out under high temperature, high pressure, strong acid or strong base conditions, with low conversion rate, many by-products, poor color, and as the carbon chains of fatty acids and fatty alcohols increase, the difficulty of the reaction will also increase, and the synthesized products are single and mainly monoester products.

[0012] The inventors of the present application have found through extensive research that by using a catalytic conversion method and further optimizing the parameters such as the type of alcohol and the type of catalyst, plant wax can be extracted from the waste of lignin sterol molecular distillation with high conversion rate and yield, and the product purity is high, which is suitable for industrial production and application. At the same time, the crude wax is purified and refined by column chromatography to further improve the product purity and expand the scope of application.

[0013] In some embodiments, in step S3, purifying the reaction mixture by column chromatography comprises:

[0014] S31: mixing the reaction mixture with an organic solvent to obtain a crude wax mixture;

[0015] S32: passing the crude wax mixture into a chromatography column, adding an eluent for elution, and separating at a third temperature and a first flow rate to obtain a separated eluent;

[0016] S33: removing the solvent from the eluent to obtain refined vegetable wax.

[0017] In some embodiments, the alcohol substance is selected from one or more of C4-C30 monohydric alcohols and C2-C10 polyhydric alcohols.

[0018] In some embodiments, the alcohol substance is selected from one or more of a C4-C30 straight-chain or branched monohydric alcohol and a C2-C10 straight-chain or branched polyhydric alcohol.

[0019] In some embodiments, the alcohol substance is selected from one or more of C6-C28 straight-chain or branched monohydric alcohols. In some embodiments, the alcohol substance is selected from one or more of C8-C25 straight-chain or branched monohydric alcohols. In some embodiments, the alcohol substance is selected from a straight chain or branched monohydric alcohol of C10, a straight chain or branched monohydric alcohol of C12, a straight chain or branched monohydric alcohol of C15, a straight chain or branched monohydric alcohol of C16, a straight chain or branched monohydric alcohol of C17, a straight chain or branched monohydric alcohol of C18, a straight chain or branched monohydric alcohol of C19, a straight chain or branched monohydric alcohol of C20, a straight chain or branched monohydric alcohol of C21, a straight chain or branched monohydric alcohol of C22, a straight chain or branched monohydric alcohol of C23, a straight chain or branched monohydric alcohol of C24, a straight chain or branched monohydric alcohol of C25, a straight chain or branched monohydric alcohol of C27 or a straight chain or branched monohydric alcohol of C29.

[0020] In some embodiments, the alcohol substance is selected from one or more of C16-C25 straight-chain monohydric alcohols.

[0021] In some embodiments, the alcohol substance is selected from one or more of n-octanol, n-octadecyl alcohol, n-behenyl alcohol and n-octacosanol.

[0022] In some embodiments, the alcohol substances are primary and secondary alcohols containing 1-28 carbon atoms, such as straight-chain alcohols such as lauryl alcohol, stearyl alcohol, eicosanol, tetracosanol, etc., polyols such as hexylene glycol and glycerol, and ethylene oxide, glycidyl ether, etc.

[0023] In some embodiments, the mass ratio of the alcohol substance to the lignin sterol by-product is 1:(1-10), for example, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5 or any value therebetween. In some embodiments, the mass ratio of the alcohol substance to the lignin sterol by-product is 1:(2-8).

[0024] In some embodiments, the catalyst is selected from one or more of an acidic catalyst, an enzyme catalyst, and an alkali metal catalyst.

[0025] In some embodiments, the acidic catalyst is selected from one or more of an inorganic acid, an organic acid, and an acidic cationic resin.

[0026] In some embodiments, the inorganic acid is selected from one or more of hydrochloric acid, sulfuric acid and nitric acid.

[0027] In some embodiments, the organic acid is selected from one or more of acetic acid, propionic acid and toluenesulfonic acid.

[0028] In some embodiments, the enzyme catalyst is selected from lipase.

