Method for extracting vegetable wax from lignin sterol by-product

Abstract

The invention discloses a method for extracting vegetable wax from a wood sterol by-product, which comprises the following steps: S1, mixing the wood sterol by-product with a solvent at a first temperature to obtain a mixed solution; s2, performing extraction treatment on the mixed solution to obtain a treated mixed solution; s3, filtering the treated mixed solution to obtain cerate and filtrate; and S4, purifying the cerate by adopting an adsorption method to obtain the vegetable wax. According to the method, the vegetable wax is efficiently extracted from the lignosterol molecular distillation waste by means of solvent extraction and adsorption, and the high-quality vegetable wax is obtained from byproducts, so that the application range of low-cost biomass raw materials is expanded, the utilization value of low-grade raw oil is increased, high-value utilization of waste resources is realized, and the method is suitable for industrial production. Meanwhile, the method has the characteristics of high treatment capacity, simple process, low toxicity, environment friendliness, low cost and the like and is suitable for industrial production.

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. Background Art

[0002] Plant wax refers to wax extracted from plants, mainly including carnauba wax, candelilla wax, rice bran wax, sunflower wax, lacquer wax, etc. It is an ester formed by long-chain fatty acids and long-chain fatty alcohols. Plant wax has a wide range of uses and is an important industrial resource. It can be mainly used to produce polishes, protective agents and emulsifiers for fiber manufacturing. 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, for example, the raw material of pinewood ointment 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 lignin sterols with a content of more than 98% 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. In the refining and dewaxing process, a large amount of wax, neutral oil, free fatty acids and other fat-soluble substances are separated. The presence of these substances will not only affect the application of wax, but also cause a large amount of waste of neutral oil.

[0004] The main methods for crude wax production in China include bag filtration and saponification. Bag filtration is now less used due to its low production efficiency, large footprint, and poor feasibility. 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. In recent years, some domestic related studies have also used supercritical CO2 leaching, ultrasound-assisted, and enzyme-ultrasound dual-assisted extraction of plant waxes, but these methods are only in the laboratory research stage and have not yet been promoted and applied. Summary of the invention

[0005] In view of the technical problems in the prior art of low plant wax extraction rate and purity and high cost, the present application provides a method for extracting plant wax from lignin sterol by-products.

[0006] In a first aspect, the present application provides a method for extracting plant wax from lignanol byproducts, comprising the following steps:

[0007] S1: mixing the lignin sterol byproduct and the solvent at a first temperature to obtain a mixed solution;

[0008] S2: extracting the mixed solution to obtain a treated mixed solution;

[0009] S3: filtering the treated mixed liquid to obtain wax paste and filtrate;

[0010] S4: Purify the wax paste by adsorption method to obtain plant wax.

[0011] In some embodiments, the solvent is selected from one or more of ketone solvents, amide solvents, ester solvents and alcohol solvents.

[0012] Solvent extraction is a separation method based on the principle that wax and oil have different solubility in solvents. This method is simple to operate, has no wastewater discharge, has good finished product quality, and the neutral oil can be recycled. It is currently the most commonly used method for producing plant waxes, and has a relatively high yield. However, plant wax produced by solvent extraction is generally called crude wax. For example, crude bran wax contains not only wax esters, but also hydrocarbons, acylglycerols, free fatty acids, free alcohols, and colloidal impurities. The presence of these substances will not only affect the application of wax, but also cause a large amount of waste of neutral oils. At the same time, some pigments and other substances in crude wax will make the wax darker in color, so it is necessary to use a refining process to obtain high-quality plant wax.

[0013] The inventors of the present application have found through extensive research that the solvent extraction method has a high conversion rate and yield for extracting plant wax from lignin sterol byproducts (lignin sterol molecular distillation waste), and the product purity is high, so it is possible to effectively extract plant wax from lignin sterol molecular distillation waste and is suitable for industrial production and application. At the same time, the crude wax of the solvent extraction method is purified and refined by adsorption method, which can improve the purity and color of the product and further expand its application range.

[0014] In some embodiments, the ketone solvent is selected from one or more of acetone, methyl ethyl ketone and methyl isobutyl ketone.

[0015] In some embodiments, the amide solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and N-propylpyrrolidone.

[0016] In some embodiments, the ester solvent is selected from one or more of ethyl acetate, ethyl formate, methyl acetate and n-propyl acetate.

[0017] 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.

[0018] In some embodiments, the solvent is selected from one or more of N,N-dimethylformamide, acetone, ethyl acetate and ethanol.

[0019] In some embodiments, the lignanol by-product is selected from waste generated during the molecular distillation process of producing lignanol.

[0020] In some embodiments, the lignanol by-product is selected from waste generated during the molecular distillation process of producing lignanol from pine oil.

