Regenerated gas recycling system and regenerated gas recycling method
By designing a regenerated gas recycling system in the methanol-to-olefin process, the gas regenerated from the carbon dioxide adsorption bed is circulated to other equipment, the problem of large nitrogen consumption is solved, the recycling of regenerated gas is realized, and operating costs and resource waste are reduced.
Patent Information
- Application Number
- CN202510555608.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-29
- Publication Date
- 2025-07-11
AI Technical Summary
In the methanol-to-olefin process, the olefin separation device consumes a large amount of nitrogen during the regeneration process, resulting in increased operating costs and waste of resources.
A regenerative gas recycling system is designed, and the regenerative gas is circulated by setting up a first regenerative emission system and a second regenerative emission system, and regenerated gas is circulated to a product gas dryer, ethylene product refining bed and propylene product refining bed to realize the recycling of regenerative gas.
It effectively reduces nitrogen consumption, reduces the operating cost of the olefin separation device, and improves resource utilization efficiency.
Smart Images
Figure CN120285933A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of methanol-to-olefins, and particularly relates to a system for recycling regeneration gas and a method for recycling regeneration gas. Background Art
[0002] In the methanol-to-olefins process, producing qualified polymer-grade ethylene and propylene products mainly relies on the olefin separation unit. This unit consists of a product gas dryer, an ethylene product refining bed, a propylene product refining bed, and a carbon dioxide adsorption bed. To maintain and improve the treatment effect of each device on the product gas, after the olefin separation unit has been operating for a period of time, it is necessary to use nitrogen to carry out regeneration operations on the product gas dryer, the ethylene product refining bed, the propylene product refining bed, and the carbon dioxide adsorption bed.
[0003] However, it is found in the actual operation process that when the product gas dryer, the ethylene product refining bed, the propylene product refining bed, and the carbon dioxide adsorption bed are regenerated simultaneously, the nitrogen consumption is about 38000 Nm 3 / h. Such a large amount of nitrogen consumption not only increases the operating cost of the unit but also causes a large amount of nitrogen to be wasted. Summary of the Invention
[0004] In view of this, this application provides a system for recycling regeneration gas and a method for recycling regeneration gas. The main purpose is to realize the reuse of regeneration nitrogen and reduce the operating cost of the unit.
[0005] To achieve the above object, this application mainly provides the following technical solutions:
[0006] In the first aspect of this application, a system for recycling regeneration gas for an olefin separation unit is provided. The olefin separation unit includes a product gas dryer, an ethylene product refining bed, a propylene product refining bed, and a carbon dioxide adsorption bed; the regeneration gas recycling system includes a nitrogen pipeline network, a first regeneration discharge system, and a second regeneration discharge system. The first regeneration discharge system and the second regeneration discharge system are respectively connected to the nitrogen pipeline network. The product gas dryer, the ethylene product refining bed, and the propylene product refining bed jointly use the first regeneration discharge system, and the carbon dioxide adsorption bed separately uses the second regeneration discharge system. The outlet of the second regeneration discharge system is connected to the inlet of the first regeneration discharge system through a circulation pipeline.
[0007] Optionally, the first regeneration and discharge system includes a first regeneration pipeline, a second regeneration pipeline, and a third regeneration pipeline. The first regeneration pipeline is connected to the inlet of the product gas dryer. The second regeneration pipeline is connected to the inlet of the ethylene product purification bed. The third regeneration pipeline is connected to the inlet of the propylene product purification bed. The first regeneration and discharge system further includes a first discharge pipeline, a second discharge pipeline, and a third discharge pipeline. The first discharge pipeline is connected to the outlet of the product gas dryer. The second discharge pipeline is connected to the outlet of the ethylene product purification bed. The third discharge pipeline is connected to the outlet of the propylene product purification bed.
[0008] Optionally, a first front pressure regulating valve is provided on the first regeneration pipeline, a second front pressure regulating valve is provided on the second regeneration pipeline, and a third front pressure regulating valve is provided on the third regeneration pipeline.
[0009] Optionally, the first regeneration and discharge system further includes a regeneration and discharge tank. The first discharge pipeline, the second discharge pipeline, and the third discharge pipeline are all connected to the inlet of the regeneration and discharge tank. The regeneration and discharge tank is used for gas-liquid separation of the regeneration waste gas and sedimentation treatment of impurities.
[0010] Optionally, a gas outlet is provided at the top of the regeneration and discharge tank. The gas outlet is connected to a flare discharge pipeline. A first end pressure regulating valve is provided on the flare discharge pipeline.
[0011] Optionally, the second regeneration and discharge system includes a fourth regeneration pipeline and a fourth discharge pipeline. The fourth regeneration pipeline is connected to the inlet of the carbon dioxide adsorption bed. The fourth discharge pipeline is connected to the outlet of the carbon dioxide adsorption bed.
[0012] Optionally, a fourth front pressure regulating valve is provided on the fourth regeneration pipeline, and a second end pressure regulating valve is provided on the fourth discharge pipeline.
