CN119504417A

CN119504417A - A long-chain dibasic acid extraction process and long-chain dibasic acid product

Info

Publication number: CN119504417A
Application number: CN202411575397.7A
Authority: CN
Inventors: 杨晨; 杨希伟; 彭相潮; 周喜龙; 刘修才
Original assignee: Cathay R&D Center Co Ltd; Cathay Jinxiang Biomaterial Co Ltd; CIBT America Inc
Current assignee: Cathay R&D Center Co Ltd; Cathay Jinxiang Biomaterial Co Ltd; CIBT America Inc
Priority date: 2021-03-03
Filing date: 2021-03-03
Publication date: 2025-02-25
Also published as: CN115028530A; CN115028530B

Abstract

The invention provides an extraction process of long-chain dibasic acid, which comprises the following steps of (1) carrying out extraction treatment on a material containing the long-chain dibasic acid, wherein the extraction treatment comprises the steps of mixing the material containing the long-chain dibasic acid with an organic mixed solvent to obtain a first mixture, carrying out heat preservation and stirring treatment on the first mixture at 50-120 ℃, standing for layering, separating an extraction phase to obtain a second mixture, and (2) recovering the long-chain dibasic acid from the second mixture, wherein the organic mixed solvent comprises any two or more of an ester compound, an organic acid compound, an alcohol compound, an ether compound, a sulfoxide compound, halogenated hydrocarbon, a hydrocarbon compound and a petroleum product. Compared with the traditional process, the extraction process of the long-chain dibasic acid provided by the embodiment of the invention avoids using a large amount of acid and alkali or activated carbon, and can realize separation of the long-chain dibasic acid from most of impurities such as pigments and the like. The purity of the obtained product is high.

Description

Extraction process of long-chain dibasic acid and long-chain dibasic acid product

Technical Field

The invention relates to an extraction and refining method of long-chain dibasic acid prepared by a biological fermentation method, in particular to a solvent extraction process of long-chain dibasic acid.

Background

The long chain dicarboxylic acid (Long chain dicarboxylic acids) refers to aliphatic dicarboxylic acid (DCn for short) with more than 10 carbon atoms in a carbon chain, and the aliphatic dicarboxylic acid comprises saturated and unsaturated dicarboxylic acid, is a fine chemical product with important and wide industrial application, and is an important basic raw material for synthesizing high-grade perfume, high-performance nylon engineering plastics, high-grade nylon hot melt adhesive, high-temperature dielectrics, high-grade paint and coating, high-grade lubricating oil, cold-resistant plasticizer, resin, medicines, pesticides and the like in the chemical industry. Because the downstream products of the long-chain dicarboxylic acid have wide development potential, the demand of the long-chain dicarboxylic acid at home and abroad is continuously increased, and the market potential is extremely high.

The biological method (fermentation method) for producing long chain dibasic acid is the application of the microbiological technology which is rising in the 70 th century in the petrochemical industry field. The method is characterized in that abundant petroleum resources are used as raw materials, two methyl groups at two ends of long-chain normal alkane are respectively oxidized to carboxyl groups at normal temperature and normal pressure by utilizing the special oxidizing capability of microorganisms and the action of intracellular enzymes of the microorganisms, various long-chain dibasic acids with corresponding chain lengths are generated, and the biological method for producing the long-chain dibasic acids overcomes the defects of a simple chemical synthesis method and a vegetable oil cracking preparation method and opens up a new way for mass production of the long-chain dibasic acids. Compared with chemical synthesis methods, biological methods for producing long carbon chain dibasic acid have the indistinct advantage and are widely valued at home and abroad. The biological method not only can provide a series of long carbon chain diacid monomers from C9 to C18 and even C22, but also can produce long chain diacid (such as long chain diacid with more than C13) which cannot be produced by a chemical synthesis method, thereby greatly expanding the application of the diacid in the industrial field.

The biological method for preparing the long-chain binary acid has mild condition and simple process. However, the fermentation liquid contains a large amount of organic matters such as bacterial cells, proteins and pigments in addition to dibasic acids. The extraction and refining process is complex in process, long in period and large in equipment investment.

In patent application CN1255483A (publication day 2000-06-07), the impurity content of protein, pigment and the like in the product is reduced by using a long-chain dibasic acid single salt crystallization process, and a long-chain dibasic acid product with total acid content of more than 99% and white appearance is prepared. The method needs repeated acidification, has poor single-salt crystallization property, has engineering problems of small particles, difficult filtration, difficult washing and the like, has high operation fineness requirement, and has higher single-salt solubility and lower binary acid yield.

In patent application CN1351006A (publication No. 2002-05-29), the content of impurities such as proteins and organic pigments in the product is reduced by using a one-time acidification and one-time melt decoloration process. The adsorbent is activated carbon, activated clay, etc. The method needs to melt the crude diacid, is easy to generate Maillard reaction at high temperature, enables the reducing group to react, affects the product, has lower product yield and high melting energy consumption, and is not suitable for industrial production.

The method of using twice or more decolorization and then acidification in aqueous phase in patent application CN102010318A (publication No. 2011-04-13) can remove some pigments and improve the purity of mixed dibasic acid. The method has the defects that the process needs to decolorize the active carbon twice or more, so that the yield of the dibasic acid is low due to a great deal of loss, and the cost is high.

Disclosure of Invention

The invention provides a process for extracting long-chain dibasic acid, which comprises the following steps:

(1) Extracting the material containing long-chain dibasic acid, wherein the extracting comprises the following steps:

Mixing the long chain dibasic acid-containing material with an organic mixed solvent to obtain a first mixture, and

Carrying out heat preservation and stirring treatment on the first mixture at 50-120 ℃, then standing for layering, and separating an extraction phase to obtain a second mixture;

(2) Recovering long chain dibasic acid from the second mixture;

The organic mixed solvent comprises any two or more of an ester compound, an organic acid compound, an alcohol compound, an ether compound, a sulfoxide compound, halogenated alkane, a hydrocarbon compound and a petroleum product, and the hydrocarbon compound comprises alkane and/or aromatic hydrocarbon.

The embodiment of the invention provides a long-chain dicarboxylic acid product, wherein the content of the long-chain dicarboxylic acid is more than or equal to 80wt%, the light transmittance of the long-chain dicarboxylic acid product is more than or equal to 70%, and the solvent residue of the long-chain dicarboxylic acid product is less than 800ppm.

