Recovery device for heavy components generated by butadiene extraction

Abstract

The utility model belongs to the technical field of butadiene recovery devices, and particularly relates to a device for recovering heavy components generated by butadiene extraction. The device comprises a packed tower, an evaporating tank, a reflux tank and a residual liquid collecting tank, a tower top gas outlet of the packed tower is connected with a condenser, the condenser is connected with the reflux tank, a reflux pump is arranged on an outlet pipeline of the reflux tank, an outlet of the reflux pump is divided into two pipelines, and the two pipelines are communicated with the evaporating tank. One is connected with the upper part of the packed tower, and the other is connected with the hydrogenation device; an evaporating tank is arranged at the liquid outlet end of the packed tower, a heat exchange pipe is arranged in the evaporating tank, a liquid outlet pipe of the evaporating tank is connected with a residual liquid collecting tank, and an outlet pipeline of the residual liquid collecting tank is connected with an ethylene device. According to the device for recovering the heavy components generated by butadiene extraction, coking is prevented, and the heavy components are pumped back to a butene device to serve as cracking raw materials, so that the maximum utilization of resources is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of butadiene recovery devices, and in particular relates to a heavy component recovery device produced by butadiene extraction. Background Art

[0002] The C4 fraction produced by thermal cracking of petroleum hydrocarbons contains a large amount of butadiene, which is usually purified by an extraction process based on extraction and rectification. Due to the different types of solvents used in the extraction and rectification process, there are many extraction processes. The three most commonly used butadiene extraction processes in industry are acetonitrile (ACN) method, dimethylformamide (DMF) method, and N-methylpyrrolidone (NMP) method. All three methods require the refining of crude butadiene, using light removal towers and heavy removal towers.

[0003] At present, the bottom material of the de-weighting tower mainly contains heavy components such as cis-2-butene, 1,2-butadiene, 1,3-butadiene, butadiene dimer, polymerization inhibitor TBC, carbon five, toluene, solvent, etc. As a by-product, the sales price is low and the economic efficiency is poor. In addition, 1,2-butadiene in the bottom material of the de-weighting tower is a highly unstable compound. It will undergo self-polymerization reaction at room temperature and react violently with oxygen, oxidants, acids, etc., which is easy to cause fire and explosion. Therefore, as a product, it has certain safety hazards.

[0004] Patent CN218686399U discloses a comprehensive utilization system of heavy components at the bottom of a butadiene extraction unit deheaving tower, but it is aimed at an extraction unit for producing butadiene by oxidative dehydrogenation, and there is no detailed description of the recovery device and process. There are certain technical limitations. The separated inhibitor TBC is mixed with butadiene dimers, etc., and returns to the distillation system, which will aggravate the polymerization of butadiene products, reduce the recovery rate of butadiene and increase the danger of the device. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the above-mentioned defects of the prior art, provide a device for recovering heavy components produced by butadiene extraction, prevent coking, and use a pump to return the heavy components to an ethylene device as a cracking raw material to achieve maximum utilization of resources.

[0006] The utility model discloses a device for recovering heavy components produced by butadiene extraction, comprising a packing tower, an evaporator, a reflux tank and a residual liquid collecting tank. The gas outlet at the top of the packing tower is connected to a condenser, the condenser is connected to the reflux tank, a reflux pump is arranged on the outlet pipeline of the reflux tank, the outlet of the reflux pump is divided into two pipelines, one is connected to the upper part of the packing tower, and the other is connected to a hydrogenation device; the liquid outlet end of the packing tower is provided with an evaporator, a heat exchange tube is arranged in the evaporator, the liquid outlet pipe of the evaporator is connected to the residual liquid collecting tank, and the outlet pipeline of the residual liquid collecting tank is connected to an ethylene device.

[0007] Preferably, the middle of the packed tower is connected with a bottom pipeline of the deweighting tower. The packed tower is a small packed tower.

[0008] Preferably, a heat exchange tube is arranged inside the evaporator, and the rest is a space structure. The heat exchange tube is a U-shaped heat exchange tube.

[0009] Preferably, the heat exchange tube is connected with a medium-pressure steam condensate pipe and a condensate outlet pipe.

[0010] Preferably, a tar inlet is provided on the residual liquid collection tank.

[0011] Preferably, a heating pipe is provided on the outer wall of the residual liquid collecting tank, and the heating pipe is connected to a low-pressure steam condensate inlet pipe and a low-pressure steam condensate outlet pipe.

[0012] Preferably, a delivery pump is provided on the outlet pipeline of the residual liquid collection tank, and the outlet pipeline of the delivery pump is connected to the ethylene device.