[0013] Optionally, the circulation pipeline includes a distribution pipeline and a first branch pipeline, a second branch pipeline, and a third branch pipeline connected to the distribution pipeline. A first circulation pressure regulating valve is provided on the first branch pipeline, a second circulation pressure regulating valve is provided on the second branch pipeline, and a third circulation pressure regulating valve is provided on the third branch pipeline. When the first regeneration and discharge system includes a first regeneration pipeline, a second regeneration pipeline, and a third regeneration pipeline, the first branch pipeline is connected to the first regeneration pipeline, the second branch pipeline is connected to the second regeneration pipeline, and the third branch pipeline is connected to the third regeneration pipeline. When the second regeneration and discharge system includes a fourth discharge pipeline, the distribution pipeline is connected to the fourth discharge pipeline.
[0014] Optionally, when a first front pressure regulating valve is provided on the first regeneration pipeline, the connection point between the first branch pipeline and the first regeneration pipeline is located on the downstream side of the first front pressure regulating valve; when a second front pressure regulating valve is provided on the second regeneration pipeline, the connection point between the second branch pipeline and the second regeneration pipeline is located on the downstream side of the second front pressure regulating valve; when a third front pressure regulating valve is provided on the third regeneration pipeline, the connection point between the third branch pipeline and the third regeneration pipeline is located on the downstream side of the third front pressure regulating valve; when a second end pressure regulating valve is provided on the fourth discharge pipeline, the connection point between the distribution pipeline and the fourth discharge pipeline is located on the upstream side of the second end pressure regulating valve.
[0015] In another aspect of the present application, a method for recycling the regeneration gas is provided, which is applied to the regeneration gas recycling system described in any one of the above. The method for recycling the regeneration gas includes:
[0016] In response to an adjustment instruction, control the operating states of the first regeneration discharge system, the second regeneration discharge system, and the circulation pipeline.
[0017] By means of the above technical solution, the present application has at least the following beneficial effects:
[0018] In the embodiment of the present application, the regeneration gas recycling system and the regeneration gas recycling method provided, by setting the first regeneration discharge system and the second regeneration discharge system, and connecting the outlet of the second regeneration discharge system to the inlet of the first regeneration discharge system through a circulation pipeline, enable the gas after the regeneration of the carbon dioxide adsorption bed to be circulated to the first regeneration system of the product gas dryer, the ethylene product refining bed, and the propylene product refining bed, realizing the recycling of the regeneration gas, effectively reducing the consumption of nitrogen, and thus reducing the operating cost of the olefin separation device. Description of the Drawings
[0019] Figure 1 It is a schematic structural diagram of a regeneration gas recycling system according to an optional embodiment of the present application.
[0020] The reference numerals are shown as:
[0021] 100, Product gas dryer; 200, Ethylene product refining bed; 300, Propylene product refining bed; 400, Carbon dioxide adsorption bed; 500, Nitrogen gas pipeline network; 600, First regeneration and emission system; 601, First regeneration pipeline; 602, Second regeneration pipeline; 603, Third regeneration pipeline; 604, First emission pipeline; 605, Second emission pipeline; 606, Third emission pipeline; 607, First front pressure regulating valve; 608, Second front pressure regulating valve; 609, Third front pressure regulating valve; 610, Regeneration and emission tank; 611, Torch emission pipeline; 612, First end pressure regulating valve; 700, Second regeneration and emission system; 701, Fourth regeneration pipeline; 702, Fourth emission pipeline; 703, Fourth front pressure regulating valve; 704, Second end pressure regulating valve; 800, Circulation pipeline; 801, Distribution pipeline; 802, First branch pipeline; 803, Second branch pipeline; 804, Third branch pipeline; 805, First circulation pressure regulating valve; 806, Second circulation pressure regulating valve; 807, Third circulation pressure regulating valve. Detailed implementation manners
[0022] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.
[0023] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.
[0024] In the present application, unless otherwise clearly specified and limited, terms such as "installed", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0025] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present application and are not intended to limit the present application.
[0026] Referring to Figure 1 As shown, according to an embodiment of the present application, a system for recycling regeneration gas for an olefin separation device is provided. The olefin separation device includes a product gas dryer 100, an ethylene product refining bed 200, a propylene product refining bed 300, and a carbon dioxide adsorption bed 400. The system for recycling regeneration gas includes a nitrogen gas network 500, a first regeneration discharge system 600, and a second regeneration discharge system 700. The first regeneration discharge system 600 and the second regeneration discharge system 700 are respectively connected to the nitrogen gas network 500. The product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300 jointly use the first regeneration discharge system 600, and the carbon dioxide adsorption bed 400 separately uses the second regeneration discharge system 700. The outlet of the second regeneration discharge system 700 is connected to the inlet of the first regeneration discharge system 600 through a circulation pipeline 800.
[0027] In this embodiment, by setting up the first regeneration discharge system 600 and the second regeneration discharge system 700, and connecting the outlet of the second regeneration discharge system 700 to the inlet of the first regeneration discharge system 600 through the circulation pipeline 800, the gas after the regeneration of the carbon dioxide adsorption bed 400 can be circulated to the first regeneration system of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, realizing the recycling of the regeneration gas, effectively reducing the consumption of nitrogen gas, and thus reducing the operating cost of the olefin separation device.