According to the extraction process of the long-chain dibasic acid, disclosed by the embodiment of the invention, the organic mixed solvent is used for extracting the material containing the long-chain dibasic acid, compared with the traditional process, a large amount of acid and alkali or activated carbon is avoided, and the separation of the long-chain dibasic acid from most of impurities such as pigments and the like can be realized. The purity of the obtained product is high.

Detailed Description

Exemplary embodiments that embody features and advantages of the present invention will be described in detail in the following description. It will be understood that the invention is capable of various modifications in various embodiments, all without departing from the scope of the invention, and that the description is intended to be illustrative in nature and not to be limiting.

The invention provides an extraction and refining process of long-chain dibasic acid, which comprises the following steps:

Mixing a material containing long-chain dibasic acid with an organic mixed solvent to obtain a first mixture;

Heating the first mixture to 50-120 ℃, carrying out heat preservation and stirring treatment at 50-120 ℃, then standing for layering, and separating liquid to obtain a second mixture (extract phase);

(2) Recovering the long chain dibasic acid from the second mixture.

In one embodiment, the extraction process is solid-liquid extraction.

In one embodiment, the step (1) includes heating the mixture of the long-chain dibasic acid-containing material and the organic mixed solvent to 50-120 ℃ under stirring.

In one embodiment, the mass of the organic mixed solvent in the second mixture is more than 60wt% of the mass of the organic mixed solvent raw material of the initial charge.

In one embodiment, the long chain dibasic acid is separated from the impurities by selecting a suitable extractant to form an extract phase and a raffinate phase, and subsequently separating the extract phase.

In one embodiment, the long chain diacid comprises any one or a combination of several of straight-chain azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanodioic acid, hexadecanedioic acid, heptadecanodioic acid, octadecanedioic acid, or 9-ene-octadecanedioic acid.

In one embodiment, the long-chain dicarboxylic acid-containing material comprises one or more of long-chain dicarboxylic acid crude products, residues obtained after solvent recovery of the long-chain dicarboxylic acid crude product recrystallization mother liquor, long-chain dicarboxylic acid-rich sediment recovered in a sewage treatment plant and other long-chain dicarboxylic acid-rich slurries.

In one embodiment, the crude long-chain dibasic acid is obtained by acidifying fermentation broth of long-chain dibasic acid with or without thallus separation, adding acid (such as sulfuric acid, hydrochloric acid, etc.), and filtering the crystals.

In one embodiment, the crude long chain dibasic acid contains a small amount of moisture, fermentation substrate residue, salts, thalli, pigments, and other impurities.

In one embodiment, after crystallization of the long chain diacid crude product in a solvent, a majority of the hetero acids (including hetero acids generated as by-products during fermentation, such as monoacids, diacids having different carbon chain lengths from the fermentation substrate, etc.) and a majority of other impurities (including pigments, sugars, inorganic salts, cell tissues of the fermenting microorganism, proteins, etc.) are dissolved in the solvent to separate from the main long chain diacid in the long chain diacid crude product. The recrystallization process adopts a method of dissolving the crude long-chain dibasic acid in a solvent and then cooling for crystallization and precipitation, so that part of long-chain dibasic acid is also dissolved in the solvent mother solution after the separation of crystals. And after the solvent mother liquor is subjected to distillation or rectification to recover most of the solvent, the residual bottom materials still contain long-chain dibasic acid.

The content of the long-chain dibasic acid in the material containing the long-chain dibasic acid is not particularly limited, and may be 10 to 99wt%, and further may be 10 to 85wt%, for example, 20wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 70wt%, 75wt%, 80wt%, and the like.

In one embodiment, the long chain dibasic acid-containing material may contain an amount of moisture of 50wt% or less, preferably 20wt% or less, and more preferably 10wt% or less.

In one embodiment, the organic solvent mixture comprises any two, three or more of esters, organic acids, alcohols, ethers, sulfoxides, haloalkanes, hydrocarbons, and petroleum products.

In one embodiment, the ester compounds include, but are not limited to, phosphorus oxide esters, fatty acid esters having 1 to 10 carbon atoms, and further having 1 to 4 carbon atoms, for example, one or more of bis (2-ethylhexyl) phosphate (P204), ethyl acetate, butyl acetate, and methyl acetate.

In one embodiment, the organic acid compound includes, but is not limited to, one or a combination of two or more of fatty acids having 1 to 5 carbon atoms, and further one or a combination of two or more of fatty acids having 1 to 4 carbon atoms. The fatty acid comprises fatty mono-acid and/or fatty di-acid, and further comprises any one, combination of two or more of formic acid, acetic acid, propionic acid and butyric acid.

In one embodiment, the organic acid compound has a density of 0.9 to 1.3g/cm ³, further 0.95 to 1.25g/cm ³.

In an embodiment, the alcohol compound may be one or more of monohydric alcohol and polyhydric alcohol, and the carbon atom of the alcohol compound may be 1 to 5, for example, any one, two or more of methanol, ethanol, propanol, butanol, isopropanol and ethylene glycol.

In one embodiment, the hydrocarbon compound comprises an alkane and/or an aromatic hydrocarbon, and the alkane may comprise a alkane and/or a cycloalkane.

In one embodiment, the alkane comprises, but is not limited to, straight-chain or branched alkane with 5-23 carbon atoms, cycloalkane or combination thereof, and further comprises any one, two or more of pentane, hexane, heptane, octane, decane, n-undecane, n-dodecane, n-tridecane and n-hexadecane.

In one embodiment, the number of carbon atoms in the aromatic hydrocarbon may be 6 to 10, including but not limited to any one, two or more of benzene, toluene, ethylbenzene and xylene.

In one embodiment, the petroleum product includes, for example, gasoline and/or kerosene.

In one embodiment, the sulfoxide compound includes, but is not limited to, dimethyl sulfoxide.

In one embodiment, the halogenated alkane comprises halogenated alkane with 1-3 carbon atoms, and further comprises one, two or three of chloroform, carbon tetrachloride and dichloromethane.

In one embodiment, the ether compound includes, but is not limited to, diethyl ether.

In one embodiment, the organic solvent mixture comprises at least a first solvent comprising a hydrocarbon, a petroleum product, or a combination thereof. Further, the first solvent includes one or more of alkanes having 5 to 23 carbon atoms.

In one embodiment, the organic mixed solvent comprises more than 50%, further comprises more than 80% by weight of the first solvent, further comprises 80-97% by weight of the first solvent, for example comprises 85%, 90% or 95% by weight of the first solvent.

