Device for fractionating catalytically cracked gasoline by using bulkhead fractionating tower
By using a partitioned fractionation tower to fractionate catalytic gasoline into light, medium, and heavy gasoline, the problem of high benzene content in catalytic gasoline is solved, achieving efficient fractionation and reduced energy consumption, thus adapting to market changes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- PEI YANG NAT DISTILLATION TECH
- Filing Date
- 2025-04-02
- Publication Date
- 2026-04-21
AI Technical Summary
In existing technologies, catalytic cracking gasoline has a high benzene content, which requires the addition of a large amount of low-benzene components during the blending process of automotive gasoline, increasing the production of automotive gasoline and not conforming to the development trend of the new energy vehicle market.
A partitioned fractionating tower is used to fractionate catalytic gasoline into three fractions: light gasoline, medium gasoline, and heavy gasoline. The medium gasoline with high benzene content is used as reforming feedstock, reducing the addition of low-benzene components. Fine separation is achieved by using the guide trapezoidal floating valve tray and double overflow structure of the partitioned fractionating tower.
It achieves efficient fractionation of catalytic gasoline, reduces benzene content, reduces the use of low-benzene components, saves the investment of a separation tower, and reduces energy consumption by more than 30%.
Smart Images
Figure CN224147992U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of catalytic cracking gasoline fractionation, and more particularly to an apparatus for fractionating catalytic cracking gasoline using a partitioned fractionation tower. Background Technology
[0002] With the implementation of the China VI B emission standard, domestic gasoline standards for sulfur, olefins, and benzene are becoming increasingly stringent. Catalytic cracking gasoline accounts for over 80% of automotive gasoline in my country, making it a major source of sulfur, olefins, and benzene. To improve fuel quality, effective after-treatment of catalytic gasoline is essential.
[0003] Existing processes typically fractionate catalytic cracking gasoline into light and heavy gasoline. Desulfurization and olefin reduction are achieved through methods such as etherification of light gasoline and hydrogenation of heavy gasoline, followed by blending to obtain automotive gasoline products. For catalytic cracking gasoline with high benzene content, a large amount of low-benzene components needs to be added during the automotive gasoline blending process to dilute the benzene content and ensure it does not exceed the standard. However, this operation increases automotive gasoline production, which contradicts the trend of increasing market share of new energy vehicles and decreasing automotive gasoline production. Therefore, to address these shortcomings, a device is proposed that utilizes a partitioned-wall fractionation tower to fractionate catalytic cracking gasoline, reducing the benzene content in the blended catalytic cracking gasoline and solving the problem of dependence on low-benzene components. Utility Model Content
[0004] To overcome the above shortcomings, this utility model provides a device for fractionating catalytic cracking gasoline using a partitioned distillation tower, which aims to improve the problem of needing to add a large amount of low-benzene components to ensure that the benzene content does not exceed the standard when high-benzene catalytic cracking gasoline is used in the blending of automotive gasoline.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] An apparatus for fractionating catalytic cracked gasoline using a partitioned fractionating tower includes a fractionating tower. The top of the fractionating tower is connected to the top of the fractionating tower condenser via a gas phase outlet. The bottom of the fractionating tower condenser is connected to the top of the fractionating tower reflux tank. A light gasoline collection tank is provided in the rectification section of the fractionating tower, and a medium gasoline collection tank is provided on the discharge side of the fractionating tower. A partition is provided in the middle of the fractionating tower. A rectification section collection tank is provided above the partition, and a riser tray is provided below the partition.
[0007] As a further description of the above technical solution:
[0008] The fractionation tower has a catalytic gasoline inlet on the feed side, a light gasoline inlet on the rectification section, a medium gasoline inlet on the discharge side, and a heavy gasoline inlet at the bottom.
[0009] As a further description of the above technical solution:
[0010] The fractionation tower reflux tank is connected to the fractionation tower through a top reflux port for top reflux. The top of the fractionation tower reflux tank is equipped with a non-condensable steam port for hydrogen-rich gas extraction.
[0011] As a further description of the above technical solution:
[0012] The oil collection tank in the rectification section is used to collect gasoline from the rectification section of the fractionation tower. The oil collection tank in the rectification section adopts a full extraction design, and the gasoline is extracted from the gasoline outlet of the rectification section. The flow rate is secondary distributed according to the reflux flow requirements of the feed side and the discharge side, and the gasoline is returned to the tower from the reflux port on the feed side and the reflux port on the discharge side.
[0013] As a further description of the above technical solution:
[0014] The riser tray is used to collect liquid phase from the feed side and the discharge side, and to perform secondary distribution of the liquid phase. The riser tray is equipped with a riser pipe to ensure that the gas phase of the stripping section enters the feed side and the discharge side through the riser pipe.
[0015] As a further description of the above technical solution:
[0016] Both the light gasoline extraction tank and the medium gasoline extraction tank are equipped with downcomers to ensure that liquid enters the lower tray from the downcomers.
[0017] As a further description of the above technical solution:
[0018] The bottom of the fractionation tower is connected to the bottom of the fractionation tower reboiler through a heavy gasoline port, and the top of the fractionation tower reboiler is connected to the fractionation tower through a vapor reflux port, thus completing the heavy gasoline vaporization and reboiling process at the bottom of the tower.
