Cracking C9 comprehensive utilization device and method

Abstract

The invention belongs to the technical field of ethylene, and relates to a cracking C9 comprehensive utilization device and method. The device comprises a reactive distillation tower, a light component removal tower, a heavy component removal tower, an extractive distillation tower, a mixed aromatic hydrocarbon refining tower, a 2-methylstyrene refining tower and an indene separation tower. Wherein the tower top of the reactive distillation tower is connected with the light component removal tower, and the tower bottom of the reactive distillation tower is connected with the heavy component removal tower; the top of the heavy component removal tower is connected with the extractive distillation tower, and the bottom of the heavy component removal tower is connected with the indene separation tower; the top of the extractive distillation tower is connected with the mixed aromatic hydrocarbon refining tower, and the bottom of the extractive distillation tower is connected with the 2-methylstyrene refining tower; the tower top of the mixed aromatic hydrocarbon refining tower is connected with the extractive distillation tower; and the tower bottom of the 2-methylstyrene refining tower is connected with the extractive distillation tower. By using the device and the method disclosed by the invention, the cyclopentadiene is separated, and meanwhile, 2-methylstyrene, indene and mixed aromatic hydrocarbon with relatively high content are separated and utilized, so that the economic added value of C9 resources is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of ethylene, and specifically, relates to a device for comprehensive utilization of cracked C9 and a method for comprehensive utilization of cracked C9. Background Art

[0002] Cracked C9 is a by-product of ethylene plants, containing a large amount of substances such as dicyclopentadiene, methylcyclopentadiene dimer, trimethylbenzene, 2-methylstyrene, indene, and naphthalene compounds, and is a valuable resource for the development of fine chemicals. Most of these substances have high utilization value, such as cyclopentadiene, 2-methylstyrene, indene, and mixed aromatics. With the continuous development of the domestic one-million-ton large ethylene technology, the output of cracked C9 fractions is increasing continuously. However, at present, most of the C9 fractions are used as fuel, and a small amount is used as solvent oil, resulting in low added value and economic benefits of the products.

[0003] Among them, cyclopentadiene (CPD) is an important organic chemical product for the production of norbornene, unsaturated polyesters, ethylene-propylene rubber, glutaraldehyde, ferrocene, etc., and can also be used in the synthesis fields of pesticides, spices, and pharmaceutical intermediates. 2-Methylstyrene is an aromatic hydrocarbon derivative and an important intermediate for pharmaceutical R & D and synthesis, and is expensive. Indene is an important fine chemical raw material and has very important uses in industry and biology. Drugs synthesized with indene as an intermediate have good effects on Parkinson's disease, HIV, mental illness, etc. Mixed aromatics (trimethylbenzene, methyl ethyl benzene) can be used as aromatic solvent oil and are widely used in the fields of printing, pesticides, and pharmaceuticals, with a broad market. Therefore, separating these active components from the C9 fraction can improve the economic value of C9 resources and promote the development of high-end chemicals in China.

[0004] The existing technologies mainly focus on the separation of cyclopentadiene, and other components are mainly used as petroleum resins or after hydrotreating as solvent oil, with low economic added value.

[0005] Cao Jiji et al. analyzed the composition of C9-C10 fractions and proposed a comprehensive utilization route. Specifically, cyclopentadiene and methylcyclopentadiene are first obtained from the cracked C9 fraction, and the remaining fraction is used to prepare petroleum resins or hydrogenated resins. CN 115124403 A introduces a method for single-column rectification separation of cracked C9 in a petroleum resin system, obtaining a mixture of dicyclopentadiene, indene, styrene, etc., which is also used for the production of petroleum resins. In the current technologies, the efficient separation of active components such as high-purity cyclopentadiene, 2-methylstyrene, mixed aromatics, and indene has not been achieved yet. Summary of the Invention

[0006] The object of the present invention is to overcome the defect that the existing preparation methods cannot achieve the efficient separation of active components such as cyclopentadiene, 2-methylstyrene, mixed aromatics, and indene with high purity, and to provide a device and method for comprehensive utilization of cracked C9.

[0007] The first aspect of the present invention provides a device for comprehensive utilization of cracked C9, including a reactive distillation column, a light component removal column, a heavy component removal column, an extractive distillation column, a mixed aromatics refining column, a 2-methylstyrene refining column, and an indene separation column; wherein,

[0008] The top of the reactive distillation column is connected to the light component removal column, and the bottom is connected to the heavy component removal column;

[0009] The top of the heavy component removal column is connected to the extractive distillation column, and the bottom is connected to the indene separation column;

[0010] The top of the extractive distillation column is connected to the mixed aromatics refining column, and the bottom is connected to the 2-methylstyrene refining column;

[0011] The top of the mixed aromatics refining column is connected to the extractive distillation column;

[0012] The bottom of the 2-methylstyrene refining column is connected to the extractive distillation column.

[0013] The second aspect of the present invention provides a method for comprehensive utilization of cracked C9, including the following steps:

[0014] (1) Depolymerize and rectify the C9 raw material in the reactive distillation column, cool the top of the column to obtain a cyclopentadiene fraction, and obtain the reactive distillation column heavy components at the bottom;

[0015] (2) Feed the cyclopentadiene fraction obtained at the top in step (1) into the light component removal column for refining, obtain light components at the top of the column, and obtain high-purity cyclopentadiene at the bottom;

[0016] (3) Feed the reactive distillation column heavy components obtained at the bottom in step (1) into the heavy component removal column for refining, obtain a fraction containing 2-methylstyrene and mixed aromatics at the top of the column, and obtain a fraction rich in indene at the bottom;

[0017] (4) Feed the fraction containing 2-methylstyrene and mixed aromatics obtained at the top in step (3) into the extractive distillation column for extractive distillation, obtain a fraction rich in mixed aromatics at the top of the column, and obtain a fraction rich in 2-methylstyrene at the bottom;

[0018] (5) Feed the fraction rich in mixed aromatics obtained at the top in step (4) into the mixed aromatics refining column for refining, obtain the extractant at the top of the column and return it to the extractive distillation column for recycling, and obtain high-quality mixed aromatics at the bottom;

[0019] (6) Feed the fraction rich in 2-methylstyrene obtained at the bottom of step (4) into a 2-methylstyrene refining column for refining. High-purity 2-methylstyrene is obtained at the top of the column, and the extractant is obtained at the bottom and returned to the extractive distillation column for recycling.

