A method and system for converting light hydrocarbon oils to produce lower carbon olefins and aromatics

Abstract

The present disclosure relates to a method and system for converting light hydrocarbon oil to produce low-carbon olefins and aromatic hydrocarbons, which comprises: feeding a light hydrocarbon oil feedstock into a reaction unit for catalytic conversion reaction to obtain a first reaction oil gas and a spent catalyst; feeding the first reaction oil gas into an oil gas separation unit for separation treatment, returning the obtained mixed C4 and mixed C5 to the reaction unit, feeding the obtained cracked naphtha into an aromatic hydrocarbon treatment unit for hydrogenation separation treatment, feeding the obtained ethane and propane into an alkane recycling unit for alkane recycling treatment; feeding the spent catalyst into a regeneration unit for regeneration treatment to obtain a regenerated catalyst, and returning the regenerated catalyst to the reaction unit for the catalytic conversion reaction. By using the method of the present disclosure, the yield of low-carbon olefins and light aromatic hydrocarbons can be improved, and the energy consumption and carbon emissions of the device can be reduced.

Description

Technical Field

[0001] This disclosure relates to the petrochemical field, specifically to a method and system for converting light hydrocarbon oils into low-carbon olefins and aromatics. Background Technology

[0002] Low-carbon olefins (ethylene, propylene) and light aromatics (BTX) play a crucial role in the petrochemical industry as important basic organic raw materials.

[0003] Ethylene, as one of the most important basic organic chemical raw materials and a leading product of the petrochemical industry, is the core of the petrochemical industry, with ethylene products accounting for more than 75% of petrochemical products. Ethylene production is one of the important indicators for measuring the level of a country's petrochemical development. Ethylene is a basic chemical raw material for synthetic fibers, synthetic rubber, synthetic plastics (polyethylene and polyvinyl chloride), and synthetic ethanol (alcohol). It is also used in the manufacture of vinyl chloride, styrene, ethylene oxide, acetic acid, acetaldehyde, and explosives.

[0004] Propylene, as an important basic petrochemical raw material second only to ethylene, is widely used in the production of polypropylene, acrylonitrile, isopropanol, phenol and acetone, butanol and octanol, acrylic acid and its esters, as well as in the production of propylene oxide and propylene glycol, epichlorohydrin and the synthesis of glycerol.

[0005] Aromatic hydrocarbons are an important basic raw material for organic chemicals. Among them, benzene, toluene, and xylene (including o-xylene, m-xylene, and p-xylene) have a wide range of applications. Their end products are used in fields such as synthetic resins, synthetic fibers, synthetic rubber, coatings, dyes, and pharmaceuticals.

[0006] In the production technology of hydrocarbon cracking to produce low-carbon olefins, tubular furnace pyrolysis is one of the main methods for ethylene and propylene production worldwide, accounting for approximately 96% of global ethylene, 65% of propylene, and 20% of aromatics production. With the increasing demand for propylene derivatives, the propylene yield obtained through pyrolysis co-production can no longer meet the growing domestic and international market demand. Therefore, improving the propylene / ethylene yield has become a hot topic. Furthermore, steam cracking technology suffers from a series of problems, including high energy consumption, high carbon emissions, high equipment investment, a narrow range of feedstock options, and significant environmental pollution. Therefore, the application scope of steam cracking technology is increasingly limited.

[0007] In recent years, other new technologies for producing low-carbon olefins and light aromatics have received increasing attention, with catalytic cracking being one of the most widely used. Traditional catalytic cracking feedstocks include heavy oils such as wax oil, atmospheric residue, and hydrotreated heavy oil; however, catalytic cracking technology using light oils as feedstocks has gradually gained importance in recent years.

