Process for separating a mixture comprising phenols and fatty alcohols

Abstract

The application provides a method for separating a mixture containing phenolic compounds and C6-C12 fatty alcohols, the method comprising: adding an auxiliary to the mixture, the auxiliary being selected from one or more of the following: Na2S2O3, K2S2O3, Na2S2O4; step two: adding an aqueous solution of an alkaline compound to the mixture; step three: separating the aqueous phase and the oil phase; step four: purifying the oil phase. The method of the application realizes effective purification and recovery of C6-C12 fatty alcohols in waste under the premise of simplifying steps, low cost and environmental protection.

Description

Technical Field

[0001] This application relates to the field of fine chemicals, and more specifically provides a method for separating a mixture containing phenolic compounds and medium- and long-chain fatty alcohols to recover high-purity medium- and long-chain fatty alcohols. Background Technology

[0002] Various medium- and long-chain fatty alcohols are widely used in various industrial fields as raw materials, solvents, additives, and functionalizing reagents. These high-value medium- and long-chain fatty alcohols are widely present in the by-product streams or wastes of related processes, and how to effectively separate and obtain high-purity, high-quality medium- and long-chain fatty alcohols from them has been a long-standing research challenge in the chemical industry.

[0003] As a typical example of medium- and long-chain fatty alcohols, 2-octanol (2-octanol) is an important chemical raw material and organic solvent. It can be used as a wetting agent, fragrance, plasticizer, and pesticide emulsifier, and also as a raw material for the production of high-grade lubricant additives. In the production of sebacic acid from castor oil (which contains a large amount of ricinoleic acid glyceride), 2-octanol is produced as a byproduct. A significant portion of this byproduct is contained in the distillation residue generated in the rectification section. This residue has a complex composition, is dark in color, and has a strong odor. Besides containing large amounts of the target compounds 2-octanol and phenol, it may also contain a certain amount of impurity compounds. Due to the complexity and interactions of the components in this residue, it is difficult to effectively separate them using conventional methods. Even rectification cannot yield high-purity, valuable 2-octanol, failing to meet the requirements of industrial production. Therefore, current technology generally considers this distillation residue as waste with no utilization value and incinerates it, burning away the high-value 2-octanol and other organic compounds. The following problems exist with this type of incineration: (1) The incineration process consumes a large amount of energy and may also generate secondary pollutants, which need to be purified and treated to meet standards before being discharged; (2) The ash residue after incineration still needs to be disposed of as hazardous waste, resulting in high operating costs and failing to fundamentally solve the environmental problem; (3) High-value 2-octanol and phenolic compounds are burned away, causing serious waste. Therefore, the incineration method is not only costly but also causes huge waste of resources and carries certain environmental risks. In particular, with increasingly stringent environmental regulations, the space for incineration as a method solely aimed at harmlessness is gradually shrinking. There is an urgent need to develop a method that can recycle, reduce, and harmlessly process waste from various processes (such as the distillation residue containing 2-octanol mentioned above) to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] To address the above problems, this application provides a method for separating a mixture containing phenolic compounds and C6-C12 fatty alcohols, the method comprising the following steps: Step 1: Add an auxiliary agent to the mixture, wherein the auxiliary agent is selected from one or more of the following: Na2S2O3, K2S2O3, Na2S2O4; Step 2: Add an aqueous solution of an alkaline compound to the mixture; Step 3: Separate the aqueous phase and the oil phase; Step 4: Purify the oil phase.

[0005] According to one embodiment of this application, the C6-C12 fatty alcohol has a straight-chain structure and / or a branched-chain structure, and contains a hydroxyl group in the molecule.

[0006] According to another embodiment of this application, the content of the C6-C12 fatty alcohol is 40-80% by weight, based on the total weight of the mixture.

[0007] According to another embodiment of this application, the phenolic compound is selected from one or more of the following: phenol, hydroquinone, methylphenol, ethylphenol, propylphenol, butylphenol, and dimethylphenol.

[0008] According to another embodiment of this application, the content of the phenolic compound is 7-40% by weight, based on the total weight of the mixture.

[0009] According to another embodiment of this application, the mixture is a distillation residue of sebacic acid byproduct 2-octanol.

[0010] According to another embodiment of this application, the mixture is the distillation residue of 2-octanol, a byproduct of the process for preparing sebacic acid from castor oil.