[0021] In some embodiments, the waste includes higher fatty acid compounds, higher fatty alcohol compounds and higher fatty acid and fatty alcohol ester compounds.

[0022] In some embodiments, the ratio of the mass of the lignansterol byproduct to the volume of the solvent (solid-liquid ratio) is 1g:0.5mL-1g:25mL, for example, 1g:0.7mL, 1g:1mL, 1g:1.3mL, 1g:1.5mL, 1g:1.7mL, 1g:1.9mL, 1g:2mL, 1g:2.5mL, 1g:3mL, 1g:3.5mL, 1g:4mL, 1g:4.5mL, 1g:5mL, 1g:5.5mL, 1g:6mL, 1g:6 .5mL, 1g:7mL, 1g:7.5mL, 1g:8mL, 1g:8.5mL, 1g:9mL, 1g:9.5mL, 1g:10mL, 1g:11mL, 1g:12mL, 1g:13mL, 1g:14mL, 1g:15mL, 1g:16mL, 1g:17mL, 1g:18mL, 1g:19mL, 1g:20mL, 1g:21mL, 1g:22mL, 1g:23mL, 1g:24mL or any value therebetween. With the increase of the solid-liquid ratio, the extraction rate of the wax decreases but the purity increases significantly. Considering the production cost and environmental protection factors, the solid-liquid ratio is within the above range.

[0023] In some embodiments, the ratio of the mass of the lignansterol byproduct to the volume of the solvent is 1 g: 1 mL to 1 g: 5 mL. In some embodiments, the ratio of the mass of the lignansterol byproduct to the volume of the solvent is 1 g: 1 mL to 1 g: 3 mL.

[0024] In some embodiments, in step S1, the first temperature is 5°C-40°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C or 35°C. In some embodiments, in step S1, the first temperature is 10°C-30°C. In some embodiments, in step S1, the first temperature is room temperature.

[0025] In some embodiments, in step S2, the extraction treatment includes: subjecting the mixed solution to an extraction treatment under first stirring and condensation reflux conditions.

[0026] In some embodiments, the temperature of the extraction process is 30-80°C, such as 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or any value therebetween. In some embodiments, the temperature of the extraction process is 40-70°C. In some embodiments, the temperature of the extraction process is 40-60°C.

[0027] In some embodiments, the extraction time is 0.5-24h, for example, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 14h, 16h, 18h, 20h or any value therebetween. In some embodiments, the extraction time is 1-12h. In some embodiments, the extraction time is 2-5h.

[0028] In some embodiments, the first stirring rate is 5-500r / min, for example, 10r / min, 30r / min, 50r / min, 70r / min, 90r / min, 100r / min, 110r / min, 130r / min, 150r / min, 170r / min, 190r / min, 200r / min, 210r / min, 230r / min, 250r / min, 270r / min, 290r / min, 300r / min, 310r / min, 330r / min, 350r / min, 370r / min, 390r / min, 400r / min, 410r / min, 430r / min, 450r / min, 470r / min, 490r / min or any value therebetween. In some embodiments, the first stirring rate is 50-450r / min. In some embodiments, the first stirring speed is 100-300 r / min.

[0029] In some embodiments, in step S4, purifying the wax paste by adsorption method comprises:

[0030] S41: mixing the wax paste with an adsorbent to obtain a mixture;

[0031] S42: refining the mixture at a second temperature and under vacuum conditions;

[0032] S43: filtering and molding the refined mixture to obtain the plant wax.

[0033] In some embodiments, in step S41, the adsorbent is selected from one or more of silica gel, clay, activated carbon, resin and activated alumina.

[0034] In some embodiments, in step S41, the adsorbent is at least two of silica gel, activated alumina and activated carbon. In some embodiments, the adsorbent is clay and silica gel. In some embodiments, activated carbon and alumina.

[0035] In some embodiments, in step S41, the mass ratio of clay to silica gel is 10:1-1:10, such as 10:1, 5:1, 3:1, 1:1, 1:3, 1:5 or 1:10, preferably 5:1, 3:1, 1:1, 1:3 or 1:5. In some embodiments, in step S41, the mass ratio of activated carbon to alumina is 10:1-1:10, such as 10:1, 5:1, 3:1, 1:1, 1:3, 1:5 or 1:10, preferably 5:1, 3:1, 1:1, 1:3 or 1:5.

[0036] In some embodiments, based on the mass of the wax paste, the mass of the adsorbent is 1%-25%, for example, 2%, 3%, 6%, 9%, 12%, 15%, 18% or 21%. In some embodiments, the mass of the adsorbent is 8%-15%.

[0037] In some embodiments, in step S41, the wax paste and the adsorbent are mixed at a second stirring rate.