[0008] Chinese patent CN101029250A discloses a method and apparatus for preparing low-carbon olefins by catalytic cracking of light hydrocarbon feedstocks. The method includes using light hydrocarbons as feedstock in a moving bed reactor to continuously carry out the cracking reaction to produce low-carbon olefins under the action of a catalytic cracking catalyst, and continuously regenerating the deactivated catalytic cracking catalyst in a moving bed regenerator. The light hydrocarbons contact and undergo a cracking reaction with the catalytic cracking catalyst that continuously enters and moves downwards in the moving bed reactor. Simultaneously, the deactivated catalyst that has moved to the bottom of the reactor is also removed from the reactor and sent to the moving bed regenerator for regeneration. The catalyst is then continuously returned to the reactor, realizing a continuous cycle of cracking reaction-regeneration. Compared with steam thermal cracking to produce low-carbon olefins, this method has a lower reaction temperature, lower energy consumption, and higher selectivity for producing low-carbon olefins.

[0009] Chinese patent CN201694999U discloses a light oil riser catalytic cracking device. This device comprises a settling tank and a regenerator arranged from top to bottom, forming a catalytic cracking unit. The upper end of the settling tank has a coarse vortex connected to the outlet of the light oil riser; the bottom end of the regenerator is connected to a regeneration inclined tube; a light oil riser reactor is disposed between the light oil riser outlet and the regeneration inclined tube; the bottom end of the light oil riser reactor, corresponding to the position of the regeneration inclined tube, is connected to one end of a regeneration circulation pipe, and the other end of the circulation pipe is connected to the lower end of the settling tank. This device solves the problem of flexibly adjusting the reaction temperature for catalytic cracking of light oils of different textures, increases the catalyst-to-oil ratio, reduces dry gas production, reduces processing losses, controls catalyst activity, and reduces catalyst consumption.

[0010] Chinese patent CN102040438A discloses a coaxial embedded riser circulating reaction-regeneration device, mainly to solve the problem of difficulty in achieving high-temperature reactions when using riser reactors for circulating reaction regeneration in existing light hydrocarbon and light oil catalytic cracking processes. This device, by employing a reaction-regeneration unit comprising a settling tank, a regenerator, and a riser reactor, wherein the main reaction zone of the riser reactor is located inside the regenerator, and the settling tank, stripping section, and riser reactor are all on the same axis, effectively solves this problem and can be used in the industrial production of ethylene and propylene from light oil cracking.

[0011] Chinese patent CN101134160A discloses a reaction apparatus for catalytic cracking to produce low-carbon olefins. This apparatus uses high-temperature regenerated flue gas from a catalytic cracking unit as a heat source and light oil products such as naphtha as feedstock for catalytic cracking to produce low-carbon olefins. The apparatus includes a main flue gas feed pipeline, a reactor, a feedstock preheater, and a water seal tank. This apparatus can save on equipment such as cracking reaction heating furnaces, flue gas turbines for recovering flue gas heat energy from the catalytic cracking unit, and carbon monoxide boilers. It also allows for comprehensive utilization of the regenerated flue gas from the catalytic cracking unit, reducing construction investment and fuel consumption, thus promoting energy conservation and lowering product production costs. However, due to the use of a tubular reactor, it is difficult to solve the problem of rapid catalyst deactivation for highly active molecular sieve catalysts.

[0012] Chinese patents CN103059925A, CN103059926A, CN103509589A, CN103509593A, CN103509594A, and CN103509595A disclose a method for the catalytic conversion of light hydrocarbon oil to produce low-carbon olefins. The light hydrocarbon oil feedstock enters the riser reactor of a catalytic cracking unit and reacts with the catalyst. After the reaction, the reactant oil and gas are separated from the spent catalyst, further separating ethylene, propylene, C2-C3 alkanes, C4 hydrocarbon fractions, and other products. The spent catalyst is regenerated by coking and recycled. These patents focus on solving the problem of insufficient heat generation due to insufficient coking in the cracking of light hydrocarbon oil. They arrange the reactor inside the regenerator and eliminate the stripping section and settling tank, reducing the total heat dissipation surface area of ​​the reaction regeneration system and reducing the reactor's heat dissipation energy consumption. However, this introduces a problem: the flow of catalyst in the regenerator causes reactor wear. Once the reactor is worn through, the reactant oil and gas can leak directly into the regenerator, causing an explosion, posing a significant safety risk. On the other hand, these patents only recycle the mixed C4 produced by the equipment, without further utilizing C2-C3 alkanes and mixed C5 rich in olefins, which is not conducive to improving the yield of low-carbon olefins in the equipment, and no specific method is proposed for the recovery and utilization of light aromatics. Summary of the Invention

[0013] The purpose of this disclosure is to provide a method and system for converting light hydrocarbon oils to produce low-carbon olefins and aromatics, in order to solve the problems of low yield of low-carbon olefins, lack of recycling of light aromatics, and low safety in the prior art.

