Propane dehydrogenation production line replacement medium separation and recovery device
By designing a displacement medium separation and recovery device for a propane dehydrogenation production line with an absorption tower and a stabilizing tower, the problem of direct flare combustion of residual displacement medium was solved, achieving propane gas recovery and reducing environmental pollution, and improving production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ANQING TAIHENG CHEM TECH CO LTD
- Filing Date
- 2025-06-09
- Publication Date
- 2026-06-12
AI Technical Summary
In existing technologies, the residual displacement medium in propane dehydrogenation production lines is burned directly through a flare, resulting in waste of raw materials and air pollution.
Design a displacement medium separation and recovery device including an absorption tower and a stabilization tower. The absorption tower absorbs and displaces propane gas in the exhaust gas, and the stabilization tower separates and recovers it. Combined with a condensation and transfer pump system, the device achieves partial recovery of propane gas and safe discharge of inert gas.
This achieved partial recovery of propane gas, reduced emissions from flare combustion, saved production costs, and reduced environmental pollution.
Smart Images
Figure CN224345662U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a propane dehydrogenation production line, specifically to a displacement medium separation and recovery device for a propane dehydrogenation production line. Background Technology
[0002] Propane dehydrogenation is a crucial process in petrochemicals. Before each start-up of its production line, a two-step replacement process is required to ensure the production environment meets requirements. This two-step replacement process involves first replacing the gas with an inert gas (e.g., nitrogen), followed by a propane replacement. Specifically, after establishing a circulation of inert gas in the product compression unit of the reaction unit, the raw material heater is heated to ensure safety during the heating process. Once the heater is heated, the inert gas in the reaction unit is replaced with raw material propane gas. Only after both replacement steps are completed and the production line environment meets requirements can formal production begin. Additionally, each system in the gas fractionation unit must also undergo this two-step replacement process after maintenance.
[0003] In the above two-step replacement method, inert gas and propane are used as replacement media. After the operation is completed, the remaining replacement media is a mixture of propane and inert gas. In existing technologies, the above-mentioned replacement media residue is generally disposed of by direct flare combustion, which has the disadvantages of wasting raw materials and polluting the atmosphere. Summary of the Invention
[0004] The purpose of this invention is to provide a propane dehydrogenation production line displacement medium separation and recovery device with reasonable structural design, energy saving and stable operation, which can partially recover propane gas in the gas emitted during the displacement process, reduce flare emissions, save production costs and reduce air pollution.
[0005] To achieve the above objectives, the present invention provides a propane dehydrogenation production line displacement medium separation and recovery device, comprising an absorption tower and a stabilizing tower. The absorption tower is connected at its middle section to the feed pipeline of the product compression unit and the feed pipeline of the gas fractionation unit. The top of the absorption tower is connected to a dry gas separator via a non-condensable gas pipeline. The top of the dry gas separator is connected to a flare main via a flare discharge pipeline, and a pressure control regulating valve is installed on the flare discharge pipeline. The bottom of the absorption tower is connected to the stabilizing tower via a rich absorbent oil pipeline, and a rich absorbent oil transfer pump is installed on the rich absorbent oil pipeline. The stabilizing tower is connected to a reflux tank via a gas phase liquefied gas pipeline, and a cooler is installed on the gas phase liquefied gas pipeline. The output end of the reflux tank is connected to the gas fractionation unit via a liquefied gas pipeline, and a liquefied gas transfer pump is installed on the liquefied gas pipeline. The bottom of the stabilizing tower is connected to the absorption tower via a lean absorbent oil pipeline, and a lean absorbent oil transfer pump is installed on the lean absorbent oil pipeline.
[0006] Preferably, a diversion pipe is provided between the liquefied gas delivery pump and the stabilizer tower to return part of the propane liquefied gas collected in the return tank to the stabilizer tower for reuse.
[0007] This utility model has the following advantages:
[0008] 1. During the two-step displacement process, the residual propane gas in the displacement medium can be partially recovered, saving material costs and improving production efficiency.
[0009] 2. It reduced emissions from flare combustion, thus lowering environmental pollution. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the structure of the displacement medium separation and recovery device for the propane dehydrogenation production line of this utility model.