[0019] As a further description of the above technical solution:
[0020] The fractionation tower uses a guide trapezoidal floating valve tray for separation, and the rectifying section and stripping section adopt a double overflow structure, while the feed side and discharge side adopt a single overflow structure.
[0021] This utility model has the following beneficial effects:
[0022] 1. In this invention, catalytic gasoline is fractionated into three types of gasoline: light gasoline, medium gasoline, and heavy gasoline. The medium gasoline, which has a high benzene content, is cut according to the reforming feedstock range and used as a reforming feedstock. This solves the problem of needing to add large amounts of low-benzene fractions during gasoline blending to ensure that the benzene content does not exceed the standard. Furthermore, because the fractionation range is more precise, the selectivity for after-treatment of each gasoline product is increased, significantly improving the adaptability of the equipment to market changes.
[0023] 2. In this utility model, by using a partitioned distillation tower to cut catalytic gasoline into three distillation range products—light gasoline, medium gasoline, and heavy gasoline—the separation effect that would normally require two distillation towers is achieved. This not only saves the investment of one tower but also reduces energy consumption by more than 30% compared to operating two towers. Attached Figure Description
[0024] Figure 1 This is a perspective view of an apparatus for fractionating catalytic cracking gasoline using a partitioned distillation tower, as proposed in this utility model.
[0025] Legend:
[0026] 1. Fractionating column; 2. Fractionating column condenser; 3. Fractionating column reflux tank; 4. Fractionating column reboiler; 5. Light gasoline collection tank; 6. Rectifying section collection tank; 7. Middle gasoline collection tank; 8. Gas riser tray; 9. Baffle plate; 10. Guided trapezoidal floating valve tray; 11. Catalytic gasoline inlet; 12. Vapor phase outlet; 13. Non-condensable vapor inlet; 14. Top reflux port; 15. Light gasoline port; 16. Rectifying section gasoline outlet; 17. Feed side reflux port; 18. Discharge side reflux port; 19. Middle gasoline port; 20. Vapor phase reflux port; 21. Heavy gasoline port. Detailed Implementation
[0027] 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 protection scope of the present utility model.
[0028] Reference Figure 1 This utility model provides an embodiment of an apparatus for fractionating catalytically cracked gasoline using a partitioned fractionating tower. The apparatus includes a fractionating tower 1, which is connected to the top of a fractionating tower condenser 2 via a gas phase outlet 12 to condense light components. The bottom of the fractionating tower condenser 2 is connected to the top of a fractionating tower reflux tank 3, allowing the condensate to flow by gravity to the reflux tank 3. The fractionating tower reflux tank 3 is connected to the fractionating tower 1 via a top reflux port 14, allowing the condensate to flow back to the fractionating tower 1. The fractionating tower reflux tank 3 is equipped with a non-condensable vapor port 13, through which the non-condensable components in the tank are extracted as hydrogen-rich byproducts.
[0029] The feed side of the fractionation tower 1 is provided with a catalytic gasoline inlet 11, through which the catalytic gasoline enters the fractionation tower 1 and undergoes preliminary separation inside the tower.
[0030] The rectifying section of fractionation column 1 is equipped with a light gasoline collection tank 5, where light gasoline is enriched and collected through light gasoline inlet 15. These light gasoline fractions can be sent to etherification treatment or directly used in blending automotive gasoline. The light gasoline collection tank 5 is equipped with a downcomer, which can directly send the liquid phase in the collection tank to the lower tray.
[0031] A rectification section oil collection tank 6 is installed above the partition 9 of the fractionation tower 1. The rectification section oil collection tank 6 is used to collect gasoline from the rectification section of the fractionation tower 1. The gasoline is completely extracted through the rectification section gasoline outlet 16. The flow rate is then distributed secondaryly according to the reflux flow requirements of the feed side and the discharge side. The gasoline is returned to the area above the feed side and the area above the discharge side through the feed side reflux port 17 and the discharge side reflux port 18 to meet the reflux flow requirements of each section.
[0032] The fractionation tower 1 is equipped with a middlings gasoline collection tank 7 on the discharge side. The middlings gasoline is controlled by distillation range according to the requirements of reforming feedstock and is collected from the middlings gasoline port 19. It is used as reforming feedstock and is no longer used in the blending of automotive gasoline. The middlings gasoline collection tank 7 is also equipped with downcomers to distribute the liquid to the lower trays.
[0033] Below the baffle 9, there is a riser tray 8, which is used to collect the liquid phase from the feed side and the discharge side and to perform secondary distribution of the liquid phase. The riser tray is equipped with a riser pipe to ensure that the gas phase of the stripping section enters the feed side and the discharge side through the riser pipe.
[0034] The bottom of fractionation column 1 is connected to the bottom of fractionation column reboiler 4 via heavy gasoline port 21, and the top of fractionation column reboiler 4 is connected to fractionation column 1 via vapor reflux port 20, completing the heavy gasoline vaporization and reboiling process at the bottom of the column. The remaining unvaporized heavy gasoline is collected as a product and sent to the S Zorb unit for refining and desulfurization or catalytic hydrodesulfurization, or it can be sent to the diesel hydrotreating unit according to market demand.