[0014] To achieve the above objectives, the first aspect of this disclosure provides a method for converting light hydrocarbon oil into low-carbon olefins and aromatics. The method includes: feeding light hydrocarbon oil feedstock into a reaction unit and contacting it with a catalytic conversion catalyst to undergo a catalytic conversion reaction, yielding a first reaction oil-gas and a spent catalyst; feeding the first reaction oil-gas into an oil-gas separation unit for a first separation process, yielding methane hydrogen gas, ethylene, propylene, ethane, propane, cracked light oil, cracked heavy oil, cracked naphtha, mixed C4, and mixed C5; returning the mixed C4 and mixed C5 to the reaction unit for the catalytic conversion reaction; feeding the cracked naphtha into an aromatics processing unit for hydrotreating to obtain light aromatics and naphtha components; feeding the ethane and propane into an alkane refining unit for alkane refining to obtain a second reaction oil-gas, returning the second reaction oil-gas to the oil-gas separation unit for the first separation process; and feeding the spent catalyst into a regeneration unit for regeneration to obtain a regenerated catalyst, returning the regenerated catalyst to the reaction unit for the catalytic conversion reaction.

[0015] Optionally, the light hydrocarbon feedstock is selected from one or more of catalytic cracking gasoline, catalytic pyrolysis gasoline, straight-run naphtha, coking naphtha, thermally cracked naphtha, thermally cracked naphtha, hydrotreated naphtha, reforming residue oil, straight-run kerosene, and hydrotreated kerosene; the catalytic conversion catalyst includes zeolite, inorganic oxides, and optionally clay; the zeolite includes mesoporous zeolite, mesoporous zeolite, and optionally macroporous zeolite; based on the total weight of the catalytic conversion catalyst, the zeolite content is 0.5-90% by weight, the inorganic oxide content is 1-99% by weight, and the clay content is 0-80% by weight; based on the total weight of the zeolite, the mesoporous zeolite content is 10-90% by weight, the mesoporous zeolite content is 10-90% by weight, and the macroporous zeolite content is 0-50% by weight.

[0016] Optionally, the reaction unit includes a fluidized bed reactor; the method further includes mixing the light hydrocarbon oil feedstock and water vapor before introducing them into the fluidized bed reactor; the reaction conditions for the catalytic conversion reaction include: a reaction temperature of 400~800℃, a reaction time of 0.1~30s, and a reaction pressure of 0.01~1.0MPaG; the weight ratio of the catalytic conversion catalyst to the light hydrocarbon oil feedstock is 1~100; and the weight ratio of the water vapor to the light hydrocarbon oil feedstock is 0.05~2.

[0017] Optionally, the method further includes cooling the first reaction oil gas through a reaction oil gas quencher before performing the first separation process; the temperature of the first reaction oil gas after cooling is 200-400°C.

[0018] Optionally, the alkane remelting unit includes a cracking furnace and an optional propane dehydrogenation unit; the method further includes feeding the ethane and propane into the cracking furnace for the remelting process, and optionally, feeding the propane after the remelting process into the propane dehydrogenation unit; the reaction conditions of the cracking furnace include: a temperature of 700~1200℃, a pressure of 0.05~0.25 MPaG, and a time of 0.05~5s; the reaction conditions of the propane dehydrogenation unit include: a temperature of 400~700℃ and a pressure of 0.05~0.35 MPaG.

