Olefin reduction catalytic device
By designing an olefin reduction catalytic unit, a combination of heavy oil riser reactor, settler and gasoline riser reactor is used to reduce the olefin content in gasoline through multiple catalytic reactions, which solves the problem of high olefin content in catalytic cracking process and achieves energy reduction and gasoline quality improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-04
- Publication Date
- 2026-03-10
AI Technical Summary
Gasoline produced by catalytic cracking has a high olefin content, which leads to high energy consumption in subsequent hydrogenation processes and fails to meet increasingly stringent gasoline quality standards.
Design an olefin reduction catalytic device that combines a heavy oil riser reactor, a settling tank, a regenerator, and a gasoline riser reactor. Utilizes a return gasoline pipe and boosted dry gas to perform multiple catalytic reactions to reduce the olefin content in gasoline.
It effectively reduces the olefin content in gasoline, reduces the burden on subsequent hydrogenation processes, lowers energy consumption, improves gasoline quality, meets environmental protection requirements, and improves the performance of automobile engines.
Smart Images
Figure CN223980471U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of petroleum hydrocarbon catalytic cracking technology, specifically to a catalytic device for reducing olefins. BACKGROUND
[0002] With the increasingly serious environmental problems, photochemical pollution frequently occurs, and olefins, as a component with active chemical properties in gasoline, are easy to cause photochemical reactions with nitrogen oxides and volatile organic compounds under light to generate secondary pollutants such as ozone and peroxyacetyl nitrate, forming photochemical smog, and the particulate matter generated by incomplete combustion of olefins also harms air quality and human health. At the same time, the quality standards of gasoline are constantly upgraded, and the limit on the content of olefins is becoming increasingly strict, and in order to reduce the formation of carbon deposits and prevent the clogging of fuel injectors, low-olefin gasoline is also urgently needed to improve performance. As the main gasoline production process, catalytic cracking, due to its own process and raw material characteristics, the content of olefins in gasoline is as high as about 40% v, which increases the burden of subsequent hydrogenation process to reduce olefins, and the energy consumption of the device is high. SUMMARY
[0003] The utility model discloses to solve the problem of high content of olefins in gasoline produced by catalytic process, and provides a catalytic device for reducing olefins to reduce the content of olefins in gasoline.
[0004] In order to solve the above technical problems, the utility model discloses a heavy oil riser reactor and settler, the heavy oil riser reactor is connected with heavy crude oil inlet pipe and lifting steam inlet pipe, the inside top of settler is equipped with first cyclonic separation system for separating oil gas and catalyst, the upper portion of heavy oil riser reactor is connected with first cyclonic separation system through pipeline, the bottom of settler is connected with stripping section, the stripping section is communicated with regenerator for catalyst regeneration through catalyst pipeline, the bottom of regenerator is connected with main air pipe, the regenerator is connected with heavy oil riser reactor through first regenerated catalyst inclined pipe, the top of settler is communicated with the lower portion of fractionating column through large oil gas pipeline, the top of fractionating column is communicated with fractionating column top oil gas separation tank through column top gas pipeline, fractionating column top oil gas separation tank is connected with crude gasoline conveying pipe, and its structural characteristics are: the crude gasoline conveying pipe is equipped with reflux gasoline pipe and outer delivery gasoline adjusting valve which are arranged in sequence along the flow direction of crude gasoline, the reflux gasoline pipe is connected with gasoline riser reactor, the bottom of gasoline riser reactor is connected with lifting dry gas inlet pipe, the gasoline riser reactor is also connected with regenerator through second regenerated catalyst inclined pipe, the inside top of settler is also equipped with second cyclonic separation system for separating oil gas and catalyst, and the top of gasoline riser reactor is connected with second cyclonic separation system through pipeline.
