An extraction process for producing heavy aromatic derivatives

Abstract

The present invention discloses an extraction process for producing heavy aromatic derivatives, which relates to the field of petroleum processing. Specifically, in the present invention, the aromatic hydrocarbon mixed oil is separated through processes such as extraction cutting and separation to prepare heavy aromatic derivatives; the present invention uses a double solvent to selectively dissolve aromatic hydrocarbons and non-aromatic hydrocarbons; in the extraction auxiliary solvent prepared by the present invention, the compatibility between terphenyl and aromatic hydrocarbons is improved, and the extraction effect is better; rare earth complexes contribute to the separation of aromatic hydrocarbons and other organic compounds, thereby improving the extraction effect of aromatic hydrocarbons; morpholine improves its extraction effect by forming an ion pair with aromatic hydrocarbons; it can also form a complex with organic lanthanum to enhance its extraction performance; the extraction auxiliary solvent prepared by the present invention breaks through the limitations of the liquid-phase solvents used in conventional extraction, has good stability and is easy to regenerate, and can conveniently achieve the rapid separation of polycyclic aromatic hydrocarbons; the extraction process for heavy aromatic derivatives of the present invention has the advantages of low extraction temperature and small solvent ratio.

Description

Technical Field

[0001] The present invention relates to the field of petroleum processing, and in particular to an extraction process for producing heavy aromatic derivatives. Background Art

[0002] The rapid development of the world petrochemical industry has accelerated the development of aromatic hydrocarbon production technology. The separation and production technology of aromatic hydrocarbons is an indispensable step in aromatic hydrocarbon production. At present, the main raw materials for producing aromatic hydrocarbons are reformate and pyrolysis gasoline. The main methods for producing aromatic hydrocarbons can be divided into two categories according to the process route principle: aromatic hydrocarbon extraction and extractive distillation. Generally speaking, if the raw material fraction is narrow and the aromatic hydrocarbon content is high, the extractive distillation process is preferably used; for raw materials with a wide fraction and a low aromatic hydrocarbon content, the aromatic hydrocarbon extraction process is preferably used.

[0003] Chinese Patent CN111500316B: A method for preparing heavy aromatic hydrocarbons by extractive distillation, comprising the following steps: In the extraction column, the light fuel oil and heavy aromatic hydrocarbons in the mixed material vaporize continuously from light to heavy according to the molecular weight. The light fuel oil and heavy aromatic hydrocarbon products in the mixed material start to separate and distill out, and then the light fuel oil and heavy aromatic hydrocarbons are respectively sent to their respective product tanks by pumps. The light raw material flowing out from the top of the extraction column is subjected to product separation and solvent recovery. After entering the product separation system, a vertical vacuum pump is started to evacuate; the distillate oil is cooled by a heat exchanger and a condenser and then flows into the light fuel oil product intermediate tank, the heavy aromatic hydrocarbon product intermediate tank and the solvent intermediate tank. Then the light fuel oil and heavy aromatic hydrocarbons are respectively sent to their respective product tanks by pumps, and the solvent is sent back to the solvent tank for reuse. The heavy raw material is further heat-exchanged with the side-line product through a heat exchanger and then transported to a heating furnace for heating and enters the extraction column. The material is sent to each product tank.

[0004] Chinese Patent CN114437818B: It relates to the petrochemical field. The present invention discloses a method for processing heavy aromatic hydrocarbon oil, including that the heavy aromatic hydrocarbon oil is distilled into a light fraction and a heavy fraction. The heavy fraction is extracted with a part of BTX benzene, toluene and xylene and the light toluene fraction to obtain a poor aromatic component and a rich aromatic component. The rich aromatic component is further distilled to separate out the light toluene fraction and the heavy toluene fraction. The heavy toluene fraction and the light fraction enter hydrorefining together. The hydrogenation product and the poor aromatic component enter a hydrocracking reactor together for further hydrocracking reaction. The cracking product is distilled to obtain C1-C4, BTX benzene, toluene and xylene and a small amount of diesel products and unconverted oil.