[0020] (7) Feed the fraction rich in indene obtained at the bottom of step (3) into an indene separation column for refining. Indene is obtained at the top of the column, and heavy components are obtained at the bottom.

[0021] In the present invention, the active components in cracked C9 are continuously separated by combining a reactive distillation column, an extractive distillation column, and a vacuum distillation column (indene separation column). The raw material used is the C9 fraction: First, the C9 fraction enters the reactive distillation column. By controlling the conditions of the reactive distillation column, dicyclopentadiene (DCPD) is continuously depolymerized in the reactive distillation column to generate CPD, which is taken out from the top of the column. After removing the light components in the light removal column, a high-purity CPD product is obtained at the bottom of the column. At the same time, the heavy components at the bottom of the reactive distillation column enter the heavy removal column. After removing the heavy components, the fraction containing 2-methylstyrene and mixed aromatics obtained at the top of the column enters the extractive distillation column. The separation of 2-methylstyrene and mixed aromatics is achieved by controlling the conditions, and then they enter the mixed aromatics refining column and the 2-methylstyrene refining column for refining respectively. The fraction containing indene obtained at the bottom of the heavy removal column enters the vacuum distillation column (indene separation column). The separation of indene is achieved by controlling the conditions. Finally, the entire device realizes the efficient separation of active components such as high-purity cyclopentadiene, 2-methylstyrene, mixed aromatics, and indene.

[0022] The device and method of the present invention can improve the utilization rate of C9 resources. While separating cyclopentadiene, the relatively high-content 2-methylstyrene, indene, and mixed aromatics are also separated and utilized, improving the economic added value of C9 resources.

[0023] Other features and advantages of the present invention will be described in detail in the following specific implementation section. Description of the Drawings

[0024] Figure 1 is a process flow diagram of the comprehensive utilization of cracked C9 in a specific implementation manner of the present invention.

[0025] Description of the Reference Numerals in the Drawings

[0026] 1 Reactive distillation column; 2 Light removal column; 3 Heavy removal column; 4 Extractive distillation column; 5 Mixed aromatics refining column; 6 2-methylstyrene refining column; 7 Indene separation column;

[0027] a C9 raw material; b Light components; c Cyclopentadiene; d Extractant; e Mixed aromatics; f 2-methylstyrene; g Indene; h Heavy components. Specific Implementation Manner

[0028] The following provides a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only for illustrating and explaining the present invention, and are not used to limit the present invention.

[0029] The present invention provides a comprehensive utilization device for cracked C9, as Figure 1 shown, which includes a reactive distillation column, a light component removal column, a heavy component removal column, an extractive distillation column, a mixed aromatics refining column, a 2-methylstyrene refining column, and an indene separation column; among them,

[0030] The top of the reactive distillation column is connected to the light component removal column, and the bottom is connected to the heavy component removal column;

[0031] The top of the heavy component removal column is connected to the extractive distillation column, and the bottom is connected to the indene separation column;

[0032] The top of the extractive distillation column is connected to the mixed aromatics refining column, and the bottom is connected to the 2-methylstyrene refining column;

[0033] The top of the mixed aromatics refining column is connected to the extractive distillation column;

[0034] The bottom of the 2-methylstyrene refining column is connected to the extractive distillation column.

[0035] According to a specific embodiment of the present invention, the reactive distillation column is provided with a C9 raw material feed pipeline, a light component discharge pipeline at the top of the reactive distillation column, and a heavy component discharge pipeline at the bottom of the reactive distillation column; the reactive distillation column is connected to the light component removal column through the light component discharge pipeline at the top of the reactive distillation column, and is connected to the heavy component removal column through the heavy component discharge pipeline at the bottom of the reactive distillation column.

[0036] According to a specific embodiment of the present invention, the light component removal column is provided with a light component discharge pipeline at the top of the light component removal column and a cyclopentadiene discharge pipeline at the bottom.

[0037] According to a specific embodiment of the present invention, the heavy component removal column is provided with a light component discharge pipeline at the top of the heavy component removal column and a heavy component discharge pipeline at the bottom of the heavy component removal column; the heavy component removal column is connected to the extractive distillation column through the light component discharge pipeline at the top of the heavy component removal column, and is connected to the indene separation column through the heavy component discharge pipeline at the bottom of the heavy component removal column.

[0038] According to a specific embodiment of the present invention, the extractive distillation column is provided with an extractant feed pipeline, a light component discharge pipeline at the top of the extractive distillation column, and a heavy component discharge pipeline at the bottom of the extractive distillation column; the extractive distillation column is connected to the mixed aromatics refining column through the light component discharge pipeline at the top of the extractive distillation column, and is connected to the 2-methylstyrene refining column through the heavy component discharge pipeline at the bottom of the extractive distillation column.

[0039] According to a specific embodiment of the present invention, a light component discharge pipeline is provided at the top of the mixed aromatics refining tower, and a mixed aromatics discharge pipeline is provided at the bottom of the tower; the light component discharge pipeline at the top of the mixed aromatics refining tower converges with the extractant feed pipeline.

[0040] According to a specific embodiment of the present invention, a 2-methylstyrene discharge pipeline is provided at the top of the 2-methylstyrene refining tower, and a heavy component discharge pipeline at the bottom of the 2-methylstyrene refining tower is provided at the bottom of the tower; the heavy component discharge pipeline at the bottom of the 2-methylstyrene refining tower converges with the extractant feed pipeline.