[0005] With the above structure, heavy feedstock enters the heavy oil riser reactor via the heavy feedstock inlet pipe, and the regenerated catalyst enters the heavy oil riser reactor via the first regenerated catalyst inclined pipe. Steam enters the heavy oil riser reactor via the riser steam inlet pipe. Under the action of the riser steam, the heavy feedstock and the regenerated catalyst rise in contact, and the heavy feedstock undergoes a catalytic cracking reaction. The resulting oil and gas enter the settling tank. After the oil and gas and the catalyst are separated by the first swirl separator, the spent catalyst enters the settling tank, passes through the stripping section and the spent catalyst pipeline, and then enters the regenerator. Air for catalyst regeneration enters the regenerator via the main air duct. The catalyst undergoes coke burn-off regeneration treatment in the regenerator. The oil and gas separated from the catalyst in the settling tank enters the fractionation tower for fractionation via the main oil and gas pipeline. The oil and gas at the top of the fractionation tower... The crude gasoline produced in the fractionation tower's top oil-gas separator enters through the top gas pipeline. A portion of the crude gasoline then flows through the return gasoline pipeline into the gasoline riser reactor. The regeneration catalyst in the regenerator enters the gasoline riser reactor via the second regeneration catalyst inclined tube. Dry gas enters the gasoline riser reactor via the dry gas lift pipe. Under the action of the lift dry gas, the gasoline and regeneration catalyst rise, and the olefins in the gasoline undergo a catalytic reaction, reducing the olefin content. The resulting oil-gas mixture is separated from the catalyst by the second cyclone separator. The catalyst then passes through a settling tank, stripping section, and the spent catalyst pipeline before entering the regenerator for regeneration. The oil-gas mixture from the gasoline riser reactor and the heavy oil riser reactor enter the main oil-gas pipeline together. This invention reduces the olefin content by subjecting a portion of the crude gasoline from the fractionation tower's top oil-gas separator to a catalytic reaction, thus reducing the burden on subsequent gasoline olefin reduction processes.
[0006] The reflux gasoline pipe is equipped with a reflux gasoline regulating valve, a flow meter, an emergency return pipeline, an emergency shut-off valve, and a second atomizing steam inlet pipe arranged sequentially along the gasoline flow direction. The emergency return pipeline is connected to the top of the oil-gas separator at the top of the fractionation tower.
[0007] An accident return valve is installed on the accident return pipeline.
[0008] A thermometer is installed on the pipe connecting the gasoline riser reactor and the second spool system.
[0009] The emergency shut-off valve is connected to the accident return valve, flow meter, and thermometer.
[0010] The bottom of the gasoline riser reactor is provided with a riser dry gasification ring for fluidizing the catalyst, and the riser dry gasification ring has multiple gas passage holes.
[0011] The gasoline riser reactor has a structure that is thinner at the bottom and thicker at the top.
[0012] The heavy feedstock oil inlet pipe is connected to the first atomizing steam inlet pipe.
[0013] The catalyst pipeline includes a catalyst standpipe and a catalyst sleeve arranged from top to bottom. The catalyst sleeve is connected to the regenerator and is connected to a pressurized air duct for blowing the catalyst into the regenerator.
[0014] The gas pipeline at the top of the tower is equipped with cooling equipment to cool the oil and gas.