In an embodiment, the organic mixed solvent includes a second solvent, and the second solvent includes one, two or more of an ester compound, an organic acid compound, an alcohol compound, an ether compound, a sulfoxide compound, and a halogenated alkane.

In one embodiment, the second solvent comprises one or more of P204, formic acid, acetic acid, propionic acid, butyric acid, methanol, ethanol, propanol, butanol, isopropanol, dimethyl sulfoxide, diethyl ether, petroleum ether, ethyl acetate, butyl acetate, methyl acetate, carbon tetrachloride, methylene dichloride and chloroform.

In one embodiment, the first solvent is different from the second solvent.

In one embodiment, the organic mixed solvent includes a first solvent and a second solvent, and the mass ratio of the first solvent to the second solvent may be (1-200): 1, further (1-100): 1, further (1-50): 1, further (1-30): 1, for example, 4:1, 9:1, 15:1, 25:1, 97:3, 40:1, 70:1.

In one embodiment, the organic mixed solvent comprises 80-97wt% of the first solvent and 3-20wt% of the first solvent, for example, 5wt%, 10wt% and 15wt% of the first solvent.

In one embodiment, the organic solvent blend comprises a solvent combination of 20wt% acetic acid and 80wt% kerosene, or 20wt% ethyl acetate and 80wt% kerosene, or 10wt% acetic acid, 10wt% butanol and 80wt% decane, or 20wt% n-butanol and 80wt% n-tridecane, or 20wt% formic acid and 80wt% kerosene, or 10wt% butanol and 90wt% n-tridecane, or 10wt% butyric acid and 90wt% decane, or 10wt% butyric acid and 90wt% n-dodecane, or 3% acetic acid and 97% kerosene.

In one embodiment, the long-chain dicarboxylic acid-containing material and the organic mixed solvent are mixed under heating, and after standing for phase separation, the long-chain dicarboxylic acid component and the impurity component are redistributed in an extraction phase and a raffinate phase, the long-chain dicarboxylic acid is enriched in the extraction phase, the impurities are left in the raffinate phase, and the long-chain dicarboxylic acid is separated out along with the separation of the extraction phase, so that the long-chain dicarboxylic acid is separated from the impurities.

In one embodiment, after stationary phase separation, the extract phase is located above and the raffinate phase is located below.

In one embodiment, the step (1) is to mix the material containing long chain dibasic acid with the organic mixed solvent and stir the mixture in the process of heating to 50-120 ℃.

In one embodiment, the temperature of step (1) may be 50 to 120 ℃, further 70 to 100 ℃, such as 60 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 105 ℃, 110 ℃, and the like.

In one embodiment, the extraction treatment of step (1) is performed in a sealed pressurized vessel.

In one embodiment, the multistage extraction is performed according to the condition parameters of step (1). The total yield of the multistage extraction can reach more than 95 percent.

In one embodiment, the material containing long-chain dibasic acid and the organic mixed solvent may be fully mixed in the step (1) by stirring to obtain a first mixture.

In one embodiment, the material containing long-chain dibasic acid and the organic mixed solvent are fully mixed in the step (1) by adopting a pump circulation mode to obtain a first mixture.

In one embodiment, the mass ratio of the long chain dibasic acid-containing material to the organic mixed solvent may be 1 (1-50), further 1 (2-30), such as 1:3.5, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, etc.

Further, in the step (1), heat preservation and stirring treatment are carried out after heating until extraction equilibrium is reached.

The term "extraction equilibrium" means that the content (wt%) of long chain dibasic acid in the extract phase is stable. In other words, even if the heat preservation and stirring treatment time is prolonged, the content of long-chain dibasic acid in the extract phase obtained after standing and layering is not increased any more, and the extraction equilibrium state is reached.

In one embodiment, the time of the heat-preserving stirring treatment in the step (1) is 0.25 to 12 hours, more preferably 0.5 to 12 hours, still more preferably 1 to 9 hours, still more preferably 1 to 6 hours, for example, 65 minutes, 100 minutes, 120 minutes, 150 minutes, 240 minutes, 300 minutes, etc.

In step (1) of one embodiment, the stationary treatment is performed after the heat-insulating stirring treatment to obtain a stable extract phase, and then the extract phase is separated.

The rest time is sufficient to form a stable extract phase and a raffinate phase.

In step (1) of one embodiment, the extract phase is separated after standing and layering until the solids content in the extract phase is no longer changing.

In one embodiment, the extraction phase layer (second mixture) containing most of the target product can be separated from the raffinate phase layer containing most of the impurity by using operations such as standing separation and centrifugal separation.

In one embodiment, the second mixture is in a clear state.

In one embodiment, the second mixture has a turbidity of 6 or less, more preferably 4 or less, and still more preferably 3 or less.

In one embodiment, the method may further comprise filtering the insoluble material in the second mixture to remove the insoluble material, and recovering the long chain dibasic acid in the second mixture.

In one embodiment, the method of recovering long chain dibasic acid from the second mixture comprises:

And cooling the second mixture, separating out solids, performing solid-liquid separation, washing and drying to obtain the long-chain dibasic acid (the first long-chain dibasic acid product). The temperature of the second mixture at the cooling end point is less than or equal to 50 ℃, further 5-50 ℃, and further 10-30 ℃.

In one embodiment, the cooling process of the second mixture includes:

a. Cooling the second mixture system to a turbidity of 6-15 NTU, then preserving heat for more than 0.25h, further 0.25-5 h, further 0.25-3 h, further 0.25-2 h, and

B. The second mixture system is cooled to the end temperature, and the rate of cooling to the end temperature may be 0.5 to 20 ℃ per hour, further 0.5 to 10 ℃ per hour, for example 1 ℃ per hour, 6 ℃ per hour, 15 ℃ per hour, 18 ℃ per hour.

Typically, the turbidity of the system reaches above 100NTU after the second mixture is cooled to the final point temperature.

In one embodiment, the method for recovering long chain diacid from the second mixture comprises directly evaporating the second mixture to remove solvent to obtain long chain diacid. In addition, the solvent removed by evaporation or the solvent mother solution after crystallization can be recycled.