[0011] According to another embodiment of this application, the mixture is obtained by hydrolyzing castor oil to produce ricinoleic acid or its salt and glycerol, then cracking the ricinoleic acid or its salt in the presence of an alkaline compound and phenol to obtain crude products of 2-octanol and phenol, separating a portion of 2-octanol by distillation, and obtaining a distillation residue containing 2-octanol and phenol, which is the mixture.

[0012] According to another embodiment of this application, the mixture is obtained as follows: ricinoleic acid glycerides in castor oil are hydrolyzed to produce ricinoleic acid or its salt and glycerol; then, ricinoleic acid or its salt is cleaved in the presence of an alkaline compound and phenol to produce a crude product containing sebacic acid or its salt, fatty acids or their salts, 2-octanol, and phenol; sebacic acid and fatty acids or their salts are separated from the crude product; then, a portion of 2-octanol is separated by distillation, simultaneously obtaining a distillation residue containing 2-octanol and phenol, which is the mixture; the fatty acids or their salts are different from the sebacic acid or its salt.

[0013] According to another embodiment of this application, the mixture optionally contains 0-30% by weight of organic matter, which is different from the phenolic compounds and C6-C12 fatty alcohols, based on the total weight of the mixture.

[0014] According to another embodiment of this application, in step one, the amount of the additive added is 0.5-10 parts by weight, based on 100 parts by weight of the mixture.

[0015] According to another embodiment of this application, the alkaline compound added in step two is selected from one or more of the following: sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0016] According to another embodiment of this application, in step two, the amount of alkaline compound added is 2-15 parts by weight, based on 100 parts by weight of the mixture.

[0017] According to another embodiment of this application, the mass ratio of water to the mixture added in steps one and two is 60:100 to 200:100.

[0018] According to another embodiment of this application, in step four, the oil phase is dehydrated and distilled.

[0019] According to another embodiment of this application, in step one, after the additive is added to the mixture, the mixture is mixed for 10-200 minutes.

[0020] According to another embodiment of this application, in step two: after adding the alkaline compound to the mixture, mixing is carried out for 10-60 minutes.

[0021] In the detailed description section below, the methods and products of this application will be further described with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 The distillation apparatus used in the embodiments of this application is shown; Figure 2A The distillation residue used in the examples is shown; Figure 2B The example shows the separation and purification of 2-octanol; Figure 3 The gas chromatogram of the distillation residue used in the embodiments of this application is shown; Figure 4 The gas chromatogram of 2-octanol obtained by separation and purification in the embodiments of this application is shown; Figure 5 The liquid chromatogram of the aqueous phase after oil-water phase separation in an embodiment of this application is shown. Detailed Implementation

[0023] The “range” disclosed in this document takes the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges that can be defined in this way are inclusive and composable; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is also expected that ranges of 60-110 and 80-120 are also included. Furthermore, if the minimum range values ​​are listed as 1 and 2, and if the maximum range values ​​are listed as 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0024] In this application, unless otherwise stated, the numerical range "ab" is a shortened representation of any combination of real numbers from a to b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this document, and "0-5" is simply a shortened representation of these numerical combinations.

[0025] Unless otherwise specified in this application, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0026] Unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0027] In this application, unless otherwise specified, the term "comprising" as used herein can be either open-ended or closed-ended. For example, "comprising" may mean that it may also include other components not listed, or it may only include the listed components.

[0028] In the method of the present invention, the object of treatment is a mixture containing phenolic compounds and fatty alcohols.

[0029] According to one embodiment of this application, the fatty alcohol is an aliphatic alcohol having a straight-chain or branched-chain structure. According to another embodiment of this application, the fatty alcohol molecule contains 6-12 carbon atoms, more preferably 7-10 carbon atoms, and even more preferably 8-9 carbon atoms. According to another embodiment of this application, the fatty alcohol molecule contains only one hydroxyl group. According to a specific embodiment of this application, the fatty alcohol is 2-octanol.

[0030] According to another embodiment of this application, before processing using the method of this application, the content of fatty alcohol in the mixture to be processed is 40-80% by weight, or 45-78% by weight, or 50-75% by weight, or 55-70% by weight, based on the total weight of the mixture.

[0031] According to another embodiment of this application, the phenolic compound is selected from one or more of the following: phenol, hydroquinone, methylphenol, ethylphenol, propylphenol, butylphenol, and dimethylphenol. According to a specific embodiment of this application, the phenolic compound is phenol.

[0032] According to another embodiment of this application, before processing using the method of this application, the content of phenolic compounds in the mixture to be processed is 7-40% by weight, or 8-35% by weight, or 10-30% by weight, or 12-25% by weight, or 15-20% by weight, based on the total weight of the mixture.