[0019] Optionally, the hydrogenation separation process includes a first hydrogenation process, a second hydrogenation process, and an aromatic hydrocarbon extraction process; the conditions for the first hydrogenation process include a temperature of 40~150℃ and a pressure of 1.0~6.0 MPaG; the conditions for the second hydrogenation process include a temperature of 300~400℃ and a pressure of 1.0~6.0 MPaG; the method for the aromatic hydrocarbon extraction process is selected from one or more of solvent liquid-liquid extraction, adsorption separation, and extraction distillation.

[0020] Optionally, the regeneration unit includes a regenerator and a reheating device; the method further includes: allowing the catalyst to be recycled to enter the regenerator and contact it with the main air for regeneration treatment to obtain regenerated flue gas and the regenerated catalyst; allowing the regenerated catalyst to enter the reheating device for heating and then returning it to the regenerator to mix with the catalyst to be recycled; the conditions for the regeneration treatment include: a temperature of 450~850℃, a pressure of 0.01~1.0MPaG, a gas apparent linear velocity of 0.5~3.5m / s in the regenerator, and an average residence time of 0.01~5.0min for the catalyst.

[0021] This disclosure provides a system for converting light hydrocarbon oil into low-carbon olefins and aromatics. The system includes: a reaction unit, a regeneration unit, an oil-gas separation unit, an aromatics processing unit, and an alkane refining unit. The reaction unit includes a light hydrocarbon oil feedstock inlet, a regeneration catalyst inlet, a mixed C4 inlet, a mixed C5 inlet, a spent catalyst outlet, and a first reaction oil-gas outlet. The regeneration unit includes a main air inlet, a regeneration flue gas outlet, a regeneration catalyst outlet, and a spent catalyst inlet. The oil-gas separation unit includes a first reaction oil-gas inlet, a second reaction oil-gas inlet, a methane hydrogen gas outlet, an ethylene outlet, a propylene outlet, a cracked light oil outlet, a cracked heavy oil outlet, a cracked naphtha outlet, a mixed C4 outlet, a mixed C5 outlet, an ethane outlet, and a propane outlet. The aromatics processing unit includes a cracked naphtha inlet, a light aromatics outlet, and naphtha components. The alkane refining unit includes an ethane inlet, a propane inlet, and a first reaction oil-gas outlet. The reaction unit has two oil and gas outlets; the regeneration catalyst inlet of the reaction unit is connected to the regeneration catalyst outlet of the regeneration unit, and the spent catalyst outlet of the reaction unit is connected to the spent catalyst inlet of the regeneration unit; the first reaction oil and gas outlet of the reaction unit is connected to the first reaction oil and gas inlet of the oil and gas separation unit; the second reaction oil and gas outlet of the alkane reprocessing unit is connected to the second reaction oil and gas inlet of the oil and gas separation unit; the mixed C4 outlet of the oil and gas separation unit is connected to the mixed C4 inlet of the reaction unit, and the mixed C5 outlet of the oil and gas separation unit is connected to the mixed C5 inlet of the reaction unit; the ethane outlet of the oil and gas separation unit is connected to the ethane inlet of the alkane reprocessing unit, and the propane outlet of the oil and gas separation unit is connected to the propane inlet of the alkane reprocessing unit; the cracked naphtha outlet of the oil and gas separation unit is connected to the cracked naphtha inlet of the aromatics processing unit.

[0022] Optionally, the reaction unit includes a fluidized bed reactor, a settling tank, and a reaction oil-gas quencher; the settling tank is a hollow cylinder and is disposed on the upper part of the fluidized bed reactor; the reaction oil-gas quencher is disposed inside the fluidized bed reactor; the reaction oil-gas quencher is located above the settling tank, or the reaction oil-gas quencher is located on the outlet pipeline of the first reaction oil-gas of the reaction unit; the inlet of the reaction oil-gas quencher is connected to the outlet of the settling tank, and the outlet of the reaction oil-gas quencher is connected to the inlet of the outlet pipeline of the first reaction oil-gas; or the inlet of the reaction oil-gas quencher is connected to the first reaction oil-gas outlet of the reaction unit; the outlet of the reaction oil-gas quencher is connected to the first reaction oil-gas inlet of the oil-gas separation unit.

