阅读说明：本技术 一种用于分离多环芳烃的低共熔溶剂及其制法和应用 (Eutectic solvent for separating polycyclic aromatic hydrocarbon and preparation method and application thereof ) 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多环芳烃分离领域的一种一种用于分离多环芳烃的低共熔溶剂及其制法和应用。所述低共熔溶剂包含氢键受体、氢键供体和路易斯酸盐；其中,所述的氢键受体和氢键供体的摩尔比例为1:0.1～1:20,优选为1：0.5～1:8,所述路易斯酸盐的加入量为低共熔溶剂总质量的0.1～20％；本发明通过路易斯酸盐的电子吸引作用增加对稠环芳烃的电子吸引,从而增加芳烃溶解性,用于分离单环芳烃和稠环芳烃。采用该低共熔溶剂可高效将稠环芳烃从有机物料中抽出。(The invention relates to a eutectic solvent for separating polycyclic aromatic hydrocarbon in the field of separation of polycyclic aromatic hydrocarbon in petroleum or petroleum fractions, and a preparation method and application thereof. The eutectic solvent comprises a hydrogen bond acceptor, a hydrogen bond donor, and a lewis acid salt; wherein the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1: 0.1-1: 20, preferably 1: 0.5-1: 8, wherein the addition amount of the Lewis acid salt is 0.1-20% of the total mass of the eutectic solvent; the method increases the electron attraction to the polycyclic aromatic hydrocarbon through the electron attraction effect of the Lewis acid salt, thereby increasing the solubility of the aromatic hydrocarbon and being used for separating the monocyclic aromatic hydrocarbon from the polycyclic aromatic hydrocarbon. The condensed-ring aromatic hydrocarbon can be efficiently extracted from the organic material by adopting the eutectic solvent.)

1. A eutectic solvent for separating polycyclic aromatic hydrocarbon is characterized in that: the eutectic solvent comprises a hydrogen bond acceptor, a hydrogen bond donor and a Lewis acid salt; wherein the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1: 0.1-1: 20; the addition amount of the Lewis acid salt is 0.1-20% of the total mass of the eutectic solvent; the hydrogen bond acceptors are phosphonium compounds and/or organic ammonium species.

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: 8.

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

the addition amount of the Lewis acid salt is 0.1-10% of the total mass of the eutectic solvent.

4. The eutectic solvent according to claim 1, characterized in that:

the hydrogen bond acceptor is selected from one or more of tetraethyl ammonium halide, tetrabutyl ammonium halide, choline chloride, betaine, methyltriethyl ammonium halide, tetrabutyl phosphonium halide, tetraphenyl phosphonium halide, methyltriphenyl phosphonium halide, ethyltriphenyl phosphonium halide and butyltriphenyl phosphonium halide; preferably one or more of tetrabutylammonium halide, tetrabutylphosphonium halide, tetraphenylphosphonium halide, methyltriphenylphosphonium halide, ethyltriphenylphosphonium halide, butyltriphenylphosphonium halide.

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

the hydrogen bond donor is selected from one or more of urea, citric acid, succinic acid, propionic acid, acetic acid, ethylene glycol, propylene glycol, glycerol, xylitol, glucose, levulinic acid, tributyl phosphate, dimethylformamide, morpholine, oxalic acid and lactic acid; preferably one or more of citric acid, succinic acid, ethylene glycol, lactic acid, propionic acid, levulinic acid and tributyl phosphate.

6. The eutectic solvent according to claim 1, characterized in that:

the Lewis acid salt is selected fromself-SnCl₂,SnCl₄,ZnCl₂,GeCl₂,InCl₃,GaCl₃,FeCl₂,FeCl₃,LaCl₃,CuCl₂,DyCl₃,CrCl₃,CrCl₂,AlCl₃，La(OTf)₃And YbCl₃One or more of; preferably SnCl₄,ZnCl₂,LaCl₃,La(OTf)₃,CrCl₃,CrCl₂One or more of (a).

7. The method for preparing the eutectic solvent according to any one of claims 1 to 6, characterized by comprising the steps of:

and mixing the hydrogen bond acceptor, the hydrogen bond donor and the Lewis acid at the temperature of 20-180 ℃, preferably at the temperature of 20-120 ℃ according to the using amount to obtain the catalyst.

8. Use of the eutectic solvent according to any one of claims 1 to 6 or the preparation method according to claim 7 for separating aromatic hydrocarbons.

9. Use of a eutectic solvent according to claim 8 for separation of aromatic hydrocarbons, characterized in that:

the eutectic solvent is 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 is 0.1: 1-50: 1, and preferably 0.5: 1-20: 1.