[0033] According to another embodiment of this application, the mixture contains only the fatty alcohols and phenolic compounds described above, and substantially no other substances.

[0034] According to another independent embodiment of this application, the mixture may contain one or more other organic compounds in addition to the fatty alcohols and phenolic compounds described above. According to another embodiment of this application, before processing using the method of this application, the content of these other organic compounds in the mixture to be processed is 0-30% by weight, or 5-29% by weight, or 10-28% by weight, or 20-27% by weight, based on the total weight of the mixture.

[0035] According to an exemplary embodiment of this application, the mixture is a byproduct or waste generated from a chemical production line. A further inventive aspect of this application is that the method of this application can efficiently separate high-purity fatty alcohols from the mixture without being negatively affected by organic compounds other than the aforementioned fatty alcohols and phenolic compounds (hereinafter referred to as "organic impurities"). As described in the background section of this application, in the prior art, organic impurities contained in the mixture interfere with the separation of fatty alcohols, and even alkali treatment and distillation cannot achieve the high yield and purity of fatty alcohols as in this invention.

[0036] In embodiments where the mixture further contains organic impurities, the type and amount of the "organic impurities" depend on the specific process, but without exception they will affect the recovery of fatty alcohols from the mixture, and all can achieve the above-mentioned beneficial effects through the method of this application.

[0037] It should also be noted that the organic impurities in the mixture often include many different types and amounts of compounds, which are difficult to characterize individually using conventional characterization methods. Moreover, as low-value non-target compounds, there is no need for qualitative and quantitative characterization. In the art, the "organic impurities" are usually treated as a whole, without the need for detailed differentiation of specific components.

[0038] According to another more specific exemplary embodiment of this application, the mixture is the distillation residue produced in the rectification section during the production of sebacic acid from castor oil.

[0039] Specifically, the process for producing sebacic acid from castor oil is a known industrial process in the art. Castor oil contains ricinoleic acid (12-hydroxy-9-octadecenoic acid) glyceride. The process first involves hydrolyzing castor oil in the presence of an alkaline compound (e.g., sodium hydroxide or sodium carbonate) to produce ricinoleic acid or its salt (e.g., sodium salt) and glycerol. Then, ricinoleic acid or its salt (e.g., sodium salt) undergoes a cracking reaction at high temperature (e.g., 250-280°C) in the presence of a strong alkali (e.g., sodium hydroxide and potassium hydroxide) and phenol to produce a crude product containing the target product sebacic acid or its salt (e.g., sodium salt), fatty acids or their salts (the fatty acids or their salts described herein are different from the sebacic acid or its salts), 2-octanol, and phenol. The crude product is then separated and purified, for example, by decolorization, acidification, and crystallization to separate sebacic acid or its salts, fatty acids or their salts, and then by distillation to separate a portion of 2-octanol. The distillation residue produced in the distillation section contains 2-octanol and phenol, which can be used as the processing object (i.e., "mixture") of the method of this application for the separation and recovery of 2-octanol. According to a non-limiting embodiment of this application, in addition to 2-octanol and phenol, the distillation residue also contains 5-30% by weight, for example 10-29% by weight, or 15-28% by weight, or 20-27% by weight of other organic compounds (i.e., so-called organic impurities). The organic impurities include residual raw materials, by-products, impurities, etc., from the "castor oil to sebacic acid" process described above. As mentioned above, the various compounds in the organic impurities are generally not specifically qualitatively or quantitatively identified in the art.

[0040] Another inventive aspect of this invention lies in the inventors' unexpected discovery, through extensive research, that a simple operation—adding the auxiliary agent first, followed by the alkaline substance—can significantly improve the separation efficiency of the target fatty alcohol and significantly increase the relative proportion of fatty alcohol in the separated oil phase, achieving high yield and high purity. The applicant's experiments revealed that changing the order of addition of the auxiliary agent and the alkaline substance—adding them simultaneously or adding the alkaline substance first followed by the auxiliary agent—significantly worsens the separation efficiency of the target fatty alcohol. This demonstrates that the reagent addition order designed in this application's method can achieve significant progress and unexpected technical effects.

[0041] According to one embodiment of this application, in step one of the method of this application, an auxiliary agent is added to the mixture (e.g., the distillation residue described above), and then the mixture is mixed for a period of time.

[0042] According to another embodiment of this application, in step one, the auxiliary agent is selected from one or more of the following: Na2S2O3, K2S2O3, and Na2S2O4.