[0041] According to a specific embodiment of the present invention, an indene discharge pipeline is provided at the top of the indene separation tower, and a heavy component discharge pipeline of the indene separation tower is provided at the bottom.

[0042] The present invention also provides a comprehensive utilization method for cracked C9, which can be carried out in the above device, including the following steps:

[0043] (1) Depolymerize and rectify the C9 raw material in a reactive distillation column, cool the top of the column to obtain a cyclopentadiene fraction, and obtain a heavy component of the reactive distillation column at the bottom of the column;

[0044] (2) Pass the cyclopentadiene fraction obtained at the top of step (1) into a light component removal tower for refining, obtain light components at the top of the tower, and obtain high-purity cyclopentadiene at the bottom of the tower;

[0045] (3) Pass the heavy component of the reactive distillation column obtained at the bottom of step (1) into a heavy component removal tower for refining, obtain a fraction containing 2-methylstyrene and mixed aromatics at the top of the tower, and obtain a fraction rich in indene at the bottom of the tower;

[0046] (4) Pass the fraction containing 2-methylstyrene and mixed aromatics obtained at the top of step (3) into an extractive distillation column for extractive distillation, obtain a fraction rich in mixed aromatics at the top of the tower, and obtain a fraction rich in 2-methylstyrene at the bottom of the tower;

[0047] (5) Pass the fraction rich in mixed aromatics obtained at the top of step (4) into a mixed aromatics refining tower for refining, obtain the extractant at the top of the tower and return it to the extractive distillation column for recycling, and obtain high-quality mixed aromatics at the bottom of the tower;

[0048] (6) Pass the fraction rich in 2-methylstyrene obtained at the bottom of step (4) into a 2-methylstyrene refining tower for refining, obtain high-purity 2-methylstyrene at the top of the tower, and obtain the extractant at the bottom of the tower and return it to the extractive distillation column for recycling;

[0049] (7) Pass the fraction rich in indene obtained at the bottom of step (3) into an indene separation tower for refining, obtain indene at the top of the tower, and obtain heavy components at the bottom of the tower.

[0050] According to the present invention, preferably, the operating conditions of the reactive distillation column include: the number of theoretical plates is 20 - 50, the top temperature is 30 - 50 °C, the top pressure is atmospheric pressure, the bottom temperature is 180 - 230 °C, and the reflux ratio is 5 - 20.

[0051] According to the present invention, preferably, the operating conditions of the light component removal column include: the number of theoretical plates is 50 - 80, the bottom temperature is 40 - 80 °C, and the reflux ratio is 10 - 30.

[0052] According to the present invention, preferably, the operating conditions of the heavy component removal column include: the number of theoretical plates is 50 - 80, the bottom temperature is 190 - 220 °C, and the reflux ratio is 5 - 15.

[0053] According to the present invention, preferably, the operating conditions of the extractive distillation column include: the number of theoretical plates is 50 - 90, the operating pressure is 5 - 20 kPa, the bottom temperature is 250 - 330 °C, the reflux ratio is 15 - 25, and the mass ratio of the extractant to the feed is 0.1 - 2, preferably 0.3 - 1.5.

[0054] According to the present invention, preferably, the operating conditions of the mixed aromatics refining column include: the number of theoretical plates is 40 - 80, the bottom temperature is 250 - 265 °C, the reflux ratio is 10 - 25, and the operating pressure is atmospheric pressure.

[0055] According to the present invention, preferably, the operating conditions of the 2 - methylstyrene refining column include: the number of theoretical plates is 50 - 80, the bottom temperature is 290 - 410 °C, and the reflux ratio is 5 - 20.

[0056] According to the present invention, preferably, the operating conditions of the indene separation column include: the number of theoretical plates is 50 - 90, the operating pressure is 5 - 30 kPa, the bottom temperature is 140 - 200 °C, and the reflux ratio is 5 - 25.

[0057] The extractant used in the present invention can be at least one of glycerol (GLY), N,N - dimethylformamide (DMF), sulfolane, and dimethyl sulfoxide (DMSO), preferably at least two of glycerol, N,N - dimethylformamide, sulfolane, and dimethyl sulfoxide, such as a compound solvent of N,N - dimethylformamide and other extractants, and the mass ratio of the two is 5 - 15:1, preferably 8 - 10:1.

[0058] In the present invention, the C9 raw material refers to the ethylene - cracked C9 fraction, which usually contains but is not limited to dicyclopentadiene, 2 - methylstyrene and its homologues, mixed aromatics, indene and its homologues.

[0059] The present invention will be further described below in conjunction with embodiments, but the scope of the present invention is not limited to these embodiments.

[0060] The component contents of the ethylene pyrolysis C9 raw material used in the following examples are as follows: dicyclopentadiene 17.69%, 2-methylstyrene and homologues 21.37%, mixed aromatics 10.8%, indene and homologues 12.28%.

[0061] The following examples all adopt the process flow as Figure 1 shown. The devices used include: reactive distillation column 1, light component removal column 2, heavy component removal column 3, extractive distillation column 4, mixed aromatics refining column 5, 2-methylstyrene refining column 6 and indene separation column 7; among them,

[0062] The reactive distillation column 1 is provided with a C9 raw material feed pipeline, a light component discharge pipeline at the top of the reactive distillation column, and a heavy component discharge pipeline at the bottom of the reactive distillation column; the reactive distillation column 1 is connected to the light component removal column 2 through the light component discharge pipeline at the top of the reactive distillation column and is connected to the heavy component removal column 3 through the heavy component discharge pipeline at the bottom of the reactive distillation column.

[0063] The light component removal column 2 is provided with a light component discharge pipeline at the top of the light component removal column and a cyclopentadiene discharge pipeline at the bottom.

[0064] The heavy component removal column 3 is provided with a light component discharge pipeline at the top of the heavy component removal column and a heavy component discharge pipeline at the bottom of the heavy component removal column; the heavy component removal column 3 is connected to the extractive distillation column 4 through the light component discharge pipeline at the top of the heavy component removal column and is connected to the indene separation column 7 through the heavy component discharge pipeline at the bottom of the heavy component removal column.