In one embodiment, the process for extracting and refining long-chain dibasic acid further comprises a step (3), wherein the step (3) comprises refining the first long-chain dibasic acid product obtained in the step (2). The refining treatment comprises any one or a combination of the following two modes:

In the first mode, solvent crystallization refining can be adopted, namely, the first long-chain binary acid product is crystallized after being dissolved by a solvent. Further, after the first long-chain dicarboxylic acid product is dissolved by a solvent, active carbon is adopted for decolorization and filtration, then cooling crystallization, filtration, washing and drying are carried out, and the long-chain dicarboxylic acid product is obtained.

In the second mode, purification is carried out by distillation under reduced pressure. The number of distillation stages depends on the purity required for the product, and multi-stage distillation can be used to increase the product purity. The reduced pressure distillation includes high vacuum distillation or molecular distillation.

When the purification treatment is performed by using a combination of the first and second embodiments, the order of use of the first and second embodiments is not particularly limited. For example, the crystallization and the high vacuum distillation or molecular distillation forms may be combined and refined, either by crystallization followed by distillation or by crystallization after distillation.

Further, in the first mode, the end temperature of the cooling crystallization is 20 to 45 ℃, and further 20 to 35 ℃.

Further, in the first mode (a), the solvent includes one or more of an alcohol compound, an organic acid compound, an ester compound, a ketone compound, and an alkane compound, the organic acid compound may be an organic monoacid having 1 to 4 carbon atoms, such as formic acid and acetic acid, the alcohol compound may be a monohydric alcohol or a dihydric alcohol having 1 to 4 carbon atoms, such as methanol, ethanol, isopropanol, and n-butanol, and the ester compound includes ethyl acetate and butyl acetate. The ketone comprises acetone and butanone, and the alkane compound comprises straight-chain or branched alkane and cycloalkane with the carbon number of 5-23. The concentration of the above substances in the solvent is 90wt% or more, for example, the solvent is a mixture of acetic acid having an acetic acid content of 90wt% or more and water.

Further, in the first mode (a), the mass ratio of the long-chain dibasic acid to the solvent is 1:1-15, and further 1:1-10. In the dissolving process, heating can be performed to promote dissolution, and the heating temperature is 50-120 ℃, and further 60-100 ℃.

Further, in the first mode, the amount of the activated carbon used in the activated carbon decoloring treatment is 0.1-5 wt%, further 0.5-4 wt%, and further 1-4 wt% of the system mass. The temperature of the activated carbon decoloring treatment is 50-120 ℃, and further 60-100 ℃.

Further, in the second mode, the pressure of the main evaporator of the molecular distillation may be 0.1 to 30Pa, and may be further 0.1 to 20Pa, for example, 1Pa, 2Pa, 5Pa, 6Pa, 8Pa, 10Pa, 12Pa, 16Pa, 18Pa, 20Pa, 25Pa. The evaporation surface temperature of the main evaporator of the molecular distillation is 130-250 ℃, and further can be 130-230 ℃, such as 140 ℃, 150 ℃, 160 ℃, 180 ℃, 200 ℃, 210 ℃, 220 ℃ and 240 ℃. The temperature of the condensation surface of the main evaporator of the molecular distillation is 110-160 ℃, and further can be 110-150 ℃, such as 120 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃ and 155 ℃. The temperature of the feed inlet of the molecular distillation is 115-160 ℃, and further can be 120-150 ℃, such as 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃ and 155 ℃.

Further, in the second aspect, the theoretical plate number of the rectifying column used for the high vacuum rectification may be 8 to 24, and further may be 9 to 18, for example, 10, 12, 18, 24. Preferably, a packed column is used, and the packing may be any packing commonly used in the art, such as corrugated wire mesh packing. The top pressure of the rectifying tower used for the high vacuum rectification can be 1-100 Pa, and further can be 25-80 Pa, for example, 20Pa, 30Pa, 60Pa, 70Pa and 80Pa. The top temperature of the rectifying tower used for the high vacuum rectification may be 160 to 250 ℃, and further may be 180 to 250 ℃, for example 170 ℃,185 ℃, 190 ℃, 195 ℃, 200 ℃, 210 ℃, 220 ℃, 225 ℃, 228 ℃, 230 ℃, 232 ℃, 235 ℃, 238 ℃, 240 ℃ and 245 ℃. The temperature of the rectifying tower used for the high vacuum rectification can be 180-270 ℃, and further 200-270 ℃, such as 190 ℃, 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃, 243 ℃, 245 ℃,248 ℃, 250 ℃, 255 ℃, 260 ℃ and 265 ℃. The reflux ratio of the high vacuum rectification may be (1-10): 1, and further may be (2-8): 1, for example, 1:1, 2:1, 5:1, 6:1, 8:1, 10:1.

In one embodiment, the yield of long chain dibasic acid may be increased by multiple solvent-mixed extractions (i.e., multiple extractions).

The embodiment of the invention also provides a long-chain diacid product, wherein the content of the long-chain diacid is more than or equal to 80wt%, the light transmittance is more than or equal to 70%, the content of the monoacid is less than or equal to 1wt%, and the solvent residue is less than 800ppm.

The extraction process of the embodiment of the invention can effectively remove the impurities such as thalli, pigment, protein and the like by adopting a simple separation mode, and overcomes the defects of large investment, high running cost and the like caused by the fact that a large amount of ceramic membrane ultrafiltration or activated carbon decolorization and filtration are required to remove thalli, pigment substances and the like in the traditional extraction and separation method.

According to the extraction process of the embodiment of the invention, the organic mixed solvent can be recycled.

The extraction process of the embodiment of the invention has high purity of the extracted long-chain binary acid product, and can be widely applied to hot melt adhesives, rust inhibitors, spices, paints, lubricating oil and nylon polymerization raw materials.

The extraction process of the embodiment of the invention can separate effective long-chain dibasic acid components from complex components, and is favorable for further refining.

The extraction process of the embodiment of the invention can recycle the adopted solvent, does not generate waste salt, generates little waste water, and has good separation effect on impurities such as pigment, inorganic salt and the like.

Hereinafter, the process for extracting long-chain dibasic acid according to an embodiment of the present invention will be described further with reference to specific examples. The analysis and detection method comprises the following steps:

1. And (3) detecting by using a dibasic acid gas chromatography:

Standard diacid samples were used as controls, reference GB5413.27-2010 for determination of fatty acids in infant food and dairy products.

2. Light transmittance measurement:

mixing the product with sodium hydroxide solution to obtain long-chain dibasic acid sodium salt aqueous solution with mass concentration of 5%, and then UV detecting light transmittance at 440 nm.

