Pre-hydrogenation reaction system of reforming device
By adding a protective reactor before the pre-hydrogenation reactor and filling it with a protective agent and a deolefination catalyst, the problem of catalyst blockage caused by impurities in naphtha was solved, and the unit was able to operate stably for a long period of time.
Patent Information
- Application Number
- CN202423230236.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2034-12-26
AI Technical Summary
The catalyst bed in the pre-hydrogenation reactor of the reforming unit is blocked due to gum and fine coke powder entrained in naphtha, resulting in increased pressure drop. This affects the long-term operation of the unit, requiring frequent cleaning and shutdowns, which in turn affects the stable operation of the combined unit.
A protective reactor is added before the pre-hydrogenation reactor, filled with a protective agent and a de-olefin catalyst to adsorb mechanical impurities and unsaturated olefins in the feed. It is located between the second and third heat exchangers to block entrained impurities and protect the main reactor from pressure drop.
It effectively blocks impurities entrained in the raw materials, protects the pre-hydrogenation reactor from pressure drop, meets the requirements for long-term operation of the unit, reduces cleaning frequency, and improves the stability of the unit.
Smart Images
Figure CN223837361U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chemical production technology, specifically to a pre-hydrogenation reaction system for a reforming unit. Background Technology
[0002] The pre-hydrogenation unit of the reforming unit uses straight-run naphtha fraction as feedstock, mainly from purchased naphtha. The sources of purchased naphtha are quite complex, mainly including atmospheric and vacuum distillation straight-run naphtha, coking naphtha, residue cracking naphtha, and coal chemical naphtha.
[0003] However, during storage in tank farms and loading / unloading and transportation by tank trucks and ships, naphtha comes into contact with air, undergoing oxidative polymerization to form larger molecular weight colloids. These colloids condense and form coke under the high-temperature conditions of the catalyst bed, clogging the catalyst bed. Coked naphtha contains fine coke powder, some of which has a weight that is roughly equal to its buoyancy in the naphtha. Even prolonged static settling fails to allow it to settle, leading to blockage in the catalyst bed and increased pressure drop. The fine coal powder in coal-processed naphtha is largely consistent with the fine coke powder in coked naphtha. During processing, the pressure drop in the pre-hydrogenation reactor increases, severely impacting the long-term operation of the unit. Regular cleaning of the unit and shunting of the pre-hydrogenation reactor are necessary. Frequent shutdowns of the unit also affect the stable operation of the combined unit. Utility Model Content
[0004] In view of the deficiencies of the prior art, this utility model provides a pre-hydrogenation reaction system for a reforming unit, which adds a protective reactor before the main reactor. Specifically, the protective reactor is set between two pre-hydrogenation feed heat exchangers. The protective reactor can effectively block impurities entrained in the feedstock, protect the main reactor from pressure drop, and meet the requirements of long-term operation of the unit.
[0005] To achieve the above objectives, the present invention provides a pre-hydrogenation reaction system for a reforming unit, comprising a feed tank, a first heat exchanger, a second heat exchanger, and a third heat exchanger connected sequentially along the shell side in the feed direction, a temperature control valve group, a protective reactor, a feed heater, and an air cooler; the feed tank is connected to a naphtha feed pipeline; the first heat exchanger is connected to the feed tank; the temperature control valve group is disposed between the second feed heat exchanger and the third heat exchanger; the protective reactor is disposed across the temperature control valve group, and is filled with a protective agent and a deolefinization catalyst; the feed heater is connected to the shell-side outlet of the third heat exchanger; the inlet of the pre-hydrogenation reactor is connected to the feed heater, and the outlet of the pre-hydrogenation reactor is connected sequentially along the discharge direction to the tube side of the third heat exchanger, the second heat exchanger, and the first heat exchanger; the air cooler is connected to the tube-side outlet of the first heat exchanger.
[0006] Furthermore, the temperature control valve assembly includes a pre-valve gate valve, a temperature control valve, and a post-valve gate valve, with a bypass valve provided between the pre-valve gate valve and the post-valve gate valve.
[0007] Furthermore, a temperature transmitter is installed at the inlet of the protective reactor, and the temperature transmitter is electrically connected to the temperature control valve.
[0008] Furthermore, the upstream of the temperature control valve assembly is connected to the protective reactor via a protector feed line, and the protective reactor is connected to the downstream of the temperature control valve assembly via a protector discharge line.
[0009] Furthermore, the feed pipe of the protector is equipped with an inlet double valve, and a first blind plate is installed between the inlet double valves.
[0010] Furthermore, the nitrogen replenishment pipeline and the feed pipeline of the protector meet after the valve of the inlet dual valve.
[0011] Furthermore, a first gate valve, a first check valve, and a second gate valve are sequentially installed along the nitrogen supply pipeline in the supply direction.