[0043] According to another embodiment of this application, the additive can be dissolved in water to form a first aqueous solution, and then this first aqueous solution can be added to the mixture. The concentration of the first aqueous solution can be 5-20% by weight, or 8-15% by weight, or 10-12% by weight.

[0044] According to another embodiment of this application, based on 100 parts by weight of the mixture, the amount of the additive added is 0.5-10 parts by weight, or 1-8 parts by weight, or 2-6 parts by weight, or 3-5 parts by weight, for example 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, 5.5 parts by weight, 6 parts by weight, 6.5 parts by weight, 7 parts by weight, 7.5 parts by weight, 8 parts by weight, 8.5 parts by weight, 9 parts by weight, 9.5 parts by weight, or within a numerical range obtained by combining any two of the above extreme values. It should be noted that, in the case of using an additive solution, the above proportions are calculated based on the solid weight of the additive contained in the first solution.

[0045] According to another embodiment of this application, in step one, a mechanical stirrer is used for stirring and mixing, and the temperature during the mixing process is 20-95°C, or 40-80°C, or 60-75°C. The mixing duration in step one is 10-200 minutes, or 20-100 minutes, or 30-60 minutes.

[0046] Next, in step two, an alkaline compound is added to the material treated in step one, and then the mixture is stirred for a period of time.

[0047] According to another embodiment of this application, in step two, the alkaline compound is selected from one or more of the following: sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0048] According to another embodiment of this application, the alkaline compound can be dissolved in water to form a second aqueous solution, and then this second aqueous solution can be added to the mixture. The concentration of the second aqueous solution can be 2-16% by weight, or 5-12% by weight, or 8-10% by weight.

[0049] According to another embodiment of this application, based on 100 parts by weight of the mixture (here, "mixture" refers to a raw mixture that has not yet been treated by the method of this invention, such as raw distillation residue), the amount of the alkaline compound added is 2-15 parts by weight, or 4-12 parts by weight, or 6-10 parts by weight, or 8-9 parts by weight. It should be noted that, for cases using an alkaline compound solution, the above proportions are calculated based on the solid weight of the alkaline compound contained in the solution.

[0050] According to another embodiment of this application, in step two, a mechanical stirrer is used for stirring and mixing, and the temperature during the mixing process is 20-95°C, or 40-80°C, or 60-75°C. The mixing duration in step two is 10-60 minutes.

[0051] According to another embodiment of this application, in step two, stirring and mixing can be continuously performed, and samples can be taken at the same intervals to detect the content of the target fatty alcohol (e.g., 2-octanol) in the oil phase. When the 2-octanol content is found to be stable and no longer increasing after two consecutive tests, stirring is stopped, and then the phase separation operation in step three is performed.

[0052] According to another embodiment of this application, the total amount of water added in steps one and two (the total amount of water introduced as an auxiliary aqueous solution and / or an alkaline compound aqueous solution) to the mixture as a raw material (e.g., distillation residue as a raw material) is in a mass ratio of 200:100 to 80:100, or 180:100 to 100:100, or 150:100 to 110:100, or 130:100 to 120:100.

[0053] Next, in step three, the material obtained in step two is allowed to stand, and then the resulting aqueous and oil phases are separated. This phase separation can be performed using a separating funnel or other devices or equipment with phase separation capabilities.

[0054] According to another embodiment of this application, step four includes dehydrating and distilling the oil phase obtained in step three.

[0055] The method described in this application can achieve at least the following advantages: 1. This invention can solve the environmental risks and resource waste caused by waste incineration. Through precise separation, it realizes the recovery of two high-value components, fatty alcohols and phenols. The process conditions are mild and the operation is simple and convenient. 2. The method of this invention is fast and efficient. Compared with the prior art, by adding auxiliaries such as Na2S2O3, K2S2O3, and Na2S2O4 before adding the aqueous solution of alkaline compounds, organic impurities that would otherwise affect the subsequent distillation and purification of 2-octanol in the oil phase can be introduced into the aqueous phase of phenol, thereby increasing the yield of 2-octanol and achieving a fatty alcohol recovery rate of over 85%. After distillation, the purity of the fatty alcohol is >99%, meeting the requirements of industrial applications. 3. The method of the present invention not only has low processing costs, but also the recovered high-value components can generate considerable direct economic benefits.

[0056] The following embodiments illustrate the methods of this application in detail, with the aim of providing a better understanding of the content of this application. It should be understood that these embodiments are merely illustrative and not restrictive.