[0011] The correspondence between the labels and component names in the attached figures is as follows:
[0012] 1. Absorber; 2. Non-condensable gas pipeline; 3. Dry gas separator; 4. Pressure control regulating valve; 5. Flare pipeline; 6. Rich absorbent oil transfer pump; 7. Rich absorbent oil pipeline; 8. Lean absorbent oil pipeline; 9. Lean absorbent oil transfer pump; 10. Gas phase liquefied gas pipeline; 11. Cooler; 12. Reflux tank; 13. Liquefied gas pipeline; 14. Liquefied gas transfer pump; 15. Stabilizer. Detailed Implementation
[0013] The following is a detailed description of the replacement medium separation and recovery device for the novel propane dehydrogenation production line, with reference to the accompanying drawings.
[0014] Depend on Figure 1 As can be seen, the propane dehydrogenation production line displacement medium separation and recovery device of this utility model includes an absorption tower 1 and a stabilizing tower 15. The absorption tower 1 is connected at its middle section to the feed pipeline of the product compression unit and the feed pipeline of the gas fractionation unit. The top of the absorption tower 1 is connected to a dry gas separator 3 via a non-condensable gas pipeline 2. The top of the dry gas separator 3 is connected to the flare main pipe via a flare pipeline 5. A pressure control regulating valve 4 is installed on the flare pipeline 5. The bottom of the absorption tower 1 is connected to the stabilizing tower 15 via a rich absorbent oil pipeline 7. The stabilizer tower 15 is connected to the reflux tank 12 via the rich absorbent oil pipeline 7. The reflux tank 12 is equipped with a cooler 11 via the gas phase liquefied gas pipeline 10. The output end of the reflux tank 12 is connected to the gas fractionation unit via the liquefied gas pipeline 13. The liquefied gas pipeline 13 is equipped with a liquefied gas transfer pump 14. The stabilizer tower 15 is connected to the absorption tower 1 via the lean absorbent oil pipeline 8 at its lower end. The lean absorbent oil pipeline 8 is equipped with a lean absorbent oil transfer pump 9.
[0015] See Figure 1 In operation, the displacement exhaust gas is transported to the absorption tower 1 through the feed pipeline. The absorption tower 1 absorbs the propane gas in the displacement exhaust gas. The absorbed rich absorbent oil is then transported to the stabilizing tower 15 by the rich absorbent oil transfer pump 6. In the stabilizing tower 15, the propane gas and absorbent oil are separated. The separated propane gas is condensed by the cooler 11 and then enters the reflux tank 12 for collection. The collected propane liquefied gas is transported to the gas fractionation unit by the liquefied gas transfer pump 14. The separated absorbent oil is transported to the absorption tower 1 by the lean absorbent oil transfer pump 9 as an absorbent for reuse. The inert gas that cannot be absorbed by the absorption tower 1 is discharged to the flare system through the dry gas separator 3 and the pressure control regulating valve 4, ensuring the system operating pressure and enabling the recovery of propane gas. This greatly reduces environmental pollution, saves costs, and improves production efficiency.
[0016] See Figure 1 A diversion pipe is provided between the liquefied gas transfer pump 14 and the stabilization tower 15 to return part of the material collected in the return tank 12 to the stabilization tower 15 for reuse.
[0017] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.
Claims
1. A displacement medium separation and recovery device for a propane dehydrogenation production line, comprising an absorption tower (1) and a stabilizing tower (15), characterized in that: The absorption tower (1) is connected at its middle section to the feed pipeline of the product compression unit and the feed pipeline of the gas fractionation unit; the top of the absorption tower (1) is connected to the dry gas separator (3) via the non-condensable gas pipeline (2), and the top of the dry gas separator (3) is connected to the flare main pipe via the flare discharge pipeline (5), and a pressure control regulating valve (4) is installed on the flare discharge pipeline (5); the bottom of the absorption tower (1) is connected to the stabilizer tower (15) via the rich absorbent oil pipeline (7), and the rich absorbent oil pipeline (7) is equipped with a rich absorbent oil conveying system. Pump (6); The stabilizer (15) is connected to the reflux tank (12) via the gas phase liquefied gas pipeline (10), and the gas phase liquefied gas pipeline (10) is equipped with a cooler (11). The output end of the reflux tank (12) is connected to the gas fractionation unit via the liquefied gas pipeline (13), and the liquefied gas pipeline (13) is equipped with a liquefied gas transfer pump (14); The stabilizer (15) is connected to the absorber (1) at its lower end via the lean absorber oil pipeline (8), and the lean absorber oil pipeline (8) is equipped with a lean absorber oil transfer pump (9).
2. The propane dehydrogenation production line displacement medium separation and recovery device as described in claim 1, characterized in that: A diversion pipe is provided between the liquefied gas transfer pump (14) and the stabilizer (15) for returning part of the material collected in the return tank (12) to the stabilizer (15) for reuse.