Dividing wall tower rectification system for refining C8-C10 < + > aromatic hydrocarbons by using dividing wall tower

Abstract

The utility model relates to the technical field of chemical industry, and discloses a dividing wall tower rectification system for refining C8-C10 + aromatic hydrocarbon by using a dividing wall tower, which comprises a rectifying tower body and a condenser, a material feeding pipe is arranged in the middle of the rectifying tower body, a vertical partition plate is arranged at the bottom of the rectifying tower body, and a material discharging pipe is arranged at the bottom of the condenser. A vertical partition plate is arranged in the lower cavity of the rectifying tower body, the vertical partition plate divides the lower cavity of the rectifying tower body into a C9 aromatic hydrocarbon extraction side and a C10 / C10 + aromatic hydrocarbon extraction side which are isolated from each other, a C9 aromatic hydrocarbon extraction pump path is arranged at the bottom of the C9 aromatic hydrocarbon extraction side, a C10 / C10 + aromatic hydrocarbon extraction pump path is arranged at the bottom of the C10 / C10 + aromatic hydrocarbon extraction side, and a C8 aromatic hydrocarbon extraction pipe is arranged at the top of the rectifying tower body; the lower cavity of the rectifying tower body is divided into the C9 aromatic hydrocarbon recovery side and the C10 / C10 + aromatic hydrocarbon recovery side which are isolated from each other by the vertical partition plate, so that the complexity of a system is reduced, the adjustment is simple and easy, the requirement of high purity of each product can be met, and the separation of C9 aromatic hydrocarbon, C10 / C10 + aromatic hydrocarbon and C8 aromatic hydrocarbon can be realized at the same time.

Description

Technical Field

[0001] This utility model relates to the field of chemical technology, and in particular to a distillation system for refining C8-C10+ aromatic hydrocarbons using a wall-mounted distillation column. Background Technology

[0002] Catalytic reforming is a crucial process in petroleum refining, generating large quantities of C8 to C10+ heavy aromatics. The reformed oil can be used as a gasoline blending agent or separated into important chemical feedstocks such as xylene, mesitylene, pseudotrimethylbenzene, methylbenzene, ethylbenzene, mesitylene, pseudotrimethylbenzene, and methyltrimethylbenzene. Catalytic reforming units are characterized by long processes, numerous pieces of equipment, and high energy consumption; therefore, achieving efficient and low-energy separation of various heavy aromatics has been a ongoing research focus.

[0003] Among them, CN113262515A proposes a partitioned distillation column for separating mixed fractions of C8-C11 n-alkanes. The column distills C8 products from the top, C9 and C10 products are collected from the side stream, and C11 products are collected from the bottom. It cannot simultaneously produce mixed xylenes that meet the standards, industrial C9 aromatics, and industrial C10 crude aromatics.

[0004] Among them, CN106242937B proposed a method for separating heavy aromatics (C9 and above heavy aromatics) from methanol-to-gasoline using crystallization and ordinary distillation in a three-tower system to obtain pseudotrimethylbenzene and mesitylene. This method first involves crystallization and then distillation, which has a long process, high energy consumption, and low economic benefits.

[0005] Among them, CN101768467B and CN105541543B respectively proposed methods for obtaining pseudotrimethylbenzene, mesitylene and aromatic solvent oil by using a traditional five-tower crystallization process and a traditional three-tower crystallization process for methanol-to-gasoline heavy aromatics, mainly C9 and above heavy aromatics. These processes use traditional separation processes, which are long, require high investment and have high energy consumption.

[0006] Among them, CN107226772A proposed a method for utilizing heavy aromatics in C9 and above fractions, which involves catalytic cracking of C9 and C10 fractions, hydrocracking of C11 and above fractions, and producing xylene and mesitylene by separating the reaction products through a traditional tower separation process. This process uses traditional tower separation, which has a long process and high energy consumption.

[0007] The aforementioned systems suffer from complexity and high energy consumption. Therefore, designing a simple and easy-to-implement distillation system that can meet the high purity requirements of various products has become an urgent problem to be solved in the industry. Utility Model Content

[0008] The main purpose of this invention is to propose a distillation system for refining C8-C10+ aromatic hydrocarbons using a wall-mounted column, in order to solve the technical problems of traditional distillation systems, such as system complexity and high energy consumption.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This utility model provides a distillation system for refining C8-C10+ aromatics using a wall-mounted column, comprising a distillation column body and a condenser. A material feed pipe is provided in the middle of the distillation column body, and a vertically upward-facing partition is provided at the bottom of the distillation column body. The vertical partition divides the lower cavity of the distillation column body into a C9 aromatics collection side and a C10 / C10+ aromatics collection side that are isolated from each other. A C9 aromatics collection pump is provided at the bottom of the C9 aromatics collection side, and a C10 / C10+ aromatics collection pump is provided at the bottom of the C10 / C10+ aromatics collection side.