10. Use of a eutectic solvent according to claim 8 for separation of aromatic hydrocarbons, characterized in that:

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 polycyclic aromatic hydrocarbon separation in petroleum or petroleum fractions, and further relates to a eutectic solvent for separating polycyclic aromatic hydrocarbon, and a preparation method and application thereof.

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.

The literature currently focuses mainly on the isolation of monocyclic aromatics, but rarely involves the isolation of polycyclic aromatics. For example, tetraethylammonium chloride has been reported in the literature as a DES with levulinic acid and ethylene glycol and is used to separate toluene/heptane mixed systems (Wang Y, Hou Y C, Wu W Z, et al. circles of a hydrogen bond and a hydrogen bond acceptor in the extraction of a toluene from n-heptane using depleted electrolytic solutions. Green Chemistry,2016,18:3089 and 3097.) the authors found that shorter alkyl chains on quaternary ammonium salts are more advantageous for separating toluene. Similar patents have been published. Patent CN107311833A describes the separation of toluene/cyclohexane systems with DES of tetrabutylammonium bromide with levulinic acid or ethylene glycol. Repeatedly rectifying by adopting a separation tower to obtain 99 percent of toluene at the tower top. But the effect of separating polycyclic aromatic hydrocarbons is not described.

Separation of polycyclic aromatics is more difficult than separation of monocyclic aromatics from non-aromatics. Monocyclic aromatics and polycyclic aromatics differ less in the polarity and dipole moment of the molecules, and thus, upon separation, the monocyclic and multicyclic aromatics are easily separated together. Therefore, a new system needs to be developed to improve the separation efficiency of the polycyclic aromatic hydrocarbon.

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 for separating polycyclic aromatic hydrocarbon and a preparation method and application thereof. The method increases the electron attraction to the polycyclic aromatic hydrocarbon through the electron attraction effect of the Lewis acid salt, thereby increasing the solubility of the aromatic hydrocarbon and being used for separating the monocyclic aromatic hydrocarbon from the polycyclic aromatic hydrocarbon. The condensed-ring aromatic hydrocarbon can be efficiently extracted from the organic material by adopting the eutectic solvent.

One of the purposes of the invention is to provide a eutectic solvent, wherein the eutectic solvent comprises a hydrogen bond acceptor, a hydrogen bond donor and a certain proportion of Lewis acid salt; wherein, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor can be 1: 0.1-1: 20, and is preferably 1: 0.5-1: 8, wherein the addition amount of the Lewis acid salt can be 0.1-20% of the total mass of the eutectic solvent, preferably 0.1-10%, more preferably 0.1-8%, and further preferably 0.4-8%.

Wherein the content of the first and second substances,

the hydrogen bond acceptor can be selected from one or more of tetraethyl ammonium halide, tetrabutyl ammonium halide, choline chloride, betaine, methyltriethylammonium halide, tetraphenyl phosphonium halide, methyltriphenyl phosphonium halide, ethyltriphenyl phosphonium halide and butyltriphenyl phosphonium halide; preferably one or more of tetrabutylammonium halide, tetrabutylphosphonium halide, tetraphenylphosphonium halide, methyltriphenylphosphonium halide and butyltriphenylphosphonium halide. The halide is selected from one of fluoride, chloride, bromide or iodide.

The hydrogen bond donor can be one or more selected from urea, citric acid, succinic acid, propionic acid, acetic acid, ethylene glycol, propylene glycol, glycerol, xylitol, glucose, levulinic acid, tributyl phosphate, dimethylformamide, morpholine, oxalic acid and lactic acid. Preferably one or more of citric acid, succinic acid, lactic acid, propionic acid, levulinic acid and tributyl phosphate.

The Lewis acid salt is selected from SnCl₂,SnCl₄,ZnCl₂,GeCl₂,InCl₃,GaCl₃,FeCl₂,FeCl₃,LaCl₃,CuCl₂,DyCl₃,CrCl₃,CrCl₂,La(OTf)₃And YbCl₃One or more of; preferably SnCl₄,ZnCl₂,LaCl₃,La(OTf)₃,CrCl₃,CrCl₂One or more of (a).

Through reaction tests, the inventor finds that the extraction selectivity of the polycyclic aromatic hydrocarbon can be greatly increased by adding a small amount of Lewis acid salt into the eutectic solvent. Compared with monocyclic aromatic hydrocarbon, polycyclic aromatic hydrocarbon has more benzene ring structures and rich pi electrons. The addition of the Lewis acid salt makes the DES have stronger attraction to the polycyclic aromatic hydrocarbon, can increase the amount of the polycyclic aromatic hydrocarbon entering the DES and improve the selectivity of the polycyclic aromatic hydrocarbon.