[0065] The extractive distillation column 4 is provided with an extractant feed pipeline at the upper part, a light component discharge pipeline at the top of the extractive distillation column, and a heavy component discharge pipeline at the bottom of the extractive distillation column; the extractive distillation column 4 is connected to the mixed aromatics refining column 5 through the light component discharge pipeline at the top of the extractive distillation column and is connected to the 2-methylstyrene refining column 6 through the heavy component discharge pipeline at the bottom of the extractive distillation column.

[0066] The mixed aromatics refining column 5 is provided with a light component discharge pipeline at the top of the mixed aromatics refining column and a mixed aromatics discharge pipeline at the bottom; the light component discharge pipeline at the top of the mixed aromatics refining column converges with the extractant feed pipeline.

[0067] The 2-methylstyrene refining column 6 is provided with a 2-methylstyrene discharge pipeline at the top and a heavy component discharge pipeline at the bottom of the 2-methylstyrene refining column; the heavy component discharge pipeline at the bottom of the 2-methylstyrene refining column converges with the extractant feed pipeline.

[0068] The indene separation column 7 is provided with an indene discharge pipeline at the top and a heavy component discharge pipeline at the bottom of the indene separation column.

[0069] Example 1

[0070] This example is used to illustrate a comprehensive utilization method of cracked C9, which is carried out in the above device by using the Figure 1 process flow shown, including the following steps:

[0071] (1) Depolymerize and rectify the C9 raw material a in the reactive distillation column 1. The number of theoretical plates of the reactive distillation column 1 is 30, the reflux ratio is set to 10, the bottom temperature is 215 °C, and the top pressure is atmospheric pressure. The top is cooled at 38 °C to obtain a cyclopentadiene fraction, and the bottom of the column obtains the heavy components of the reactive distillation column.

[0072] (2) Feed the cyclopentadiene fraction obtained at the top in step (1) into the light component removal column 2 for purification. The number of theoretical plates of the light component removal column 2 is 60, the reflux ratio is set to 15, and the bottom temperature is 53 °C. The light component b is obtained at the top, and high-purity cyclopentadiene c is obtained at the bottom.

[0073] (3) Feed the heavy components of the reactive distillation column obtained at the bottom in step (1) into the heavy component removal column 3 for purification. The number of theoretical plates of the heavy component removal column 3 is 60, the reflux ratio is set to 5, and the bottom temperature is 202 °C. The fraction containing 2-methylstyrene and mixed aromatics is obtained at the top, and the fraction rich in indene is obtained at the bottom.

[0074] (4) Feed the fraction containing 2-methylstyrene and mixed aromatics obtained at the top in step (3) into the extractive distillation column 4 for extractive distillation. The extractant d (glycerol + N,N-dimethylformamide, with a mass ratio of 9:1) is fed into the upper part of the extractive distillation column 4 at room temperature. The number of theoretical plates of the extractive distillation column 4 is 80, the reflux ratio is set to 15, the bottom temperature is 298 °C, and it operates at 10 kPa. The mass flow ratio of the extractant d to the raw material is 0.5. The fraction rich in mixed aromatics is obtained at the top, and the fraction rich in 2-methylstyrene is obtained at the bottom.

[0075] (5) Feed the fraction rich in mixed aromatics obtained at the top in step (4) into the mixed aromatics purification column 5 for purification. The number of theoretical plates of the mixed aromatics purification column 5 is 60, it operates at atmospheric pressure, the reflux ratio is set to 20, the bottom temperature is 258 °C. The extractant is obtained at the top and returned to the extractive distillation column 4 for recycling, and high-quality mixed aromatics e are obtained at the bottom.

[0076] (6) Feed the fraction rich in 2-methylstyrene obtained at the bottom in step (4) into the 2-methylstyrene purification column 6 for purification. The number of theoretical plates of the 2-methylstyrene purification column 6 is 60, it operates at atmospheric pressure, the reflux ratio is set to 10, the bottom temperature is 377 °C. High-purity 2-methylstyrene f is obtained at the top, and the extractant is obtained at the bottom and returned to the extractive distillation column 4 for recycling.

[0077] (7) Feed the indene-rich fraction obtained at the bottom of the column in step (3) into the indene separation column 7 for purification. The theoretical number of plates of the indene separation column 7 is 60, the operating pressure is 10 kPa, the reflux ratio is set to 10, the column bottom temperature is 145.2 °C, indene g is obtained at the top of the column, and a heavy component h is obtained at the column bottom.

[0078] Example 2

[0079] This example is used to illustrate a comprehensive utilization method of cracked C9, which is carried out in the above device using the Figure 1 process flow shown, including the following steps:

[0080] (1) Carry out depolymerization rectification on the C9 raw material a in the reactive distillation column 1. The theoretical number of plates of the reactive distillation column 1 is 30, the reflux ratio is set to 10, the column bottom temperature is 215 °C, the top pressure of the column is atmospheric pressure, the overhead is cooled at 38 °C to obtain a cyclopentadiene fraction, and a reactive distillation column heavy component is obtained at the column bottom.

[0081] (2) Feed the cyclopentadiene fraction obtained at the top of the column in step (1) into the light component removal column 2 for purification. The theoretical number of plates of the light component removal column 2 is 60, the reflux ratio is set to 15, the column bottom temperature is 53 °C, light component b is obtained at the top of the column, and high-purity cyclopentadiene c is obtained at the column bottom.

[0082] (3) Feed the reactive distillation column heavy component obtained at the column bottom in step (1) into the heavy component removal column 3 for purification. The theoretical number of plates of the heavy component removal column 3 is 60, the reflux ratio is set to 8, the column bottom temperature is 202 °C, a fraction containing 2-methylstyrene and mixed aromatics is obtained at the top of the column, and an indene-rich fraction is obtained at the column bottom.