[0011] The top of the distillation column is provided with a C8 aromatic hydrocarbon collection pipe, and the outlet end of the C8 aromatic hydrocarbon collection pipe is connected to the feed end of the condenser. The discharge end of the condenser is connected to a conveying pump line. The discharge end of the conveying pump line returns part of the C8 aromatic hydrocarbon to the top of the distillation column via a first conveying pipe, and the discharge end of the conveying pump line is connected to a C8 aromatic hydrocarbon collection path via a second conveying pipe.

[0012] As a preferred technical solution of this utility model, it also includes a first reboiler, the feed end of the first reboiler being connected to the bottom of the C9 aromatic hydrocarbon extraction side, and the discharge end of the first reboiler being connected to the C9 aromatic hydrocarbon extraction side.

[0013] As a preferred embodiment of the present invention, it further includes a second reboiler, wherein the feed end of the second reboiler is connected to the bottom of the C10 / C10+ aromatic hydrocarbon extraction side, and the discharge end of the second reboiler is connected to the C10 / C10+ aromatic hydrocarbon extraction side.

[0014] As a preferred embodiment of this utility model, the top of the vertical partition is at a higher level than the material feed pipe.

[0015] As a preferred embodiment of this utility model, the material feed pipe is located on the C10 and C10+ aromatic hydrocarbon extraction side.

[0016] As a preferred embodiment of this invention, the temperature on the C9 aromatic hydrocarbon extraction side is 250-280℃.

[0017] As a preferred embodiment of this utility model, the top temperature of the distillation column is 215-230℃.

[0018] As a preferred embodiment of this invention, the temperature of the C10 and C10+ aromatic hydrocarbon extraction side is 300-320℃.

[0019] The beneficial effects of this utility model are:

[0020] 1. In this indirect-wall distillation system for refining C8-C10+ aromatics, the bottom of the distillation column is equipped with a vertically upward-facing baffle. The baffle divides the lower cavity of the distillation column into two isolated C9 aromatics collection sides and C10 / C10+ aromatics collection sides. This reduces the complexity of the system and allows for the simultaneous separation of C9, C10 / C10+, and C8 aromatics. The outlet end of the C8 aromatics collection pipe is connected to the feed end of the condenser, and the discharge end of the condenser is connected to a conveying pump. The discharge end of the conveying pump recirculates a portion of the C8 aromatics back to the top of the distillation column via a first conveying pipe, and the discharge end of the conveying pump is connected to a C8 aromatics collection path via a second conveying pipe for partial recirculation. This can meet the high purity requirements of each product. If the heavy component of the C8 product at the top of the column exceeds the standard, the reflux ratio can be increased to meet the requirement.

[0021] 2. This indirect-wall distillation system for refining C8-C10+ aromatics utilizes a first and second reboiler. The first reboiler reboiles and heats the C9 aromatics output side, while the second reboiler heats the C10 / C10+ aromatics output side. When the light components of C9 and C10 / C10+ aromatics exceed the standard, the requirements can be met by increasing the heat load of their respective reboilers. This allows the present invention to simultaneously produce standard-compliant mixed xylene, industrial-grade C9 aromatics, and industrial-grade C10 crude aromatics. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a partition wall column distillation system for refining C8-C10+ aromatic hydrocarbons using a partition wall column, according to this utility model.

[0024] In the diagram: 1. Distillation column body; 2. Condenser; 3. Vertical baffle; 4. C9 aromatic hydrocarbon collection side; 5. C10 / C10+ aromatic hydrocarbon collection side; 6. C9 aromatic hydrocarbon collection pump line; 7. C10 / C10+ aromatic hydrocarbon collection pump line; 8. C8 aromatic hydrocarbon collection pipe; 9. Conveyor pump line; 10. First conveyor pipe; 11. Second conveyor pipe; 12. C8 aromatic hydrocarbon collection path; 13. First reboiler; 14. Second reboiler; 15. Material feed pipe.