[0005] Chinese Patent CN115197739A: A system and production method for flexibly producing high-boiling aromatic solvents are disclosed. The system adopts a three-distillation-column process. By introducing the heavy aromatic fraction raw material into the first distillation column for rectification to remove heavy components, the overhead product of the first distillation column enters the second distillation column for separation. The top of the second distillation column produces the first solvent oil product, the bottom of the second distillation column produces the second solvent oil product, and the bottom of the first distillation column produces heavy aromatics that can be used as diesel blending components. The third distillation column precisely cuts the material at the top or bottom of the second distillation column, and can intermittently produce the third solvent oil product and the fourth solvent oil product. By precisely controlling the operating pressure, temperature, and reflux ratio of each distillation column, and at the same time through raw material blending, the distillation range of the solvent oil product can be adjusted to ensure the chromaticity of the solvent oil product, and solvent oil products of multiple grades can be produced.

[0006] The above-mentioned patent and the prior art process flow are long, with many equipment and difficult to operate; the extraction tower has a high operating temperature, high energy consumption; a large solvent ratio, high cost; and the separation effect of aromatics and non-aromatics is not ideal. Summary of the Invention

[0007] The main object of the present invention is to provide an extraction process for producing heavy aromatic derivatives to overcome the deficiencies in the prior art.

[0008] Another object of the present invention is also to provide an extraction auxiliary solvent and its preparation method.

[0009] To achieve the foregoing invention objects, the technical solutions adopted by the present invention include:

[0010] An embodiment of the present invention provides an extraction process for producing heavy aromatic derivatives, which includes:

[0011] A1: Feed the raw material fuel oil through the raw material flowmeter to the bottom heat exchange systems of Extraction Tower 1, Extraction Tower 2, and Extraction Tower 3 for heat exchange, and then send it to the reaction tower to remove the moisture in the raw material.

[0012] A2: After the raw material at the bottom of the reaction tower is heated up by the heating furnace, it is sent to the vacuum extraction tower for cutting. The pressure in the tower is maintained at -95 to -99 kPa, and the extraction line 1 fraction, extraction line 2 fraction, extraction line 3 fraction, and bottom tower oil are cut out respectively according to the temperature gradient of the vacuum extraction tower. The bottom tower oil is heat-exchanged with the raw material and then condensed to 100 - 150 °C and sent to the finished product tank area.

[0013] A3: One extraction line is cooled to 50 - 70 °C and sent to Extraction Column 1 for extraction together with the solvent and the extraction auxiliary solvent; the solvent and the fuel oil mixed components are discharged from the top of the column and then enter the Solvent Separation Column 1 for heating and separation. The solvent at the top is condensed to 50 - 70 °C. After separation in Solvent Separation Column 1, the solvent is sent to the Solvent Recovery Tank for recycling; the bottom heavy aromatic hydrocarbon derivatives are combined with the bottom heavy aromatic hydrocarbon derivatives in A4 and then condensed and cooled to 60 - 80 °C and sent to the finished product tank area.

[0014] A4: One extraction line is heated by heat exchange to 100 - 150 °C and sent to Extraction Column 2 for extraction together with the solvent and the extraction auxiliary solvent; the solvent and the fuel oil mixed components are discharged from the top of the column and then enter the Solvent Separation Column 2 for heating and separation. The solvent at the top is condensed to 50 - 70 °C. After separation in Solvent Separation Column 2, the solvent is sent to the Solvent Recovery Tank for recycling; the bottom heavy aromatic hydrocarbon derivatives are combined with the bottom heavy aromatic hydrocarbon derivatives in A3 and then condensed and cooled to 70 - 100 °C and sent to the finished product tank area.