[0015] This utility model's olefin reduction catalytic device, through the setting of a reflux gasoline pipe and a gasoline riser reactor, sends a portion of the crude gasoline produced by the fractionation tower top oil-gas separator into the gasoline riser reactor. The regenerated catalyst in the regenerator is also sent into the gasoline riser reactor. The riser dry gas lifts the gasoline and regenerated catalyst, and the gasoline undergoes a contact catalytic reaction in the gasoline riser reactor, thereby reducing the olefin concentration and thus reducing the olefin content in the crude gasoline and the burden on the subsequent olefin reduction unit. When an emergency such as low flow rate occurs in the gasoline riser reactor, the emergency shut-off valve is closed and the emergency return valve is opened, allowing the refluxed crude gasoline to return to the fractionation tower top oil-gas separator through the emergency return pipeline, thus keeping the gasoline riser reactor safe. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of this utility model;
[0017] In the diagram: 1. Heavy feedstock inlet pipe; 2. First atomizing steam inlet pipe; 3. Heavy oil riser reactor; 4. First cyclone separator system; 5. Settler; 6. Stripping section; 7. Regenerator riser; 8. Regenerator sleeve; 9. Regenerator; 10. Main oil and gas pipeline; 11. Gasoline riser reactor; 111. Rising dry gas flow ring; 12. Second cyclone separator system; 13. First oil and gas inlet pipe; 14. Second oil and gas inlet pipe; 141. First thermocouple; 142. Second thermocouple; 15. First regenerated catalyst inclined tube; 151. First slide valve; 16. Second regenerated catalyst inclined tube; 161. Second slide valve; 17. Rising steam inlet pipe; 18. Main duct; 19. Booster duct; 20. Fractionating tower; 201. Baffle; 202. Circulation. 203. Oil slurry reflux pipe; 204. Circulating oil slurry pump; 205. Heat exchanger; 206. Internal circulation reflux pipe; 207. Top circulation reflux pipe; 21. Light diesel stripping tower; 211. Light diesel delivery pipe; 212. Diesel pump; 22. Tower top gas pipeline; 221. Demineralized water cooler; 222. Air cooler; 223. Water cooler; 23. Top oil-gas separator of fractionation tower; 24. Crude gasoline delivery pipe; 241. Crude gasoline pump; 242. External gasoline regulating valve; 25. Return gasoline pipe; 251. Return gasoline regulating valve; 252. First flow meter; 253. Second flow meter; 254. Emergency shut-off valve; 26. Emergency return pipeline; 261. Emergency return valve; 27. Lifting dry gas inlet pipe; 28. Second atomizing steam inlet pipe. Detailed Implementation
[0018] Reference Figure 1 An olefin reduction catalytic device includes a heavy oil riser reactor 3 for catalyzing heavy feedstock oil, a settling tank 5 for conveying the catalyst after separation from oil and gas downwards, a regenerator 9 for catalyst regeneration, a fractionating tower 20, a fractionating tower top oil-gas separator 23, and oil-gas conveying pipelines, catalyst conveying pipelines, atomizing steam pipelines, air pipelines, and lifting medium pipelines. A stripping section 6 is provided below the settling tank 5, and the stripping section 6 is connected to the regenerator 9 through a catalyst regeneration pipeline. The device also includes a gasoline riser reactor 11 for catalytic olefin reduction of a portion of the crude gasoline produced by the fractionating tower top oil-gas separator 23. The gasoline riser reactor 11 is connected to the fractionating tower top oil-gas separator 23 through a return gasoline pipeline 25. Inside the settling tank 5, there are two sets of cyclone separators that separate the catalyst in the oil and gas entering the heavy oil riser reactor 3 and the gasoline riser reactor 11, respectively.
[0019] Reference Figure 1 The lower part of the heavy oil riser reactor 3 is connected to the heavy feedstock oil inlet pipe 1, which is connected to the first atomizing steam inlet pipe 2. The bottom of the heavy oil riser reactor 3 is connected to a lifting steam inlet pipe 17 for lifting the heavy feedstock oil and catalyst. Regulating valves are installed on the heavy feedstock oil inlet pipe 1, the first atomizing steam inlet pipe 2, and the lifting steam inlet pipe 17. A first swirl separator system 4 is located above the interior of the settling tank 5 to separate the oil and gas from the catalyst in the heavy oil riser reactor 3. This swirl separator system is existing technology. The upper part of the heavy oil riser reactor 3 is connected to the first swirl separator system 4 via a first oil and gas inlet pipe 13. After the oil and gas are separated from the catalyst, the catalyst enters the stripping section 6 downwards within the settling tank 5. Figure 1 As shown, the catalyst preparation pipeline includes a catalyst preparation riser 7 and a catalyst preparation sleeve 8 arranged from top to bottom. The top of the catalyst preparation riser 7 is connected to the bottom of the stripping section 6, and the bottom of the catalyst preparation riser 7 is connected to the top of the catalyst preparation sleeve 8. The catalyst preparation sleeve 8 is connected to the regenerator 9, and the bottom of the catalyst preparation sleeve 8 is connected to a pressurized air duct 19 for blowing the catalyst preparation into the regenerator 9. Figure 1 The settling tank 5 and the regenerator 9 are arranged coaxially, but they can also be arranged separately and side by side. The bottom of the regenerator 9 is connected to the main air duct 18. The air for catalyst regeneration enters the regenerator 9 through the main air duct 18. The catalyst to be regenerated is burned and regenerated in the regenerator 9. The regenerator 9 is connected to the bottom of the heavy oil riser reactor 3 through the first regenerated catalyst inclined tube 15. The first regenerated catalyst inclined tube 15 is equipped with a first slide valve 151. The regenerated catalyst enters the heavy oil riser reactor 3 through the first regenerated catalyst inclined tube 15 to carry out catalytic cracking reaction on the heavy feedstock oil. The main air duct 18 and the booster air duct 19 are both equipped with regulating valves.