3. Turbidity test of the second mixture (extract phase) the extract phase was clear before cooling, and crystals precipitated during cooling resulted in an increase in turbidity of the system. Turbidity (Unit: NTU) test method-using nephelometry, test method reference U.S. EPA 180.1.

4. The yield of the long-chain dibasic acid is calculated by the method that the yield (%) = (mass (kg) of long-chain dibasic acid product x long-chain dibasic acid content (%))/(mass (kg) of bottom material x mass content (%) of long-chain dibasic acid in bottom material) x 100%.

Preparative example 1

Referring to a fermentation method of an example 4 of patent document CN1570124A, a dodecandioic acid fermentation liquid is obtained, the dodecandioic acid fermentation liquid is firstly subjected to membrane filtration and sterilization to obtain a filtrate, 3 weight percent of active carbon of the mass of the dodecandioic acid in the filtrate is added for decoloring at 60 ℃, and the decolored filtrate is subjected to acidification, precipitation, filtration and drying to obtain a dodecandioic acid crude product (purity is 98.2 weight percent).

Crude dodecadiacid was purified according to example 30 of CN1570124 a. And (3) recovering the solvent from the solvent mother solution after filtering the crystals in the refining process by a rectifying tower, wherein the remainder is the bottom material. (wherein the total content of 9-18 carbon dibasic acids is 76.5 wt%).

PREPARATION EXAMPLE 2

A tridecanedioic acid fermentation broth was obtained by the fermentation method of example 5 of patent document CN 1570124A. The tridecanedioic acid fermentation broth is added with sulfuric acid to be acidified to pH2.7, and the tridecanedioic acid crude product (purity 85 wt%) is obtained after filtration.

Example 30, with reference to CN1570124a, employs solvent refining. And recovering the solvent from the solvent mother liquor after filtering the crystals in the solvent refining process by a rectifying tower, wherein the remainder is tower bottom material (the content of 9-18 carbon dibasic acid is 55.2 wt%).

Example 1

The raw materials used are the bottoms prepared according to the method of preparation example 1.

(1) Adding a mixed solvent prepared according to the mass ratio of 20% acetic acid and 80% kerosene into the bottom material according to the mass ratio of the bottom material to the solvent according to the mass ratio of 1:4, heating to 90 ℃, standing and layering after heat preservation and stirring for 75 minutes, and separating an extraction phase to obtain a second mixture (turbidity is 0.81 NTU).

(2) And cooling the second mixture to 26 ℃, filtering, washing, and drying at 95 ℃ to obtain the first long-chain dibasic acid product.

The process of cooling the second mixture to 26 ℃ comprises the steps of firstly cooling the second mixture to 8.0NTU in turbidity of the system, then preserving heat for 0.5h, and then cooling the second mixture to 26 ℃ at a rate of 5 ℃ per hour.

After the tower bottom material is treated in the steps (1) - (2), the yield of the long-chain dibasic acid is 53%.

(3) The first long chain diacid product was added to a 3 times weight of a mixture of 95wt% (acetic acid content) acetic acid and water and dissolved by heating at 95 ℃. Adding 2.5wt% of active carbon into the solution, decoloring at 95 ℃ for 30min, filtering, cooling the obtained filtrate to 30 ℃ for crystallization, then carrying out solid-liquid separation, washing the obtained solid with water, and drying to obtain the long-chain binary acid product.

The obtained product was subjected to tests of purity, light transmittance, impurity content and the like, and the relevant results are shown in table 1.

And (3) sequentially carrying out multistage extraction on the raffinate obtained in the step (2), wherein the total extraction yield reaches more than 95%.

Example 2

The starting material used was a bottom material prepared according to the method of preparation 1.

(1) Adding a mixed solvent prepared according to the mass ratio of 20% ethyl acetate and 80% kerosene into the bottom material according to the mass ratio of the bottom material to the solvent of 1:4, heating to 90 ℃, standing and layering after heat preservation and stirring for 65 minutes, and separating an extraction phase to obtain a second mixture (turbidity is 1.0 NTU).

(2) And cooling the second mixture to 30 ℃, filtering, washing, and drying at 95 ℃ to obtain the first long-chain dibasic acid product.

Wherein the second mixture is cooled to 30 ℃ as follows:

firstly, the second mixture is cooled to the turbidity of 8.0NTU, then is insulated for 0.5h, and then is cooled to 30 ℃ at the speed of 5 ℃ per hour.

(3) The first long chain diacid product was added to a 4 times weight of a mixture of 95wt% (acetic acid content) acetic acid and water and dissolved by heating at 95 ℃. Adding 1.8wt% of active carbon into the solution, decoloring at 95 ℃ for 30min, filtering, cooling the obtained filtrate to 30 ℃ for crystallization, then carrying out solid-liquid separation, washing the obtained solid with water, and drying to obtain the long-chain binary acid product.

Example 3

(1) Adding a mixed solvent prepared according to the mass ratio of 20% butanol and 80% n-tridecane into the bottom material according to the mass ratio of the bottom material to the solvent of 1:6, heating to 90 ℃, standing and layering after heat preservation and stirring for 100 minutes, and separating an extraction phase to obtain a second mixture (turbidity is 1.1 NTU).

Wherein the second mixture is cooled to 30 ℃ as follows:

Firstly, the second mixture is cooled to the turbidity of 8.0NTU, then is insulated for 0.5h, and then is cooled to 40 ℃ at the speed of 5 ℃ per hour.

Example 4

(1) Adding a mixed solvent prepared according to the mass ratio of 20% acetic acid and 80% kerosene into the bottom material according to the mass ratio of the bottom material to the solvent of 1:6, heating to 90 ℃, standing and layering after stirring for 100 minutes under heat preservation, and separating an extraction phase to obtain a second mixture (turbidity is 0.82 NTU).

Wherein the second mixture is cooled to 30 ℃ as follows:

firstly, the second mixture is cooled to the turbidity of 8.0NTU, then is insulated for 0.8h, and then is cooled to 30 ℃ at the speed of 7 ℃ per hour.

(3) And (3) carrying out molecular distillation on the first long-chain binary acid product, wherein the pressure of a main evaporator of a molecular distillation device is 18Pa, the temperature of an evaporation surface of the main evaporator is 160 ℃, the temperature of a condensation surface of the main evaporator is 128 ℃, the temperature of a feed inlet is 130 ℃, and collecting fractions to obtain the long-chain binary acid product.