[0015] A5: One extraction line is heated by heat exchange to 100 - 150 °C and sent to Extraction Column 3 for extraction together with the solvent and the extraction auxiliary solvent; the solvent and the fuel oil mixed components are discharged from the top of the column and then enter the Solvent Separation Column 3 for heating and separation. The solvent at the top is condensed to 50 - 70 °C. After separation in Solvent Separation Column 3, the solvent is sent to the Solvent Recovery Tank for recycling; the bottom heavy aromatic hydrocarbon derivatives are condensed to 70 - 100 °C and sent to the finished product tank area.

[0016] A6: All the tail gas generated during the production process is sent to the heating furnace for incineration treatment.

[0017] Further, the flow rate of the raw material fuel oil is 50 - 60 t / h.

[0018] Further, the temperature after heat exchange is controlled at 200 - 260 °C.

[0019] Further, the heating furnace is heated to 360 - 400 °C.

[0020] Further, the flow rate of the extraction line 1 is 2 - 5 t / h, and the solvent addition amount is 3 - 10 t / h.

[0021] Further, the flow rate of the extraction line 2 is 8 - 20 t / h, and the solvent addition amount is 10 - 25 t / h.

[0022] Further, the flow rate of the extraction line 3 is 3 - 10 t / h, and the solvent addition amount is 5 - 15 t / h.

[0023] Further, the solvent is a mixture of furfural and N-methylpyrrolidone, and the mass ratio is furfural:N-methylpyrrolidone = 1 - 9:9.

[0024] Furthermore, the addition amount of the extraction auxiliary solvent is 3-8% of the total mass of the solvent, and its preparation method is as follows:

[0025] Mix 28-56 parts of allyl tributylphosphonium chloride, 10-20 parts of morpholine sulfonamide, 0.001-0.02 parts of organolanthanide complex, 3-7 parts of diethanolamine, 200-300 parts of N-methylpyrrolidone at 60-70 °C and stir for 40-80 minutes to obtain the extraction auxiliary solvent.

[0026] Furthermore, the preparation method of the organolanthanide complex is as follows:

[0027] Weigh 3-6 parts of 2'-amino-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid and 1-3 parts of lanthanum nitrate, then add 80-100 parts of N-methylpyrrolidone, mix and stir at 60-70 °C for 40-80 minutes, remove N-methylpyrrolidone by vacuum distillation, and let it stand and cool naturally to room temperature to obtain the organolanthanide complex.

[0028] The reaction mechanism of the extraction auxiliary solvent is as follows:

[0029] (1) Allyl tributylphosphonium chloride and morpholine sulfonamide carry out an amino addition reaction under the catalysis of diethanolamine;

[0030] (2) Further, allyl tributylphosphonium chloride carries out an amino addition reaction with the organolanthanide complex.

[0031] Technical effects:

[0032] The extraction process of the heavy aromatic hydrocarbon derivative of the present invention has the following remarkable effects compared with the prior art:

[0033] 1. The present invention uses a double solvent to selectively dissolve aromatic hydrocarbons and non-aromatic hydrocarbons; the aromatic hydrocarbon components are dissolved in the solvent, while the non-aromatic hydrocarbons are less dissolved, so two phases with different compositions and densities are formed; finally, a mixture of a solvent with a very low aromatic hydrocarbon content and light fuel oil is obtained at the top of the tower, and a mixture of a solvent with a very high aromatic hydrocarbon content and aromatic hydrocarbons is obtained at the bottom of the tower, so as to achieve the separation effect of aromatic hydrocarbons and non-aromatic hydrocarbons;

[0034] 2. The extraction process of the heavy aromatic hydrocarbon derivative of the present invention has the advantages of low extraction temperature and small solvent ratio;

[0035] 3. In the extraction auxiliary solvent prepared by the present invention, the compatibility between terphenyl and aromatic hydrocarbons is improved, and the extraction effect is better; rare earth complexes help to separate aromatic hydrocarbons and other organic compounds, thus improving the extraction effect of aromatic hydrocarbons; morpholine improves its extraction effect by forming an ion pair with aromatic hydrocarbons; it can also form a complex with organolanthanum to enhance its extraction performance;

[0036] 4. The extraction auxiliary solvent prepared by the present invention breaks the limitation of the liquid-phase solvent used in conventional extraction, has good stability and is easy to regenerate, and can conveniently achieve the rapid separation of polycyclic aromatic hydrocarbons.