[0020] Reference Figure 1The top of the settling tank 5 is connected to the lower part of the fractionation tower 20 via the large oil and gas pipeline 10. A baffle 201, which can be herringbone shaped, is located at the lower part of the fractionation tower 20, above the connection between the large oil and gas pipeline 10 and the fractionation tower 20. A circulating slurry return pipe 202 is located at the bottom of the fractionation tower 20, with one end connected to the bottom of the fractionation tower 20 and the other end connected to the part above the baffle 201 of the fractionation tower 20. The circulating slurry return pipe 202 is equipped with a circulating slurry pump 203 and a heat exchanger 204. The circulating slurry pump 203 draws the bottom oil in the fractionation tower 20 from the bottom and then returns it to the fractionation tower 20 to wash the catalyst in the oil and gas. The heat exchanger 204 absorbs the excess heat in the circulating slurry and cools it down. The fractionation tower 20 is also equipped with an internal circulating reflux pipe 205 and a top circulating reflux pipe 206. All six sections are equipped with circulating pumps and cooling devices, which is a standard feature in the field. The middle section of the fractionation tower 20 is connected to the light diesel stripping tower 21 via a pipeline. The bottom of the light diesel stripping tower 21 is connected to a light diesel delivery pipe 211 that delivers light diesel. A diesel pump 212 is installed on the light diesel delivery pipe 211, which is a standard feature in the field. The top of the fractionation tower 20 is connected to the top of the fractionation tower top oil-gas separator 23 via a tower top gas pipeline 22. The tower top gas pipeline 22 is equipped with cooling devices for cooling the oil and gas. Specifically, the tower top gas pipeline 22 is equipped with a demineralized water cooler 221, an air cooler 222, and a water cooler 223 arranged sequentially along the oil and gas flow direction. The bottom of the fractionation tower top oil-gas separator 23 is connected to a crude gasoline delivery pipe 24 for discharging the crude gasoline produced by separation. The crude gasoline delivery pipe 24 is equipped with a crude gasoline pump 241, a return gasoline pipe 25, and an external gasoline regulating valve 242 arranged sequentially along the crude gasoline flow direction.