[0028] Among them, the recycle gas recycling system can be applied in fields such as methanol to olefins, and can specifically be applied in an olefin separation unit. In the olefin separation unit, the product gas dryer 100 is used to remove moisture in the product gas, prevent the moisture from freezing in subsequent processes, blocking pipelines or affecting the normal operation of other equipment, and at the same time avoid the reaction between the moisture and the product, which may affect the product quality. The ethylene product refining bed 200 is used to further remove impurities in the ethylene product, such as methanol, aldehydes, water, etc. These impurities will reduce the purity of ethylene and affect its performance in the polymerization reaction. Through the adsorption, reaction, etc. of the ethylene product refining bed 200, the ethylene product can meet the polymerization-grade standard. The function of the propylene product refining bed 300 is similar to that of the ethylene product refining bed 200. It mainly purifies the propylene product and removes impurities such as methanol, dimethyl ether, and water in it to ensure the high purity of the propylene product and meet the requirements of subsequent industrial production, especially polypropylene production. The carbon dioxide adsorption bed 400 is used to adsorb carbon dioxide in the product gas. If carbon dioxide exists in the product, it will not only dilute the product concentration, but may also participate in side reactions under certain process conditions, affecting the product quality and production efficiency. The carbon dioxide content in the product gas can be effectively reduced through the carbon dioxide adsorption bed 400.
[0029] Specifically, in the actual application scenario, during the regeneration process of the product gas dryer 100 and the ethylene product refining bed 200, the recycle gas discharged contains trace amounts of moisture. These moisture will have an adverse impact on subsequent processes. For example, it may freeze and block pipelines in a low-temperature environment, or react with some reaction raw materials to produce side reactions. Therefore, this type of recycle gas containing trace amounts of moisture cannot be directly reused. Regarding the propylene product refining bed 300, its regeneration cycle is relatively long, and the amount of gas generated during the regeneration process is small, only about 6000 Nm 3 / h. In the olefin separation unit, the demand for recycle gas by other equipment is large, and the amount of regeneration gas generated by the propylene product refining bed 300 is far from meeting this demand. In contrast, the regeneration cycle of the carbon dioxide adsorption bed 400 is 72 hours, which is relatively short. During each regeneration process, the amount of regeneration gas generated is about 22000 Nm 3 / h. This gas volume is quite considerable and can meet the demand for the regeneration gas of other equipment such as the product gas dryer 100 and the ethylene product refining bed 200, thus providing the feasibility for realizing the recycling of the regeneration gas. Based on this, in this embodiment, considering the respective characteristics of the product gas dryer 100, the ethylene product refining bed 200, the propylene product refining bed 300, and the carbon dioxide adsorption bed 400 and the regeneration gas conditions, in order to effectively realize the recycling of the regeneration gas, the following system layout is adopted: The product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300 are jointly connected to the first regeneration discharge system 600. This is because the regeneration gas generated by the product gas dryer 100 and the ethylene product refining bed 200 contains trace moisture and cannot be directly reused, and the regeneration period of the propylene product refining bed 300 is long and the gas volume is insufficient. Integrating them into the same system is convenient for subsequent unified treatment. The carbon dioxide adsorption bed 400 uses the second regeneration discharge system 700 alone. Its regeneration period is only 72 hours, which is relatively short, and the regeneration gas volume can reach about 22000 Nm 3 / h, which is sufficient to supply the regeneration gas demand of other equipment. For this reason, an additional circulation pipeline 800 is set up to connect the outlet of the second regeneration discharge system 700 to the inlet of the first regeneration discharge system 600. In this way, the gas generated during the regeneration of the carbon dioxide adsorption bed 400 can enter the first regeneration discharge system 600 through this circulation pipeline 800, providing a gas source for the regeneration processes of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, thus successfully building a path for the recycling of the regeneration gas.
[0030] Among them, when using nitrogen to regenerate the product gas dryer 100, the ethylene product refining bed 200, the propylene product refining bed 300, and the carbon dioxide adsorption bed 400, both the first regeneration discharge system 600 and the second regeneration discharge system 700 are connected to the nitrogen pipeline network 500. The nitrogen pipeline network 500 is the supply source of nitrogen in the whole system. After the olefin separation unit has been operating for a period of time, it is necessary to use nitrogen to regenerate each equipment, and the nitrogen pipeline network 500 provides the required nitrogen for these regeneration operations.
[0031] Specifically, when regenerating the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, nitrogen enters the first regeneration discharge system 600 from the nitrogen pipeline network 500, and then sequentially or simultaneously regenerates the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, and then is discharged through the first regeneration discharge system 600. When regenerating the carbon dioxide adsorption bed 400, nitrogen enters the second regeneration discharge system 700 from the nitrogen pipeline network 500, and after regenerating the carbon dioxide adsorption bed 400, it is discharged through the second regeneration discharge system 700.