[0083] (4) Feed the fraction containing 2-methylstyrene and mixed aromatics obtained at the top of the column in step (3) into the extractive distillation column 4 for extractive distillation. The extractant d (glycerol + N,N-dimethylformamide, with a mass ratio of 9:1) is fed into the upper part of the extractive distillation column 4 at room temperature. The theoretical number of plates of the extractive distillation column 4 is 80, the reflux ratio is set to 20, the column bottom temperature is 311 °C, and it operates at 10 kPa. The mass flow ratio of the extractant d to the raw material is 0.5. A fraction rich in mixed aromatics is obtained at the top of the column, and a fraction rich in 2-methylstyrene is obtained at the column bottom.

[0084] (5) Feed the fraction rich in mixed aromatics obtained at the top of the column in step (4) into the mixed aromatics purification column 5 for purification. The theoretical number of plates of the mixed aromatics purification column 5 is 60, it operates at atmospheric pressure, the reflux ratio is set to 20, the column bottom temperature is 258 °C, the extractant is obtained at the top of the column and returned to the extractive distillation column 4 for recycling, and high-quality mixed aromatics e is obtained at the column bottom.

[0085] (6) Feed the fraction rich in 2-methylstyrene obtained at the bottom of step (4) into the 2-methylstyrene refining column 6 for refining. The theoretical number of trays of the 2-methylstyrene refining column 6 is 60, it operates at atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the column is 377 °C. High-purity 2-methylstyrene f is obtained at the top of the column, and the extractant is obtained at the bottom and returned to the extractive distillation column 4 for recycling.

[0086] (7) Feed the fraction rich in indene obtained at the bottom of step (3) into the indene separation column 7 for refining. The theoretical number of trays of the indene separation column 7 is 60, the operating pressure is 10 kPa, the reflux ratio is set to 10, the bottom temperature of the column is 145.2 °C. Indene g is obtained at the top of the column, and the heavy components h are obtained at the bottom of the column.

[0087] Example 3

[0088] This example is used to illustrate a comprehensive utilization method of cracked C9, which is carried out in the above device using the Figure 1 shown process flow, including the following steps:

[0089] (1) Carry out depolymerization rectification on the C9 raw material a in the reactive distillation column 1. The theoretical number of trays of the reactive distillation column 1 is 40, the reflux ratio is set to 8, the bottom temperature of the column is 215 °C, the top pressure of the column is atmospheric pressure. The cyclopentadiene fraction is cooled at 38 °C at the top of the column, and the reactive distillation column heavy components are obtained at the bottom of the column.

[0090] (2) Feed the cyclopentadiene fraction obtained at the top of step (1) into the light component removal tower 2 for refining. The theoretical number of trays of the light component removal tower 2 is 50, the reflux ratio is set to 20, the bottom temperature of the column is 53 °C. Light components b are obtained at the top of the column, and high-purity cyclopentadiene c is obtained at the bottom of the column.

[0091] (3) Feed the reactive distillation column heavy components obtained at the bottom of step (1) into the heavy component removal tower 3 for refining. The theoretical number of trays of the heavy component removal tower 3 is 60, the reflux ratio is set to 5, the bottom temperature of the column is 202 °C. The fraction containing 2-methylstyrene and mixed aromatics is obtained at the top of the column, and the fraction rich in indene is obtained at the bottom of the column.

[0092] (4) Feed the fraction containing 2-methylstyrene and mixed aromatics obtained at the top of step (3) into the extractive distillation column 4 for extractive distillation. The extractant d (dimethyl sulfoxide + N,N-dimethylformamide, the mass ratio of the two is 9:1) is fed into the upper part of the extractive distillation column 4 at room temperature. The theoretical number of trays of the extractive distillation column 4 is 80, the reflux ratio is set to 20, the bottom temperature of the column is 279 °C, it operates at 15 kPa. The mass flow ratio of the extractant d to the raw material is 0.5. The fraction rich in mixed aromatics is obtained at the top of the column, and the fraction rich in 2-methylstyrene is obtained at the bottom of the column.

[0093] (5) Feed the fraction rich in mixed aromatics obtained from the top of the tower in step (4) into the mixed aromatics refining column 5 for refining. The theoretical number of trays of the mixed aromatics refining column 5 is 60, it operates under atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the tower is 258 °C, the extractant obtained from the top of the tower is returned to the extractive distillation column 4 for recycling, and high-quality mixed aromatics e are obtained at the bottom of the tower.

[0094] (6) Feed the fraction rich in 2-methylstyrene obtained from the bottom of the tower in step (4) into the 2-methylstyrene refining column 6 for refining. The theoretical number of trays of the 2-methylstyrene refining column 6 is 90, it operates under atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the tower is 304 °C, high-purity 2-methylstyrene f is obtained from the top of the tower, and the extractant obtained from the bottom of the tower is returned to the extractive distillation column 4 for recycling.

[0095] (7) Feed the fraction rich in indene obtained from the bottom of the tower in step (3) into the indene separation column 7 for refining. The theoretical number of trays of the indene separation column 7 is 70, the operating pressure is 15 kPa, the reflux ratio is set to 10, the bottom temperature of the tower is 153 °C, indene g is obtained from the top of the tower, and heavy components h are obtained at the bottom of the tower.

[0096] Example 4

[0097] This example is used to illustrate a method for comprehensive utilization of cracked C9, which is carried out in the above device using the Figure 1 shown process flow, including the following steps:

[0098] (1) Carry out depolymerization rectification of the C9 raw material a in the reactive distillation column 1. The theoretical number of trays of the reactive distillation column 1 is 40, the reflux ratio is set to 15, the bottom temperature of the tower is 215 °C, the top pressure of the tower is atmospheric pressure, the overhead is cooled at 38 °C to obtain a cyclopentadiene fraction, and the reactive distillation column heavy components are obtained at the bottom of the tower.