Example 5

(1) Adding a mixed solvent prepared according to the mass ratio of 10% butyric acid and 90% n-dodecane into the bottom material according to the mass ratio of the bottom material to the solvent of 1:10, heating to 90 ℃, standing and layering after heat preservation and stirring for 100 minutes, and separating an extraction phase to obtain a second mixture (turbidity is 0.15 NTU).

Wherein the second mixture is cooled to 30 ℃ as follows:

Example 6

The starting material used was a bottom material prepared according to the method of preparation 2.

(1) Adding a mixed solvent prepared according to the mass ratio of 10% butyric acid and 90% n-dodecane into the bottom material according to the mass ratio of the bottom material to the solvent of 1:10, heating to 90 ℃, keeping the temperature and stirring for 100 minutes, standing for layering, and separating an extraction phase to obtain a second mixture (turbidity is 0.14 NTU).

Wherein the second mixture is cooled to 30 ℃ as follows:

Firstly, the second mixture is cooled to the turbidity of 8.0NTU, then is insulated for 0.5h, and then is cooled to 30 ℃ at the speed of 8 ℃ per hour.

Example 7

(1) Adding a mixed solvent prepared according to the mass ratio of 10% butyric acid and 90% n-dodecane into the bottom material according to the mass ratio of the bottom material to the solvent of 1:8, heating to 65 ℃, standing and layering after heat preservation and stirring for 120 minutes, and separating an extraction phase to obtain a second mixture (turbidity is 0.16 NTU).

(2) And cooling the second mixture to 32 ℃, filtering, washing, and drying at 95 ℃ to obtain the first long-chain dibasic acid product.

Wherein the second mixture is cooled to 32 ℃ as follows:

firstly, the second mixture is cooled to the turbidity of 8.0NTU, then is insulated for 0.5h, and then is cooled to 32 ℃ at the speed of 5 ℃ per hour.

Example 8

(2) And directly cooling the second mixture to 35 ℃ at a rate of 12 ℃ per hour, filtering, washing and drying at 95 ℃ to obtain the first long-chain dibasic acid product.

(3) And (3) carrying out high-vacuum rectification on the first long-chain dicarboxylic acid product, wherein the tower plate number of a rectifying tower is 12, the tower top pressure is 60Pa, the tower top temperature is 238 ℃, the tower bottom temperature is 250 ℃, the reflux ratio is 5:1, collecting fractions, and cooling to obtain the long-chain dicarboxylic acid product.

Example 9

The raw material adopted is the crude product of the dodecadiacid prepared according to the method of preparation example 1.

(1) Adding a mixed solvent prepared according to the mass ratio of 10% butyric acid and 90% n-pentane into the crude dodecadiacid according to the mass ratio of the crude dodecadiacid to the solvent of 1:3, heating to 90 ℃, keeping the temperature and stirring for 100 minutes, standing and layering, and separating an extraction phase to obtain a second mixture (turbidity is 0.25 NTU).

(2) And cooling the second mixture to 35 ℃, filtering, washing, and drying at 95 ℃ to obtain the first dodecadiacid product.

Wherein the second mixture is cooled to 35 ℃ as follows:

firstly, the second mixture is cooled to the turbidity of 10.0NTU, then is insulated for 0.5h, and then is cooled to 35 ℃ at the speed of 15 ℃ per hour.

(3) And (3) carrying out high-vacuum rectification on the first dodecadiacid product, wherein the tower plate number of a rectifying tower is 12, the tower top pressure is 60Pa, the tower top temperature is 238 ℃, the tower bottom temperature is 250 ℃, the reflux ratio is 5:1, collecting fractions, and cooling to obtain the dodecadiacid product.

Example 10

(1) Adding a mixed solvent prepared according to the mass ratio of 10% acetic acid, 10% butanol and 80% decane into the crude dodecadiacid according to the mass ratio of the crude dodecadiacid to the solvent of 1:6, heating to 90 ℃, keeping the temperature, stirring for 100 minutes, standing for layering, and separating an extract phase to obtain a second mixture (turbidity is 0.37 NTU).

(2) And cooling the second mixture to 30 ℃, filtering, and drying at 95 ℃ to obtain the first dodecadiacid product.

Wherein the second mixture is cooled to 30 ℃ as follows:

firstly, the second mixture is cooled to the turbidity of 8.0NTU, then is insulated for 1.5h, and then is cooled to 30 ℃ at the speed of 15 ℃ per hour.

(3) And (3) carrying out high-vacuum rectification on the dodecadiacid, wherein the tower plate number of a rectifying tower is 12, the tower top pressure is 60Pa, the tower top temperature is 238 ℃, the tower bottom temperature is 250 ℃, the reflux ratio is 5:1, collecting fractions, and cooling to obtain the dodecadiacid product.

Example 11

(1) Adding a mixed solvent prepared according to the mass ratio of 3% acetic acid and 97% kerosene into the crude dodecadiacid according to the mass ratio of the crude dodecadiacid to the solvent of 1:20, heating to 90 ℃, keeping the temperature and stirring for 100 minutes, standing and layering, and separating an extraction phase to obtain a second mixture (turbidity is 0.18 NTU).

Wherein, the cooling process of cooling the second mixture extract phase to 35 ℃ is as follows:

Firstly, the second mixture is cooled to the turbidity of 7.5NTU, then is insulated for 2 hours, and then is cooled to 35 ℃ at the speed of 15 ℃ per hour.

(3) The dodecadibasic acid was added to a mixture of 95wt% (acetic acid content) of acetic acid and water in an amount 3 times by weight, and dissolved by heating at 95 ℃. Adding 2.5wt% of active carbon into the solution, decoloring at 95 ℃ for 30min, filtering, cooling the obtained filtrate to 30 ℃ for crystallization, then carrying out solid-liquid separation, washing the obtained solid with water, and drying to obtain the dodecandioic acid product.

Example 12

(1) Adding a mixed solvent prepared according to the mass ratio of 10% butyric acid and 90% n-pentane into the bottom material according to the mass ratio of the bottom material to the solvent of 1:4, heating to 80 ℃, standing and layering after heat preservation and stirring for 75 minutes, and separating an extraction phase to obtain a second mixture (turbidity is 0.24 NTU).

The process of cooling the second mixture to 26 ℃ comprises the steps of firstly cooling the second mixture to the system turbidity of 11NTU, then preserving heat for 0.5h, and then cooling to 26 ℃ at the speed of 7 ℃ per hour.

