阅读说明：本技术 一种低共熔溶剂及其制法和用于分离芳烃的应用 (Eutectic solvent, preparation method thereof and application thereof in separation of aromatic hydrocarbon ) 是由 宋奇 郑均林 金开萍 于 2019-09-30 设计创作，主要内容包括：本发明涉及石油或石油馏分中芳烃与非芳烃的分离领域,具体涉及一种低共熔溶剂及其制法和用于分离芳烃的应用。所述的低共熔溶剂包含氢键受体和氢键供体,所述的氢键受体和氢键供体的摩尔比例为1:0.3～1:22。所述氢键受体为化物中的一种或多种。本发明的技术方案调整低共熔溶剂的氢键给体和氢键受体结构,使低共熔溶剂对芳烃亲和力增加,增加该溶剂的抽提芳烃的效率,采用该低共熔溶剂可高效将非芳烃和芳烃进行分离。(The invention relates to the field of separation of aromatic hydrocarbon and non-aromatic hydrocarbon in petroleum or petroleum fractions, in particular to a eutectic solvent, a preparation method thereof and application thereof in separation of aromatic hydrocarbon. The eutectic solvent comprises a hydrogen bond acceptor and a hydrogen bond donor, and the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1: 0.3-1: 22. The hydrogen bond acceptor is)

1. A eutectic solvent, characterized in that: the eutectic solvent comprises a hydrogen bond acceptor and a hydrogen bond donor, and the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1: 0.3-1: 22 in terms of molar ratio; the hydrogen bond acceptor isOne or more of the compounds.

2. The eutectic solvent according to claim 1, characterized in that: the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1: 0.5-1: 20, and the preferred molar ratio is 1: 0.5-1: 10.

3. The eutectic solvent according to claim 1 or 2, characterized in that:

the above-mentionedThe structural general formula of the compound is as follows:

wherein the content of the first and second substances,

the R is₁、R₂、R₃、R₄Independent of each otherOne or more selected from C1-C18 alkyl, C1-C18 cycloalkyl, C1-C18 terminal alkylene, phenyl, benzyl, carboxyl alkyl and epoxy alkyl; preferably, said R is₁、R₂、R₃、R₄Independently selected from one or more of C1-C5 alkyl, C1-C5 terminal alkenyl, C1-C5 carboxylic acid alkyl and phenyl; x is halogen.

4. The eutectic solvent according to claim 3, characterized in that:

the above-mentionedThe compound is phosphorus halide; the phosphorus halide is selected from one or more of tetraphenylphosphonium halide, methyltriphenylphosphonium halide, ethyltriphenylphosphonium halide, isopropyltriphenylphosphonium halide, allyltriphenylphosphonium halide, cyclopropyltriphenylphosphonium halide, (3-benzyloxypropyl) triphenylphosphonium halide, acetontriphenylphosphonium halide, butyltriphenylphosphonium halide, 4-carboxybutyltriphenylphosphonium halide, 2- (1, 3-dioxolan-2-yl) ethyltriphenylphosphonium halide; the above-mentionedThe compound is preferably one or more of tetraphenylphosphonium halide, methyltriphenylphosphonium halide, ethyltriphenylphosphonium halide, 4-carboxybutyltriphenylphosphonium halide, butyltriphenylphosphonium halide.

5. The eutectic solvent according to claim 1 or 2, characterized in that:

the hydrogen bond donor is selected from one or more of ethylene glycol, propylene glycol, glycerol, isopropanol, butanediol, pentanediol, hexanediol, ethyl glycolate, ethyl acetate, monoethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, urea, lactic acid, propionic acid, butyric acid, malic acid, citric acid, maleic acid, leucine, glycine, glutamic acid, alanine, sorbitol, isosorbide, glucose, xylose, fructose, maltose and arabinose.

6. The eutectic solvent according to claim 5, characterized in that:

the polyethylene glycol is at least one selected from polyethylene glycol 100, polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600 and polyethylene glycol 800.

7. The eutectic solvent according to claim 1 or 2, characterized in that:

the hydrogen bond donor is selected from one or more of ethylene glycol, propylene glycol, glycerol, isopropanol, butanediol, pentanediol, ethyl glycolate, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400 and polyethylene glycol 600.

8. The method for preparing the eutectic solvent according to any one of claims 1 to 7, wherein:

and mixing and stirring the hydrogen bond acceptor and the hydrogen bond donor according to the using amount at 0-180 ℃, wherein the preferable temperature range is 20-120 ℃.