[0029] In some embodiments, the alkali metal catalyst is selected from one or more of alkali metal hydroxides, alkali metal carbonates, and alkali metal alkoxides.

[0030] In some embodiments, the alkali metal is selected from sodium, potassium or lithium.

[0031] In some embodiments, the alkali metal catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium ethoxide and potassium ethoxide.

[0032] In some embodiments, the acidic cationic resin is selected from one or more of styrene-based acidic cationic resins.

[0033] In some embodiments, the catalyst is selected from one or more of sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, styrene acidic cationic resin, sodium hydroxide and potassium hydroxide.

[0034] In some embodiments, the mass ratio of the catalyst to the alcohol substance is 1:(1-50), such as 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or any value therebetween. In some embodiments, the mass ratio of the catalyst to the alcohol substance is 1:(2-40).

[0035] In some embodiments, in step S1, the first temperature is 30°C-120°C, for example, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C. In some embodiments, in step S1, the first temperature is 40°C-100°C.

[0036] In some embodiments, in step S1, the mixing time is greater than or equal to the time required for the alcohol substance to be completely dissolved.

[0037] In some embodiments, in step S1, the mixing time is the time required for the alcohol substance to be completely dissolved.

[0038] In some embodiments, in step S2, the second temperature is 30° C.-120° C., for example, 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., 105° C., 110° C. or 115° C. In some embodiments, in step S2, the second temperature is 40° C.-100° C. With the increase of the reaction temperature, the conversion rate and purity of the product are improved to a certain extent.

[0039] In some embodiments, in step S2, the reaction time is 1 h-12 h, for example, 3 h, 5 h, 7 h, 9 h, 10 h or 11 h. In some embodiments, in step S2, the reaction time is 2 h-10 h. As the reaction time increases, the extraction rate and purity of the wax tend to stabilize.

[0040] In some embodiments, the adsorbent in the chromatography column is selected from one or more of silica gel, clay, activated carbon, resin and activated alumina. Taking into account the dispersibility of the adsorbent in the solvent and the purity and whiteness of the product wax, according to some preferred embodiments of the present application, the adsorbent is selected from one or more of silica gel, clay and activated carbon.

[0041] In some embodiments, in step S31, the volume ratio of the mixed solution after the reaction to the organic solvent is 1:(20-50), for example, 1:25, 1:30, 1:35, 1:40, 1:45 or any value therebetween.

[0042] In some embodiments, in step S32, the number of elutions is 3-5 times.

[0043] In some embodiments, the eluent is the same as the organic solvent.

[0044] In some embodiments, the third temperature (column chromatography adsorption temperature) is 25° C.-50° C., for example, 30° C., 35° C., 40° C. or 45° C. According to some preferred embodiments of the present application, the third temperature is 30° C.-40° C. to ensure complete dissolution of crude wax and industrial operation conditions.

[0045] In some embodiments, the first flow rate is 1-5 mL / min, for example, 2 mL / min, 3 mL / min, or 4 mL / min.

[0046] In some embodiments, the organic solvent is selected from one or more of ketone solvents, alcohol solvents, ester solvents, halogenated alkane solvents with a carbon number of 1-5, and alkane solvents with a carbon number of 5-12.

[0047] In some embodiments, the eluent is selected from one or more of ketone solvents, alcohol solvents, ester solvents, halogenated alkane solvents with a carbon number of 1-5, and alkane solvents with a carbon number of 5-12.

[0048] In some embodiments, the ketone solvent is selected from one or more of acetone, methyl ethyl ketone and methyl isobutyl ketone.

[0049] In some embodiments, the alcohol solvent is selected from one or more of C1-C6 alcohols. In some embodiments, the alcohol solvent is selected from one or more of methanol, ethanol and n-propanol.

[0050] In some embodiments, the ester solvent is selected from one or more of ethyl acetate, ethyl formate, methyl acetate and n-propyl acetate.

[0051] In some embodiments, the halogenated alkane solvent having a carbon number of 1-5 is selected from one or more of dichloromethane, chloroform and trichloroethane.