[0037] 5. The extraction process of the heavy aromatic hydrocarbon derivative of the present invention has a short process flow, few equipment units, simple operation, flexible feeding, large operation flexibility, low energy consumption and material consumption, less floor area and less investment. Description of the Drawings

[0038] Figure 1 It is a process flow diagram of an extraction process for producing heavy aromatic hydrocarbon derivatives of the present invention. Detailed Embodiments

[0039] In view of the deficiencies in the prior art, the inventors of this case have proposed the technical solution of the present invention through long-term research and a large number of practices. The following will further explain the technical solution, its implementation process and principle, etc.

[0040] In the embodiment of the present invention, the hydrocarbon component analysis method adopts SH / T0659-1998.

[0041] Example 1

[0042] An extraction process for producing heavy aromatic hydrocarbon derivatives, and its operation steps are as follows:

[0043] A1: The raw material fuel oil is transported to the bottom heat exchange systems of Extraction Tower 1, Extraction Tower 2 and Extraction Tower 3 through a raw material flowmeter for heat exchange, and after heat exchange, it is sent to a reaction tower to remove the moisture in the raw material.

[0044] A2: The raw material at the bottom of the reaction tower is heated up by a heating furnace and then sent to a vacuum extraction tower for cutting. The pressure in the tower is maintained at -95 to -99 kPa. According to the temperature gradient of the vacuum extraction tower, extraction line 1 fraction, extraction line 2 fraction, extraction line 3 fraction and bottom tower oil are cut out respectively. The bottom tower oil is heat-exchanged with the raw material and then condensed to 100 °C and enters the finished product tank area.

[0045] A3: Extraction line 1 is cooled to 50 °C and sent to Extraction Tower 1 for extraction together with the solvent and the extraction auxiliary solvent; the solvent and fuel oil mixed component is discharged from the top of the tower and then enters the solvent separation tower 1 for heating and separation. The top solvent is condensed to 50 °C, and after being separated by the solvent separation tower 1, the solvent is sent to the solvent recovery tank for recycling; the heavy aromatic hydrocarbon derivative material at the bottom of the tower is merged with the heavy aromatic hydrocarbon derivative material at the bottom in A4 and then condensed and cooled to 60 °C and sent to the finished product tank area.

[0046] A4: The second extraction line is heated to 100°C through heat exchange, and then fed into the second extraction column together with the solvent and the extraction auxiliary solvent for extraction; the solvent and the fuel oil mixed components are discharged from the top of the column, and then enter the second solvent separation column for heating and separation. The solvent at the top is condensed to 50°C. After separation in the second solvent separation column, the solvent is sent to the solvent recovery tank for recycling; the bottom heavy aromatic hydrocarbon derivative material is merged with the bottom heavy aromatic hydrocarbon derivative material in A3 and then condensed and cooled to 70°C and sent to the finished product tank area;

[0047] A5: The third extraction line is heated to 100°C through heat exchange, and then fed into the third extraction column together with the solvent and the extraction auxiliary solvent for extraction; the solvent and the fuel oil mixed components are discharged from the top of the column, and then enter the third solvent separation column for heating and separation. The solvent at the top is condensed to 50°C. After separation in the third solvent separation column, the solvent is sent to the solvent recovery tank for recycling; the bottom heavy aromatic hydrocarbon derivative material is condensed to 70°C and sent to the finished product tank area;

[0048] A6: All the tail gases generated during the production process are sent to the heating furnace for incineration treatment.