(3) The first long chain diacid product was added to a 3 times weight of a mixture of 95wt% (acetic acid content) acetic acid and water and dissolved by heating at 95 ℃. Adding 2.5wt% of active carbon into the solution, decoloring at 95 ℃ for 35min, filtering, cooling the obtained filtrate to 28 ℃ for crystallization, then carrying out solid-liquid separation, washing the obtained solid with water, and drying to obtain the long-chain binary acid product.

Comparative example 1

(1) Adding kerosene into the bottom material according to the mass ratio of the bottom material to the kerosene of 1:4, heating to 90 ℃, keeping the temperature and stirring for 75 minutes, standing and layering, and separating an extraction phase to obtain a second mixture (turbidity is 0.52 NTU).

The process of cooling the second mixture to 26 ℃ comprises the steps of firstly cooling the second mixture to 8.0 of turbidity of the system, then preserving heat for 0.5h, and then cooling to 26 ℃ at a rate of 5 ℃ per hour.

After the tower bottom material is treated in the steps (1) - (2), the yield of the long-chain dibasic acid is 1.4 percent.

Comparative example 2

(1) Adding acetic acid into the bottom material according to the mass ratio of the bottom material to the acetic acid of 1:4, heating to 90 ℃, keeping the temperature and stirring for 75 minutes, standing without obvious delamination, and filtering to remove insoluble substances to obtain a second mixture (dark brown with turbidity of >50 NTU).

The process of cooling the second mixture to 26 ℃ is that firstly, the second mixture is cooled to the turbidity of 8.0 of the system, then the second mixture is insulated for 0.5h, and then the second mixture is cooled to 15 ℃ at the speed of 5 ℃ per hour.

The yield of the long-chain dibasic acid after the tower bottom materials are treated in the steps (1) - (2) is 16 percent through calculation.

Preparation of hot melt adhesive

The long-chain binary acid products obtained in each example and comparative example are used for preparing hot melt adhesives, and the preparation process is as follows:

(1) Under nitrogen atmosphere, 260g of pentanediamine, 200g of adipic acid, 322g of long-chain dibasic acid product, 65g of isophthalic acid, 250g of caprolactam and water were uniformly mixed to prepare an 80wt% salt solution having a pH of 7.89 at a concentration of 10 wt%.

(2) Filtering and heating the salt solution obtained in the step (1), increasing the pressure in a reaction system to 1.7MPa, exhausting, maintaining the pressure, reducing the pressure in the reaction system to 0.01MPa (gauge pressure) when the pressure is over 244 ℃ and maintaining the pressure for 20min, maintaining the temperature of the reaction system to 264 ℃ after the pressure reduction is over-0.09 MPa, maintaining the vacuum time for 22min and maintaining the temperature after the vacuum to 269 ℃ to obtain the polyamide hot melt adhesive melt.

(3) And (3) melting and discharging, granulating under water, wherein the water temperature of cooling water is 20 ℃, and the cooling time is 35min, so as to obtain the polyamide hot melt adhesive resin slice.

The hot melt adhesive resin chips were subjected to peel strength test and yellow index test. Test method for peel strength referring to test standard FZ/T80007.1-2006 using adhesive liner peel strength, test for yellowness index (YI value) referring to ASTM D6290. See table 1 for specific test results.

TABLE 1

As can be seen from Table 1, the mixed solvent used in the invention has good extraction effect on long-chain binary acid, has higher extraction efficiency, and simultaneously, the extraction system can avoid impurities such as pigment, mycoprotein and the like from entering an extraction phase, thereby avoiding the defects of large investment, high running cost and the like caused by the traditional extraction and separation method that a large amount of ceramic membrane ultrafiltration or activated carbon decolorization or filtration is required to remove the thallus and pigment substances and the like. The long-chain binary acid product has wide application field and the prepared hot melt adhesive product has good performance.

Unless otherwise defined, all terms used herein are intended to have the meanings commonly understood by those skilled in the art.

The described embodiments of the present invention are intended to be illustrative only and not to limit the scope of the invention, and various other alternatives, modifications, and improvements may be made by those skilled in the art within the scope of the invention, and therefore the invention is not limited to the above embodiments but only by the claims.

Claims

1. A process for extracting a long-chain dibasic acid, comprising the following steps:

(1) extracting a material containing a long-chain dibasic acid; the extraction process comprising:

Mixing the material containing the long-chain dibasic acid with an organic mixed solvent to obtain a first mixture; and

The first mixture is subjected to a heat preservation and stirring treatment at 50 to 120° C., and then allowed to stand for stratification, and the extract phase is separated to obtain a second mixture;

(2) recovering the long-chain dibasic acid from the second mixture;

Wherein, the organic mixed solvent comprises a first solvent and a second solvent, the first solvent is selected from hydrocarbon compounds, petroleum products or a combination thereof, and the second solvent is selected from one, two or more of ester compounds, organic acid compounds and alcohol compounds;

The mass ratio of the material containing the long-chain dibasic acid to the organic mixed solvent is 1:(1-50).

2. The extraction process according to claim 1, wherein:

The ester compounds include phosphorus-oxygen ester compounds, fatty acid ester compounds with 1 to 10 carbon atoms, and further include one or a combination of two or more of di(2-ethylhexyl) phosphate, ethyl acetate, butyl acetate, and methyl acetate;

And/or, the organic acid compound includes one or a combination of two or more fatty acids having 1 to 5 carbon atoms;

And/or, the alcohol compound includes monohydric alcohol and/or polyhydric alcohol having 1 to 5 carbon atoms, and further includes any one of methanol, ethanol, propanol, butanol, isopropanol, and ethylene glycol, or a combination of two or more thereof;

And/or, the hydrocarbon compound includes one, two or more of linear or branched alkanes, cycloalkanes and aromatic hydrocarbons with carbon atoms of 5 to 23; further includes one, two or more of pentane, hexane, heptane, octane, decane, n-undecane, n-tridecane, n-dodecane, n-hexadecane, benzene, toluene and ethylbenzene;

And/or, the petroleum product includes gasoline and/or kerosene.

3. The extraction process according to claim 1, wherein the mass ratio of the material containing the long-chain dibasic acid to the organic mixed solvent is 1:(2-30);

And/or, the water content of the material containing the long-chain dibasic acid is ≤50wt%, further ≤20wt%, further ≤10wt%;

And/or, the content of the long-chain dibasic acid in the material containing the long-chain dibasic acid is 10 to 99 wt %;

And/or, the insulation temperature of step (1) is 70-100° C.;

And/or, the time of the heat preservation and stirring treatment in step (1) is 0.25 to 12 hours, further 0.5 to 12 hours.