[0013] The heavy component recovery device produced by butadiene extraction described in the utility model, when working, the heavy component materials from the deweighting tower mainly contain cis-2-butene, 1,2-butadiene, 1,3-butadiene, butadiene dimer, polymerization inhibitor TBC, carbon five, toluene, solvent, etc., and enter the packing tower for distillation by utilizing the different boiling points between the components. Cis-2-butene, 1,2-butadiene, 1,3-butadiene, part of carbon five, etc. are extracted from the top of the packing tower, condensed by the condenser, enter the reflux tank, and then transported by the reflux pump. A part of it continues to enter the packing tower as reflux, and the other part enters the hydrogenation device as a raw material for hydrogenation, or as an acetylene dilution gas for butadiene extraction. Below the packing tower is an evaporator, and inside the evaporator is a U-shaped heat exchange tube, which is heated by medium-pressure steam condensate. There is enough space structure inside the evaporator to facilitate cleaning of the dirt inside the evaporator. A small amount of cis-2-butylene, 1,2-butadiene, inhibitor TBC, part of carbon five, toluene, solvent, etc. are extracted from the bottom of the packed tower and flow into the residual liquid collection tank by gravity. They are easy to coke and are relatively viscous, which is not conducive to transportation. Therefore, a heating pipe is installed on the outer wall of the residual liquid collection tank, and a tar inlet is set on the residual liquid collection tank. Ethylene tar or other soluble oils are used for dissolution, and then the tar is transported to the ethylene unit through a delivery pump as a raw material for ethylene cracking.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] The utility model discloses a device for recovering heavy components produced by butadiene extraction, and develops a small distillation device to remove residual liquids such as butadiene dimer, polymerization inhibitor TBC, carbon five, toluene and solvent to obtain components such as cis-butene-2, 1,2-butadiene and 1,3-butadiene. These components can be used as alkyne diluent gas for butadiene extraction, thereby reducing the amount of diluent gas at the top of the first extraction tower, and can also be used as raw materials for alkyne hydrogenation, thereby increasing the yield of butene-1 or 1,3-butadiene. The heavy components are easy to coke, and are dissolved by using ethylene tar or other soluble oils to prevent coking. They are then sent back to the butene device by using a delivery pump as cracking raw materials to achieve maximum resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a device for recovering heavy components produced by butadiene extraction according to the utility model.

[0017] In the figure: 1. Packing tower; 2. Evaporation tank; 3. Reflux tank; 4. Residual liquid collecting tank; 5. Heat exchange tube; 6. Spatial structure; 7. Reflux pump; 8. Delivery pump; 9. Medium-pressure steam condensate pipe; 10. Condensate outlet pipe; 11. Deweighting tower bottom pipeline; 12. Tar inlet; 13. Low-pressure steam condensate inlet pipe; 14. Low-pressure steam condensate outlet pipe; 15. Condenser; 16. Heating pipe. DETAILED DESCRIPTION

[0018] The utility model is further described below in conjunction with specific embodiments.

[0019] The connections of the pipelines described in the present invention are all existing chemical pipeline connections, which can be implemented by those skilled in the art and will not be discussed further. The setting and connection of the packing tower 1 and the evaporation tank 2 also belong to the conventional settings of the prior art, which can ensure the smooth self-flow of materials, and are also the prior art mastered by those skilled in the art, so they will not be discussed further. The specific internal structures of other devices are not the improvement points of the present invention, so they will not be discussed further.

[0020] like Figure 1 As shown, the heavy component recovery device produced by butadiene extraction described in the utility model comprises a packed tower 1, an evaporator 2, a reflux tank 3, and a residual liquid collecting tank 4. The gas outlet at the top of the packed tower 1 is connected to a condenser 15, the condenser 15 is connected to the reflux tank 3, a reflux pump 7 is arranged on the outlet pipeline of the reflux tank 3, and the outlet of the reflux pump 7 is divided into two pipelines, one is connected to the upper part of the packed tower 1, and the other is connected to the hydrogenation device; the liquid outlet end of the packed tower 1 is provided with an evaporator 2, the evaporator 2 is provided with a heat exchange tube 5, the liquid outlet pipe of the evaporator 2 is connected to the residual liquid collecting tank 4, and the outlet pipeline of the residual liquid collecting tank 4 is connected to the ethylene device.

[0021] The middle of the packed tower 1 is connected with a deweighting tower bottom pipeline 11. The packed tower 1 is a small packed tower.

[0022] The interior of the evaporation tank 2 is provided with a heat exchange tube 5, and the rest is a space structure 6. The heat exchange tube 5 is a U-shaped heat exchange tube.