[0049] The flow rate of the raw material fuel oil is 50 t / h.

[0050] The temperature after heat exchange is controlled at 200°C.

[0051] The heating furnace is heated to 360°C.

[0052] The flow rate of the first extraction line is 2 t / h, and the solvent addition amount is 3 t / h.

[0053] The flow rate of the second extraction line is 8 t / h, and the solvent addition amount is 10 t / h.

[0054] The flow rate of the third extraction line is 3 t / h, and the solvent addition amount is 5 t / h.

[0055] The solvent is a mixture of furfural and N-methylpyrrolidone, and the mass ratio is furfural:N-methylpyrrolidone = 1:9.

[0056] The addition amount of the extraction auxiliary solvent is 3% of the total mass of the solvent, and its preparation method is as follows:

[0057] 28 kg of allyl tributylphosphonium chloride, 10 kg of morpholine sulfonamide, 0.001 kg of organolanthanide complex, 3 kg of diethanolamine, and 200 kg of N-methylpyrrolidone are mixed and stirred at 60°C for 40 minutes to obtain the extraction auxiliary solvent.

[0058] The preparation method of the organolanthanide complex is as follows:

[0059] Weigh 3 kg of 2'-amino-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid and 1 kg of lanthanum nitrate, then add 80 kg of N-methylpyrrolidone and mix and stir at 60 °C for 40 minutes. Remove N-methylpyrrolidone by vacuum distillation, and let it stand and cool naturally to room temperature to obtain the organolanthanum complex.

[0060] Example 2

[0061] An extraction process for producing heavy aromatic derivatives, and its operation steps are as follows:

[0062] A1: Feed the raw material fuel oil through the raw material flowmeter to the bottom heat exchange systems of Extraction Tower 1, Extraction Tower 2, and Extraction Tower 3 for heat exchange, and then send it to the reaction tower to remove the moisture in the raw material.

[0063] A2: After the raw material at the bottom of the reaction tower is heated up by the heating furnace, send it to the vacuum extraction tower for cutting. The pressure in the tower is maintained at -95 to -99 kPa, and draw out the extraction first-line fraction, extraction second-line fraction, extraction third-line fraction, and bottom oil according to the temperature gradient of the vacuum extraction tower. After heat exchange with the raw material, the bottom oil is condensed to 125 °C and sent to the finished product tank area.

[0064] A3: Cool the extraction first-line to 60 °C, and send it together with the solvent and extraction auxiliary solvent to Extraction Tower 1 for extraction; the solvent and fuel oil mixed component is discharged from the top of the tower, and then enters the solvent separation tower 1 for heating and separation. The top solvent is condensed to 60 °C, and after being separated by the solvent separation tower 1, the solvent is sent to the solvent recovery tank for recycling; the bottom heavy aromatic derivative material passes through the same line as the bottom heavy aromatic derivative material in A4 and then is condensed and cooled to 70 °C and sent to the finished product tank area.

[0065] A4: Heat the extraction second-line to 125 °C, and send it together with the solvent and extraction auxiliary solvent to Extraction Tower 2 for extraction; the solvent and fuel oil mixed component is discharged from the top of the tower, and then enters the solvent separation tower 2 for heating and separation. The top solvent is condensed to 60 °C, and after being separated by the solvent separation tower 2, the solvent is sent to the solvent recovery tank for recycling; the bottom heavy aromatic derivative material passes through the same line as the bottom heavy aromatic derivative material in A3 and then is condensed and cooled to 85 °C and sent to the finished product tank area.

[0066] A5: Heat the extraction third-line to 125 °C, and send it together with the solvent and extraction auxiliary solvent to Extraction Tower 3 for extraction; the solvent and fuel oil mixed component is discharged from the top of the tower, and then enters the solvent separation tower 3 for heating and separation. The top solvent is condensed to 60 °C, and after being separated by the solvent separation tower 3, the solvent is sent to the solvent recovery tank for recycling; the bottom heavy aromatic derivative material is condensed to 85 °C and sent to the finished product tank area.