[0038] In some embodiments, in step S41, the second stirring rate is 50-300r / min, for example, 70r / min, 90r / min, 100r / min, 110r / min, 130r / min, 150r / min, 170r / min, 190r / min, 200r / min, 210r / min, 230r / min, 250r / min, 270r / min or 290r / min. In some embodiments, the second stirring rate is 100-200r / min.

[0039] In some embodiments, in step S42, the second temperature is 80°C-150°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 140°C or any value therebetween. In some embodiments, the second temperature is 85°C-120°C.

[0040] In some embodiments, in step S42, the refining time is 1-24 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours or any value therebetween. In some embodiments, in step S42, the refining time is 3-6 hours.

[0041] In some embodiments, in step S43, the refined mixture is filtered by heat preservation, and the filtrate is poured into a mold to form it, and then it is demolded after being cooled and formed to obtain the vegetable wax.

[0042] In some embodiments, the method comprises the following steps:

[0043] S1: mixing the lignin sterol byproduct and the solvent at a first temperature to obtain a mixed solution;

[0044] S2: extracting the mixed solution to obtain a treated mixed solution;

[0045] S3: filtering the treated mixed liquid to obtain wax paste and filtrate;

[0046] S41: mixing the wax paste with an adsorbent to obtain a mixture;

[0047] S42: refining the mixture at a second temperature and under vacuum conditions;

[0048] S43: filtering and molding the refined mixture to obtain the plant wax.

[0049] In a second aspect, the present application provides a plant wax obtained according to the method described in the first aspect.

[0050] Compared with the prior art, this application has the following advantages:

[0051] (1) The present application utilizes solvent extraction to extract plant wax from lignin sterol molecular distillation waste with a high extraction rate and yield, and the product purity is also high.

[0052] (2) The solvent extraction method was optimized and the parameters were adjusted, including the amount of solvent and operating temperature, taking into account the cost and actual working conditions, to make it more promising for industrial application.

[0053] (3) 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.

[0054] (4) Compared with traditional solvent dewaxing, the filtration speed is increased by 30-50% and the dewaxing temperature difference is reduced by 5-10℃.

[0055] (5) The method provided in the present application includes efficiently extracting plant wax from lignin sterol molecular distillation waste by means of solvent extraction, etc., obtaining high-quality plant wax from by-products, expanding the scope of application of low-cost biomass raw materials, increasing the utilization value of low-grade crude oil, realizing high-value utilization of waste resources, and reducing pollution to the environment. It is of great significance to promote sustainable development and drive the development of related industries. At the same time, it has the characteristics of large processing capacity, simple process, low toxicity, environmental protection and low cost, and is suitable for industrial production.

[0056] (6) The prepared plant wax has a white micro-bead appearance, and has the characteristics of short melting range, low viscosity, high whiteness, good lubrication and dispersibility. The prepared plant wax can play the role of lubrication, demoulding, brightening, anti-aging and anti-water loss, and has a wider application prospect in the fields of plastics, coatings, inks and rubber. This application further enhances the industrial value of the waste of lignin sterol molecular distillation. DETAILED DESCRIPTION

[0057] 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.

[0058] 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.

[0059] Example 1

[0060] 25 mL of solvent acetone was mixed with 20 g of lignin sterol molecular distillation waste raw material liquid to obtain a mixed solution, and the extraction temperature was 50° C., and the stirring rate was maintained at 150 r / min and the extraction was performed for 5 hours under condensation reflux conditions. After the extraction, the mixed solution was filtered to obtain wax paste and filtrate.

[0061] The wax paste was mixed with the adsorbent white clay / silica gel (1:1) at a stirring rate of 200 r / min, and refined for 5 hours at an adsorption temperature of 100°C and under vacuum conditions. The mass of the adsorbent was 9% of the mass of the wax paste. After completion, the wax paste was filtered in a heat preservation manner. After the filtration was completed, the filtrate was immediately poured into a mold to form it, and the mold was removed after it was completely cooled and formed. The mass of the sample after demolding was 4.1g, the yield was 41.0%, and the purity was determined to be 90.1%.

[0062] Example 2

[0063] The only difference from Example 1 is that 25 mL of solvent ethanol is used to replace 25 mL of solvent acetone. The final product yield is 33.2% and the purity is 72.3%.

[0064] Example 3

[0065] The only difference from Example 1 is that 25 mL of DMF solvent is used to replace 25 mL of acetone solvent. The final product yield is 65.8% and the purity is 64.1%.

[0066] Example 4

[0067] The only difference from Example 1 is that 25 mL of ethyl acetate is used to replace 25 mL of acetone. The final product yield is 25.2% and the purity is 78.4%.

[0068] Example 5

[0069] The only difference from Example 1 is that the amount of acetone used is 50 mL. The final product yield is 17.1% and the purity is 82.3%.

[0070] Example 6

[0071] The only difference from Example 1 is that the extraction temperature is 80° C. The final product yield is 27.2% and the purity is 75.3%.