[0025] The purpose, features, and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0027] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0028] Example

[0029] like Figure 1 As shown, this utility model discloses a distillation system for refining C8-C10+ aromatics using a partition wall column. The system includes a distillation column body 1 and a condenser 2. A feed pipe 15 is located in the middle of the distillation column body 1. A vertically upward-facing partition 3 is located at the bottom of the distillation column body 1, dividing the lower cavity of the distillation column body 1 into two isolated sections: a C9 aromatics collection side 4 and a C10 / C10+ aromatics collection side 5. A C9 aromatics collection pump path 6 is located at the bottom of the C9 aromatics collection side 4, and a C10 / C10+ aromatics collection pump path 7 is located at the bottom of the C10 / C10+ aromatics collection side 5. This system utilizes a vertical partition to divide the interior of the distillation column into multiple regions, each of which can achieve different separation requirements through different combinations. Partition wall columns are commonly used for the separation of multiple component systems or for special distillation separations.

[0030] The bottom of the distillation column 1 is equipped with vertically upward-facing baffles 3, thus forming a partitioned column. The main function of the partitioned column is to combine two conventional columns into one. Therefore, compared with traditional multi-component distillation columns, the equipment investment is reduced by saving the cost of a separate distillation column, its auxiliary equipment, piping, and instrumentation, and the footprint of the unit is also reduced accordingly. In addition, energy consumption is reduced, and due to the thermal coupling within the partitioned column, the energy consumption of the distillation process can be significantly reduced. The operating pressure of the partitioned column in this invention is 600-700 kPaA.

[0031] The top of the distillation column 1 is equipped with a C8 aromatic hydrocarbon outflow pipe 8, and the outlet end of the C8 aromatic hydrocarbon outflow pipe 8 is connected to the feed end of the condenser 2. The discharge end of the condenser 2 is connected to a conveying pump line 9. The discharge end of the conveying pump line 9 refluxes a portion of the C8 aromatic hydrocarbons back to the top of the distillation column 1 via a first conveying pipe 10, and the discharge end of the conveying pump line 9 is connected to a C8 aromatic hydrocarbon outflow line 12 via a second conveying pipe 11. This partial reflux can meet the high purity requirements of various products. If the heavy component of the C8 product at the top of the column exceeds the standard, the reflux ratio can be increased to meet the requirement.

[0032] The bottom of the distillation column body 1 is provided with a vertically upward baffle 3, which divides the lower cavity of the distillation column body 1 into two isolated C9 aromatic hydrocarbon collection side 4 and C10 / C10+ aromatic hydrocarbon collection side. This reduces the complexity of the system and can simultaneously separate C9 aromatic hydrocarbons, C10 / C10+ aromatic hydrocarbons, and C8 aromatic hydrocarbons. The outlet end of the C8 aromatic hydrocarbon collection pipe is connected to the feed end of the condenser 2, and the discharge end of the condenser 2 is connected to a conveying pump line 9. The discharge end of the conveying pump line 9 refluxes part of the C8 aromatic hydrocarbons to the top of the distillation column body 1 via a first conveying pipe 10, and the discharge end of the conveying pump line 9 is connected to a C8 aromatic hydrocarbon collection line 12 via a second conveying pipe 11 for partial reflux. This can meet the high purity requirements of each product. When the heavy component of the C8 product at the top of the column exceeds the standard, the reflux ratio can be increased to meet the standard. A reflux ratio of 5 to 8 can be used.

[0033] The system also includes a first reboiler 12, whose feed end is connected to the bottom of the C9 aromatic hydrocarbon extraction side 4, and whose discharge end is also connected to the C9 aromatic hydrocarbon extraction side 4. It also includes a second reboiler 13, whose feed end is connected to the bottom of the C10 / C10+ aromatic hydrocarbon extraction side 5, and whose discharge end is also connected to the C10 / C10+ aromatic hydrocarbon extraction side 5. The system comprises a first reboiler 13 and a second reboiler 14. The first reboiler 13 is used to reboil and heat the C9 aromatic hydrocarbon extraction side 4, and the second reboiler 14 is used to heat the C10 / C10+ aromatic hydrocarbon extraction side. When the light components of C9 aromatic hydrocarbons and C10 / C10+ aromatic hydrocarbons exceed the standard, the requirements can be met by increasing the heat load of their respective reboilers. This allows the present invention to simultaneously produce mixed xylene, industrial C9 aromatic hydrocarbons, and industrial C10 crude aromatic hydrocarbons that meet the standards.

[0034] The top of the vertical partition 3 is at a higher horizontal level than the material feed pipe 15. The material feed pipe 15 is located on the C10 and C10+ aromatic hydrocarbon extraction side 5.

[0035] The temperature of the C9 aromatic hydrocarbon extraction side 4 is 250-280℃; the temperature of the top of the distillation column 1 is 215-230℃; and the temperature of the C10 and C10+ aromatic hydrocarbon extraction side 5 is 300-320℃. This zoned temperature control results in better separation.