9. Use of the eutectic solvent according to any one of claims 1 to 7 or the preparation method according to claim 8 for separating aromatic hydrocarbons.

10. Use of a eutectic solvent in the separation of aromatic hydrocarbons according to claim 9, characterized in that the eutectic solvent acts as an extractant in the separation of aromatic hydrocarbons;

when the eutectic solvent is used as an extractant, the mass ratio of the eutectic solvent to the aromatic hydrocarbon-containing material flow is 0.1: 1-50: 1, preferably 0.5: 1-10: 1.

11. use of a eutectic solvent in the separation of aromatic hydrocarbons according to claim 9, characterized in that the eutectic solvent acts as an extractant in the separation of aromatic hydrocarbons;

when the eutectic solvent is used as an extractant, the extraction temperature is 5-150 ℃, and preferably 15-80 ℃.

Technical Field

The invention relates to the field of separation of aromatic hydrocarbon and non-aromatic hydrocarbon in petroleum or petroleum fractions, in particular to a eutectic solvent, a preparation method thereof and application thereof in separation of aromatic hydrocarbon.

Background

The separation of aromatic hydrocarbons from non-aromatic hydrocarbons is an important step in industrial production. In industrial practice, the reacted material flow contains non-aromatic components such as alkane, cyclane and trace alkene besides aromatic hydrocarbon, and the non-aromatic components are close to the boiling point of the aromatic hydrocarbon, so that azeotrope is easy to form, and the separation difficulty is increased. The solvent extraction and extraction rectification technology developed in the existing industry has better separation effect and is widely applied, but has the problems of high energy consumption, easy deterioration of the extraction solvent, easy corrosion of the device and the like, and has still room for improvement in the technology. In addition, the effective separation of the polycyclic aromatic hydrocarbon in the aromatic hydrocarbon has important significance for upgrading the diesel oil and improving the enterprise benefit. Therefore, the development of a novel efficient green extraction solvent and the improvement of the separation efficiency of aromatic hydrocarbon are the future development directions.

The Deep Eutectic Solvent (DES) is used as a novel green solvent, has the properties similar to those of ionic liquid, extremely low volatility and stable physical properties, and shows excellent dissolving and separating capacity for various organic mixture systems. The eutectic solvent used in the separation process is generally formed by hydrogen bond acceptor (such as organic salt choline chloride, quaternary ammonium salt, quaternary phosphonium salt and the like) and hydrogen bond donor (such as urea, hexanediol, sorbitol, butanediol, malic acid, amino acid, glucose and the like), and thus has strong polarity. Eutectic solvents can also achieve a certain specific functional property by designing different combinations of hydrogen bond acceptors and hydrogen bond donors. Compared with the traditional ionic liquid, the eutectic solvent generally has polarity, is simple to prepare, has weak corrosivity, and can be biodegraded. Due to the excellent characteristics, the eutectic solvent has the tendency of replacing the traditional organic solvent and ionic liquid for chemical separation, has good application prospect in the extraction and separation of aromatic hydrocarbon and alkane mixtures, and is greatly concerned.

In the separation process of aromatic hydrocarbon and non-aromatic hydrocarbon, the higher the extraction rate of single-stage aromatic hydrocarbon and the purity of aromatic hydrocarbon in extract liquid are, the higher the extraction efficiency is, the lower the equipment investment required in continuous operation is, and the more the industrial application prospect is. The extraction rate of single-stage aromatics extracted at present is within 10 percent, and the purity of extracted aromatics is below 50 percent, so a new system needs to be developed to improve the extraction efficiency.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention provides a eutectic solvent. In particular to a eutectic solvent and application thereof in separating aromatic hydrocarbon. The technical scheme of the invention adjusts the hydrogen bond donor and hydrogen bond acceptor structures of the eutectic solvent, so that the affinity of the eutectic solvent to the aromatic hydrocarbon is increased, and the efficiency of the solvent for extracting the aromatic hydrocarbon is increased. The non-aromatic hydrocarbon and the aromatic hydrocarbon can be efficiently separated by adopting the eutectic solvent.

The invention aims to provide a eutectic solvent, which comprises a hydrogen bond acceptor and a hydrogen bond donor, wherein the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1: 0.3-1: 22; preferably 1:0.5 to 1:20, more preferably 1:0.5 to 1:10, and still more preferably 1:2 to 1: 8.