[0035] The fractionation tower 1 uses a guide trapezoidal floating valve tray 10 as its separation element. The rectification section and stripping section adopt a double overflow structure, while the feed side and discharge side adopt a single overflow structure.
[0036] The fractionation tower operates at a pressure of 0.68 MPa (g), a top temperature of 105℃, and a bottom temperature of 290℃. Distillation range data for each oil product are shown in Table 1, and benzene content is shown in Table 2.
[0037] Table 1 Oil distillation range data
[0038]
[0039] Table 2 Data on benzene content in oil products
[0040]
[0041] Working principle:
[0042] First, catalytic gasoline enters the feed side of fractionation tower 1 through catalytic gasoline inlet 11 for preliminary separation. The light gasoline component and part of the medium gasoline component rise to the rectification section in the gas phase, while the remaining medium gasoline component and heavy gasoline component gradually descend to the stripping section in the liquid phase.
[0043] In the rectification section, light gasoline and medium gasoline components are separated. The light gasoline component is enriched near the top of the column and is collected via a side stream as a light gasoline product, which can be used in gasoline blending after etherification. The lighter, non-condensable components are collected from the top of the column as a hydrogen-rich product. The medium gasoline component and a small amount of light gasoline component at the bottom of the rectification section are refluxed to the feed and discharge sides.
[0044] The medium-strength gasoline component and the heavy-strength gasoline component are separated in the stripping section. The heavy-strength gasoline component is collected from the bottom of the column and can be used in gasoline blending after hydrodesulfurization, or it can enter the diesel hydrotreating unit. The gaseous phases of the medium-strength gasoline component and the heavy-strength gasoline component at the top of the stripping section enter the two sides of the baffle 9, respectively.
[0045] On the discharge side, the middle gasoline components gradually accumulate in the middle of the discharge side and are eventually extracted as middle gasoline product via the side stream. Middle gasoline has the highest benzene content; therefore, it is cut according to the reforming feedstock distillation range and used directly as reforming feedstock after extraction, without being used in blending automotive gasoline.
[0046] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An apparatus for fractionating catalytic cracking gasoline by using a partition wall fractionation column, comprising a fractionation column (1), a fractionation column condenser (2), and a fractionation column reflux tank (3), characterized in that: The top of the fractionation tower (1) is connected to the top of the fractionation tower condenser (2) through the gas phase outlet (12). The bottom of the fractionation tower condenser (2) is connected to the top of the fractionation tower reflux tank (3). The rectification section of the fractionation tower (1) is provided with a light gasoline collection tank (5). The discharge side of the fractionation tower (1) is provided with a medium gasoline collection tank (7). A partition (9) is provided in the middle of the fractionation tower (1). A rectification section collection tank (6) is provided above the partition (9). A gas riser tray (8) is provided below the partition (9).
2. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: The fractionation tower (1) is provided with a catalytic gasoline inlet (11) on the feed side, a light gasoline inlet (15) on the rectification section, a medium gasoline inlet (19) on the discharge side of the fractionation tower (1), and a heavy gasoline inlet (21) at the bottom end of the fractionation tower (1).
3. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: The fractionation tower reflux tank (3) is connected to the fractionation tower (1) through the top reflux port (14) for top reflux. The top of the fractionation tower reflux tank (3) is provided with a non-condensable steam port (13) for hydrogen-rich gas extraction.
4. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: The oil collection tank (6) of the rectification section is used to collect gasoline in the rectification section of the fractionation tower (1). The oil collection tank (6) of the rectification section adopts a full extraction design. It is extracted from the gasoline outlet (16) of the rectification section. The flow rate is distributed in a secondary manner according to the requirements of the feed side and the discharge side for the return flow rate. The return flow is returned to the tower from the feed side return port (17) and the discharge side return port (18).
5. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: The riser tray (8) is used to collect liquid phase from the feed side and the discharge side and to perform secondary distribution of the liquid phase. The riser tray (8) is equipped with a riser pipe to ensure that the gas phase of the stripping section enters the feed side and the discharge side through the riser pipe.
6. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: Both the light gasoline extraction collection tank (5) and the medium gasoline extraction collection tank (7) are equipped with downcomers to ensure that liquid enters the lower tray from the downcomers.
7. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: The device also includes a fractionation tower reboiler (4), the bottom end of the fractionation tower (1) is connected to the bottom end of the fractionation tower reboiler (4) through a heavy gasoline port (21), and the top end of the fractionation tower reboiler (4) is connected to the fractionation tower (1) through a gas phase reflux port (20) to complete the heavy gasoline vaporization and reboiling process at the bottom of the tower.
8. The apparatus for fractionating catalytically cracked gasoline by using a partition-wall fractionation column according to claim 1, characterized in that: The fractionation tower (1) uses a guide trapezoidal floating valve tray (10) as its separation element. The rectification section and stripping section adopt a double overflow structure, while the feed side and discharge side adopt a single overflow structure.