[0067] A6: All the tail gas generated during the production process is sent to the heating furnace for incineration treatment.

[0068] The flow rate of the raw material fuel oil is 55 t / h.

[0069] The temperature after heat exchange is controlled at 230 °C.

[0070] The heating furnace is heated to 380 °C.

[0071] The flow rate of the first draw line is 3 t / h, and the solvent addition amount is 7 t / h.

[0072] The flow rate of the second draw line is 15 t / h, and the solvent addition amount is 18 t / h.

[0073] The flow rate of the third draw line is 7 t / h, and the solvent addition amount is 10 t / h.

[0074] The solvent is a mixture of furfural and N-methylpyrrolidone, and the mass ratio is furfural:N-methylpyrrolidone = 4:9.

[0075] The addition amount of the extraction auxiliary solvent is 5% of the total mass of the solvent, and its preparation method is as follows:

[0076] Mix 45 kg of allyl tributylphosphonium chloride, 15 kg of morpholine sulfonamide, 0.01 kg of organolanthanide complex, 5 kg of diethanolamine, and 250 kg of N-methylpyrrolidone at 65 °C and stir for 60 minutes to obtain the extraction auxiliary solvent.

[0077] The preparation method of the organolanthanide complex is as follows:

[0078] Weigh 4 kg of 2'-amino-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid and 2 kg of lanthanum nitrate, then add 90 kg of N-methylpyrrolidone, mix and stir at 65 °C for 60 minutes, distill off N-methylpyrrolidone under reduced pressure, and let it stand and cool naturally to room temperature to obtain the organolanthanide complex.

[0079] Example 3

[0080] An extraction process for producing heavy aromatic derivatives, and its operation steps are as follows:

[0081] A1: Feed the raw material fuel oil through the raw material flowmeter to the bottom heat exchange systems of Extraction Tower 1, Extraction Tower 2, and Extraction Tower 3 for heat exchange, and then send it to the reaction tower to remove the moisture in the raw material;

[0082] A2: After the raw material at the bottom of the reaction tower is heated up by the heating furnace, it is sent to the vacuum extraction tower for cutting. The pressure in the tower is maintained at -95 to -99 kPa. According to the temperature gradient of the vacuum extraction tower, the first draw fraction, the second draw fraction, the third draw fraction, and the bottom oil are cut out respectively. After heat exchange with the raw material, the bottom oil is condensed to 150 °C and enters the finished product tank area;

[0083] A3: One extraction line is cooled to 70°C and sent to Extraction Column 1 together with the solvent and the extraction auxiliary solvent for extraction; the solvent and the fuel oil mixed components are discharged from the top of the column, and then enter the Solvent Separation Column 1 for heating and separation. The solvent at the top is condensed to 70°C. After separation in Solvent Separation Column 1, the solvent is sent to the Solvent Recovery Tank for recycling; the heavy aromatic hydrocarbon derivative material at the bottom of the column is combined with the heavy aromatic hydrocarbon derivative material at the bottom of A4 and then condensed and cooled to 80°C and sent to the finished product tank area;

[0084] A4: One extraction line is heated to 150°C through heat exchange and sent to Extraction Column 2 together with the solvent and the extraction auxiliary solvent for extraction; the solvent and the fuel oil mixed components are discharged from the top of the column, and then enter the Solvent Separation Column 2 for heating and separation. The solvent at the top is condensed to 70°C. After separation in Solvent Separation Column 2, the solvent is sent to the Solvent Recovery Tank for recycling; the heavy aromatic hydrocarbon derivative material at the bottom of the column is combined with the heavy aromatic hydrocarbon derivative material at the bottom of A3 and then condensed and cooled to 100°C and sent to the finished product tank area;

