Aromatization reaction device for reducing aromatic hydrocarbon loss in light hydrocarbon aromatization
By using rich gas pipelines and four-way valve technology in the aromatization reactor, the problem of aromatic hydrocarbon loss during reactor switching was solved, achieving efficient recovery of high-value products and improving the economy and safety of the unit.
Patent Information
- Application Number
- CN202511783808.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-02-06
AI Technical Summary
In existing technologies, when switching catalysts in aromatization reactors, high-value aromatic products are directly purged into the sludge system, resulting in product loss and increased costs. Furthermore, traditional replacement processes are unstable, affecting the operational safety of the unit.
An aromatization reaction unit is used, and hydrocarbon oil and gas in the reactor are carried to the recovery tank for separation through a rich gas pipeline. Subsequently, nitrogen purging and catalyst coking regeneration are carried out to reduce aromatic loss, and a four-way valve is used to maintain a stable flow rate to avoid catalyst bed damage.
It effectively reduces aromatics loss, decreases light oil pollution, lowers refining costs, and improves the stability and economic benefits of the unit operation.
Smart Images
Figure CN121471941A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of light hydrocarbon aromatization apparatus technology, and more particularly to an aromatization reaction apparatus for reducing the loss of aromatics during light hydrocarbon aromatization. Background Technology
[0002] The light hydrocarbon aromatization unit is a key piece of equipment in the petrochemical industry. Its main function is to selectively convert low-carbon hydrocarbons such as liquefied petroleum gas (LPG) and light naphtha into high-value-added aromatic products such as benzene, toluene, and xylene (BTX), which is of great significance for improving resource utilization efficiency and economic benefits.
[0003] During the continuous operation of an aromatization unit, the catalyst gradually deactivates due to coking. To maintain continuous and stable operation, multiple reactors are typically switched in parallel: the coked reactor is removed from the reaction sequence for catalyst regeneration through coking to restore its activity, while a regenerated reactor is switched back into the system. A key step in this switching process is to thoroughly replace the aromatic-rich hydrocarbon gas remaining inside the removed reactor to ensure that an explosive mixture is avoided during subsequent air-based coking regeneration, thus guaranteeing operational safety.
[0004] like Figure 6 As shown, the traditional replacement process commonly used in the industry currently involves using high-pressure nitrogen to repeatedly pressurize and depressurize the cut-out reactor to displace the hydrocarbon oil and gas inside. This displaced oil and gas, due to its complex origin, unstable quantity, and the presence of nitrogen, is typically discharged as light waste oil into the plant's waste oil tank, ultimately mixed with other low-value waste oils and used as fuel oil components or sold at a lower price.
[0005] However, this traditional treatment method has significant drawbacks: the oil and gas remaining inside the reactor, which has just been cut from the reaction sequence, are high-value products that have just completed the aromatization reaction, rich in aromatic components such as benzene, toluene, and xylene. Directly purging this into the waste oil system essentially results in the direct loss of valuable products, not only increasing the material consumption of the unit and the production cost per unit product, but also adding to the corresponding storage, transportation, and energy costs as this light waste oil still needs to be recycled or treated. Summary of the Invention
[0006] This invention addresses the shortcomings of existing technologies by providing an aromatization reaction apparatus that reduces aromatic hydrocarbon loss during light hydrocarbon aromatization. The aromatization reactor in this apparatus is connected to a rich gas pipeline at its inlet. When switching aromatization reactors, the internal hydrocarbon oil and gas are first carried to a second recovery tank via rich gas purging. Subsequently, they are separated in a separation tower to recover high-value aromatic hydrocarbons. The aromatization reactor is then purged with high-pressure nitrogen gas, followed by catalyst coking regeneration. This effectively reduces aromatic hydrocarbon loss, decreases the amount of light sludge, and lowers the cost of refining light sludge.