[0052] In some embodiments, the alkane solvent having a carbon number of 5-12 is selected from one or more of cyclopentane, n-hexane, cyclohexane, methylcyclohexane, isopentane, n-octane and isooctane.

[0053] In some embodiments, the organic solvent is selected from one or more of n-hexane, acetone, dichloromethane, methanol and ethyl acetate. Taking into account the polarity and solubility of the solvent, according to some preferred embodiments of the present application, the organic solvent is n-hexane, acetone or dichloromethane.

[0054] In some embodiments, the eluent is selected from one or more of n-hexane, acetone, dichloromethane, methanol and ethyl acetate. Considering the properties of the filler and the separation system, according to some preferred embodiments of the present application, the eluent is n-hexane, acetone or dichloromethane.

[0055] In some embodiments, the lignanol by-product is selected from waste generated during the molecular distillation process of producing lignanol.

[0056] In some embodiments, the lignanol by-product is selected from waste generated during the molecular distillation process of producing lignanol from pine oil.

[0057] In some embodiments, the waste includes higher fatty acid compounds, higher fatty alcohol compounds and higher fatty acid and fatty alcohol ester compounds.

[0058] In some embodiments, the method comprises the following steps:

[0059] (1) mixing the lignin sterol molecular distillation waste raw material liquid with an alcohol substance, and heating and refluxing at a certain temperature;

[0060] (2) After the alcohol is fully dissolved, add the catalyst and continue heating under reflux at a certain temperature for 1-12 hours;

[0061] (3) after the reaction is completed, dissolving the mixed solution in a certain amount of organic solvent to prepare a mixed solution;

[0062] (4) mixing the adsorbent and the organic solvent to form a chromatography column by a wet method, passing the mixed solution through the chromatography column, and adding the eluent again for elution, and separating at a certain flow rate under the condition of 25 to 50° C.;

[0063] (5) collecting the separated eluate, performing rotary evaporation and desolventizing to obtain refined vegetable wax.

[0064] In a second aspect, the present application provides a refined plant wax obtained according to the method described in the first aspect.

[0065] Compared with the prior art, this application has the following advantages:

[0066] (1) The present application utilizes chemical preparation synthesis, i.e., catalytic conversion, to extract plant wax from lignin sterol molecular distillation waste with a high extraction rate and yield, and the product purity is also high.

[0067] (2) The chemical synthesis process was optimized and the parameters were adjusted, including the type of alcohol, type of catalyst, amount of solvent, operating temperature and other factors, taking into account the cost and actual working conditions, to make it more promising for industrial application.

[0068] (3) Some catalysts required in the chemical reaction synthesis process can be regenerated and activated for use, which greatly reduces the reaction cost.

[0069] (4) Solve the problem that the wax crystals of the conventional dewaxing solvents in the dewaxing of the extracted oil are small and difficult to filter, and the wax crystals are large and contain little oil.

[0070] (5) Compared with traditional solvent dewaxing, the filtration speed is increased by 30-50% and the dewaxing temperature difference is reduced by 5-10℃.

[0071] (6) The purity of plant wax was further improved by column chromatography, and the decolorization effect was particularly significant.

[0072] (7) The prepared plant wax has a white micro-bead appearance and has the characteristics of short melting range, low viscosity, high whiteness and good lubrication and dispersibility. It can play the role of lubrication, demolding, brightening, anti-aging and anti-water loss. It has a wider application prospect in the fields of plastics, coatings, inks and rubber, and further enhances the industrial value of the waste of lignin sterol molecular distillation. DETAILED DESCRIPTION

[0073] The present application is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application, but not to limit the protection scope of the present application.

[0074] In the following examples and comparative examples, the lignansterol molecular distillation waste raw material liquid comes from the waste of lignansterol molecular distillation in the production of pine oil paste, and is mainly composed of higher fatty acid compounds, higher fatty alcohol compounds and higher fatty acid fatty alcohol ester compounds.