[0023] Optionally, the regeneration unit includes a fluidized bed regenerator and a heat replenishment device; the fluidized bed regenerator includes a regenerated flue gas outlet, a heat replenishment medium inlet disposed at the lower part of the fluidized bed regenerator, and a heat replenishment medium outlet disposed at the upper part of the fluidized bed regenerator; the heat replenishment device includes a heat replenishment medium inlet and a heat replenishment medium outlet; the heat replenishment medium inlet of the fluidized bed regenerator is connected to the heat replenishment medium outlet of the heat replenishment device, and the heat replenishment medium outlet of the fluidized bed regenerator is connected to the heat replenishment medium inlet of the heat replenishment device; the system further includes a flue gas treatment unit; the flue gas treatment unit includes a flue gas energy recovery device and a flue gas purification device; the regenerated flue gas outlet of the fluidized bed regenerator is connected to the inlet of the flue gas energy recovery device; the outlet of the flue gas energy recovery device is connected to the inlet of the flue gas purification device.

[0024] Through the above technical solution, low-carbon olefins are sequentially processed through a reaction unit and an oil-gas separation unit. The resulting mixed C4 and mixed C5 are directly returned to the reaction unit for refining, the separated ethane and propane are processed through an alkane refining unit, the resulting reaction oil and gas are returned to the oil-gas separation unit for further separation, and the separated cracked naphtha is processed through an aromatics processing unit to obtain light aromatics. This can improve the yield of reaction oil and gas and aromatics, thereby increasing the yield of low-carbon olefins and light aromatics. This disclosure separates the second reaction oil and gas, mixed C4 and mixed C5 refining oil and gas through an oil-gas separation unit, which can reduce equipment investment and land occupation, and can reduce the energy consumption of the unit. In addition, separating the regeneration unit from the reaction unit can reduce the risk of reactor wear caused by catalyst flow in the regenerator, and increase the safety of the unit.

[0025] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 This is a process flow diagram of a method for converting light hydrocarbon oils into low-carbon olefins and aromatics.

[0028] Explanation of reference numerals in the attached figures

[0029] 1. Reaction Unit; 2. Regeneration Unit; 3. Flue Gas Treatment Unit; 4. Oil-Gas Separation Unit; 5. Aromatics Treatment Unit; 6. Alkane Reprocessing Unit; 11. Main Air; 12. Light Hydrocarbon Oil Feedstock; 13. Regenerated Catalyst; 14. Catalyst to be Regenerated; 15. First Reaction Oil and Gas; 16. Regenerated Flue Gas; 17. Purified Flue Gas; 18. Methane Hydrogen Gas; 19. Ethylene; 20. Propylene; 21. Cracked Light Oil; 22. Cracked Heavy Oil; 23. Cracked Naphtha; 24. Ethane; 25. Propane; 26. Mixed C4; 27. Mixed C5; 28. Second Reaction Oil and Gas; 29. ​​Light Aromatics; 30. Naphtha Components. Detailed Implementation

[0030] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0031] In this disclosure, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its normal operating state, while "inner" and "outer" refer to their position relative to the device's outline. 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 one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] The first aspect of this disclosure provides a method for converting light hydrocarbon oil into low-carbon olefins and aromatics. The method includes: feeding light hydrocarbon oil feedstock 12 into a reaction unit 1 and contacting it with a catalytic conversion catalyst to undergo a catalytic conversion reaction, yielding a first reaction oil-gas 15 and a spent catalyst 14; feeding the first reaction oil-gas 15 into an oil-gas separation unit 4 for a first separation process, yielding methane hydrogen gas 18, ethylene 19, propylene 20, ethane 24, propane 25, cracked light oil 21, cracked heavy oil 22, cracked naphtha 23, mixed C4 26, and mixed C5 27; and returning the mixed C4 26 and the mixed C5 27 to... The catalytic conversion reaction is carried out in the reaction unit 1; the cracked naphtha 23 is fed into the aromatics processing unit 5 for hydrotreating to obtain light aromatics 29 and naphtha component 30; the ethane 24 and propane 25 are fed into the alkane refining unit 6 for alkane refining to obtain second reaction oil and gas 28, which is then returned to the oil and gas separation unit 4 for the first separation treatment; the spent catalyst 14 is fed into the regeneration unit 2 for regeneration to obtain regenerated catalyst 13, which is then returned to the reaction unit 1 for the catalytic conversion reaction.