[0057] Example

[0058] The distillation residues treated in the following examples and comparative examples were generated from the distillation section of the castor oil high-temperature cracking production line for sebacic acid at Wilmar Polymer Materials (Lianyungang) Co., Ltd. (e.g., Figure 2A As shown), gas chromatography (Agilent 7890A gas chromatograph) determined that it contained 55.3 wt% 2-octanol and 17.8 wt% phenol (the gas chromatogram of the distillation residue is shown in the figure). Figure 3 (as shown), and the balance of organic impurities, which, according to the conventions of the art, do not require a study of the specific composition of the organic impurities.

[0059] All other reagents used in the following examples and comparative examples were commercially available analytical grade reagents, and the water used was deionized water.

[0060] Example 1

[0061] Add 300g of distillation residue to a 1000ml reactor equipped with a mechanical stirrer (the mechanical stirrer is an LC-OES-60 type mechanical stirrer purchased from Shanghai Lichen Equipment Co., Ltd.), then add 100g of a 10% by weight Na2S2O3 aqueous solution, raise the reactor temperature to 75℃, and stir at 300rpm for 30 minutes at this temperature.

[0062] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 300 rpm at 75°C. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using an Agilent 7890A gas chromatograph. Stop stirring when the 2-octanol content no longer increases in two consecutive test results (after 120 minutes), and allow the reactor to cool naturally to room temperature.

[0063] The material in the reaction vessel was transferred to a separating funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 195g, and the total aqueous phase was approximately 505g. The composition of the oil phase was determined using an Agilent 7890A gas chromatograph (e.g., ...). Figure 4 As shown), the aqueous phase composition was determined using an Agilent 1260 liquid chromatograph (e.g., Figure 5 (As shown). The oil phase contained 84.9% by weight of 2-octanol and 0.10% by weight of sodium phenolate; the aqueous phase contained 12.95% by weight of sodium phenolate, and 2-octanol was not detected.

[0064] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump manufactured by Hokaido, and then dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section and distilled using a YFT-2S glass distillation column (e.g., manufactured by Shanghai Yuanhuai Company). Figure 1 The distillation column (as shown) was subjected to distillation. During the distillation process, the pressure of the distillation column was maintained at 5 mbar, the bottom temperature of the distillation column was about 100℃, the top temperature of the column was controlled at about 65℃, the reflux ratio was controlled at 1:5, and the top product was refined 2-octanol. The calculated yield of 2-octanol was 85.61%, and the purity was 99.3%.

[0065] Example 2

[0066] In this Example 2, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0067] Add 300g of distillation residue to a 1000ml reaction vessel equipped with a mechanical stirrer, then add 100g of a 5% by weight Na2S2O3 aqueous solution. Raise the temperature of the reaction vessel to 75°C and stir at 300rpm for 30 minutes at this temperature.

[0068] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0069] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 218 g, and the total aqueous phase was approximately 482 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 75.83% by weight of 2-octanol and 0.09% by weight of sodium phenolate; the aqueous phase contained 13.59% by weight of sodium phenolate, and 2-octanol was not detected.

[0070] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 82.13% and a purity of 99.3%.

[0071] Example 3

[0072] In this embodiment 3, the same reaction vessel, mechanical stirring device, vacuum pump, distillation column, and gas and liquid chromatography equipment as in embodiment 1 were used.

[0073] Add 300g of distillation residue to a 1000ml reaction vessel equipped with a mechanical stirrer, then add 100g of a 3% by weight Na2S2O3 aqueous solution. Raise the temperature of the reaction vessel to 75°C and stir at 300rpm for 30 minutes at this temperature.

[0074] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0075] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 229 g, and the total aqueous phase was approximately 471 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 72.23% by weight of 2-octanol and 0.11% by weight of sodium phenolate; the aqueous phase contained 13.93% by weight of sodium phenolate, and 2-octanol was not detected.

[0076] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 80.91% and a purity of 99.4%.

[0077] Example 4

[0078] In this Example 4, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0079] Add 300 g of distillation residue to a 1000 ml reactor equipped with a mechanical stirrer, then add 100 g of a 10% by weight K2S2O3 aqueous solution. Raise the reactor temperature to 75°C and stir at 300 rpm for 30 minutes at this temperature.

[0080] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0081] The materials in the reaction vessel were transferred to a separating funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total amount of the oil phase was approximately 200g, and the total amount of the aqueous phase was approximately 500g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 82.7% by weight of 2-octanol and 0.10% by weight of sodium phenolate; the aqueous phase contained 13.03% by weight of sodium phenolate, and 2-octanol was not detected.