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons, comprising at least two sets of aromatization reactors connected in parallel, wherein the inlet pipes of each aromatization reactor are connected to switchable feedstock pipes, nitrogen pipes, and rich gas pipes, and the outlet pipes of each aromatization reactor are connected to switchable separation tanks and recovery tanks; the catalyst coke regeneration step of the aromatization reactor includes: 1) switching the inlet pipe of the aromatization reactor to connect to the rich gas pipe, switching the aromatization reactor's... 1) The outlet pipeline is connected to the recovery tank; 2) The residual hydrocarbon oil and gas in the aromatization reactor is carried to the recovery tank by rich gas; 3) The hydrocarbon oil and gas collected in the recovery tank is subsequently separated by a separation tower; 4) The inlet pipeline of the aromatization reactor is switched to connect to the nitrogen pipeline, and the outlet pipeline of the aromatization reactor is switched to connect to the separation tank; 5) The residue in the aromatization reactor is carried to the separation tank by nitrogen purging, and the liquid in the separation tank is discharged to the light sludge tank; 6) Oxygen-containing nitrogen or air is introduced into the nitrogen pipeline to regenerate the catalyst in the aromatization reactor by coking. Using the above-mentioned device and catalyst coking regeneration steps, the hydrocarbon oil and gas that were originally retained in the aromatization reactor and purged to the light sludge tank by nitrogen are carried to the recovery tank by rich gas, without introducing nitrogen impurities. Furthermore, the mixed aromatic products are subsequently produced by separation in the separation tower, which has certain economic benefits, effectively reducing aromatic loss, reducing the amount of light sludge, and lowering the cost of light sludge reprocessing.
[0008] In the above technical solution, preferably, the aromatization reactor has several catalyst layers, and a circulation pipe passing through a first filter is provided between adjacent catalyst layers. Because the catalyst particles in the catalyst layers may break down to a certain extent due to the impact force of flow rate changes and the thermal stress of temperature changes during long-term use, becoming fine catalyst debris, these debris will be carried away with the material flow during processing and blocked in subsequent catalyst layers, reducing the flow efficiency. By setting up the first filter, the carried-away catalyst debris can be filtered out, preventing catalyst debris from remaining in the subsequent catalyst layers and reducing the flow rate of the catalyst layers, thereby improving the reaction efficiency.
[0009] In the above technical solution, preferably, the aromatization reaction apparatus includes a first heat exchanger, and the inlet pipe of the aromatization reactor is connected to a second filter. The first filter and the second filter are disposed in the first heat exchanger, and a heat-conducting medium is disposed in the first heat exchanger to exchange heat between the flowing materials in the first filter and the second filter. Since the aromatization reaction is an exothermic reaction, excessively high temperatures will affect the products of the aromatization reaction and exacerbate coking on the catalyst. This heat exchange method can, on the one hand, increase the temperature of the material that does not enter the aromatization reactor, achieving the purpose of energy saving, and on the other hand, reduce the temperature of the material during the reaction process, thereby reducing the rate of coking on the catalyst and improving the product yield.
[0010] In the above technical solution, preferably, the heat-conducting medium is heat-conducting oil.
[0011] In the above technical solution, preferably, the aromatization reaction apparatus includes several second heat exchangers, the outlet pipe of the aromatization reactor is connected to the tube side of the second heat exchangers, and the inlet pipe of the aromatization reactor is connected to the shell side of the second heat exchangers. This structure is used to exchange heat between the hot material flowing out of the outlet pipe of the aromatization reactor and the material that does not enter the aromatization reactor, thereby achieving energy saving.