[0033] Through the above technical solution, low-carbon olefins are sequentially processed through reaction unit 1 and oil-gas separation unit 4. The resulting mixed C4 26 and mixed C5 27 are directly returned to reaction unit 1 for refining. The separated ethane 24 and propane 25 are processed through alkane refining unit 6. The resulting reaction oil and gas are returned to oil-gas separation unit 4 for further separation. The separated cracked naphtha 23 is processed through aromatics processing unit 5 to obtain light aromatics 29. This can improve the yield of reaction oil and gas and aromatics, thereby increasing the yield of low-carbon olefins and light aromatics 29. This disclosure separates the second reaction oil and gas 28, mixed C4 26 and mixed C5 27 refining oil and gas through oil-gas separation unit 4, which can reduce equipment investment and land occupation, and can reduce the energy consumption of the unit. In addition, separating regeneration unit 2 from reaction unit 1 can reduce the risk of reactor wear caused by catalyst flow in the regenerator and increase the safety of the unit.

[0034] The light hydrocarbon oil feedstock 12 used in this disclosure is a conventional choice in the art, and this application does not make any special requirements. For example, the light hydrocarbon oil feedstock 12 is selected from one or more of catalytic cracking gasoline, catalytic cracking gasoline, straight-run naphtha, coking naphtha, thermal cracking naphtha, thermal cracking naphtha, hydrotreated naphtha, reforming residue oil, straight-run kerosene, and hydrotreated kerosene.

[0035] The catalytic conversion catalyst used in this disclosure includes zeolite, inorganic oxides, and optionally clay; the zeolite includes mesoporous zeolite, mesoporous zeolite, and optionally macroporous zeolite; based on the total weight of the catalytic conversion catalyst, the zeolite content is 0.5-90% by weight, the inorganic oxide content is 1-99% by weight, and the clay content is 0-80% by weight; based on the total weight of the zeolite, the mesoporous zeolite content is 10-90% by weight, the mesoporous zeolite content is 10-90% by weight, and the macroporous zeolite content is 0-50% by weight.

[0036] In one embodiment, the reaction unit 1 consists of a fluidized bed reactor, a settling tank, a stripping section, an oil-agent separation device, and a high-temperature reaction oil-gas quencher.

[0037] The fluidized bed reactor used in this disclosure is a conventional choice in the art, and this application does not make any special requirements. For example, in one embodiment of this disclosure, the fluidized bed reactor includes one or more reactor combinations such as a constant diameter riser reactor, a gradually expanding diameter riser reactor, a constant diameter dense phase fluidized bed reactor, and a gradually expanding diameter dense phase fluidized bed reactor, preferably a constant diameter riser reactor and / or a gradually expanding diameter riser reactor.

[0038] In one embodiment, the fluidized bed reactor is arranged inside and / or outside the settler. Preferably, the settler is arranged inside the fluidized bed reactor and is located at the top of the fluidized bed reactor; the settler is a hollow cylindrical type.

[0039] In one embodiment, the oil separation device includes one or more of a fast separator, a cyclone separator, a cyclone separator, and a filter; and is arranged inside or outside the settling tank. This is a conventional choice in the art, and this application does not make any special requirements.

[0040] In one embodiment, the reaction oil-gas quencher is disposed inside the fluidized bed reactor; the reaction oil-gas quencher is located above the settling tank, or the reaction oil-gas quencher is located on the first reaction oil-gas outlet pipeline of reaction unit 1; the inlet of the reaction oil-gas quencher is connected to the outlet of the settling tank, so that the oil-gas separated by the oil-agent separation device can enter the reaction oil-gas quencher for rapid cooling; the outlet of the reaction oil-gas quencher is connected to the inlet of the first reaction oil-gas outlet pipeline, so that the cooled reaction oil-gas enters the subsequent device as the first reaction oil-gas 15; or, the inlet of the reaction oil-gas quencher is connected to the first reaction oil-gas outlet of reaction unit 1, so that the first reaction oil-gas 15 can enter the reaction oil-gas quencher for rapid cooling; the outlet of the reaction oil-gas quencher is connected to the first reaction oil-gas inlet of the oil-gas separation unit 4, so that the cooled first reaction oil-gas 15 can enter the subsequent device.