[0032] Among them, a circulation pipeline 800 is connected to the outlet of the second regeneration emission system 700, and one end of the circulation pipeline 800 far from the second regeneration emission system 700 is connected to the inlet of the first regeneration emission system 600. Thus, the gas (regenerated gas) discharged after the regeneration of the carbon dioxide adsorption bed 400 can enter the first regeneration emission system 600 through the circulation pipeline 800 and be reused for the regeneration of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, realizing the recycling of the regenerated gas.
[0033] Specifically, when nitrogen enters the first regeneration emission system 600 from the nitrogen pipeline network 500 and then sequentially regenerates the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, the regenerated gas of the carbon dioxide adsorption bed 400 transported by the circulation pipeline 800 can be incorporated during the regeneration gap of each device to supplement the amount of regeneration gas, maintain an efficient regeneration process, and reduce the consumption of fresh nitrogen; when nitrogen enters the first regeneration emission system 600 from the nitrogen pipeline network 500 and then simultaneously regenerates the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, the regenerated gas from the second regeneration emission system 700 will quickly mix with the fresh nitrogen, be distributed according to the demand ratio of each device, assist in regeneration in all directions, maximize the advantage of recycling the regenerated gas, significantly reduce the nitrogen consumption in the regeneration link of the entire olefin separation device, and improve the resource utilization efficiency.
[0034] In some possible embodiments disclosed in the present application, as shown in Figure 1 the first regeneration emission system 600 includes a first regeneration pipeline 601, a second regeneration pipeline 602, and a third regeneration pipeline 603. The first regeneration pipeline 601 is connected to the inlet of the product gas dryer 100, the second regeneration pipeline 602 is connected to the inlet of the ethylene product refining bed 200, and the third regeneration pipeline 603 is connected to the inlet of the propylene product refining bed 300; the first regeneration emission system 600 further includes a first discharge pipeline 604, a second discharge pipeline 605, and a third discharge pipeline 606. The first discharge pipeline 604 is connected to the outlet of the product gas dryer 100, the second discharge pipeline 605 is connected to the outlet of the ethylene product refining bed 200, and the third discharge pipeline 606 is connected to the outlet of the propylene product refining bed 300.
[0035] In this embodiment, by providing independent first regeneration pipeline 601, second regeneration pipeline 602 and third regeneration pipeline 603 which are respectively connected to the inlets of product gas dryer 100, ethylene product refining bed 200 and propylene product refining bed 300, nitrogen can enter the first regeneration discharge system 600 from the nitrogen pipeline network 500, and then the product gas dryer 100, ethylene product refining bed 200 and propylene product refining bed 300 can be regenerated simultaneously. At the same time, the independently provided first discharge pipeline 604, second discharge pipeline 605 and third discharge pipeline 606, which are respectively connected to the outlets of each device, can efficiently and timely discharge the waste gas generated during the regeneration of each device. In addition, the regenerated gas from the second regeneration discharge system 700 will quickly mix with fresh nitrogen, be distributed according to the demand ratio of each device, assist in regeneration in all directions, maximize the advantage of recycling the regenerated gas, significantly reduce the nitrogen consumption in the regeneration section of the entire olefin separation unit, and improve the resource utilization efficiency.
[0036] In the above embodiment, refer to Figure 1 As shown, a first front pressure regulating valve 607 is provided on the first regeneration pipeline 601, a second front pressure regulating valve 608 is provided on the second regeneration pipeline 602, and a third front pressure regulating valve 609 is provided on the third regeneration pipeline 603.
[0037] It should be noted that different devices may have different pressure requirements for the regeneration gas. For example, for the product gas dryer 100, ethylene product refining bed 200 and propylene product refining bed 300, due to their internal structures, packing characteristics and the substances being processed, nitrogen with different pressures is required for regeneration operations to achieve the best regeneration effect. Through these three pressure regulating valves, the pressure of the incoming nitrogen can be precisely adjusted according to the needs of each device, ensuring that each device can be regenerated under appropriate pressure conditions, improving the regeneration efficiency and effect. In addition, when the regenerated gas from the second regeneration discharge system 700 enters the first regeneration discharge system 600 through the circulation pipeline 800 and mixes with fresh nitrogen. The pressure regulating valve can flexibly adjust the pressure of different pipelines according to the actual needs of each device, and then optimize the distribution ratio of fresh nitrogen among the product gas dryer 100, ethylene product refining bed 200 and propylene product refining bed 300, enabling the regenerated gas to be utilized more reasonably, further improving the resource utilization efficiency, reducing the nitrogen consumption and the operation cost of the device.
[0038] Here, the first front pressure regulating valve 607, the second front pressure regulating valve 608 and the third front pressure regulating valve 609 can all be solenoid valves.
[0039] In the above embodiment, refer to Figure 1As shown, the first regeneration emission system 600 further includes a regeneration emission tank 610. The first emission pipeline 604, the second emission pipeline 605, and the third emission pipeline 606 are all connected to the inlet of the regeneration emission tank 610. The regeneration emission tank 610 is used for gas-liquid separation of the regeneration waste gas and sedimentation treatment of impurities.