The hydrogen bond acceptor may be one or more of a phosphonium compound;

the above-mentionedThe general structural formula of the compound can be as follows:

wherein the content of the first and second substances,

the R is₁、R₂、R₃、R₄Can be independently selected from one or more of C1-C18 alkyl, C1-C18 cycloalkyl, C1-C18 terminal alkylene, phenyl, benzyl, carboxyl alkyl and epoxy alkyl; preferably, R₁、R₂、R₃、R₄Can be one or more selected from C1-C5 alkyl, C1-C5 terminal alkenyl, C1-C5 carboxylic acid alkyl and phenyl; x is halogen.

Preferably, the hydrogen bond acceptor may be specifically a phosphonium compound containing phenyl and phenyl derivative substituents; further, the phosphonium compound may be a phosphorus halide compound; the phosphorus halide is selected from the group consisting of tetraphenylphosphonium halide, methyltriphenylphosphonium halide, ethyltriphenylphosphonium halide, isopropyltriphenylphosphonium halide, allyltriphenylphosphonium halide, cyclopropyltriphenylphosphonium halide, (3-benzyloxypropyl)One or more of triphenylphosphonium halide, acetontriphenylphosphonium halide, butyltriphenylphosphonium halide, 4-carboxybutyltriphenylphosphonium halide, 2- (1, 3-dioxolan-2-yl) ethyltriphenylphosphonium halide. The above-mentionedThe compound is preferably one or more of tetraphenylphosphonium halide, methyltriphenylphosphonium halide, ethyltriphenylphosphonium halide, 4-carboxybutyltriphenylphosphonium halide, butyltriphenylphosphonium halide. Wherein the halide is one of fluoride, chloride, bromide and iodide.

The hydrogen bond donor can be a compound containing a condensed ether structure and a polyether structure; specifically, the additive can be one or more selected from ethylene glycol, propylene glycol, glycerol, isopropanol, butanediol, pentanediol, hexanediol, ethyl glycolate, ethyl acetate, monoethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, urea, lactic acid, propionic acid, butyric acid, malic acid, citric acid, maleic acid, leucine, glycine, glutamic acid, alanine, sorbitol, isosorbide, glucose, xylose, fructose, maltose and arabinose; wherein, the polyethylene glycol can be selected from at least one of polyethylene glycol 100, polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400, polyethylene glycol 600 and polyethylene glycol 800. The hydrogen bond donor is preferably one or more of ethylene glycol, propylene glycol, glycerol, isopropanol, butanediol, pentanediol, ethyl glycolate, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol 200, polyethylene glycol 300, polyethylene glycol 400 and polyethylene glycol 600.

The invention also aims to provide a preparation method of the eutectic solvent.

The method comprises the step of mixing and stirring the hydrogen bond acceptor and the hydrogen bond donor according to the dosage at 0-180 ℃. Wherein the preferable temperature range is 20-120 ℃.

The invention also aims to provide application of the eutectic solvent in separation of aromatic hydrocarbon.

In the application method, the application method comprises the following steps,

the eutectic solvent can be used as an extractant. When the eutectic solvent is used as an extractant, the mass ratio of the eutectic solvent to the aromatic hydrocarbon-containing material flow can be 0.1: 1-50: 1, preferably 0.1: 1-20: 1, more preferably 0.5: 1-10: 1.

when the eutectic solvent is used as an extractant, the extraction temperature can be 5-150 ℃, preferably 10-100 ℃, and more preferably 15-80 ℃.

Considering that the separation target is to separate aromatic hydrocarbon from alkane, the application introduces benzene ring group into the structure of hydrogen bond acceptor when designing DES, and adjusts the original alkyl substituted organic amine or alkyl substituted phosphonium compound into phenyl substituted phosphonium compound, thereby increasing the affinity of DES and aromatic hydrocarbon based on similar compatibility principle. Meanwhile, polyether, alcohol and esters which are beneficial to aromatic hydrocarbon separation and contain ether-oxygen bonds are used as hydrogen bond donors, so that the efficiency of DES (DES) for extracting aromatic hydrocarbon is further improved. The present invention has been completed through trial and error adjustment based on the above concept. By adopting the eutectic solvent provided by the embodiment of the invention, the high-efficiency extraction of the aromatic hydrocarbon can be realized.

Detailed Description

The following detailed description of the embodiments of the present invention is provided, but it should be noted that the scope of the present invention is not limited by the embodiments, but is defined by the appended claims.