The second purpose of the invention is to provide a preparation method of the eutectic solvent, which comprises the following steps:

and mixing and stirring the hydrogen bond acceptor, the hydrogen bond donor and the Lewis acid salt uniformly at the temperature of 20-180 ℃, preferably 20-120 ℃, and more preferably at the temperature of 20-85 ℃ according to the using amount to obtain the hydrogen bond acceptor-hydrogen bond donor-Lewis acid salt.

The invention also provides the application of the eutectic solvent in the separation of aromatic hydrocarbon, wherein,

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, and preferably 0.5: 1-20: 1.

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

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.

To illustrate the results of the present invention, in the context of the present specification, single stage aromatics extraction "(A) was used_pah%) and polycyclic aromatic hydrocarbons to S_pahThe test results are described. The method for calculating the single-stage aromatic extraction rate comprises the following steps: a. the_pahPercent (total polycyclic aromatic hydrocarbon content of raw oil-total polycyclic aromatic hydrocarbon content remaining after one extraction)/total polycyclic aromatic hydrocarbon content in raw oil x 100%. Polycyclic aromatic hydrocarbon fraction S_pahThe amount of polycyclic aromatic hydrocarbons in the extracted aromatic hydrocarbons/the amount of other aromatic hydrocarbons in the extracted oil × 100%. S_pahHigher values indicate high selectivity to polycyclic aromatics. When S is_pahWhen the content is higher than 1, the extracted polycyclic aromatic hydrocarbon is dominant and has the function of selectively extracting the polycyclic aromatic hydrocarbon. In addition, in industrial plants S_pahThe higher the content, the lower the energy consumption of the separation of the polycyclic aromatic hydrocarbon can be realized by the DES and the multiple extractions of the polycyclic aromatic hydrocarbon in the separation tower. In addition, the raw oil is obtained by mixing toluene, naphthalene and tridecane, and the mass ratio of the toluene, the naphthalene and the tridecane is 30/30/40.

The invention is further illustrated by the following examples.

[ COMPARATIVE EXAMPLE 1 ]

Weighing 32.2g of hydrogen bond acceptor tetrabutylammonium bromide, weighing 34.8g of hydrogen bond donor levulinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor (hydrogen bond donor/hydrogen bond acceptor) is 3, mixing, heating to 50 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt.

And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 25 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 14% and a polycyclic aromatic hydrocarbon ratio (Spah) of 0.4.

[ example 1 ]

Weighing 16.1g of hydrogen bond acceptor tetrabutylammonium bromide, weighing 17.4g of hydrogen bond donor levulinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor (the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor in examples 1-14) is 3, adding 0.17g of Lewis acid salt stannic chloride accounting for 0.5% of the total mass of the eutectic solvent, mixing, heating to 50 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 25 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. Taking out a small amount of upper layer model oil and the lower layer DES layer, and performing gas chromatography to obtain a single-stage aromatic extraction rate A% of 57% and a polycyclic aromatic hydrocarbon ratio (Spah) of 1.0.

[ example 2 ]

Weighing 3.4g of hydrogen bond acceptor tetraphenylphosphonium bromide, weighing 3.5g of hydrogen bond donor succinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 4, adding 0.03g of Lewis acid salt zinc chloride accounting for 0.4 percent of the total mass of the eutectic solvent, mixing, heating to 20 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 60 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 a polycyclic aromatic hydrocarbon ratio (Spah) of 0.8.

[ example 3 ]

Weighing 17.9g of hydrogen bond acceptor methyl triphenyl phosphonium bromide, weighing 2.9g of hydrogen bond donor levulinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 0.5, adding 0.12g of Lewis acid salt germanium chloride accounting for 0.6 percent of the total mass of the eutectic solvent, mixing, heating to 50 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 25 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 a polycyclic aromatic hydrocarbon ratio (Spah) of 0.7.

[ example 4 ]

Weighing 3.6g of hydrogen bond acceptor methyl triphenyl phosphonium bromide and 5.9g of hydrogen bond donor succinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 5, adding 0.1g of Lewis acid salt gallium chloride accounting for 1% of the total mass of the eutectic solvent, mixing, heating to 80 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 40 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 44% and a polycyclic aromatic hydrocarbon ratio (Spah) of 0.9.

[ example 5 ]

Weighing 12g of hydrogen bond acceptor butyl triphenyl phosphonium bromide and 21.6g of hydrogen bond donor lactic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 8, adding 0.17g of Lewis acid salt stannic chloride accounting for 0.5 percent of the total mass of the eutectic solvent, mixing, heating to 60 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 80 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 a polycyclic aromatic hydrocarbon ratio (Spah) of 1.0.