[0040] It should be noted that during the regeneration process of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, the discharged gas may contain a small amount of liquid components. For example, the regeneration discharged gas of the product gas dryer 100 may contain liquid droplets formed by trace amounts of moisture. By setting the regeneration emission tank 610, the liquid in these gases can be separated, preventing the liquid from entering the subsequent pipelines or equipment and avoiding problems such as corrosion of the pipelines and interference with the operation of the equipment. At the same time, during the operation and regeneration processes of each equipment, some solid impurities may be discharged with the gas, such as adsorbent powder in the equipment and rust in the pipeline. The regeneration emission tank 610 provides a relatively stable space, enabling the impurities in the gas to gradually settle to the bottom of the tank under the action of gravity, thereby purifying the regeneration waste gas and reducing the impact of impurities on the subsequent system, such as avoiding clogging of the pipelines by impurities and affecting the normal operation of other equipment, which helps to maintain the stability and reliability of the entire system and extend the service life of the equipment.
[0041] Here, refer to Figure 1 As shown, a gas outlet is provided at the top of the regeneration emission tank 610. The gas outlet is connected to a flare emission pipeline 611, and a first end pressure regulating valve 612 is provided on the flare emission pipeline 611. It can be understood that by setting the flare emission pipeline 611, a safe emission channel is provided for the gas separated in the regeneration emission tank 610. The waste gas generated during the regeneration process may contain some flammable, explosive, or environmentally harmful gas components. By guiding these gases to a safe location for combustion emission through the flare emission pipeline 611, the accumulation of gases in the plant area can be prevented, avoiding safety accidents such as explosions and fires, and ensuring the safe operation of the entire olefin separation unit. By setting the first end pressure regulating valve 612, the gas pressure on the flare emission pipeline 611 can be adjusted. During the regeneration process, the gas pressure in the regeneration emission tank 610 may fluctuate. By adjusting the first end pressure regulating valve 612, the pressure of the discharged gas can be ensured to be stable within a safe range, enabling the gas to be smoothly discharged to the flare system for combustion. At the same time, it also avoids damage to the emission pipeline and related equipment caused by excessive pressure, or poor gas discharge caused by too low pressure, affecting the normal operation of the regeneration system.
[0042] Among them, the first end pressure regulating valve 612 can also be a solenoid valve.
[0043] In some possible implementation embodiments disclosed in the present application, refer to Figure 1As shown, the second regeneration and emission system 700 includes a fourth regeneration pipeline 701 and a fourth emission pipeline 702. The fourth regeneration pipeline 701 is connected to the inlet of the carbon dioxide adsorption bed 400, and the fourth emission pipeline 702 is connected to the outlet of the carbon dioxide adsorption bed 400.
[0044] In this embodiment, by setting the fourth regeneration pipeline 701 to be connected to the inlet of the carbon dioxide adsorption bed 400, nitrogen can enter the carbon dioxide adsorption bed 400 separately from the nitrogen pipeline network 500 through the fourth regeneration pipeline 701 for regeneration operation, ensuring the independence and stability of the regeneration process of the carbon dioxide adsorption bed 400 without being interfered by the regeneration processes of other equipment. By setting the fourth emission pipeline 702 to be connected to the outlet of the carbon dioxide adsorption bed 400, the waste gas generated after the regeneration of the carbon dioxide adsorption bed 400 can be smoothly discharged through the fourth emission pipeline 702, avoiding the accumulation of waste gas in the equipment, which may affect the regeneration effect or cause damage to the equipment.
[0045] Specifically, in an actual application scenario, nitrogen enters the carbon dioxide adsorption bed 400 separately from the nitrogen pipeline network 500 through the fourth regeneration pipeline 701. The gas after the regeneration of the carbon dioxide adsorption bed 400 is discharged through the fourth emission pipeline 702 and then enters the first regeneration and emission system 600 through the circulation pipeline 800, providing a gas source for the regeneration of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, thereby realizing the effective recycling of the regeneration gas, reducing the consumption of nitrogen, and reducing the operating cost of the olefin separation unit.
[0046] In the above embodiment, referring to Figure 1 As shown, a fourth front-end pressure regulating valve 703 is provided on the fourth regeneration pipeline 701, and a second end pressure regulating valve 704 is provided on the fourth emission pipeline 702.
[0047] Here, by adjusting the fourth front-end pressure regulating valve 703, the nitrogen pressure entering the carbon dioxide adsorption bed 400 can be precisely controlled. By adjusting the second end pressure regulating valve 704, the emission pressure of the regeneration gas of the carbon dioxide adsorption bed 400 can be controlled.
[0048] Among them, the fourth front-end pressure regulating valve 703 and the second end pressure regulating valve 704 can also be solenoid valves.