[0082] The oil phase material was first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It was then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column was maintained at 5 mbar, the bottom temperature was approximately 100°C, the top temperature was controlled at approximately 65°C, and the reflux ratio was controlled at 1:5. The top product was refined 2-octanol, with a calculated yield of 83.91% and a purity of 99.2%.

[0083] Example 5

[0084] In this Example 5, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0085] Add 300 g of distillation residue to a 1000 ml reactor equipped with a mechanical stirrer, then add 100 g of a 5% by weight K2S2O3 aqueous solution. Raise the reactor temperature to 75°C and stir at 300 rpm for 30 minutes at this temperature.

[0086] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0087] The materials in the reaction vessel were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 224 g, and the total aqueous phase was approximately 476 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 73.78% by weight of 2-octanol and 0.11% by weight of sodium phenolate; the aqueous phase contained 13.73% by weight of sodium phenolate, and 2-octanol was not detected.

[0088] The oil phase material was first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It was then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column was maintained at 5 mbar, the bottom temperature was approximately 100°C, the top temperature was controlled at approximately 65°C, and the reflux ratio was controlled at 1:5. The top product was refined 2-octanol, with a calculated yield of 82.16% and a purity of 99.4%.

[0089] Example 6

[0090] In this Example 6, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0091] Add 300g of distillation residue to a 1000ml reaction vessel equipped with a mechanical stirrer, then add 100g of a 3% by weight K2S2O3 aqueous solution. Raise the temperature of the reaction vessel to 75°C and stir at 300rpm for 30 minutes at this temperature.

[0092] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0093] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 231 g, and the total aqueous phase was approximately 469 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 71.65% by weight of 2-octanol and 0.09% by weight of sodium phenolate; the aqueous phase contained 13.94% by weight of sodium phenolate, and 2-octanol was not detected.

[0094] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 80.76% and a purity of 99.3%.

[0095] Example 7

[0096] In this embodiment 7, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in embodiment 1 were used.

[0097] Add 300 g of distillation residue to a 1000 ml reactor equipped with a mechanical stirrer, then add 100 g of a 10% by weight Na2S2O4 aqueous solution. Raise the reactor temperature to 75°C and stir at 300 rpm for 30 minutes at this temperature.

[0098] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0099] The materials in the reaction vessel were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 194 g, and the total aqueous phase was approximately 506 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 85.1% by weight of 2-octanol and 0.11% by weight of sodium phenolate; the aqueous phase contained 12.94% by weight of sodium phenolate, and 2-octanol was not detected.

[0100] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 84.9% and a purity of 99.3%.

[0101] Example 8

[0102] In this Example 8, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0103] Add 300 g of distillation residue to a 1000 ml reactor equipped with a mechanical stirrer, then add 100 g of a 5% by weight Na2S2O4 aqueous solution. Raise the reactor temperature to 75°C and stir at 300 rpm for 30 minutes at this temperature.

[0104] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0105] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 220 g, and the total aqueous phase was approximately 480 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 75.23% by weight of 2-octanol and 0.10% by weight of sodium phenolate; the aqueous phase contained 13.61% by weight of sodium phenolate, and 2-octanol was not detected.

[0106] The oil phase material was first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It was then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column was maintained at 5 mbar, the bottom temperature was approximately 100°C, the top temperature was controlled at approximately 65°C, and the reflux ratio was controlled at 1:5. The top product was refined 2-octanol, with a calculated yield of 82.21% and a purity of 99.2%.

[0107] Example 9

[0108] In this Example 9, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0109] Add 300g of distillation residue to a 1000ml reaction vessel equipped with a mechanical stirrer, then add 100g of a 3% by weight Na2S2O4 aqueous solution. Raise the temperature of the reaction vessel to 75°C and stir at 300rpm for 30 minutes at this temperature.

[0110] Add 300g of 8% (w / w) NaOH aqueous solution to the reactor, and then continue stirring at 75℃ and 300rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0111] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 230 g, and the total aqueous phase was approximately 470 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 72.09% by weight of 2-octanol and 0.10% by weight of sodium phenolate; the aqueous phase contained 13.91% by weight of sodium phenolate, and 2-octanol was not detected.

[0112] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 81.03% and a purity of 99.4%.

[0113] Comparative Example 1

[0114] In this Comparative Example 1, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0115] Add 300 g of distillation residue to a 1000 mL reactor equipped with a mechanical stirrer, then add 300 g of an 8% (w / w) NaOH aqueous solution. Raise the reactor temperature to 75°C and stir continuously at 300 rpm at this temperature. Sample the material in the reactor every 10 minutes, separate the oil phase, and analyze the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive measurements, and allow the reactor to cool naturally to room temperature.