[0012] In the above technical solution, preferably, the inlet pipe of the aromatization reactor can be switched to connect the raw material pipe, the nitrogen pipe, and the rich gas pipe via a four-way valve. The four-way valve includes a shell, and a valve core is rotatably disposed inside the shell. Three feed ports are evenly distributed around the rotation center of the valve core on one end face of the shell, and a discharge port is disposed at the rotation center of the valve core on the other end face of the shell. The valve core is provided with a 120° fan-shaped annular flow port disposed around the rotation center of the valve core and a flow groove located on the discharge port side and aligned with the discharge port. The fan-shaped annular flow port is connected to the flow groove, and the three feed ports are located within the rotation trajectory range of the fan-shaped annular flow port side. In the prior art, during coke regeneration in the aromatization reactor, the pipe connected to the inlet pipe is generally switched via a valve body. During the reactor switching process, flow interruption may occur, and the flow rate of the fluid (including raw material gas, rich gas, or nitrogen) often changes drastically. This instantaneous flow fluctuation will cause significant impact on the catalyst bed in the reactor. Long-term, frequent, and sudden changes in flow rate can easily lead to catalyst particle displacement, localized accumulation, or even breakage, resulting in bed blockage. This type of blockage cannot be eliminated by coke regeneration and will gradually affect the reactor's mass transfer efficiency and processing capacity. The aforementioned four-way valve, while controlling the opening and closing of the feed, nitrogen, and rich gas pipelines via the valve body, switches the pipeline connected to the aromatization reactor's inlet pipeline by rotating the valve core. During the switching process, the feed area of one or two feed inlets aligned with the annular flow port remains the same, ensuring a relatively constant flow rate. This maintains fluid velocity stability during the switching and replacement processes in the aromatization reactor, preventing catalyst bed structure damage caused by sudden flow changes. Therefore, it maintains bed unobstructed flow during long-term operation, further reducing aromatic hydrocarbon loss and improving the unit's economic efficiency and stability.
[0013] In the above technical solution, preferably, a sealing element is fixedly installed inside the feed inlet, and the sealing element is interference-fitted against the side wall of the valve core. This structure is used to improve the sealing performance between the feed inlet and the valve core.
[0014] In the above technical solution, preferably, an indicating cavity is provided on the side of the housing, the valve core is disc-shaped, and an indicating wheel, driven by the valve core via a synchronous belt in a 1:1 ratio, is rotatably disposed within the indicating cavity. A pointer is provided on the indicating wheel, and a transparent window is provided at one end of the indicating cavity. The transparent window displays symbols or text that cooperate with the pointer. This structure allows direct observation of the four-way valve's operating status through the transparent window, enabling direct observation of which feed port is currently connected.
[0015] In the above technical solution, preferably, a motor for driving the valve core rotation is provided on the side of the housing. This structure allows for convenient control of the valve core rotation, thereby achieving automated control.
[0016] Compared with the prior art, the present invention has the following beneficial effects: by using the above-mentioned device and catalyst coking regeneration step, the hydrocarbon oil gas that was originally purged to the light waste oil tank by nitrogen in the aromatization reactor is carried into the recovery tank by rich gas, without introducing nitrogen impurities. Furthermore, the mixed aromatic products are produced by separation in the subsequent separation tower, which has certain economic benefits. It can effectively reduce aromatic loss, reduce the amount of light waste oil, and reduce the cost of light waste oil recycling. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the overall connection structure according to an embodiment of the present invention.
[0018] Figure 2 This is a schematic diagram of the overall structure of the four-way valve in an embodiment of the present invention.
[0019] Figure 3 This is an exploded view of the four-way valve in an embodiment of the present invention.
[0020] Figure 4 This is a schematic diagram of the four-way valve switching process in an embodiment of the present invention.
[0021] Figure 5 This is a schematic diagram of the four-way valve working process in an embodiment of the present invention.
[0022] Figure 6 This is a schematic diagram of the overall connection structure of the background technology of this invention. Detailed Implementation
[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments: See below Figures 1 to 6An aromatization reactor for reducing aromatic hydrocarbon loss during light hydrocarbon aromatization includes two parallel aromatization reactors 1. The inlet pipes of each aromatization reactor 1 are connected to switchable feedstock pipes 2, nitrogen pipes 3, and rich gas pipes 4. The outlet pipes of each aromatization reactor 1 are connected to switchable separation tanks 5 and recovery tanks 6. The catalyst coke regeneration step of the aromatization reactor 1 includes: 1) switching the inlet pipe of the aromatization reactor 1 to connect to the rich gas pipe 4, and switching the outlet pipe of the aromatization reactor 1 to connect to the recovery tank 6; 2) using the rich gas to... 1) The residual hydrocarbon oil and gas in the aromatization reactor 1 is carried to the recovery tank 6; 2) The hydrocarbon oil and gas collected in the recovery tank 6 is subsequently separated by a separation tower; 3) The inlet pipe of the aromatization reactor 1 is switched to connect to the nitrogen pipe 3, and the outlet pipe of the aromatization reactor 1 is switched to connect to the separation tank 5; 4) The residue in the aromatization reactor 1 is carried to the separation tank 5 by nitrogen purging, and the liquid in the separation tank 5 is discharged to the light sludge tank; 5) Oxygen-containing nitrogen or air is introduced into the nitrogen pipe 3 to regenerate the catalyst in the aromatization reactor 1 by coking. By using the above-mentioned device and catalyst coking regeneration steps, the hydrocarbon oil and gas that were originally left in the aromatization reactor 1 and purged to the light sludge tank by nitrogen are carried into the recovery tank 6 by rich gas, without introducing nitrogen impurities. Furthermore, the mixed aromatic products are produced by subsequent separation in the separation tower, which has certain economic benefits. It can effectively reduce aromatic loss, reduce the amount of light sludge, and reduce the cost of light sludge reprocessing.