[0021] Reference Figure 1The reflux gasoline pipe 25 is connected to the lower part of the gasoline riser reactor 11. The reflux gasoline pipe 25 is equipped with a reflux gasoline regulating valve 251, a first flow meter 252, a second flow meter 253, an emergency return pipe 26, an emergency shut-off valve 254, and a second atomizing steam inlet pipe 28, arranged sequentially along the gasoline flow direction. The emergency return pipe 26 is connected to the top of the fractionation tower top oil-gas separator 23. The emergency return pipe 26 is equipped with an emergency return valve 261, and the emergency shut-off valve 254 is connected to the first flow meter 252. The second flow meter 253 and the emergency return valve 261 are connected. When the emergency shut-off valve 254 is closed, the emergency return valve 261 is opened, and gasoline returns to the oil-gas separator 23 at the top of the fractionation tower. The bottom of the gasoline riser reactor 11 is connected to the riser dry gas inlet pipe 27. Both the riser dry gas inlet pipe 27 and the second atomizing steam inlet pipe 28 are equipped with regulating valves. The regenerator 9 is connected to the bottom of the gasoline riser reactor 11 through the second regeneration catalyst inclined pipe 16. The second regeneration catalyst inclined pipe 16 is equipped with a second slide valve 16. 1. The regenerated catalyst in regenerator 9 enters gasoline riser reactor 11 through second regenerated catalyst inclined tube 16 to catalyze the gasoline, reducing the olefin content in the gasoline. The bottom of gasoline riser reactor 11 is equipped with a dry gas flow ring 111 for fluidizing the catalyst. The dry gas flow ring 111 has multiple gas passage holes, such as a two-row multi-hole design. The dry gas flow ring 111 acts as a fluidizer, aiding flow and improving the lifting effect of dry gas on the catalyst and gasoline. Above the interior of settler 5, a second swirl separator system 12 is provided for separating the oil and gas and catalyst from gasoline riser reactor 11. The top of gasoline riser reactor 11 is connected to the second swirl separator system 12 via a second oil and gas inlet pipe 14. The second swirl separator system 12 is equipped with a thermometer. Specifically, the second oil and gas inlet pipe 14 is equipped with a first thermocouple 141 and a second thermocouple 142 to measure the temperature of the oil and gas after the reaction. An emergency shut-off valve 254 is connected to the first thermocouple 141 and the second thermocouple 142 for control. Figure 1 As shown, the gasoline riser reactor 11 adopts a structure that is thinner at the bottom and thicker at the top, which prolongs the time of gasoline catalytic reaction and improves the olefin reduction effect.
[0022] It should be noted that actual tanks, towers and other equipment are also equipped with accessories such as pressure gauges and thermometers, and pipelines are also equipped with accessories such as pumps, fans, hand valves, check valves, filters and pressure gauges. These are standard features in this field and are not shown in the accompanying drawings or text.
[0023] The operating process of the olefin reduction catalytic device of this invention is as follows:
[0024] 1. Reaction-Regeneration Section
[0025] Heavy feedstock oil enters the heavy feedstock oil inlet pipe 1. Atomized steam is introduced into the heavy feedstock oil inlet pipe 1 through the first atomized steam inlet pipe 2 to atomize the heavy feedstock oil. After atomization, the oil enters the heavy oil riser reactor 3. The regenerated high-temperature catalyst enters the heavy oil riser reactor 3 through the first regenerated catalyst inclined pipe 15. Steam is introduced into the heavy oil riser reactor 3 from the bottom through the riser steam inlet pipe 17. The heavy oil and catalyst rise in contact, completing the heating, vaporization and catalytic reaction of the feedstock. The reacted oil and gas and catalyst are separated by the first swirl separation system 4. The catalyst enters the lower stripping section 6 through the settling tank 5. The oil and gas enter the fractionation tower 20 through the large oil and gas pipeline 10 at the top of the settling tank 5.
[0026] The catalyst enters the regenerating sleeve 8 through the regenerating riser 7, and is blown into the regenerator 9 by pressurized air, where it is regenerated. The regenerated catalyst enters the bottom of the heavy oil riser reactor 3 through the first regenerated catalyst inclined tube 15. Steam is introduced into the heavy oil riser reactor 3 through the riser steam inlet pipe 17, using steam as the riser medium to complete the catalyst acceleration and rectification process, and then comes into contact with the atomized heavy feedstock oil.
[0027] Air for catalyst regeneration is introduced into the regenerator 9 from the bottom through the main air duct 18, and the catalyst is regenerated by burning. Pressurized air is blown into the waiting sleeve 8 through the pressurized air duct 19, which acts as ventilation to blow the waiting catalyst to the regenerator 9, thus completing the catalyst cycle.
[0028] 2. Fractionation section
[0029] The reaction oil and gas from the settling tank 5 enters the fractionation tower 20 through the large oil and gas pipeline 10. It then comes into contact with the circulating oil slurry from the circulating oil slurry pump 203 and the heat exchanger 204 through the baffle 201, washing the catalyst in the reaction oil and gas and removing excess heat.