[0116] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 245 g, and the total aqueous phase was approximately 355 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 67.13% by weight of 2-octanol and 0.12% by weight of sodium phenolate; the aqueous phase contained 18.31% by weight of sodium phenolate, and 2-octanol was not detected.

[0117] The oil phase material was first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It was then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column was maintained at 5 mbar, the bottom temperature was approximately 100°C, the top temperature was controlled at approximately 65°C, and the reflux ratio was controlled at 1:5. The top product was refined 2-octanol, with a calculated yield of 71.3% and a purity of 99.2%.

[0118] Comparative Example 2

[0119] In this Comparative Example 2, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0120] Add 300 g of distillation residue to a 1000 mL reactor equipped with a mechanical stirrer, then add 400 g of an 8% (w / w) NaOH aqueous solution. Raise the reactor temperature to 75°C and stir continuously at 300 rpm at this temperature. Sample the material in the reactor every 10 minutes, separate the oil phase, and analyze the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive measurements, and allow the reactor to cool naturally to room temperature.

[0121] The materials in the reaction vessel were transferred to a separating funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 246 g, and the total aqueous phase was approximately 454 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 67.16% by weight of 2-octanol and 0.09% by weight of sodium phenolate; the aqueous phase contained 14.41% by weight of sodium phenolate, and 2-octanol was not detected.

[0122] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 72.5% and a purity of 99.3%.

[0123] Comparative Example 3

[0124] In this comparative example 3, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0125] Add 300 g of distillation residue to a 1000 mL reactor equipped with a mechanical stirrer. Then add 100 g of a 10% by weight NaCl aqueous solution and 400 g of an 8% by weight NaOH aqueous solution. Raise the reactor temperature to 75°C and stir continuously at 300 rpm at this temperature. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive detection results, and allow the reactor to cool naturally to room temperature.

[0126] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 246 g, and the total aqueous phase was approximately 554 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 67.12% by weight of 2-octanol and 0.09% by weight of sodium phenolate; the aqueous phase contained 11.88% by weight of sodium phenolate, and 2-octanol was not detected.

[0127] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 72.5% and a purity of 99.2%.

[0128] Comparative Example 4

[0129] In this comparative example 4, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0130] Add 300 g of distillation residue to a 1000 mL reactor equipped with a mechanical stirrer. Then add 100 g of a 10% by weight NaSO4 aqueous solution and 400 g of an 8% by weight NaOH aqueous solution. Raise the reactor temperature to 75°C and stir continuously at 300 rpm at this temperature. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive detection results, and allow the reactor to cool naturally to room temperature.

[0131] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 247 g, and the total aqueous phase was approximately 553 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 67.13% by weight of 2-octanol and 0.09% by weight of sodium phenolate; the aqueous phase contained 11.89% by weight of sodium phenolate, and 2-octanol was not detected.

[0132] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 72.5% and a purity of 99.3%.

[0133] As can be seen from the comparative examples 1-4 above, if the additives of this application are not added, but only NaOH or other additives such as sodium chloride and sodium sulfate commonly used in the prior art are used, the yield of 2-octanol is significantly lower than that of Examples 1-9.

[0134] Comparative Example 5

[0135] In this comparative example 5, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0136] Add 300g of distillation residue to a 1000ml reaction vessel equipped with a mechanical stirrer, then add 300g of an 8% by weight NaOH aqueous solution. Raise the temperature of the reaction vessel to 75°C and stir at 300rpm for 30 minutes at this temperature.

[0137] At this point, add 100 g of a 10% by weight Na₂S₂O₄ aqueous solution to the reactor, and continue stirring at 75°C and 300 rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive test results, and allow the reactor to cool naturally to room temperature.

[0138] The materials in the reaction vessel were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 238 g, and the total aqueous phase was approximately 462 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 69.46% by weight of 2-octanol and 0.10% by weight of sodium phenolate; the aqueous phase contained 14.21% by weight of sodium phenolate, and 2-octanol was not detected.

[0139] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 73.8% and a purity of 99.3%.

[0140] Comparative Example 6

[0141] In this comparative example 6, the same reaction vessel, mechanical stirrer, vacuum pump, distillation column, and gas and liquid chromatography equipment as in Example 1 were used.