[0041] In the above embodiments, this disclosure involves introducing water vapor and light hydrocarbon oil through the inlet of a riser reactor, where they contact the catalytic conversion catalyst in the riser reactor to undergo a catalytic conversion reaction, yielding catalytic conversion reaction products. These products then enter a fluidized bed reactor, passing through an oil-agent separation device in a settler to separate the liquid reaction products from the reaction gas. The reaction gas exits through a top outlet device. The reaction gas is cooled by a reaction gas quencher above the settler and then enters the subsequent equipment as first reaction gas 15. Alternatively, the reaction gas can directly enter the top outlet pipeline as first reaction gas 15, entering the reaction gas quencher for cooling before entering the subsequent equipment. The reaction gas quencher rapidly reduces the temperature of the reaction gas, preventing excessive thermal cracking and coking in the pipeline, thus avoiding safety hazards caused by coking. It also effectively utilizes the heat in the high-temperature reaction gas.

[0042] In one embodiment, the reaction conditions for the catalytic conversion reaction include: a reaction temperature of 400-800℃, preferably 500-750℃, more preferably 600-700℃; a reaction time of 0.1-30s, preferably 0.2-10s, more preferably 0.4-5s; a reaction pressure of 0.01-1.0MPaG, preferably 0.05-0.5MPaG, more preferably 0.08-0.25MPaG; a weight ratio of the catalytic conversion catalyst to the light hydrocarbon feedstock 12 of 1-100, preferably 5-50, more preferably 20-40; and a weight ratio of water vapor to the light hydrocarbon feedstock 12 of 0.05-2, preferably 0.1-1, more preferably 0.2-0.4.

[0043] By adopting the above-described embodiments, the activity of the catalytic conversion reaction can be improved, thereby increasing the yield and selectivity of low-carbon olefins. In order to further improve the activity of the catalytic conversion reaction, the conditions for the catalytic conversion reaction are limited.

[0044] In one embodiment, the regeneration unit 2 includes a fluidized bed regenerator and a reheating device. The method further includes: allowing the spent catalyst 14 to enter the regenerator and contact the main air 11 for regeneration treatment, resulting in regenerated flue gas 16 and the regenerated catalyst 13; and allowing the regenerated catalyst 13 to enter the reheating device for heating before returning to the regenerator and mixing with the spent catalyst 14. The fluidized bed regenerator includes a regenerated flue gas outlet, a reheating medium inlet located at the lower part of the fluidized bed regenerator, and a reheating medium outlet located at the upper part of the fluidized bed regenerator. The reheating device includes a reheating medium inlet and a reheating medium outlet. The reheating medium inlet of the fluidized bed regenerator is connected to the reheating medium outlet of the reheating device, and the reheating medium outlet of the fluidized bed regenerator is connected to the reheating medium inlet of the reheating device, so that the reheating medium can be uniformly mixed with the fuel in the reheating system via the reheating device before entering the bottom of the fluidized bed regenerator to contact the main air 11 for combustion and heat recovery. The fuel for the supplementary heating system is fuel sourced from outside the unit and / or produced by the unit itself. Preferably, the fuel for the supplementary heating system is one or more of the following: methane hydrogen gas 18, cracked light oil 21, and cracked heavy oil 22 produced by the unit itself.

[0045] In one embodiment, the regeneration conditions include: a temperature of 450~850℃, a pressure of 0.01~1.0MPaG, a gas apparent linear velocity of 0.5~3.5m / s in the regenerator, and an average catalyst residence time of 0.01~5.0min.

[0046] In this embodiment, the regeneration unit 2 is equipped with a heat replenishment system, which effectively solves the problem of heat imbalance between the two reactors caused by low coke production and high reaction heat requirements during the catalytic cracking of light hydrocarbon oil, thereby improving the activity of the regenerated catalyst 13.