[0024] In this embodiment, the aromatization reactor 1 has two catalyst layers 7, and a circulation pipe 9 passing through a first filter 8 is provided between the two catalyst layers 7. During long-term use, the catalyst particles in the catalyst layer 7 may break down into fine catalyst debris due to the impact force from changes in flow rate and the thermal stress from temperature changes. During processing, these catalyst debris are carried away with the material flow and blocked in subsequent catalyst layers 7, reducing the flow rate. By setting up the first filter 8, the carried-away catalyst debris can be filtered out, preventing it from remaining in the subsequent catalyst layer 7 and reducing its flow rate, thereby improving the reaction efficiency.
[0025] In this embodiment, the aromatization reaction apparatus includes a first heat exchanger 10, and a second filter 11 is connected to the inlet pipe of the aromatization reactor 1. The first filter 8 and the second filter 11 are disposed in the first heat exchanger 10, and a heat-conducting medium is disposed in the first heat exchanger 10 to exchange heat between the flowing materials in the first filter 8 and the second filter 11. Since the aromatization reaction is an exothermic reaction, excessively high temperatures will affect the products of the aromatization reaction and exacerbate coking on the catalyst. This heat exchange method can, on the one hand, increase the temperature of the material that has not yet entered the aromatization reactor 1, thereby saving energy, and on the other hand, reduce the temperature of the material during the reaction process, thereby reducing the rate of coking on the catalyst and improving the product yield.
[0026] In this embodiment, heat transfer medium is heat transfer oil to improve the heat conduction effect.
[0027] In this embodiment, the aromatization reaction apparatus includes several second heat exchangers 12. The outlet pipe of the aromatization reactor 1 is connected to the tube side of the second heat exchanger 12, and the inlet pipe of the aromatization reactor 1 is connected to the shell side of the second heat exchanger 12. This structure is used to exchange heat between the hot material flowing out of the outlet pipe of the aromatization reactor 1 and the material that has not entered the aromatization reactor 1, thereby achieving energy saving.
[0028] In this embodiment, the inlet pipe of the aromatization reactor 1 can be switched to connect to the raw material pipe 2, the nitrogen pipe 3, and the rich gas pipe 4 via a four-way valve 13. The four-way valve 13 includes a housing 14, and a valve core 15 is rotatably disposed inside the housing 14. Three feed ports 16 are evenly distributed around the rotation center of the valve core 15 on one end face of the housing 14. The three feed ports 16 are connected to the raw material pipe 2, the nitrogen pipe 3, and the rich gas pipe 4 in a one-to-one correspondence. An outlet port 17 is disposed at the rotation center of the valve core 15 on the other end face of the housing 14. The outlet port 17 is connected to the inlet pipe of the aromatization reactor 1. The valve core 15 is provided with a 120° fan-shaped annular flow port 18 disposed around the rotation center of the valve core 15 and a flow groove 19 located on the side of the outlet port 17 and aligned with the outlet port 17. The fan-shaped annular flow port 18 is connected to the flow groove 19. The three feed ports 16 are located within the rotation trajectory range of the side of the fan-shaped annular flow port 18. In existing technologies, during coke regeneration in aromatization reactor 1, the inlet pipe is typically switched via a valve. During this switching process, flow interruptions can occur, with the flow rates of fluids, including feed gas, enriched gas, or nitrogen, frequently changing drastically. These instantaneous flow fluctuations significantly impact the catalyst bed within the reactor. Long-term, frequent abrupt changes in flow rate can easily lead to catalyst particle displacement, localized accumulation, or even breakage, resulting in bed blockage. This type of blockage cannot be eliminated through coke regeneration and will gradually affect the reactor's mass transfer efficiency and processing capacity. The aforementioned four-way valve 13, under the premise of controlling the opening and closing of the raw material pipeline 2, nitrogen pipeline 3 and rich gas pipeline 4 by the valve body, switches the pipeline connected to the inlet pipeline of the aromatization reactor 1 by rotating the valve core 15. During the switching process, the feeding area of one or two feed ports 16 aligned with the fan-shaped flow port 18 is always the same, which can ensure that the flow rate remains basically unchanged. It can maintain the stability of the fluid flow rate during the switching and replacement process of the aromatization reactor 1, avoid the destruction of the catalyst bed structure caused by sudden changes in flow rate, and thus maintain the unobstructed flow of the bed during long-term operation, further reduce aromatic loss and improve the economy and stability of the unit operation.