[0099] (2) Feed the cyclopentadiene fraction obtained from the top of the tower in step (1) into the light component removal tower 2 for refining. The theoretical number of trays of the light component removal tower 2 is 50, the reflux ratio is set to 15, the bottom temperature of the tower is 53 °C, light components b are obtained from the top of the tower, and high-purity cyclopentadiene c is obtained at the bottom of the tower.

[0100] (3) Feed the reactive distillation column heavy components obtained from the bottom of the tower in step (1) into the heavy component removal tower 3 for refining. The theoretical number of trays of the heavy component removal tower 3 is 50, the reflux ratio is set to 10, the bottom temperature of the tower is 202 °C, a fraction containing 2-methylstyrene and mixed aromatics is obtained from the top of the tower, and a fraction rich in indene is obtained at the bottom of the tower.

[0101] (4) Feed the fraction containing 2-methylstyrene and mixed aromatics obtained at the top of the column in step (3) into the extractive distillation column 4 for extractive distillation. The extractant d (dimethyl sulfoxide + N,N-dimethylformamide, with a mass ratio of 9:1) is fed into the upper part of the extractive distillation column 4 at room temperature. The extractive distillation column 4 has 80 theoretical plates, a reflux ratio of 15, a bottom temperature of 280 °C, and operates at 10 kPa. The mass flow ratio of the extractant d to the raw material is 0.5. A fraction rich in mixed aromatics is obtained at the top of the column, and a fraction rich in 2-methylstyrene is obtained at the bottom of the column.

[0102] (5) Feed the fraction rich in mixed aromatics obtained at the top of the column in step (4) into the mixed aromatics purification column 5 for purification. The mixed aromatics purification column 5 has 70 theoretical plates, operates at atmospheric pressure, has a reflux ratio of 10, and a bottom temperature of 258 °C. The extractant is obtained at the top of the column and returned to the extractive distillation column 4 for recycling, and high-quality mixed aromatics e are obtained at the bottom of the column.

[0103] (6) Feed the fraction rich in 2-methylstyrene obtained at the bottom of the column in step (4) into the 2-methylstyrene purification column 6 for purification. The 2-methylstyrene purification column 6 has 80 theoretical plates, operates at atmospheric pressure, has a reflux ratio of 15, and a bottom temperature of 297 °C. High-purity 2-methylstyrene f is obtained at the top of the column, and the extractant is obtained at the bottom of the column and returned to the extractive distillation column 4 for recycling.

[0104] (7) Feed the fraction rich in indene obtained at the bottom of the column in step (3) into the indene separation column 7 for purification. The indene separation column 7 has 60 theoretical plates, an operating pressure of 15 kPa, a reflux ratio of 10, and a bottom temperature of 153 °C. Indene g is obtained at the top of the column, and a heavy component h is obtained at the bottom of the column.

[0105] Example 5

[0106] This example is used to illustrate a method for comprehensive utilization of cracked C9, which is carried out in the above device using the Figure 1 process flow shown, including the following steps:

[0107] (1) Carry out depolymerization distillation of the C9 raw material a in the reactive distillation column 1. The reactive distillation column 1 has 40 theoretical plates, a reflux ratio of 8, a bottom temperature of 215 °C, and a top pressure of atmospheric pressure. The cyclopentadiene fraction is cooled at 38 °C at the top of the column, and the reactive distillation column heavy component is obtained at the bottom of the column.

[0108] (2) Feed the cyclopentadiene fraction obtained at the top of the column in step (1) into the light component removal column 2 for purification. The light component removal column 2 has 50 theoretical plates, a reflux ratio of 15, and a bottom temperature of 53 °C. Light component b is obtained at the top of the column, and high-purity cyclopentadiene c is obtained at the bottom of the column.

[0109] (3) The heavy components obtained at the bottom of the reactive distillation column in step (1) are fed into the heavy component removal column 3 for purification. The theoretical number of plates of the heavy component removal column 3 is 60, the reflux ratio is set to 8, the bottom temperature of the column is 202 °C, a fraction containing 2-methylstyrene and mixed aromatic hydrocarbons is obtained at the top of the column, and a fraction rich in indene is obtained at the bottom of the column.

[0110] (4) The fraction containing 2-methylstyrene and mixed aromatic hydrocarbons obtained at the top of the column in step (3) is fed into the extractive distillation column 4 for extractive distillation. The extractant d (sulfolane + DMF, with a mass ratio of 9:1 between the two) is fed into the upper part of the extractive distillation column 4 at room temperature. The theoretical number of plates of the extractive distillation column 4 is 80, the reflux ratio is set to 15, the bottom temperature of the column is 293 °C, and it operates at 10 kPa. The mass flow ratio of the extractant d to the raw material is 0.4. A fraction rich in mixed aromatic hydrocarbons is obtained at the top of the column, and a fraction rich in 2-methylstyrene is obtained at the bottom of the column.

[0111] (5) The fraction rich in mixed aromatic hydrocarbons obtained at the top of the column in step (4) is fed into the mixed aromatic hydrocarbon purification column 5 for purification. The theoretical number of plates of the mixed aromatic hydrocarbon purification column 5 is 60, it operates at atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the column is 258 °C, the extractant is obtained at the top of the column and returned to the extractive distillation column 4 for recycling, and high-quality mixed aromatic hydrocarbon e is obtained at the bottom of the column.

[0112] (6) The fraction rich in 2-methylstyrene obtained at the bottom of the column in step (4) is fed into the 2-methylstyrene purification column 6 for purification. The theoretical number of plates of the 2-methylstyrene purification column 6 is 80, it operates at atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the column is 408 °C, high-purity 2-methylstyrene f is obtained at the top of the column, and the extractant is obtained at the bottom of the column and returned to the extractive distillation column 4 for recycling.

[0113] (7) The fraction rich in indene obtained at the bottom of the column in step (3) is fed into the indene separation column 7 for purification. The theoretical number of plates of the indene separation column 7 is 60, the operating pressure is 15 kPa, the reflux ratio is set to 10, the bottom temperature of the column is 153 °C, indene g is obtained at the top of the column, and heavy components h are obtained at the bottom of the column.