[0049] In some possible embodiments disclosed in the present application, referring to Figure 1As shown in the figure, the circulation pipeline 800 includes a distribution pipeline 801, and a first branch pipeline 802, a second branch pipeline 803, and a third branch pipeline 804 that are connected to the distribution pipeline 801. A first circulation pressure regulating valve 805 is provided on the first branch pipeline 802, a second circulation pressure regulating valve 806 is provided on the second branch pipeline 803, and a third circulation pressure regulating valve 807 is provided on the third branch pipeline 804. When the first regeneration and emission system 600 includes a first regeneration pipeline 601, a second regeneration pipeline 602, and a third regeneration pipeline 603, the first branch pipeline 802 is connected to the first regeneration pipeline 601, the second branch pipeline 803 is connected to the second regeneration pipeline 602, and the third branch pipeline 804 is connected to the third regeneration pipeline 603. When the second regeneration and emission system 700 includes a fourth emission pipeline 702, the distribution pipeline 801 is connected to the fourth emission pipeline 702.
[0050] In this embodiment, through the distribution pipeline 801, the first branch pipeline 802, the second branch pipeline 803, and the third branch pipeline 804, the circulation pipeline 800 can reasonably distribute the regeneration gas from the fourth emission pipeline 702 into the regeneration pipelines of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300. At the same time, the first circulation pressure regulating valve 805, the second circulation pressure regulating valve 806, and the third circulation pressure regulating valve 807 provided on each branch pipeline can independently adjust the pressure of the regeneration gas entering different devices, ensuring that each device can obtain the regeneration gas with appropriate pressure and flow rate during the regeneration process, meeting the regeneration requirements of different devices, and improving the regeneration effect.
[0051] Among them, the first circulation pressure regulating valve 805, the second circulation pressure regulating valve 806, and the third circulation pressure regulating valve 807 can also be solenoid valves.
[0052] In the above embodiment, as shown in Figure 1 the figure, when a first front-end pressure regulating valve 607 is provided on the first regeneration pipeline 601, the connection point between the first branch pipeline 802 and the first regeneration pipeline 601 is located on the downstream side of the first front-end pressure regulating valve 607; when a second front-end pressure regulating valve 608 is provided on the second regeneration pipeline 602, the connection point between the second branch pipeline 803 and the second regeneration pipeline 602 is located on the downstream side of the second front-end pressure regulating valve 608; when a third front-end pressure regulating valve 609 is provided on the third regeneration pipeline 603, the connection point between the third branch pipeline 804 and the third regeneration pipeline 603 is located on the downstream side of the third front-end pressure regulating valve 609; when a second end pressure regulating valve 704 is provided on the fourth emission pipeline 702, the connection point between the distribution pipeline 801 and the fourth emission pipeline 702 is located on the upstream side of the second end pressure regulating valve 704.
[0053] Here, the first front pressure regulating valve 607, the second front pressure regulating valve 608, and the third front pressure regulating valve 609 are respectively located on the upstream side of the connection points between their respective regeneration pipelines and the branch pipelines. First, the regeneration treatment can be carried out using the regeneration gas transported by the circulation pipeline 800, enabling them to give full play to their functions. Only when the circulated regeneration gas volume is insufficient to meet the equipment regeneration requirements, the fresh nitrogen gas in the nitrogen gas pipeline network 500 will, after being regulated by the first front pressure regulating valve 607, the second front pressure regulating valve 608, and the third front pressure regulating valve 609, mix with the remaining regeneration gas and enter equipment such as the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300 together to continue the regeneration operation. At the same time, when a second end pressure regulating valve 704 is provided on the fourth discharge pipeline 702, the connection point between the distribution pipeline 801 and the fourth discharge pipeline 702 is arranged on the upstream side of the second end pressure regulating valve 704, so that the regeneration gas discharged from the carbon dioxide adsorption bed 400 will flow preferentially into the distribution pipeline 801 of the circulation pipeline 800 before the pressure is regulated by the second end pressure regulating valve 704, and then be transported to the regeneration pipelines of each equipment through the branch pipelines.
[0054] Furthermore, as a specific implementation of the above regeneration gas recycling system, an embodiment of the present application provides a regeneration gas recycling method, which includes:
[0055] In response to an adjustment instruction, control the operating states of the first regeneration discharge system 600, the second regeneration discharge system 700, and the circulation pipeline 800.
[0056] In this embodiment, by controlling the operating states of the first regeneration discharge system 600, the second regeneration discharge system 700, and the circulation pipeline 800, the gas after the regeneration of the carbon dioxide adsorption bed 400 can enter the first regeneration discharge system 600 through the circulation pipeline 800, providing a gas source for the regeneration of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300, thereby realizing the recycling of the regeneration gas, effectively reducing the consumption of nitrogen gas, and reducing the operating cost of the olefin separation device.
[0057] Among them, in some specific examples, if an adjustment instruction for individual regeneration of each device is received, the system will perform the following operations: close the first circulation pressure regulating valve 805, the second circulation pressure regulating valve 806, and the third circulation pressure regulating valve 807 on the circulation pipeline 800. At the same time, open the front-end pressure regulating valve on the regeneration pipeline corresponding to the device to be regenerated. In this way, nitrogen can flow in from the nitrogen pipeline network 500 to carry out individual regeneration operations on the specified device to be regenerated; in other specific examples, when the system receives an adjustment instruction for simultaneous regeneration of each device, its action logic is different: the system will open the first circulation pressure regulating valve 805, the second circulation pressure regulating valve 806, and the third circulation pressure regulating valve 807 so that the regenerated gas from the second regeneration emission system 700 can smoothly enter the regeneration pipelines of each device through the circulation pipeline 800. At the same time, close the first front-end pressure regulating valve 607, the second front-end pressure regulating valve 608, and the third front-end pressure regulating valve 609, so that in this stage, the regeneration process mainly relies on the recycled regenerated gas to complete, making full use of the gas generated after the regeneration of the carbon dioxide adsorption bed 400, reducing the dependence on fresh nitrogen, improving the resource utilization efficiency, and realizing the synchronous regeneration of multiple devices.