4. The extraction process according to claim 1, wherein the organic mixed solvent contains more than 80 wt% of the first solvent;

Furthermore, the organic mixed solvent comprises 80 to 97 wt % of the first solvent and 3 to 20 wt % of the second solvent.

5. The extraction process according to claim 1, wherein the step (2) further comprises filtering the second mixture to remove insoluble matter therein, and then recovering the long-chain dibasic acid in the obtained filtrate.

6. The extraction process according to claim 1 or 5, wherein the step (2) comprises: cooling the second mixture to precipitate solids, solid-liquid separation, washing, and drying to obtain a long-chain dibasic acid, and the terminal temperature of the cooling is less than or equal to 50°C;

Alternatively, the second mixture is subjected to evaporation treatment to remove the solvent to obtain the long-chain dibasic acid.

7. The extraction process according to claim 6, wherein the cooling process of the second mixture comprises:

a. Cooling the second mixture to a turbidity of 6 to 15 NTU and then keeping warm for more than 0.25 h;

b. Continue cooling the second mixture to the end temperature.

8. The extraction process according to claim 7, wherein in step a, the holding time is 0.25 to 5 h, further 0.25 to 3 h, further 0.25 to 2 h;

And/or, in step b, the cooling rate is 0.5 to 20°C/h, further 0.5 to 10°C/h.

9. The extraction process according to claim 6 or 7, wherein the turbidity of the system reaches above 100 NTU after the second mixture is cooled to the end temperature.

10 . The extraction process according to claim 1 , 6 or 7 , wherein the turbidity of the second mixture is 6 or less, further 4 or less, further 3 or less.

11. The extraction process according to claim 1, further comprising step (3): subjecting the first long-chain dibasic acid product obtained in step (2) to a refining treatment, wherein the refining treatment comprises any one of the following methods or a combination of two methods:

Method (I): dissolving the first long-chain dibasic acid product in a solvent and then crystallizing;

Method (two): the first long-chain dibasic acid product is refined by vacuum distillation.

12. The extraction process according to claim 11, in method (1), the first long-chain dibasic acid product is dissolved in a solvent, decolorized and filtered using activated carbon, then cooled and crystallized, filtered, washed, and dried to obtain a long-chain dibasic acid product.

13. The extraction process according to claim 11 or 12, wherein in method (1), the solvent comprises one or more of alcohol compounds, organic acid compounds, ester compounds, ketone compounds, and alkane compounds;

And/or, the mass ratio of the long-chain dibasic acid to the solvent is 1:1-15, further 1:1-10.

14. The extraction process according to claim 13, wherein the organic acid compound is an organic monobasic acid having 1 to 4 carbon atoms, such as formic acid or acetic acid;

and/or, the alcohol compound is a monohydric alcohol or a dihydric alcohol having 1 to 4 carbon atoms, such as methanol, ethanol, isopropanol and n-butanol;

And/or, the ester compound includes ethyl acetate and butyl acetate;

And/or, the ketones include acetone and butanone;

And/or, the alkane compounds include straight-chain or branched alkanes and cycloalkanes having 5 to 23 carbon atoms.

15. The extraction process according to claim 12,

During the dissolution process with the solvent, heating is performed to promote dissolution, and the heating temperature is 50 to 120° C., and further 60 to 100° C.;

And/or, the amount of activated carbon used in the activated carbon decolorization process is 0.1wt% to 5wt% of the system mass;

and/or, the temperature of the activated carbon decolorization treatment is 50 to 120° C.;

And/or, the terminal temperature of the temperature drop crystallization is 20-45°C.

16. The extraction process according to claim 11, in method (ii), the reduced pressure distillation includes high vacuum distillation or molecular distillation.

17. The extraction process according to claim 16, wherein the pressure of the main evaporator of the molecular distillation is 0.1-30 Pa;

and/or, the evaporation surface temperature of the main evaporator of molecular distillation is 130-250° C.;

and/or, the condensing surface temperature of the main evaporator of molecular distillation is 110 to 160°C;

And/or, the feed inlet temperature of the molecular distillation is 115-160°C.

18. The extraction process according to claim 16, wherein the distillation tower used in the high vacuum distillation has a theoretical plate number of 8 to 24;

And/or, the top pressure of the distillation tower is 1 to 100 Pa;

and/or, the top temperature of the distillation tower is 160-250° C.;

and/or, the bottom temperature of the distillation tower is 180-270° C.;

And/or, the reflux ratio is (1-10):1.

19. The extraction process according to claim 1, wherein the material containing long-chain dibasic acid comprises one or more of crude long-chain dibasic acid, residue after solvent recovery from recrystallization mother liquor of crude long-chain dibasic acid, precipitate rich in long-chain dibasic acid recovered from a sewage treatment plant, and slurry of other long-chain dibasic acids;

And/or, the long-chain dibasic acid includes any one or more combinations of azelaic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedicarboxylic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedicarboxylic acid or 9-ene-octadecanedicarboxylic acid.

20. The extraction process according to claim 1, wherein the organic mixed solvent comprises a first solvent and a second solvent, the first solvent is selected from hydrocarbon compounds, petroleum products or a combination thereof, and the second solvent is selected from organic acid compounds;

The hydrocarbon compound includes one, two or more of linear or branched alkanes, cycloalkanes and aromatic hydrocarbons with carbon atoms of 5 to 23, and further includes one, two or more of pentane, hexane, heptane, octane, decane, n-undecane, n-tridecane, n-dodecane, n-hexadecane, benzene, toluene and ethylbenzene;

The petroleum products include gasoline and/or kerosene;

The organic acid compound includes one or a combination of two or more fatty acids having 1 to 5 carbon atoms.

21. According to the extraction process of claim 2 or 20, the organic acid compound includes one or a combination of two or more of fatty acids with 1 to 4 carbon atoms, and further, the fatty acid includes fatty monoacids and/or fatty diacids, and further includes any one or a combination of two or more of formic acid, acetic acid, propionic acid, and butyric acid.

22. A long-chain dibasic acid product, wherein the long-chain dibasic acid content is ≥80wt%, and/or the light transmittance of the long-chain dibasic acid product is ≥70%, and/or the solvent residue of the long-chain dibasic acid product is <800ppm.