[0114] Example 6

[0115] This example is used to illustrate a method for comprehensive utilization of cracked C9, which is carried out in the above device using the Figure 1 shown process flow, including the following steps:

[0116] (1) The C9 raw material a is subjected to depolymerization distillation in the reactive distillation column 1. The theoretical number of plates of the reactive distillation column 1 is 50, the reflux ratio is set to 8, the bottom temperature of the column is 215 °C, the top pressure of the column is atmospheric pressure, the cyclopentadiene fraction is obtained by cooling at 38 °C at the top of the column, and the heavy components of the reactive distillation column are obtained at the bottom of the column.

[0117] (2) Feed the cyclopentadiene fraction obtained from the top of the tower in step (1) into the light component removal tower 2 for purification. The theoretical number of trays of the light component removal tower 2 is 50, the reflux ratio is set to 15, the bottom temperature of the tower is 53 °C, light component b is obtained from the top of the tower, and high-purity cyclopentadiene c is obtained from the bottom of the tower.

[0118] (3) Feed the heavy components of the reactive distillation tower obtained from the bottom of the tower in step (1) into the heavy component removal tower 3 for purification. The theoretical number of trays of the heavy component removal tower 3 is 60, the reflux ratio is set to 8, the bottom temperature of the tower is 202 °C, a fraction containing 2-methylstyrene and mixed aromatics is obtained from the top of the tower, and a fraction rich in indene is obtained from the bottom of the tower.

[0119] (4) Feed the fraction containing 2-methylstyrene and mixed aromatics obtained from the top of the tower in step (3) into the extractive distillation tower 4 for extractive distillation. The extractant d (sulfolane + DMF, with a mass ratio of 9:1) is fed into the upper part of the extractive distillation tower 4 at room temperature. The theoretical number of trays of the extractive distillation tower 4 is 60, the reflux ratio is set to 20, the bottom temperature of the tower is 274 °C, and it operates at 10 kPa. The mass flow ratio of the extractant d to the raw material is 0.3. A fraction rich in mixed aromatics is obtained from the top of the tower, and a fraction rich in 2-methylstyrene is obtained from the bottom of the tower.

[0120] (5) Feed the fraction rich in mixed aromatics obtained from the top of the tower in step (4) into the mixed aromatics purification tower 5 for purification. The theoretical number of trays of the mixed aromatics purification tower 5 is 60, it operates at atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the tower is 258 °C. The extractant is obtained from the top of the tower and returned to the extractive distillation tower 4 for recycling, and high-quality mixed aromatics e are obtained from the bottom of the tower.

[0121] (6) Feed the fraction rich in 2-methylstyrene obtained from the bottom of the tower in step (4) into the 2-methylstyrene purification tower 6 for purification. The theoretical number of trays of the 2-methylstyrene purification tower 6 is 80, it operates at atmospheric pressure, the reflux ratio is set to 15, the bottom temperature of the tower is 408 °C. High-purity 2-methylstyrene f is obtained from the top of the tower, and the extractant is obtained from the bottom of the tower and returned to the extractive distillation tower 4 for recycling.

[0122] (7) Feed the fraction rich in indene obtained from the bottom of the tower in step (3) into the indene separation tower 7 for purification. The theoretical number of trays of the indene separation tower 7 is 60, the operating pressure is 15 kPa, the reflux ratio is set to 10, the bottom temperature of the tower is 153 °C. Indene g is obtained from the top of the tower, and heavy components h are obtained from the bottom of the tower.

[0123] Test Example 1

[0124] Test the yields and purities of cyclopentadiene, 2-methylstyrene, mixed aromatics, and indene obtained in each example. The results are shown in Table 1 below.

[0125] Pre - test the content of dicyclopentadiene and its monomer, the content of 2 - methylstyrene, the content of mixed aromatics, and the content of indene in the C9 fraction to obtain the content of the corresponding components in this batch of C9 fraction.

[0126] The yield is calculated using the following formula:

[0127] The yield of cyclopentadiene = the mass of the obtained dicyclopentadiene / the content of dicyclopentadiene and its monomer in the C9 fraction × 100%.

[0128] The yield of 2 - methylstyrene = the mass of the obtained 2 - methylstyrene / the content of 2 - methylstyrene in the C9 fraction × 100%.

[0129] The yield of mixed aromatics = the mass of the obtained mixed aromatics / the content of mixed aromatics in the C9 fraction × 100%.

[0130] The yield of indene = the mass of the obtained indene / the content of indene in the C9 fraction × 100%.

[0131] Table 1

[0132]

[0133] As can be seen from Table 1, by using the device and method of the present invention, the efficient separation of active components such as cyclopentadiene, 2 - methylstyrene, mixed aromatics, and indene with relatively high purity is achieved.

[0134] The above has described the embodiments of the present invention. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

[0135] The endpoints and any values disclosed herein are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

Claims

1. A comprehensive utilization device for cracked C9, comprising a reactive distillation column, a light component removal column, a heavy component removal column, an extractive distillation column, a mixed aromatics refining column, a 2-methylstyrene refining column, and an indene separation column; wherein, The top of the reactive distillation column is connected to the light component removal column, and the bottom is connected to the heavy component removal column; The top of the heavy component removal column is connected to the extractive distillation column, and the bottom is connected to the indene separation column; The top of the extractive distillation column is connected to the mixed aromatics refining column, and the bottom is connected to the 2-methylstyrene refining column; The top of the mixed aromatics refining column is connected to the extractive distillation column; The bottom of the 2-methylstyrene refining column is connected to the extractive distillation column.

2. The cracking C9 comprehensive utilization device according to claim 1, wherein, The reactive distillation column is provided with a C9 raw material feed pipeline, a light component discharge pipeline at the top of the reactive distillation column, and a heavy component discharge pipeline at the bottom of the reactive distillation column; the reactive distillation column is connected to the light component removal column through the light component discharge pipeline at the top of the reactive distillation column, and is connected to the heavy component removal column through the heavy component discharge pipeline at the bottom of the reactive distillation column.