[0058] Furthermore, the adjustment instruction for individual regeneration of each device also includes: adjusting the opening degree of the first end pressure regulating valve 612 and / or the second end pressure regulating valve 704. Specifically, when any one of the product gas dryer 100, the ethylene product refining bed 200, or the propylene product refining bed 300 is regenerated individually, it is necessary to adjust the opening degree of the first end pressure regulating valve 612. This is because the regeneration exhaust gases of these three devices all pass through the first discharge pipeline 604, the second discharge pipeline 605, or the third discharge pipeline 606 in the first regeneration emission system 600 and finally converge to the regeneration emission tank 610. The first end pressure regulating valve 612 is arranged on the flare discharge pipeline 611 connected to the gas outlet at the top of the regeneration emission tank 610. Adjusting its opening degree can control the discharge pressure of the regeneration exhaust gas discharged from these devices, and thus indirectly affect the pressure and flow rate of nitrogen entering the device to be regenerated. When the carbon dioxide adsorption bed 400 is regenerated individually, adjust the opening degree of the second end pressure regulating valve 704. The second end pressure regulating valve 704 is located on the fourth discharge pipeline 702 of the carbon dioxide adsorption bed 400. By adjusting its opening degree, the nitrogen pressure entering the carbon dioxide adsorption bed 400 and the regenerated gas pressure discharged from the carbon dioxide adsorption bed 400 can be directly controlled to ensure that the regeneration process of the carbon dioxide adsorption bed 400 proceeds under suitable working conditions. It should be noted that by adjusting the opening degree of the end pressure regulating valve, it can be ensured that the individual regeneration process of the device can proceed smoothly under suitable working conditions, so as to achieve the best regeneration effect and maintain the stability and safety of the entire system. In this embodiment, the opening degree of the end pressure regulating valve needs to be adjusted to have a pressure drop of 0.3 MPa compared with the front-end pressure regulating valve.
[0059] Furthermore, the adjustment instructions for simultaneous regeneration of each device also include: adjusting the opening degrees of the first circulating pressure regulating valve 805, the second circulating pressure regulating valve 806, the third circulating pressure regulating valve 807, and the first terminal pressure regulating valve 612. Specifically, when each device regenerates simultaneously, the first circulating pressure regulating valve 805, the second circulating pressure regulating valve 806, and the third circulating pressure regulating valve 807 are respectively responsible for adjusting the pressure of the regeneration gas flowing into the regeneration pipelines of the product gas dryer 100, the ethylene product refining bed 200, and the propylene product refining bed 300. By adjusting the opening degrees of these three circulating pressure regulating valves, it is possible to ensure that the regeneration gas coming from the second regeneration discharge system 700 through the circulating pipeline 800 enters each device at an appropriate pressure, meeting its unique regeneration requirements and enhancing the regeneration effect. At the same time, adjusting the opening degree of the first terminal pressure regulating valve 612 on the flare discharge pipeline 611 connected to the gas outlet at the top of the regeneration discharge tank 610 can, on the one hand, control the pressure of the regenerated waste gas discharged to the flare system, ensuring the safe and stable progress of the discharge process, preventing damage to the discharge pipeline or causing safety hazards due to excessive pressure, and also avoiding poor exhaust of the waste gas due to too low pressure, which affects the regeneration process; on the other hand, it has an indirect regulating effect on the pressure distribution within the entire first regeneration discharge system 600. It should be noted that by reasonably setting the opening degree of the first terminal pressure regulating valve 612 and cooperating with each circulating pressure regulating valve, it is possible to optimize the distribution ratio of fresh nitrogen and regeneration gas among each device, achieve efficient utilization of resources, further reduce nitrogen consumption, and improve the operating efficiency and economy of the regeneration link of the entire olefin separation unit. In this embodiment, the opening degree of the terminal pressure regulating valve needs to be adjusted to have a pressure drop of 0.3 MPa compared with the circulating pressure regulating valve.
[0060] Those skilled in the art can easily understand that, on the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.
[0061] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art in the technical field of the present application, without departing from the technical principle of the present application, several improvements and variations can still be made, and these improvements and variations should also be regarded as within the protection scope of the present application.