[0012] Furthermore, the discharge pipeline of the protector is equipped with a double outlet valve, and a second blind plate is installed between the double outlet valves.
[0013] Furthermore, the flare line and the protector discharge line meet in front of the outlet double valve.
[0014] Furthermore, a third gate valve, a second check valve, and a fourth gate valve are sequentially installed along the discharge direction on the flare pipeline.
[0015] The beneficial effects of this invention are as follows: A protective reactor is added before the pre-hydrogenation reactor. The protective reactor is filled with a protective agent and a de-olefin catalyst to adsorb mechanical impurities in the feed and remove unsaturated olefins from the feed. The protective reactor is located between the second and third heat exchangers. This protective reactor can effectively block impurities entrained in the feed, protect the pre-hydrogenation reactor from pressure drop, and meet the requirements for long-term operation of the unit. Attached Figure Description
[0016] Figure 1 This is a process flow diagram of a pre-hydrogenation reaction system for a reforming unit according to one embodiment of the present invention;
[0017] In the picture:
[0018] 100. Raw material tank; 110. Naphtha feed pipeline.
[0019] 200. First heat exchanger,
[0020] 300. Second heat exchanger
[0021] 400. Third heat exchanger
[0022] 500. Temperature control valve assembly; 510. Pre-valve gate valve; 520. Temperature control valve; 530. Post-valve gate valve; 540. Bypass valve; 550. Protector feed line; 551, 553. Inlet double valves; 552. First blind flange; 560. Protector discharge line; 561, 563. Outlet double valves; 562. Second blind flange; 570. Nitrogen replenishment line; 571. First gate valve; 572. First check valve; 573. Second gate valve; 580. Flare line; 581. Third gate valve; 582. Second check valve; 583. Fourth gate valve.
[0023] 600. Protective reactor; 610. Temperature transmitter.
[0024] 700. Feeding heating furnace
[0025] 800. Pre-hydrogenation reactor
[0026] 900. Air cooler. Detailed Implementation
[0027] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.
[0028] A pre-hydrogenation reaction system for a reforming unit includes a feed tank 100, a first heat exchanger 200, a second heat exchanger 300, and a third heat exchanger 400 connected sequentially along the feed direction in their shell sides, a temperature control valve assembly 500, a protection reactor 600, a feed heater 700, a pre-hydrogenation reactor 800, and an air cooler 900; the feed tank 100 is connected to a naphtha feed pipeline 110; the first heat exchanger 200 is connected to the feed tank 100; and the temperature control valve assembly 500 is located between the second heat exchanger 300 and the third heat exchanger. Between 400; a protective reactor 600 is installed across the temperature control valve group 500, and the protective reactor 600 is filled with a protective agent and a deolefin catalyst; the feed heater 700 is connected to the shell-side outlet of the third heat exchanger 400; the inlet of the pre-hydrogenation reactor 800 is connected to the feed heater 700, and the outlet of the pre-hydrogenation reactor 800 is connected sequentially to the tube side of the third heat exchanger 400, the second heat exchanger 300, and the first heat exchanger 200 along the discharge direction; the air cooler 900 is connected to the tube-side outlet of the first heat exchanger 200.
[0029] The aforementioned reforming unit's pre-hydrogenation reaction system adds a protective reactor 600 before the pre-hydrogenation reactor 800. The protective reactor 600 is filled with a protective agent and a de-olefins catalyst to adsorb mechanical impurities in the feed and remove unsaturated olefins from the feedstock. The protective reactor 600 is located between the second heat exchanger 300 and the third heat exchanger 400. This protective reactor 600 effectively blocks impurities entrained in the feedstock, preventing pressure drop in the pre-hydrogenation reactor 800 and meeting the requirements for long-term operation of the unit. It should be noted that placing the protective reactor 600 between the second heat exchanger 300 and the third heat exchanger 400 is a more reasonable choice, as the temperature at this location meets the requirements of the protective reactor. If it were placed upstream for heat exchange, the temperature would be too low to meet the requirements.
[0030] In one embodiment, the temperature control valve assembly 500 includes a pre-valve gate valve 510, a temperature control valve 520, and a post-valve gate valve 530, with bypass valves 540 provided on the pre-valve gate valve 510 and the post-valve gate valve 530.
[0031] In one embodiment, a temperature transmitter 610 is installed at the inlet of the protective reactor 600, and the temperature transmitter 610 is electrically connected to the temperature control valve 520. A temperature bypass is provided on the shell side between the second heat exchanger 300 and the third heat exchanger 400 to control the temperature of the protective reactor 600; when the inlet temperature of the protective reactor 600 is high, the temperature control valve 520 is gradually opened; when the inlet temperature is low, the temperature control valve 520 is gradually closed. In this embodiment, the temperature transmitter 610 is a PT100 resistance temperature detector.