[0072] Example 7

[0073] The only difference from Example 1 is that the stirring rate is 50 r / min. The final product yield is 25.4% and the purity is 85.3%.

[0074] Example 8

[0075] The only difference from Example 1 is that the adsorption temperature is 80° C. The final product yield is 25.8% and the purity is 81.7%.

[0076] Example 9

[0077] The only difference from Example 1 is that the amount of adsorbent used is 3%. The final product yield is 39.8% and the purity is 82.3%.

[0078] Example 10

[0079] 25 mL of solvent acetone was mixed with 20 g of lignin sterol molecular distillation waste raw material liquid to obtain a mixed solution, and the extraction temperature was 50° C., and the stirring rate was maintained at 150 r / min and the extraction was performed for 5 hours under condensation reflux conditions. After the extraction, the mixed solution was filtered to obtain wax paste and filtrate.

[0080] The wax paste was mixed with the adsorbent activated carbon / alumina (1:1) at a stirring rate of 200 r / min, and refined for 5 hours at an adsorption temperature of 100°C and under vacuum conditions. The mass of the adsorbent was 9% of the mass of the wax paste. After completion, the wax paste was filtered in a heat preservation manner. After the filtration was completed, the filtrate was immediately poured into a mold to form it, and the mold was removed after it was completely cooled and formed. The yield was 34.9%, and the purity was determined to be 75.4%.

[0081] 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 lignansterol byproducts, comprising the following steps: S1: mixing the lignin sterol byproduct and the solvent at a first temperature to obtain a mixed solution; S2: extracting the mixed solution to obtain a treated mixed solution; S3: filtering the treated mixed liquid to obtain wax paste and filtrate; S4: Purifying the wax paste by an adsorption method to obtain plant wax; Preferably, the solvent is selected from one or more of ketone solvents, amide solvents, ester solvents and alcohol solvents.

2. The method according to claim 1, characterized in that The ketone solvent is selected from one or more of acetone, methyl ethyl ketone and methyl isobutyl ketone; and / or The amide solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and N-propylpyrrolidone; and / or The ester solvent is selected from one or more of ethyl acetate, ethyl formate, methyl acetate and n-propyl acetate; and / or The alcohol solvent is selected from one or more of C1-C6 alcohols, preferably selected from methanol, ethanol and n-propanol; Preferably, the solvent is selected from one or more of N,N-dimethylformamide, acetone, ethyl acetate and ethanol; and / or The ratio of the mass of the lignin sterol by-product to the volume of the solvent is 1g:0.5mL-1g:25mL, preferably 1g:1mL-1g:5mL.

3. The method according to claim 1 or 2, characterized in that: In step S1, the first temperature is 5°C-40°C, preferably 10°C-30°C; and / or In step S2, the extraction treatment includes: subjecting the mixed liquid to an extraction treatment under first stirring and condensation reflux conditions.

4. The method according to claim 3, characterized in that The extraction treatment temperature is 30-80°C, preferably 40-70°C, more preferably 40-60°C; and / or The extraction treatment time is 0.5-24h, preferably 1-12h, more preferably 2-5h; and / or The first stirring rate is 5-500 r / min, preferably 50-450 r / min, more preferably 100-300 r / min.

5. The method according to any one of claims 1 to 4, characterized in that In step S4, purifying the wax paste by adsorption method includes: S41: mixing the wax paste with an adsorbent to obtain a mixture; S42: refining the mixture at a second temperature and under vacuum conditions; S43: filtering and molding the refined mixture to obtain the plant wax.

6. The method according to claim 5, characterized in that In step S41, the adsorbent is selected from one or more of silica gel, clay, activated carbon, resin and activated alumina, preferably at least two of silica gel, activated alumina and activated carbon, more preferably clay and silica gel, or activated carbon and alumina; and / or Based on the mass of the wax paste, the mass of the adsorbent is 1%-25%, preferably 8%-15%.

7. The method according to claim 5 or 6, characterized in that: In step S41, the wax paste and the adsorbent are mixed at a second stirring rate. Preferably, the second stirring rate is 50-300 r / min, preferably 100-200 r / min; and / or In step S42, the second temperature is 80°C-150°C, preferably 85°C-120°C; and / or In step S42, the refining time is 1-24 hours, preferably 3-6 hours.

8. The method according to any one of claims 5 to 7, characterized in that: In step S43, the refined mixture is filtered while being kept warm, and the filtrate is poured into a mold to be formed, and the mold is removed after the mixture is cooled and formed, thereby obtaining the vegetable wax.

9. The method according to any one of claims 1 to 7, 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 lignin sterol by-products include higher fatty acid compounds, higher fatty alcohol compounds and higher fatty acid and fatty alcohol ester compounds.

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