[0085] A5: One extraction line is heated to 150°C through heat exchange and sent to Extraction Column 3 together with the solvent and the extraction auxiliary solvent for extraction; the solvent and the fuel oil mixed components are discharged from the top of the column, and then enter the Solvent Separation Column 3 for heating and separation. The solvent at the top is condensed to 70°C. After separation in Solvent Separation Column 3, the solvent is sent to the Solvent Recovery Tank for recycling; the heavy aromatic hydrocarbon derivative material at the bottom of the column is condensed to 100°C and sent to the finished product tank area;

[0086] A6: All the tail gas generated during the production process is sent to the heating furnace for incineration treatment.

[0087] The flow rate of the raw material fuel oil is 60 t / h.

[0088] The temperature after heat exchange is controlled at 260°C.

[0089] The heating furnace is heated to 400°C.

[0090] The flow rate of the extraction line 1 is 5 t / h, and the solvent addition amount is 10 t / h.

[0091] The flow rate of the extraction line 2 is 20 t / h, and the solvent addition amount is 25 t / h.

[0092] The flow rate of the extraction line 3 is 10 t / h, and the solvent addition amount is 15 t / h.

[0093] The solvent is a mixture of furfural and N-methylpyrrolidone, and the mass ratio is furfural:N-methylpyrrolidone = 9:9.

[0094] The addition amount of the extraction auxiliary solvent is 8% of the total mass of the solvent, and its preparation method is:

[0095] 56 kg of allyl tributylphosphonium chloride, 20 kg of morpholine sulfonamide, 0.02 kg of organolanthanide complex, 7 kg of diethanolamine, and 300 kg of N-methylpyrrolidone are mixed and stirred at 70 °C for 80 minutes to obtain an extraction auxiliary solvent.

[0096] The preparation method of the organolanthanide complex is as follows:

[0097] Weigh 6 kg of 2'-amino-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid and 3 kg of lanthanum nitrate, then add 100 kg of N-methylpyrrolidone and mix and stir at 70 °C for 80 minutes. N-methylpyrrolidone is removed by vacuum distillation, and it is allowed to stand and cool naturally to room temperature to obtain the organolanthanide complex.

[0098] Comparative Example 1

[0099] In this example, the extraction auxiliary solvent is not added, and the others are the same as in Example 1.

[0100] The test results of the above examples are as follows:

[0101]

[0102]

[0103] Through the data analysis of the above examples and comparative examples, the compatibility between terphenyl and aromatic hydrocarbons in the extraction auxiliary solvent prepared by the present invention is improved, and the extraction effect is better; rare earth complexes contribute to the separation of aromatic hydrocarbons and other organic compounds, thereby improving the extraction effect of aromatic hydrocarbons; morpholine improves its extraction effect by forming an ion pair with aromatic hydrocarbons; it can also form a complex with organolanthanum to enhance its extraction performance; the extraction auxiliary solvent prepared by the present invention breaks through the limitations of the liquid-phase solvents used in conventional extraction, has good stability and is easy to regenerate, and can conveniently achieve the rapid separation of polycyclic aromatic hydrocarbons.