[0032] In one embodiment, the upstream end of the temperature control valve assembly 500 is connected to the protection reactor 600 via the protector feed line 550, and the protection reactor 600 is connected to the downstream end of the temperature control valve assembly 500 via the protector discharge line 560.
[0033] In one embodiment, the feed line 550 of the protector is provided with inlet double valves 551 and 553, and a first blind flange 552 is provided between the inlet double valves 551 and 553. When the protector reactor 600 needs maintenance, the first blind flange 552 can be used to isolate the inlet double valves 551 and 553, thereby isolating the inlet end of the protector reactor 600 for easy maintenance.
[0034] In one embodiment, the nitrogen replenishment line 570 and the protector feed line 550 meet after the inlet dual valves 551 and 553. Nitrogen gas is introduced through the nitrogen replenishment line 570 and used as a process replacement when the protector reactor 600 is under maintenance.
[0035] In one embodiment, a first gate valve 571, a first check valve 572, and a second gate valve 573 are sequentially arranged along the nitrogen supply line 570 in the supply direction. In this embodiment, the first check valve 572 is provided between the first gate valve 571 and the second gate valve 573 to prevent backflow of the medium.
[0036] In one embodiment, the protector discharge line 560 is equipped with outlet double valves 561 and 563, and a second blind flange 562 is provided between the outlet double valves 561 and 563. When the protector reactor 600 needs maintenance, the second blind flange 562 can be used to isolate the outlet double valves 561 and 563, thereby isolating the outlet end of the protector reactor 600 for easy maintenance.
[0037] In one embodiment, the flare line 580 and the protector discharge line 560 meet before the outlet dual valves 561 and 563. The flare line 580 is mainly used for process pressure relief when the protector reactor 600 is under maintenance.
[0038] In one embodiment, a third gate valve 581, a second check valve 582, and a fourth gate valve 583 are sequentially arranged along the discharge direction on the flare line 580. In this embodiment, the second check valve 582 is arranged between the third gate valve 581 and the fourth gate valve 583 to prevent backflow of the medium.
[0039] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0041] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "above," "below," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.
Claims
1. A pre-hydrogenation reaction system for a reforming unit, characterized in that: include Raw material tank, connected to naphtha feed pipeline; A first heat exchanger, a second heat exchanger, and a third heat exchanger are sequentially connected along the shell side in the feed direction, and the first heat exchanger is connected to the raw material tank. A temperature control valve assembly is disposed between the second heat exchanger and the third heat exchanger; A protective reactor is provided across the temperature control valve assembly, and the protective reactor is filled with a protective agent and a deolefination catalyst. A feed heating furnace is connected to the shell-side outlet of the third heat exchanger; The pre-hydrogenation reactor has its inlet connected to the feed heater, and its outlet is sequentially connected to the tube side of the third heat exchanger, the second heat exchanger, and the first heat exchanger along the discharge direction. An air cooler is connected to the tube-side outlet of the first heat exchanger.
2. The pre-hydrogenation reaction system for a reforming unit according to claim 1, characterized in that: The temperature control valve group includes a gate valve before the valve, a temperature control valve, and a gate valve after the valve, with a bypass valve provided between the gate valve before the valve and the gate valve after the valve.
3. The pre-hydrogenation reaction system for a reforming unit according to claim 2, characterized in that: A temperature transmitter is installed at the inlet of the protected reactor, and the temperature transmitter is electrically connected to the temperature control valve.
4. A pre-hydrogenation reaction system for a reforming unit according to any one of claims 1-3, characterized in that: The temperature control valve group is connected to the protective reactor via a protector feed line before the valve, and the protective reactor is connected to the temperature control valve group via a protector discharge line after the valve.
5. The pre-hydrogenation reaction system for a reforming unit according to claim 4, characterized in that: The feed pipe of the protector is equipped with two inlet valves, and a first blind plate is installed between the two inlet valves.
6. The pre-hydrogenation reaction system for a reforming unit according to claim 5, characterized in that: The nitrogen replenishment pipeline and the feed pipeline of the protector meet after the valve of the inlet double valve.
7. The pre-hydrogenation reaction system for a reforming unit according to claim 6, characterized in that: The nitrogen replenishment pipeline is equipped with a first gate valve, a first check valve, and a second gate valve in sequence along the replenishment direction.
8. The pre-hydrogenation reaction system for a reforming unit according to claim 4, characterized in that: The protector's discharge pipeline is equipped with dual outlet valves, and a second blind plate is installed between the dual outlet valves.
9. A pre-hydrogenation reaction system for a reforming unit according to claim 8, characterized in that: The flare line and the protector discharge line meet in front of the outlet double valve.
10. A pre-hydrogenation reaction system for a reforming unit according to claim 9, characterized in that: The flare pipeline is equipped with a third gate valve, a second check valve, and a fourth gate valve in sequence along the discharge direction.