All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, including definitions, will control.

When the specification concludes with claims with the heading "known to those skilled in the art", "prior art", or the like, to derive materials, substances, methods, procedures, devices, or components, etc., it is intended that the subject matter derived from the heading encompass those conventionally used in the art at the time of filing this application, but also include those that are not currently in use, but would become known in the art to be suitable for a similar purpose.

In the context of the present specification, anything or things which are not mentioned, except where explicitly stated, are directly applicable to those known in the art without any changes. Moreover, any embodiment described herein may be freely combined with one or more other embodiments described herein, and the technical solutions or concepts resulting therefrom are considered part of the original disclosure or original disclosure of the invention, and should not be considered as new matters not disclosed or contemplated herein, unless a person skilled in the art would consider such a combination to be clearly unreasonable.

Any particular value disclosed herein (including endpoints of ranges of values) is not to be limited to the precise value of that value, but rather is to be understood to also encompass values close to the precise value, i.e., to be understood as modified by the term "about". Also, for the disclosed ranges of values, any combination between the endpoints of the ranges, between the endpoints and specific points within the ranges, and between specific points within the ranges can result in one or more new ranges of values, which should also be considered as specifically disclosed herein.

To describe the results of the present invention, in the context of the present specification, the results of the test are described in terms of "single stage aromatics extraction" (A%) and extract aromatics purity (P%). The method for calculating the single-stage aromatic extraction rate comprises the following steps: and A%, (total aromatic hydrocarbon content of raw oil-total aromatic hydrocarbon content after extraction)/total aromatic hydrocarbon content in raw oil x 100%. Higher A% values indicate better single extraction. The withdrawn aromatics purity (P%) -the aromatics content in the extracted oil/total amount of withdrawn hydrocarbons. In the invention, the raw oil is obtained by mixing tetrahydronaphthalene and tridecane, and the mass ratio of the tetrahydronaphthalene to the tridecane is 70/30.

The invention is further illustrated by the following examples.

The starting materials used in the examples are all commercially available.

[ COMPARATIVE EXAMPLE 1 ]

Weighing 41.9g of choline chloride and 55.8g of ethylene glycol according to the molar ratio of 3, mixing and stirring at 50 ℃ to obtain a uniform and transparent solution, and cooling to room temperature to obtain the eutectic solvent DES. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of the eutectic solvent DES to the raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 12% and an aromatic purity P% of 46%.

[ example 1 ]

Weighing 17.9g of methyltriphenylphosphonium bromide and 35g of tetraethylene glycol, wherein the molar ratio of the methyltriphenylphosphonium bromide to the tetraethylene glycol (hydrogen bond donor/hydrogen bond acceptor in examples 1-18) is 4, mixing and stirring at 50 ℃ to obtain a uniform and transparent solution, and cooling to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 56% and an aromatic purity P% of 96%.

[ example 2 ]

17.9g of methyltriphenylphosphonium bromide and 37.5g of triethylene glycol are weighed, the molar ratio of the methyl triphenylphosphonium bromide to the triethylene glycol is 5, the mixture is mixed and stirred at 60 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 48% and an aromatic purity P% of 91%.

[ example 3 ]

Weighing 17.9g of methyl triphenyl phosphonium bromide and 30g of polyethylene glycol 200, wherein the molar ratio of the two is 3, mixing and stirring the mixture at 60 ℃ to obtain a uniform and transparent solution, and then cooling the solution to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 30 deg.C with DES and raw oil at a mass ratio of 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 51% and an aromatic purity P% of 92%.

[ example 4 ]

Weighing 21g of tetraphenylphosphonium bromide and 2.7g of diethylene glycol with the molar ratio of 2, mixing and stirring at 60 ℃ to obtain a uniform and transparent solution, and cooling to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 46% and an aromatic purity P% of 93%.

[ example 5 ]

Weighing 16.3g of ethyl triphenyl phosphonium chloride and 150g of polyethylene glycol 600, wherein the molar ratio of the ethyl triphenyl phosphonium chloride to the polyethylene glycol 600 is 5, mixing and stirring the components at 40 ℃ to obtain a uniform and transparent solution, and then cooling the solution to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 47% and an aromatic purity P% of 92%.

[ example 6 ]

Weighing 16.1g of butyltriphenyl phosphonium bromide and 256g of polyethylene glycol 800, wherein the molar ratio of the butyltriphenyl phosphonium bromide to the polyethylene glycol 800 is 8, mixing and stirring at 120 ℃ to obtain a uniform and transparent solution, and cooling to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 60 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 54% and an aromatic purity P% of 90%.