[0075] Example 1

[0076] (1) 20 g of lignin sterol molecular distillation waste raw material liquid and 5 g of n-docosanol were mixed and heated under reflux at 80° C. After the alcohol substance was fully dissolved, 0.3 g of D001 macroporous strong acid styrene-based cationic resin catalyst was added, and the mixture was heated under reflux at 80° C. for 6 h to obtain a reaction mixture.

[0077] (2) The reaction mixture is dissolved in 585 mL of n-hexane to prepare 600 mL of a mixed solution. Silica gel (for thin layer chromatography, 70-230 mesh) and n-hexane are mixed by a wet method to prepare a chromatography column (30×300 mm), and the mixed solution is passed through the chromatography column. The column temperature of the chromatography column is maintained at 30° C. to ensure that the wax does not precipitate, and the crude wax solution is slowly poured in. The effluent is collected at a flow rate of 3 mL / min, and the eluent n-hexane is added again for 2-3 times of elution. The separated eluent is collected and desolventized by rotary evaporation at 50° C. to obtain 9.1 g of refined plant wax, which is white in color and has a purity of 97.0%.

[0078] The cationic resin catalyst used in this experiment can be repeatedly regenerated and activated for use, greatly reducing the reaction cost.

[0079] Example 2

[0080] (1) 20 g of lignin sterol molecular distillation waste raw material liquid and 5 g of n-docosanol were mixed and heated under reflux at 80° C. After the alcohol substance was fully dissolved, 0.3 g of p-toluenesulfonic acid was added, and the mixture was heated under reflux at 80° C. for 6 h to obtain a reaction mixture.

[0081] (2) The reaction mixture is dissolved in 585 mL of n-hexane to prepare 600 mL of a mixed solution. Silica gel (for thin layer chromatography, 70-230 mesh) and n-hexane are mixed by a wet method to prepare a chromatography column (30×300 mm), and the mixed solution is passed through the chromatography column. The column temperature of the chromatography column is maintained at 30° C. to ensure that the wax does not precipitate, and the crude wax solution is slowly poured in. The effluent is collected at a flow rate of 3 mL / min, and the eluent n-hexane is added again for 2-3 times of elution. The separated eluent is collected and desolventized by rotary evaporation at 50° C. to obtain 9.3 g of refined plant wax, which is white in color and has a purity of 97.5%.

[0082] Example 3

[0083] The only difference from Example 1 is that in step (1), an equal amount of n-octadecyl alcohol is used to replace n-docosanol in Example 1. Finally, 8.5 g of refined plant wax is obtained, the wax color is yellowish, and the purity is 87.4%.

[0084] Example 4

[0085] The only difference from Example 1 is that in step (1), an equal amount of n-octacosanol is used to replace n-docosanol in Example 1. Finally, 8.8 g of refined vegetable wax is obtained, the wax color is yellowish, and the purity is 85.2%.

[0086] Example 5

[0087] The only difference from Example 1 is that in step (1), an equal amount of n-octanol is used to replace n-docosanol in Example 1. Finally, 7.5 g of refined vegetable wax is obtained, the wax color is yellowish, and the purity is 80.2%.

[0088] Example 6

[0089] The only difference from Example 1 is that in step (1), 3 g of n-docosanol is used. Finally, 8.3 g of refined vegetable wax is obtained, which is white in color and has a purity of 90.7%.

[0090] Example 7

[0091] The only difference from Example 1 is that in step (1), 10 g of n-docosanol is used. Finally, 9.4 g of refined vegetable wax is obtained, which is white in color and has a purity of 96.0%.

[0092] Example 8

[0093] The only difference from Example 1 is that in step (1), 15 g of n-docosanol is used. Finally, 10.7 g of refined vegetable wax is obtained, which is white in color and has a purity of 87.2%.

[0094] Example 9

[0095] The only difference from Example 1 is that in step (1), 20 g of n-docosanol is used. Finally, 12.2 g of refined vegetable wax is obtained, which is white in color and has a purity of 82.3%.