[0142] Add 300 g of distillation residue to a 1000 mL reactor equipped with a mechanical stirrer. Then add 300 g of 8% (w / w) NaOH aqueous solution and 100 g of 10% (w / w) Na₂S₂O₄ aqueous solution. Raise the reactor temperature to 75°C and stir continuously at 300 rpm. Sample the material in the reactor every 10 minutes, separate the oil phase, and detect the 2-octanol content in the oil phase using gas chromatography. Stop stirring when the 2-octanol content no longer increases in two consecutive detection results, and allow the reactor to cool naturally to room temperature.

[0143] The materials in the reactor were transferred to a separatory funnel and allowed to stand for 30 minutes to separate the aqueous and oil phases. The total oil phase was approximately 240 g, and the total aqueous phase was approximately 460 g. The composition of the oil phase was analyzed using gas chromatography, and the composition of the aqueous phase was analyzed using liquid chromatography. The oil phase contained 68.95% by weight of 2-octanol and 0.10% by weight of sodium phenolate; the aqueous phase contained 14.28% by weight of sodium phenolate, and 2-octanol was not detected.

[0144] The oil phase material is first evacuated to a pressure of 20 mbar using a vacuum pump and dehydrated at 75°C for 60 minutes. It is then transferred to the distillation section for rectification. During rectification, the pressure in the distillation column is maintained at 5 mbar, the bottom temperature is approximately 100°C, the top temperature is controlled at approximately 65°C, and the reflux ratio is controlled at 1:5. The top product is refined 2-octanol, with a calculated yield of 73.1% and a purity of 99.3%.

[0145] As can be seen from the comparative examples 5-6 above, when the addition order of "adding the auxiliary agent first and then the alkali" is not adopted as designed in this invention, but rather "adding the alkali first and then the auxiliary agent" or "adding the alkali and the auxiliary agent at the same time", the yield of 2-octanol is significantly lower than that of Examples 1-9.

Claims

1. A method for separating a mixture comprising phenolic compounds and C6-C12 fatty alcohols, the method comprising the following steps: Step 1: Add an auxiliary agent to the mixture, wherein the auxiliary agent is selected from one or more of the following: Na2S2O3, K2S2O3, Na2S2O4; Step 2: Add an aqueous solution of an alkaline compound to the mixture; Step 3: Separate the aqueous phase and the oil phase; Step 4: Purify the oil phase.

2. The method according to claim 1, characterized in that, The C6-C12 fatty alcohol has a straight-chain structure and / or a branched-chain structure, and contains a hydroxyl group in the molecule; Based on the total weight of the mixture, the content of the C6-C12 fatty alcohol is 40-80% by weight.

3. The method according to claim 1, characterized in that, The phenolic compound is selected from one or more of the following: phenol, hydroquinone, methylphenol, ethylphenol, propylphenol, butylphenol, and dimethylphenol; Based on the total weight of the mixture, the content of the phenolic compounds is 7-40% by weight.

4. The method according to claim 1, characterized in that, The mixture is a distillation residue of sebacic acid byproduct 2-octanol. Preferably, the mixture is a distillation residue of castor oil byproduct 2-octanol produced from sebacic acid. More specifically, the mixture is obtained by hydrolyzing castor oil to produce ricinoleic acid or its salt and glycerol, then cracking ricinoleic acid or its salt in the presence of an alkaline compound and phenol to obtain crude products of 2-octanol and phenol. A portion of the 2-octanol is separated by distillation, and a distillation residue containing 2-octanol and phenol is obtained. This distillation residue is the mixture. The fatty acid or its salt is different from the sebacic acid or its salt.

5. The method according to any one of claims 1-4, characterized in that, Based on the total weight of the mixture, the mixture may optionally also contain 0-30% by weight of organic matter, which is different from the phenolic compounds and C6-C12 fatty alcohols.

6. The method according to any one of claims 1-4, characterized in that, In step one, the amount of the additive added is 0.5-10 parts by weight, based on 100 parts by weight of the mixture.

7. The method according to any one of claims 1-4, characterized in that, The alkaline compound added in step two is selected from one or more of the following: sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

8. The method according to any one of claims 1-4, characterized in that, In step two, the amount of alkaline compound added is 2-15 parts by weight, based on 100 parts by weight of the mixture. In steps one and two, the mass ratio of water to the mixture is 60:100 to 200:

100.

9. The method according to any one of claims 1-4, characterized in that, In step four, the oil phase is dehydrated and distilled.

10. The method according to any one of claims 1-4, characterized in that, In step one, after adding the additive to the mixture, the mixture is mixed for 10-200 minutes; In step two: after adding the alkaline compound to the mixture, mix for 10-60 minutes.

Images