[ example 7 ]

26.6g of 4-carboxybutyltriphenylphosphonium bromide and 27g of triethylene glycol are weighed, the molar ratio of the two is 3, the materials are mixed and stirred at 80 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 45% and an aromatic purity P% of 90%.

[ example 8 ]

21.6g of isopropyl triphenyl phosphonium iodide and 120g of polyethylene glycol 400 are weighed, the molar ratio of the isopropyl triphenyl phosphonium iodide to the polyethylene glycol 400 is 6, the mixture is mixed and stirred at the temperature of 80 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 80 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 46% and an aromatic purity P% of 94%.

[ example 9 ]

22.2g of 4-carboxybutyltriphenylphosphonium bromide and 26.1g of pentanediol were weighed, the molar ratio of the two was 5, and the mixture was stirred at 50 ℃ to obtain a uniform and transparent solution, which was then cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 25 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 46% and an aromatic purity P% of 85%.

[ example 10 ]

17.9g of methyltriphenylphosphonium bromide and 19.7g of (ethylene glycol + polyethylene glycol 200) are weighed, the molar ratio of the two is 2, the two are mixed and stirred at 25 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 15 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 59% and an aromatic purity P% of 93%.

[ example 11 ]

Weighing 22.2g of 4-carboxybutyltriphenylphosphonium bromide and 13.5g of butanediol with the molar ratio of 3, mixing and stirring at 50 ℃ to obtain a uniform and transparent solution, and cooling to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 60 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 49% and an aromatic purity P% of 89%.

[ example 12 ]

17.7g of 4-carboxybutyltriphenylphosphonium bromide and 12.5g of ethyl glycolate were weighed, the molar ratio of the two was 3, and the mixture was stirred at 50 ℃ to obtain a uniform and transparent solution, which was then cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 50 deg.C with DES and raw oil at a mass ratio of 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 57% and an aromatic purity P% of 84%.

[ example 13 ]

Weighing 17.7g of 4-carboxybutyltriphenylphosphonium bromide and 11.1g of glycerol, wherein the molar ratio of the two is 3, mixing and stirring at 60 ℃ to obtain a uniform and transparent solution, and cooling to room temperature to obtain the eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 40 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 49% and an aromatic purity P% of 96%.

[ example 14 ]

10.7g of methyltriphenylphosphonium bromide and 13.5g of triethylene glycol are weighed, the molar ratio of the two is 3, the two are mixed and stirred at 70 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 40 deg.C, wherein the mass ratio of DES to raw oil is 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 58% and an aromatic purity P% of 93%.

[ example 15 ]

10.7g of methyltriphenylphosphonium bromide and 13.5g of triethylene glycol are weighed, the molar ratio of the two is 3, the two are mixed and stirred at 70 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 40 deg.C, wherein the mass ratio of DES to raw oil is 1: 2. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 42% and an aromatic purity P% of 94%.

[ example 16 ]

10.7g of methyltriphenylphosphonium bromide and 13.5g of triethylene glycol are weighed, the molar ratio of the two is 3, the two are mixed and stirred at 70 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 30 deg.C, wherein the mass ratio of DES to raw oil is 2: 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and the lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 48% and an aromatic purity P% of 90%.

[ example 17 ]

10.7g of methyltriphenylphosphonium bromide and 13.5g of triethylene glycol are weighed, the molar ratio of the two is 3, the two are mixed and stirred at 70 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 30 deg.C, wherein the mass ratio of DES to raw oil is 6: 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 56% and an aromatic purity P% of 91%.

[ example 18 ]

10.7g of methyltriphenylphosphonium bromide and 13.5g of triethylene glycol are weighed, the molar ratio of the two is 3, the two are mixed and stirred at 70 ℃ to form a uniform and transparent solution, and then the solution is cooled to room temperature to obtain a eutectic solvent. Adding raw oil into the eutectic solvent, mixing, and extracting at 30 deg.C, wherein the mass ratio of DES to raw oil is 10: 1. Standing for 24 hours, and then dividing the mixed solution into an upper layer and a lower layer, wherein the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And then taking out a small amount of upper layer model oil and a lower layer DES layer for gas chromatography analysis, and calculating to obtain a single-stage aromatic extraction rate A% of 67% and an aromatic purity P% of 89%.

TABLE 1