[0096] Example 10

[0097] The only difference from Example 1 is that in step (1), an equal amount of sodium hydroxide is used to replace the cationic resin in Example 1. Finally, 8.0 g of refined plant wax is obtained, the wax color is yellowish, and the purity is 90.3%.

[0098] Embodiment 11

[0099] The only difference from Example 1 is that in step (1), an equal amount of lipase (triacylglycerol acyl hydrolase) is used to replace the cationic resin in Example 1. Finally, 7.8 g of refined plant wax is obtained, the wax color is yellowish, and the purity is 78.1%.

[0100] Example 12

[0101] The only difference from Example 1 is that in step (1), an equal amount of sodium ethoxide is used to replace the cationic resin in Example 1. Finally, 7.5 g of refined plant wax is obtained, the wax color is yellowish, and the purity reaches 83.6%.

[0102] Example 13

[0103] (1) 20 g of lignin sterol molecular distillation waste raw material liquid and 5 g of docosanol were mixed and heated under reflux at 80° C. After the alcohol substance was fully dissolved, 0.3 g of concentrated sulfuric acid was added, and the mixture was heated under reflux at 80° C. for 6 h to obtain a reaction mixture.

[0104] (2) The reaction mixture was dissolved in 585 mL of n-hexane to prepare 600 mL of a mixed solution. Silica gel (for thin layer chromatography, 70-230 mesh) and n-hexane were mixed by a wet method to prepare a chromatography column (30×300 mm). The mixed solution was passed through the chromatography column. The column temperature was maintained at 30° C. to ensure that the wax did not precipitate. The crude wax solution was slowly poured in. The effluent was collected at a flow rate of 3 mL / min, and the eluent n-hexane was added again for 2-3 times of elution. The separated eluent was collected and desolventized by rotary evaporation at 50° C. to obtain 7.1 g of refined plant wax, which was white in color and had a purity of 86.0%.

[0105] Embodiment 14

[0106] (1) 20 g of lignin sterol molecular distillation waste raw material liquid and 5 g of docosanol were mixed and heated under reflux at 80° C. After the alcohol substance was fully dissolved, 0.3 g of D001 macroporous strong acid styrene-based cationic resin catalyst was added, and the mixture was heated under reflux at 80° C. for 6 h to obtain a reaction mixture.

[0107] (2) The reaction mixture was dissolved in 585 mL of n-hexane to prepare 600 mL of a mixed solution, and the activated carbon and n-hexane were mixed by a wet method to prepare a chromatography column (30×300 mm), and the mixed solution was passed through the chromatography column, and the column temperature of the chromatography column was maintained at 30° C. to ensure that the wax did not precipitate, and the crude wax solution was slowly poured in, and the effluent was collected at a flow rate of 3 mL / min, and the eluent n-hexane was added again for 2-3 times of elution. The separated eluate was collected and desolventized by rotary evaporation at 50° C. to obtain 8.8 g of refined plant wax, which was white in color and had a purity of 84.3%.

[0108] The above embodiments are only used to illustrate the technical solution of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the present application.

Claims

1. A method for extracting plant wax from lignin sterol byproducts by catalytic conversion, comprising the following steps: S1: mixing the lignin sterol byproduct and the alcohol substance at a first temperature to obtain a first mixed solution; S2: mixing the first mixed solution with the catalyst and reacting them at a second temperature to obtain a reacted mixed solution; S3: Purifying the mixed solution after the reaction by column chromatography to obtain refined vegetable wax; Preferably, the alcohol substance is selected from one or more of C4-C30 monohydric alcohols and C2-C10 polyhydric alcohols.

2. The method according to claim 1, characterized in that In step S3, purifying the reaction mixture by column chromatography includes: S31: mixing the reaction mixture with an organic solvent to obtain a crude wax mixture; S32: passing the crude wax mixture into a chromatography column, adding an eluent for elution, and separating at a third temperature and a first flow rate to obtain a separated eluent; S33: removing the solvent from the eluent to obtain refined vegetable wax.