[0104] It should be understood that the above examples are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. An extraction process for producing heavy aromatic derivatives, and its operating steps are as follows: A1: Feed the raw material fuel oil through a raw material flowmeter to the bottom heat exchange systems of Extraction Tower 1, Extraction Tower 2, and Extraction Tower 3 for heat exchange. After heat exchange, it is sent to a reaction tower to remove the moisture in the raw material. A2: After the raw material at the bottom of the reaction tower is heated up by a heating furnace, it is sent to a vacuum extraction tower for cutting. The pressure inside the tower is maintained at -95 to -99 kPa. According to the temperature gradient of the vacuum extraction tower, the extraction first-line fraction, extraction second-line fraction, extraction third-line fraction, and bottom tower oil are cut out respectively. After the bottom tower oil is heat-exchanged with the raw material, it is condensed to 100 - 150 °C and sent to the finished product tank area. A3: The extraction first-line is cooled to 50 - 70 °C, and together with the solvent and extraction auxiliary solvent, it is sent to Extraction Tower 1 for extraction. The solvent and fuel oil mixed component is discharged from the top of the tower and then enters the solvent separation tower 1 for heating separation. The solvent at the top is condensed to 50 - 70 °C. After being separated by the solvent separation tower 1, the solvent is sent to the solvent recovery tank for recycling. The heavy aromatic derivative material at the bottom of the tower is combined with the heavy aromatic derivative material at the bottom in A4 and then condensed and cooled to 60 - 80 °C and sent to the finished product tank area. A4: The extraction second-line is heat-exchanged to 100 - 150 °C, and together with the solvent and extraction auxiliary solvent, it is sent to Extraction Tower 2 for extraction. The solvent and fuel oil mixed component is discharged from the top of the tower and then enters the solvent separation tower 2 for heating separation. The solvent at the top is condensed to 50 - 70 °C. After being separated by the solvent separation tower 2, the solvent is sent to the solvent recovery tank for recycling. The heavy aromatic derivative material at the bottom of the tower is combined with the heavy aromatic derivative material at the bottom in A3 and then condensed and cooled to 70 - 100 °C and sent to the finished product tank area. A5: The extraction third-line is heat-exchanged to 100 - 150 °C, and together with the solvent and extraction auxiliary solvent, it is sent to Extraction Tower 3 for extraction. The solvent and fuel oil mixed component is discharged from the top of the tower and then enters the solvent separation tower 3 for heating separation. The solvent at the top is condensed to 50 - 70 °C. After being separated by the solvent separation tower 3, the solvent is sent to the solvent recovery tank for recycling. The heavy aromatic derivative material at the bottom of the tower is condensed to 70 - 100 °C and sent to the finished product tank area. A6: All the tail gas generated during the production process is sent to the heating furnace for incineration treatment. The addition amount of the extraction auxiliary solvent is 3 - 8% of the total mass of the solvent, and its preparation method is as follows: Mix 28 - 56 parts of allyl tributylphosphonium chloride, 10 - 20 parts of morpholine sulfonamide, 0.001 - 0.02 parts of organic lanthanum complex, 3 - 7 parts of diethanolamine, and 200 - 300 parts of N-methylpyrrolidone at 60 - 70 °C and stir for 40 - 80 minutes to obtain the extraction auxiliary solvent. The preparation method of the organic lanthanum complex is as follows: Weigh 3 - 6 parts of 2'-amino-[1,1':4',1″-terphenyl]-4,4″-dicarboxylic acid and 1 - 3 parts of lanthanum nitrate, then add 80 - 100 parts of N-methylpyrrolidone and mix and stir at 60 - 70 °C for 40 - 80 minutes. Distill off N-methylpyrrolidone under reduced pressure and let it stand and cool naturally to room temperature to obtain the organic lanthanum complex.

2. The extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The flow rate of the raw material fuel oil is 50 - 60 t / h.

3. The extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The temperature after heat exchange is controlled at 200 - 260 °C.

4. The extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The described heating furnace is heated to 360 - 400 °C.

5. The extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The flow rate of the first draw line is 2 - 5 t / h, and the solvent addition amount is 3 - 10 t / h.

6. The extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The flow rate of the second draw line is 8 - 20 t / h, and the solvent addition amount is 10 - 25 t / h.

7. An extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The flow rate of the third draw line is 3 - 10 t / h, and the solvent addition amount is 5 - 15 t / h.

8. The extraction process for producing heavy aromatic derivatives according to claim 1, characterized in that: The solvent is a mixture of furfural and N-methylpyrrolidone, and the mass ratio thereof is furfural:N-methylpyrrolidone = 1 - 9:9.

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