[0030] The oil and gas at the top of the fractionation tower 20 enter the top gas pipeline 22, and are cooled to 35°C by the demineralized water cooler 221, air cooler 222, and water cooler 223. The gas then enters the top oil-gas separator 23 for gas-liquid phase separation. The separated crude gasoline is extracted by the crude gasoline pump 241. One path is regulated by the external gasoline regulating valve 242 and sent to the subsequent absorption and stabilization unit (not shown in the figure, outside the scope of this utility model). The other path enters the return gasoline pipe 25, passing through the return gasoline regulating valve 251, the first flow meter 252, the second flow meter 253, and the emergency shut-off valve 254. The atomized vapor is introduced into the return gasoline pipe 25 via the second atomizing steam pipe 28. After atomization, the gasoline enters the gasoline riser reactor 11. The gasoline riser reactor 11 adopts a bottom-narrow, top-coarse design, which prolongs the reaction time between the gasoline and the catalyst, facilitating the olefin reduction reaction of the gasoline. An emergency return pipeline 26 is installed before the emergency shut-off valve 254. During normal operation, the emergency return valve 261 is closed. In an emergency, gasoline can enter the oil-gas separator 23 at the top of the fractionation tower via the emergency return pipeline 26. For example, when the first flow meter 252 and the second flow meter 253 are both below 5 t / h, the low-flow-rate feed cut-off interlock is triggered: the emergency shut-off valve 254 automatically closes, the emergency return valve 261 automatically opens, and the regulating valve on the second atomizing steam inlet pipe 28 of the gasoline riser reactor 11 is fully open to maintain the fluidization state of the catalyst and prevent... To prevent catalyst buildup and reduce the partial pressure of oil and gas in the gasoline riser reactor 11, ensuring it remains in a safe state; when both the first thermocouple 141 and the second thermocouple 142 are below 450°C, a low-temperature feed cut-off interlock is triggered: the emergency cut-off valve 254 automatically closes, the accident return valve 261 automatically opens, and the regulating valve on the second atomized steam inlet pipe 28 entering the gasoline riser reactor 11 is fully open, maintaining the fluidization state of the catalyst, preventing catalyst buildup, and simultaneously reducing the partial pressure of oil and gas in the gasoline riser reactor 11, ensuring it remains in a safe state.
[0031] The regenerated catalyst enters the bottom of the gasoline riser reactor 11 via the second regenerated catalyst inclined tube 16. Rising dry gas is introduced into the gasoline riser reactor 11 from the bottom via rising dry gas inlet pipe 27, using rising dry gas as the rising medium. The rising dry gas flow ring 111 improves the rising effect. Under the action of the rising dry gas, catalyst acceleration and rectification are completed. The dry gas comes from the stabilization unit, and its main components are methane, ethane, ethylene, and hydrogen. The gasoline and gas after catalytic reaction and the catalyst enter the second cyclone separator 12 to separate the catalyst and the gasoline and gas. The catalyst enters the lower stripping section 6 via the settling tank 5, while the gasoline and gas enter the large gasoline and gas pipeline 10 at the top of the settling tank 5, where they mix with the gasoline and gas from the heavy oil riser reactor 3 and then enter the fractionation tower 20.
[0032] This utility model discloses an olefin reduction catalytic device. The heavy oil riser reactor employs conventional catalytic technology, while the gasoline riser reactor uses cooled, fractionated crude gasoline as feedstock and riser dry gas as the lifting medium, lowering the reaction temperature and creating favorable conditions for alkylation, hydrogen transfer, and isomerization reactions of olefins in gasoline. The crude gasoline enters the gasoline riser reactor separately, allowing olefin molecules to directly contact the highly active regenerated catalyst, increasing the concentration of active sites and promoting olefin reduction reactions. The reduced olefin content in the feedstock entering the subsequent gasoline hydrotreating unit lowers hydrogen consumption and energy consumption, while also mitigating problems such as carbon deposits in automotive engines and fuel injector clogging caused by high-olefin gasoline. The lower olefin content in gasoline improves the selectivity and depth of subsequent desulfurization reactions, making it easier to meet environmental protection requirements. This device improves the quality of gasoline products, meeting increasingly stringent gasoline quality standards and enhancing market competitiveness.