[0036] Working principle: A vertically upward-facing baffle 3 is provided at the bottom of the distillation column body 1. This baffle 3 divides the lower cavity of the distillation column body 1 into two isolated C9 aromatic hydrocarbon collection sides 4 and C10 / C10+ aromatic hydrocarbon collection sides. This reduces the complexity of the system and allows for the simultaneous separation of C9, C10 / C10+, and C8 aromatic hydrocarbons. The outlet end of the C8 aromatic hydrocarbon collection pipe is connected to the feed end of the condenser 2, and the discharge end of the condenser 2 is connected to a conveying pump line 9. The discharge end of the conveying pump line 9, via a first conveying pipe 10, returns a portion of the C8 aromatic hydrocarbons to the distillation column body 1. At the top, the discharge end of the conveying pump line 9 is connected to the C8 aromatic hydrocarbon collection line 12 via the second conveying pipe 11 for partial reflux, which can meet the high purity requirements of each product. When the heavy component of the C8 product at the top of the tower exceeds the standard, the reflux ratio can be increased to meet the requirement. A first reboiler 13 and a second reboiler 14 are provided. The first reboiler 13 is used to reboil and heat the C9 aromatic hydrocarbon collection side 4, and the second reboiler 14 is used to heat the C10 / C10+ aromatic hydrocarbon collection side. When the light component of C9 aromatic hydrocarbons and C10 / C10+ aromatic hydrocarbons exceeds the standard, the requirements can be met by increasing the heat load of their respective reboilers. In this way, this utility model can simultaneously produce mixed xylene, industrial C9 aromatic hydrocarbons, and industrial C10 crude aromatic hydrocarbons that meet the standards.

[0037] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

[0038] Furthermore, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies both A and B. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. A C8-C10+ aromatic rectification system using a dividing wall column, characterized in that: The rectifying tower body (1) is provided with a material feeding pipe (15) in the middle part, and a vertical partition plate (3) vertically upward is arranged at the bottom of the rectifying tower body (1), which separates the lower cavity of the rectifying tower body (1) into a C9 aromatic hydrocarbon extraction side (4) and a C10 / C10+ aromatic hydrocarbon extraction side (5) isolated from each other, the bottom of the C9 aromatic hydrocarbon extraction side (4) is provided with a C9 aromatic hydrocarbon extraction pump path (6), and the bottom of the C10 / C10+ aromatic hydrocarbon extraction side (5) is provided with a C10 / C10+ aromatic hydrocarbon extraction pump path (7); The top of the rectifying tower body (1) is provided with a C8 aromatic hydrocarbon extraction pipe (8), and the outlet end of the C8 aromatic hydrocarbon extraction pipe (8) is connected with the feeding end of the condenser (2), and the discharge end of the condenser (2) is connected with a conveying pump path (9), the discharge end of the conveying pump path (9) returns part of the C8 aromatic hydrocarbon to the top of the rectifying tower body (1) through a first conveying pipe (10), and the discharge end of the conveying pump path (9) is connected with a C8 aromatic hydrocarbon extraction path (12) through a second conveying pipe (11).

2. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 1, characterized in that, Further comprising a first reboiler (13), the feeding end of the first reboiler (13) is communicated with the bottom of the C9 aromatic hydrocarbon extraction side (4), and the discharge end of the first reboiler (13) is communicated with the C9 aromatic hydrocarbon extraction side (4).

3. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 2, characterized in that, Further comprising a second reboiler (14), the feeding end of the second reboiler (14) is communicated with the bottom of the C10 / C10+ aromatic hydrocarbon extraction side (5), and the discharge end of the second reboiler (14) is communicated with the C10 / C10+ aromatic hydrocarbon extraction side (5).

4. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 2, wherein, The horizontal height of the top end of the vertical partition plate (3) is higher than the setting horizontal height of the material feeding pipe (15).

5. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 2, wherein, The material feeding pipe (15) is arranged in the C10 and C10+ aromatic hydrocarbon extraction side (5).

6. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 1, wherein, The temperature of the C9 aromatic hydrocarbon extraction side (4) is 250-280℃.

7. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 5, wherein, The tower top temperature of the rectifying tower body (1) is 215-230℃.

8. The system for rectifying C8-C10+ aromatic hydrocarbons by using a partition wall column according to claim 5, wherein, The temperature of the C10 and C10+ aromatic hydrocarbon extraction side (5) is 300-320℃.

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