[ example 6 ]

Weighing 10.2g of hydrogen bond acceptor tetrabutyl phosphonium bromide, weighing 6.7g of hydrogen bond donor propionic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3, adding 0.42g of Lewis acid salt ferric chloride accounting for 2.4% of the total mass of the eutectic solvent, mixing, heating to 60 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 25 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 42% and a polycyclic aromatic hydrocarbon ratio (Spah) of 0.8.

[ example 7 ]

Weighing 3.7g of hydrogen bond acceptor ethyl triphenyl phosphonium bromide, weighing 7g of hydrogen bond donor levulinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 6, adding 0.11g of Lewis acid salt lanthanum chloride accounting for 1% of the total mass of the eutectic solvent, mixing, heating to 50 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 40 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 48% and a polycyclic aromatic hydrocarbon ratio (Spah) of 0.9.

[ example 8 ]

Weighing 14.3g of hydrogen bond acceptor methyl triphenyl phosphonium bromide and 18g of hydrogen bond donor lactic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 5, adding 0.48g of Lewis acid salt lanthanum chloride accounting for 1.5 percent of the total mass of the eutectic solvent, mixing, heating to 120 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 1, and the extraction process is carried out at 25 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 a polycyclic aromatic hydrocarbon ratio (Spah) of 0.7.

[ example 9 ]

Weighing 11.1g of hydrogen bond acceptor ethyl triphenyl phosphonium bromide, weighing 5.6g of hydrogen bond donor ethylene glycol, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3, adding 0.08g of Lewis acid salt zinc chloride accounting for 0.5% of the total mass of the eutectic solvent, mixing, heating to 80 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. Adding raw oil into the eutectic solvent, wherein the mass ratio of DES to raw oil (DES/raw oil) is 0.3, and extracting at 60 deg.C. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. Taking out a small amount of upper layer model oil and the lower layer DES layer, and performing gas chromatography to obtain a single-stage aromatic extraction rate A% of 60% and a polycyclic aromatic hydrocarbon ratio (Spah) of 1.0.

[ example 10 ]

Weighing 10.2g of hydrogen bond acceptor tetrabutyl phosphonium bromide, weighing 24g of hydrogen bond donor tributyl phosphate, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3, adding 0.34g of Lewis acid salt copper chloride accounting for 1% of the total mass of the eutectic solvent, mixing, heating to 20 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 2, and the extraction process is carried out at 25 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 42% and a polycyclic aromatic hydrocarbon ratio (Spah) of 0.8.

[ example 11 ]

Weighing 17.9g of hydrogen bond acceptor methyl triphenyl phosphonium bromide and 9g of hydrogen bond donor urea, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3, adding 2.15g of Lewis acid salt chromium trichloride accounting for 7.4 percent of the total mass of the eutectic solvent, mixing, heating to 120 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 10, and the extraction process is carried out at 50 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. Taking out a small amount of upper layer model oil and the lower layer DES layer, and performing gas chromatography analysis to obtain a single-stage aromatic extraction rate A% of 50% and a polycyclic aromatic hydrocarbon ratio (Spah) of 0.8.

[ example 12 ]

Weighing 7.1g of hydrogen bond acceptor methyl triphenyl phosphonium bromide and 7.1g of hydrogen bond donor succinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3, adding 0.71g of Lewis acid salt chromium dichloride accounting for 5% of the total mass of the eutectic solvent, mixing, heating to 80 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. Adding raw oil into the eutectic solvent, mixing, wherein the mass ratio of DES to raw oil is 20, and extracting at 50 deg.C. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 a polycyclic aromatic hydrocarbon ratio (Spah) of 1.

[ example 13 ]

Weighing 14.3g of hydrogen bond acceptor methyl triphenyl phosphonium bromide, weighing 14.2g of hydrogen bond donor succinic acid, wherein the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 3, adding 0.14g of Lewis acid salt zinc chloride accounting for 0.5 percent of the total mass of the eutectic solvent, mixing, heating to 85 ℃, stirring, and cooling to room temperature to obtain the eutectic solvent containing Lewis acid salt. And adding raw oil into the eutectic solvent for mixing, wherein the mass ratio of DES to raw oil is 20, and the extraction process is carried out at 80 ℃. The eutectic solvent and model oil were mixed vigorously 5 times and allowed to stand for 24 hours to reach full equilibrium. The mixed liquid after extraction is automatically divided into an upper layer and a lower layer, the upper layer is residual model oil, and the lower layer is a DES layer extracted with aromatic hydrocarbon. And 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 a polycyclic aromatic hydrocarbon ratio (Spah) of 0.9.