[0029] Taking the switch from raw material pipeline 2 to rich gas pipeline 4 as an example, before the switch, raw material pipeline 2 is connected to the fan-shaped annular flow port 18. At this time, the valve controlling raw material pipeline 2 is in the open state. When the switch is required, first open the valve controlling rich gas pipeline 4, and then rotate the valve core 15 to make the fan-shaped annular flow port 18 rotate towards the feed port 16 connected to rich gas pipeline 4. The two sides of the fan-shaped annular flow port 18 gradually pass over the feed port 16 connected to raw material pipeline 2 and the feed port 16 connected to rich gas pipeline 4. The area of the fan-shaped annular flow port 18 aligned with the feed port 16 connected to raw material pipeline 2 gradually decreases, and the area of the fan-shaped annular flow port 18 aligned with the feed port 16 connected to rich gas pipeline 4 gradually increases until the feed port 16 connected to raw material pipeline 2 completely leaves the area of the fan-shaped annular flow port 18 and the feed port 16 connected to rich gas pipeline 4 completely enters the area of the fan-shaped annular flow port 18. Then close the valve controlling raw material pipeline 2 to complete the switch. During this process, the areas of the inlet 16 connected to the raw material pipeline 2 and the inlet 16 connected to the rich gas pipeline 4 remain unchanged, ensuring stable fluid flow rate during the switching and replacement processes of the aromatization reactor 1. After switching from the raw material pipeline 2 to the rich gas pipeline 4, the valve flowing into the recovery tank 6 is opened, and then the valve flowing into the separation tank 5 is closed, allowing the rich gas to carry hydrocarbon oil and gas into the recovery tank 6. Since the outlet pipeline of the aromatization reactor 1 itself has a pressure control structure, it is only necessary to ensure that the inlet flow rate on the inlet pipeline side remains basically constant to avoid sudden changes in flow rate.
[0030] In this embodiment, a sealing element 20 is fixedly installed inside the feed inlet 16, and the sealing element 20 is press-fitted against the side wall of the valve core 15. This structure is used to improve the sealing performance between the feed inlet 16 and the valve core 15.
[0031] In this embodiment, an indicator cavity 21 is provided on the side of the housing 14. The valve core 15 is disc-shaped. An indicator wheel 22, which is rotatably mounted inside the indicator cavity 21 and driven by the valve core 15 via a synchronous belt in a 1:1 ratio, is mounted on both sides of the valve core 15 and the indicator wheel 22. Synchronous pulleys are fixed on the two synchronous pulleys, and synchronous belts are wound around them. A pointer 23 is provided on the indicator wheel 22. A transparent window 24 is provided at one end of the indicator cavity 21. The transparent window 24 is provided with symbols or text that cooperate with the pointer. With this structure, when the valve core 15 rotates, the indicator wheel 22 rotates synchronously, and the operating status of the four-way valve 13 can be directly observed through the transparent window 24, allowing direct observation of which feed port is currently connected.