[0023] The heat exchange tube 5 is connected with a medium-pressure steam condensate pipe 9 and a condensate outlet pipe 10 .

[0024] The residual liquid collecting tank 4 is provided with a tar inlet 12 .

[0025] A heat tracing pipe 16 is provided on the outer wall of the residual liquid collecting tank 4 , and the heat tracing pipe 16 is connected to a low-pressure steam condensate inlet pipe 13 and a low-pressure steam condensate outlet pipe 14 .

[0026] The outlet pipeline of the residual liquid collecting tank 4 is provided with a delivery pump 8, and the outlet pipeline of the delivery pump 8 is connected to the ethylene device.

[0027] The heavy component recovery device produced by butadiene extraction described in the utility model, when working, the heavy component materials from the deweighting tower mainly contain cis-2-butene, 1,2-butadiene, 1,3-butadiene, butadiene dimer, polymerization inhibitor TBC, carbon five, toluene, solvent, etc., and enter the packed tower 1 for distillation by utilizing the different boiling points between the components. Cis-2-butene, 1,2-butadiene, 1,3-butadiene, part of carbon five, etc. are extracted from the top of the packed tower 1, condensed by the condenser 15, enter the reflux tank 3, and then transported by the reflux pump 7. A part of it continues to enter the packed tower 1 as reflux, and the other part enters the hydrogenation device as a raw material for hydrogenation, or as an acetylene dilution gas for butadiene extraction. Below the packed tower 1 is the evaporator 2, and inside the evaporator 2 is a U-shaped heat exchange tube 5, which is heated by medium-pressure steam condensate. There is enough space structure 6 inside the evaporator 2 to facilitate cleaning of dirt inside the evaporator. A small amount of cis-2-butene, 1,2-butadiene, polymerization inhibitor TBC, part of carbon five, toluene, solvent, etc. are extracted from the bottom of the packed tower 1 and flow into the residual liquid collecting tank 4 by gravity. They are easy to coke and are relatively viscous, which is not conducive to transportation. Therefore, a heating pipe 16 is provided on the outer wall of the residual liquid collecting tank 4, and a tar inlet 12 is provided on the residual liquid collecting tank 4. Ethylene tar or other soluble oils are used for dissolution, and then the tar is transported to the ethylene device through a delivery pump 8 as a raw material for ethylene cracking.

[0028] Of course, the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and any equivalent changes and improvements made by ordinary technicians in the technical field within the essential scope of the present invention shall fall within the scope of the patent coverage of the present invention.

Claims

1. A device for recovering heavy components produced by butadiene extraction, characterized in that: The invention comprises a packing tower (1), an evaporation tank (2), a reflux tank (3), and a residual liquid collecting tank (4). The gas outlet at the top of the packing tower (1) is connected to a condenser (15), the condenser (15) is connected to the reflux tank (3), a reflux pump (7) is arranged on the outlet pipeline of the reflux tank (3), the outlet of the reflux pump (7) is divided into two pipelines, one is connected to the upper part of the packing tower (1), and the other is connected to a hydrogenation device; the liquid outlet end of the packing tower (1) is provided with an evaporation tank (2), a heat exchange tube (5) is arranged in the evaporation tank (2), the liquid outlet pipe of the evaporation tank (2) is connected to the residual liquid collecting tank (4), and the outlet pipeline of the residual liquid collecting tank (4) is connected to an ethylene device.

2. The heavy component recovery device produced by butadiene extraction according to claim 1, characterized in that: The middle part of the packed tower (1) is connected to a deweighting tower bottom pipeline (11).

3. The heavy component recovery device produced by butadiene extraction according to claim 1, characterized in that: The interior of the evaporation tank (2) is provided with a heat exchange tube (5), and the rest is a space structure (6).

4. The heavy component recovery device produced by butadiene extraction according to claim 3, characterized in that: The heat exchange tube (5) is connected to a medium-pressure steam condensate pipe (9) and a condensate outlet pipe (10).

5. The heavy component recovery device produced by butadiene extraction according to claim 1, characterized in that: The residual liquid collecting tank (4) is provided with a tar inlet (12).

6. The heavy component recovery device produced by butadiene extraction according to claim 1, characterized in that: A heat tracing pipe (16) is arranged on the outer wall of the residual liquid collecting tank (4), and the heat tracing pipe (16) is connected to a low-pressure steam condensate inlet pipe (13) and a low-pressure steam condensate outlet pipe (14).

7. The device for recovering heavy components produced by butadiene extraction according to claim 1, characterized in that: A delivery pump (8) is provided on the outlet pipeline of the residual liquid collection tank (4).

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