3. The cracking C9 comprehensive utilization device according to claim 1, wherein, The top of the light component removal column is provided with a light component discharge pipeline at the top of the light component removal column, and the bottom is provided with a cyclopentadiene discharge pipeline.

4. The cracking C9 comprehensive utilization device according to claim 1, wherein, The heavy component removal column is provided with a light component discharge pipeline at the top of the heavy component removal column and a heavy component discharge pipeline at the bottom of the heavy component removal column; the heavy component removal column is connected to the extractive distillation column through the light component discharge pipeline at the top of the heavy component removal column, and is connected to the indene separation column through the heavy component discharge pipeline at the bottom of the heavy component removal column.

5. The cracking C9 comprehensive utilization device according to claim 1, wherein, The extractive distillation column is provided with an extractant feed pipeline, a light component discharge pipeline at the top of the extractive distillation column, and a heavy component discharge pipeline at the bottom of the extractive distillation column; the extractive distillation column is connected to the mixed aromatics refining column through the light component discharge pipeline at the top of the extractive distillation column, and is connected to the 2-methylstyrene refining column through the heavy component discharge pipeline at the bottom of the extractive distillation column.

6. The cracking C9 comprehensive utilization device according to claim 5, wherein, The top of the mixed aromatics refining column is provided with a light component discharge pipeline at the top of the mixed aromatics refining column and a mixed aromatics discharge pipeline at the bottom; the light component discharge pipeline at the top of the mixed aromatics refining column converges with the extractant feed pipeline.

7. The cracking C9 comprehensive utilization device according to claim 5, wherein, The top of the 2-methylstyrene refining column is provided with a 2-methylstyrene discharge pipeline, and the bottom is provided with a heavy component discharge pipeline at the bottom of the 2-methylstyrene refining column; the heavy component discharge pipeline at the bottom of the 2-methylstyrene refining column converges with the extractant feed pipeline.

8. The cracking C9 comprehensive utilization device according to claim 1, wherein, The top of the indene separation column is provided with an indene discharge pipeline, and the bottom is provided with a heavy component discharge pipeline at the bottom of the indene separation column.

9. A comprehensive utilization method for cracked C9, comprising the following steps: (1) Depolymerize and rectify the C9 raw material in the reactive distillation column, cool the top to obtain a cyclopentadiene fraction, and obtain the reactive distillation column heavy components at the bottom; (2) Feed the cyclopentadiene fraction obtained at the top in step (1) into the light component removal column for refining, obtain light components at the top, and obtain high-purity cyclopentadiene at the bottom; (3) Feed the reactive distillation column heavy components obtained at the bottom in step (1) into the heavy component removal column for refining, obtain a fraction containing 2-methylstyrene and mixed aromatics at the top, and obtain a fraction rich in indene at the bottom; (4) The fraction containing 2-methylstyrene and mixed aromatics obtained from the top of the tower in step (3) is fed into an extractive distillation column for extractive distillation. A fraction rich in mixed aromatics is obtained from the top of the tower, and a fraction rich in 2-methylstyrene is obtained from the bottom of the tower. (5) The fraction rich in mixed aromatics obtained from the top of the tower in step (4) is fed into a mixed aromatics refining column for refining. The extractant is obtained from the top of the tower and returned to the extractive distillation column for recycling use, and high-quality mixed aromatics are obtained from the bottom of the tower. (6) The fraction rich in 2-methylstyrene obtained from the bottom of the tower in step (4) is fed into a 2-methylstyrene refining column for refining. High-purity 2-methylstyrene is obtained from the top of the tower, and the extractant is obtained from the bottom of the tower and returned to the extractive distillation column for recycling use. (7) The fraction rich in indene obtained from the bottom of the tower in step (3) is fed into an indene separation column for refining. Indene is obtained from the top of the tower, and heavy components are obtained from the bottom of the tower.

10. The method for comprehensive utilization of cracked C9 according to claim 9, wherein the operating conditions of the reactive distillation column include: the number of theoretical plates is 20 - 50, the top temperature of the tower is 30 - 50 °C, the top pressure of the tower is atmospheric pressure, the bottom temperature of the tower is 180 - 230 °C, and the reflux ratio is 5 - 20; the operating conditions of the light component removal column include: the number of theoretical plates is 50 - 80, the bottom temperature of the tower is 40 - 80 °C, and the reflux ratio is 10 - 30; the operating conditions of the heavy component removal column include: the number of theoretical plates is 50 - 80, the bottom temperature of the tower is 190 - 220 °C, and the reflux ratio is 5 - 15; the operating conditions of the extractive distillation column include: the number of theoretical plates is 50 - 90, the operating pressure is 5 - 20 kPa, the bottom temperature of the tower is 250 - 330 °C, the reflux ratio is 15 - 25, and the mass ratio of the extractant to the feed is 0.1 - 2, preferably 0.3 - 1.5; the operating conditions of the mixed aromatics refining column include: the number of theoretical plates is 40 - 80, the bottom temperature of the tower is 250 - 265 °C, the reflux ratio is 10 - 25, and the operating pressure is atmospheric pressure; the operating conditions of the 2-methylstyrene refining column include: the number of theoretical plates is 50 - 80, the bottom temperature of the tower is 290 - 410 °C, and the reflux ratio is 5 - 20; the operating conditions of the indene separation column include: the number of theoretical plates is 50 - 90, the operating pressure is 5 - 30 kPa, the bottom temperature of the tower is 140 - 200 °C, and the reflux ratio is 5 - 25.

11. The comprehensive utilization method of cracked C9 according to claim 9 or 10, wherein, The extractant is at least one of glycerol, N,N-dimethylformamide, sulfolane, and dimethyl sulfoxide.

12. The comprehensive utilization method of cracked C9 according to claim 9 or 10, wherein, The C9 raw material is ethylene cracking C9 fraction.

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