[0032] In this embodiment, a motor 25 for driving the valve core 15 to rotate is provided on the side of the housing 14. This structure allows for convenient control of the valve core 15's rotation, thereby achieving automated control.
[0033] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. An aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons, characterized in that: The reactor comprises at least two parallel aromatization reactors (1), the inlet pipes of which are connected to switchable raw material pipes (2), nitrogen pipes (3) and rich gas pipes (4), and the outlet pipes of which are connected to switchable separation tanks (5) and recovery tanks (6); the catalyst coke regeneration step of the aromatization reactor (1) includes: 1) switching the inlet pipe of the aromatization reactor (1) to connect to the rich gas pipe (4), and switching the outlet pipe of the aromatization reactor (1) to connect to the recovery tank (6); 2) using rich gas to regenerate the catalyst in the aromatization reactor. (1) The residual hydrocarbon oil and gas in the reactor is carried to the recovery tank (6); 3) The hydrocarbon oil and gas collected in the recovery tank (6) is then separated by the separation tower; 4) The inlet pipe of the aromatization reactor (1) is switched to connect to the nitrogen pipe (3), and the outlet pipe of the aromatization reactor (1) is switched to connect to the separation tank (5); 5) The residue in the aromatization reactor (1) is carried to the separation tank (5) by nitrogen purging, and the liquid in the separation tank (5) is discharged to the light sludge tank; 6) Oxygen-containing nitrogen or air is introduced into the nitrogen pipe (3) to burn and regenerate the catalyst in the aromatization reactor (1).
2. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 1, characterized in that: The aromatization reactor (1) has several catalyst layers (7), and there is a circulation pipe (9) between two adjacent catalyst layers (7) that passes through a first filter (8).
3. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 2, characterized in that: The aromatization reaction apparatus includes a first heat exchanger (10), and the inlet pipe of the aromatization reactor (1) is connected to a second filter (11). The first filter (8) and the second filter (11) are disposed in the first heat exchanger (10), and a heat-conducting medium is disposed in the first heat exchanger (10) to exchange heat between the flowing materials in the first filter (8) and the second filter (11).
4. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 3, characterized in that: The heat-conducting medium is heat-conducting oil.
5. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 1, characterized in that: The aromatization reaction apparatus includes several second heat exchangers (12), the outlet pipe of the aromatization reactor (1) is connected to the tube side of the second heat exchanger (12), and the inlet pipe of the aromatization reactor (1) is connected to the shell side of the second heat exchanger (12).
6. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 1, characterized in that: The inlet pipe of the aromatization reactor (1) can be switched to the raw material pipe (2), the nitrogen pipe (3) and the rich gas pipe (4) through a four-way valve (13). The four-way valve (13) includes a shell (14), and a valve core (15) is rotatably arranged inside the shell (14). Three feed ports (16) are evenly distributed around the rotation center of the valve core (15) on one end face of the shell (14). An outlet port (17) is arranged at the rotation center of the valve core (15) on the other end face of the shell (14). A fan-shaped annular flow port (18) of 120° around the rotation center of the valve core (15) and a flow groove (19) located on the side of the outlet port (17) and aligned with the outlet port (17) are arranged on the valve core (15). The fan-shaped annular flow port (18) is connected to the flow groove (19). The three feed ports (16) are located within the rotation trajectory range of the fan-shaped annular flow port (18).
7. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 6, characterized in that: A sealing element (20) is fixedly installed inside the feed inlet (16), and the sealing element (20) is press-fitted against the side wall of the valve core (15).
8. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 6, characterized in that: The housing (14) has an indicator cavity (21) on its side. The valve core (15) is disc-shaped. An indicator wheel (22) is rotatably arranged inside the indicator cavity (21) and is driven by the valve core (15) via a synchronous belt in a 1:1 ratio. A pointer (23) is provided on the indicator wheel (22). A transparent window (24) is provided at one end of the indicator cavity (21). The transparent window (24) is provided with identification symbols or text that cooperate with the pointer (23).
9. The aromatization reaction apparatus for reducing the loss of aromatics during the aromatization of light hydrocarbons as described in claim 6, characterized in that: The housing (14) is provided with a motor (25) for driving the valve core (15) to rotate.