Claims
1. A system for recycling regeneration gas, characterized in that, For an olefin separation unit, the olefin separation unit includes a product gas dryer (100), an ethylene product refining bed (200), a propylene product refining bed (300) and a carbon dioxide adsorption bed (400); the regeneration gas recycling system includes a nitrogen pipeline network (500), a first regeneration discharge system (600) and a second regeneration discharge system (700). The first regeneration discharge system (600) and the second regeneration discharge system (700) are respectively connected to the nitrogen pipeline network (500). The product gas dryer (100), the ethylene product refining bed (200) and the propylene product refining bed (300) jointly use the first regeneration discharge system (600), and the carbon dioxide adsorption bed (400) separately uses the second regeneration discharge system (700). The outlet of the second regeneration discharge system (700) is connected to the inlet of the first regeneration discharge system (600) through a circulation pipeline (800).
2. The regenerated gas recycling system according to claim 1, wherein The first regeneration discharge system (600) includes a first regeneration pipeline (601), a second regeneration pipeline (602) and a third regeneration pipeline (603). The first regeneration pipeline (601) is connected to the inlet of the product gas dryer (100), the second regeneration pipeline (602) is connected to the inlet of the ethylene product refining bed (200), and the third regeneration pipeline (603) is connected to the inlet of the propylene product refining bed (300); the first regeneration discharge system (600) further includes a first discharge pipeline (604), a second discharge pipeline (605) and a third discharge pipeline (606). The first discharge pipeline (604) is connected to the outlet of the product gas dryer (100), the second discharge pipeline (605) is connected to the outlet of the ethylene product refining bed (200), and the third discharge pipeline (606) is connected to the outlet of the propylene product refining bed (300).
3. The regeneration gas recycling system according to claim 2, characterized in that, A first front pressure regulating valve (607) is provided on the first regeneration pipeline (601), a second front pressure regulating valve (608) is provided on the second regeneration pipeline (602), and a third front pressure regulating valve (609) is provided on the third regeneration pipeline (603).
4. The regeneration gas recycling system according to claim 2, characterized in that, The first regeneration discharge system (600) further includes a regeneration discharge tank (610). The first discharge pipeline (604), the second discharge pipeline (605) and the third discharge pipeline (606) are all connected to the inlet of the regeneration discharge tank (610). The regeneration discharge tank (610) is used for gas-liquid separation of the regeneration waste gas and sedimentation treatment of impurities.
5. The regenerated gas recycling system according to claim 4, wherein A gas outlet is provided at the top of the regeneration discharge tank (610). The gas outlet is connected to a flare discharge pipeline (611), and a first end pressure regulating valve (612) is provided on the flare discharge pipeline (611).
6. The regeneration gas recycling system according to claim 1, wherein The second regeneration and emission system (700) includes a fourth regeneration pipeline (701) and a fourth emission pipeline (702). The fourth regeneration pipeline (701) is communicated with the inlet of the carbon dioxide adsorption bed (400), and the fourth emission pipeline (702) is communicated with the outlet of the carbon dioxide adsorption bed (400).
7. The regenerated gas recycling system according to claim 6, wherein A fourth front pressure regulating valve (703) is provided on the fourth regeneration pipeline (701), and a second end pressure regulating valve (704) is provided on the fourth emission pipeline (702).
8. The regeneration gas recycling system according to claim 1, wherein The circulation pipeline (800) includes a distribution pipeline (801) and a first branch pipeline (802), a second branch pipeline (803) and a third branch pipeline (804) communicated with the distribution pipeline (801). A first circulation pressure regulating valve (805) is provided on the first branch pipeline (802), a second circulation pressure regulating valve (806) is provided on the second branch pipeline (803), and a third circulation pressure regulating valve (807) is provided on the third branch pipeline (804); when the first regeneration and emission system (600) includes a first regeneration pipeline (601), a second regeneration pipeline (602) and a third regeneration pipeline (603), the first branch pipeline (802) is communicated with the first regeneration pipeline (601), the second branch pipeline (803) is communicated with the second regeneration pipeline (602), and the third branch pipeline (804) is communicated with the third regeneration pipeline (603); when the second regeneration and emission system (700) includes a fourth emission pipeline (702), the distribution pipeline (801) is communicated with the fourth emission pipeline (702).
9. The regenerated gas recycling system according to claim 8, characterized in that, When a first front pressure regulating valve (607) is provided on the first regeneration pipeline (601), the connection point between the first branch pipeline (802) and the first regeneration pipeline (601) is located on the downstream side of the first front pressure regulating valve (607); when a second front pressure regulating valve (608) is provided on the second regeneration pipeline (602), the connection point between the second branch pipeline (803) and the second regeneration pipeline (602) is located on the downstream side of the second front pressure regulating valve (608); when a third front pressure regulating valve (609) is provided on the third regeneration pipeline (603), the connection point between the third branch pipeline (804) and the third regeneration pipeline (603) is located on the downstream side of the third front pressure regulating valve (609); when a second end pressure regulating valve (704) is provided on the fourth emission pipeline (702), the connection point between the distribution pipeline (801) and the fourth emission pipeline (702) is located on the upstream side of the second end pressure regulating valve (704).
10. A method for recycling regeneration gas, characterized in that, Applied to the regenerated gas recycling system according to any one of claims 1-9, the regenerated gas recycling method includes: In response to an adjustment instruction, controlling the operating states of the first regeneration and emission system (600), the second regeneration and emission system (700) and the circulation pipeline (800).