3. The method according to claim 1 or 2, characterized in that: The alcohol substance is selected from one or more of C8-C28 straight-chain or branched monohydric alcohols, preferably one or more of C16-C25 straight-chain monohydric alcohols, more preferably one or more of n-octanol, n-octadecanol, n-behenyl alcohol and n-octacosanol; and / or The mass ratio of the alcohol substance to the lignin sterol by-product is 1:(1-10), preferably 1:(2-8).

4. The method according to any one of claims 1 to 3, characterized in that The catalyst is selected from one or more of an acid catalyst, an enzyme catalyst, and an alkali metal catalyst; Preferably, the acidic catalyst is selected from one or more of an inorganic acid, an organic acid, and an acidic cationic resin; Preferably, the enzyme catalyst is selected from lipase; Preferably, the alkali metal catalyst is selected from one or more of alkali metal hydroxides, alkali metal carbonates and alkali metal alkoxides; More preferably, the catalyst is selected from one or more of sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, styrene acidic cationic resin, sodium hydroxide and potassium hydroxide; and / or The mass ratio of the catalyst to the alcohol substance is 1:(1-50), preferably 1:(2-40).

5. The method according to any one of claims 1 to 4, wherein in step S1, the first temperature is 30°C-120°C, preferably 40°C-100°C; and / or In step S1, the mixing time is greater than or equal to the time for the alcohol substance to dissolve; and / or In step S2, the second temperature is 30°C-120°C, preferably 40°C-100°C; and / or In step S2, the reaction time is 1 h-12 h, preferably 2 h-10 h.

6. The method according to any one of claims 2 to 5, characterized in that: The adsorbent in the chromatography column is selected from one or more of silica gel, kaolin, activated carbon, resin and activated alumina, preferably one or more of silica gel, kaolin and activated carbon.

7. The method according to any one of claims 2 to 6, characterized in that: In step S31, the volume ratio of the mixed solution after the reaction to the organic solvent is 1:(20-50); and / or The organic solvent is selected from one or more of ketone solvents, alcohol solvents, ester solvents, halogenated alkane solvents with a carbon number of 1 to 5, and alkane solvents with a carbon number of 5 to 12; In step S32, the number of elutions is 3-5 times; and / or In step S32, the eluent is selected from one or more of a ketone solvent, an alcohol solvent, an ester solvent, a halogenated alkane solvent having a carbon number of 1-5, and an alkane solvent having a carbon number of 5-12; and / or The third temperature is 25°C-50°C, preferably 30°C-40°C; and / or The first flow rate was 1-5 mL / min.

8. The method according to claim 7, characterized in that The ketone solvent is selected from one or more of acetone, methyl ethyl ketone and methyl isobutyl ketone; and / or The alcohol solvent is selected from one or more of C1-C6 alcohols, preferably one or more of methanol, ethanol and n-propanol; The ester solvent is selected from one or more of ethyl acetate, ethyl formate, methyl acetate and n-propyl acetate; and / or The halogenated alkane solvent having a carbon number of 1 to 5 is selected from one or more of dichloromethane, chloroform and trichloroethane; and / or The alkane solvent having a carbon number of 5-12 is selected from one or more of cyclopentane, n-hexane, cyclohexane, methylcyclohexane, isopentane, n-octane and isooctane; Preferably, the organic solvent is selected from one or more of n-hexane, acetone, dichloromethane, methanol and ethyl acetate; Preferably, the eluent is selected from one or more of n-hexane, acetone, dichloromethane, methanol and ethyl acetate.

9. The method according to any one of claims 1 to 8, characterized in that The lignanol by-product is selected from waste generated during the molecular distillation process of producing lignanol; Preferably, the lignansterol byproduct is selected from waste generated during the molecular distillation process of pinewood paste to produce lignansterol; Preferably, the waste includes higher fatty acid compounds, higher fatty alcohol compounds and higher fatty acid and fatty alcohol ester compounds.

10. A refined vegetable wax obtained according to the method according to any one of claims 1 to 9.