Claims
1. A catalytic apparatus for reducing olefins, comprising a heavy oil riser reactor (3) and a settler (5), the heavy oil riser reactor (3) being connected with a heavy oil feed pipe (1) and a riser steam pipe (17), the settler (5) being provided with a first cyclone system (4) at the top of the inside of the settler (5) for separating oil gas and catalyst, the upper part of the heavy oil riser reactor (3) being connected with the first cyclone system (4) through a pipe, the bottom of the settler (5) being connected with a stripping section (6), the stripping section (6) being communicated with a regenerator (9) for catalyst regeneration through a spent catalyst pipe, the bottom of the regenerator (9) being connected with a main air pipe (18), the regenerator (9) being connected with the heavy oil riser reactor (3) through a first regenerated catalyst inclined pipe (15), the top of the settler (5) being communicated with the lower part of a fractionating column (20) through a large oil gas pipe line (10), the top of the fractionating column (20) being communicated with a fractionating column top oil gas separation tank (23) through a column top gas pipe line (22), the fractionating column top oil gas separation tank (23) being connected with a crude gasoline delivery pipe (24), characterized in that: The crude gasoline delivery pipe (24) is provided with a return gasoline pipe (25), an outer gasoline delivery adjusting valve (242) arranged in sequence along the direction of crude gasoline flow, the return gasoline pipe (25) is connected with the gasoline riser reactor (11), the bottom of the gasoline riser reactor (11) is connected with a riser dry gas pipe (27), the gasoline riser reactor (11) is also connected with the regenerator (9) through a second regenerated catalyst inclined pipe (16), the inside of the upper part of the settler (5) is also provided with a second cyclone separation system (12) for separating oil gas and catalyst, the top of the gasoline riser reactor (11) is connected with the second cyclone separation system (12) through a pipe.
2. The olefin-reduction catalytic device of claim 1, wherein: The return gasoline pipe (25) is provided with a return gasoline adjusting valve (251), a flow meter, an accident return pipe (26), an emergency shut-off valve (254) and a second atomized steam pipe (28) arranged in sequence along the direction of gasoline flow, the accident return pipe (26) is connected to the top of the fractionating tower top oil gas separation tank (23).
3. The olefin-reduction catalytic device of claim 2, wherein: The accident return pipe (26) is provided with an accident return valve (261).
4. The olefin-reducing catalytic device of claim 3, wherein: The pipe connecting the gasoline riser reactor (11) with the second cyclone separation system (12) is provided with a temperature gauge.
5. The olefin-reducing catalytic device of claim 4, wherein: The emergency shut-off valve (254) is connected with the accident return valve (261), the flow meter and the temperature gauge.
6. The olefin-reduction catalytic device of claim 1, wherein: The bottom of the gasoline riser reactor (11) is provided with a riser dry gas fluidization ring (111) for fluidizing catalyst, a plurality of air holes are formed in the riser dry gas fluidization ring (111).
7. The olefin-reduction catalytic device of claim 1, wherein: The gasoline riser reactor (11) has a structure of being thin at the bottom and thick at the top.
8. The olefin-reduction catalytic device of claim 1, wherein: The heavy raw oil pipe (1) is connected with a first atomized steam pipe (2).
9. The olefin-reduction catalytic device of claim 1, wherein: The spent catalyst pipe includes a spent vertical pipe (7) and a spent sleeve (8) arranged from top to bottom, the spent sleeve (8) is communicated with the regenerator (9), the spent sleeve (8) is connected with a booster air pipe (19) for blowing spent catalyst into the regenerator (9).
10. The olefin-reduction catalytic device of claim 1, wherein: The tower top gas pipe (22) is provided with a cooling device for cooling oil gas.