[0047] In one embodiment, the method further includes cooling the first reaction oil gas 15 by passing it through a reaction oil gas quencher before performing the first separation process; the temperature of the first reaction oil gas 15 after cooling is 200-400°C.

[0048] In one embodiment, the alkane remelting unit 6 includes a cracking furnace and an optional propane dehydrogenation unit; the method further includes feeding ethane 24 and propane 25 into the cracking furnace for the remelting process, and optionally, feeding the remelted propane 25 into the propane dehydrogenation unit; the reaction conditions of the cracking furnace include: a temperature of 700~1200℃, a pressure of 0.05~0.25 MPaG, and a time of 0.05~5s; the reaction conditions of the propane dehydrogenation unit include: a temperature of 400~700℃ and a pressure of 0.05~0.35 MPaG.

[0049] The cracking furnace and propane dehydrogenation method used in this disclosure are conventional equipment in the art, and this application does not make any special requirements. For example, in one embodiment of this disclosure, the cracking furnace is one or more of the following: CBL cracking furnace, SRT type cracking furnace, USC type cracking furnace, KTI GK cracking furnace, and millisecond cracking furnace; the propane dehydrogenation method can be selected from one or more of the following: fixed bed propane dehydrogenation technology, moving bed propane dehydrogenation technology, and fluidized bed propane dehydrogenation technology.

[0050] In this embodiment, the second reaction oil gas 28 obtained after processing ethane 24 and propane 25 in the alkane recycling unit 6 is returned to the oil gas separation unit 4, enabling the reuse of ethane 24 and propane 25 and further increasing the yield of ethylene 19 and propylene 20, i.e., increasing the yield of low-carbon olefins. The second reaction oil gas 28 enters the oil gas separation unit 4 alone, or it can be mixed with the first reaction oil gas 15 before entering the oil gas separation unit 4.

[0051] In one embodiment, the aromatics processing unit 5 includes a cracked naphtha hydrogenation unit and an aromatics extraction unit. A first hydrogenation treatment and a second hydrogenation treatment are performed in the cracked naphtha hydrogenation unit; specifically, cracked naphtha 23 is introduced into the cracked naphtha hydrogenation unit and contacted with a first hydrogenation catalyst for the first hydrogenation treatment; the resulting reaction stream is then contacted with a second hydrogenation catalyst for the second hydrogenation treatment.

[0052] In one embodiment, the first hydrogenation catalyst is a Pd-based catalyst and / or a Co-Mo-Ni-based catalyst, and the second hydrogenation catalyst is a Pd-based catalyst and / or a Co-Mo-Ni-based catalyst.

[0053] In one embodiment, the hydrogenation separation process includes a first hydrogenation process, a second hydrogenation process, and an aromatics extraction process; the conditions for the first hydrogenation process include: a temperature of 40~150℃ and a reaction pressure of 1.0~6.0 MPaG; the conditions for the second hydrogenation process include: a temperature of 300~400℃ and a reaction pressure of 1.0~6.0 MPaG.

[0054] In one embodiment, the hydrogenation product from the outlet of the cracked naphtha hydrogenation unit is fed into an aromatics extraction unit for aromatics extraction. The aromatics extraction method used in this disclosure is a conventional choice in the art, and this application does not make any special requirements. For example, in one embodiment of this disclosure, the aromatics extraction method is selected from one or more of solvent liquid-liquid extraction, adsorption separation, and extraction distillation.

[0055] To further improve the yield of low-carbon olefins and light aromatics 29, naphtha component 30 obtained from the aromatics processing unit 5 is returned to the reaction unit 1.

[0056] In one embodiment, the flue gas treatment unit 3 includes a flue gas energy recovery device and a flue gas purification device; the regenerated flue gas outlet of the fluidized bed regenerator is connected to the inlet of the flue gas energy recovery device so that the regenerated flue gas 16 can enter the flue gas energy recovery device for energy recovery; the outlet of the flue gas energy recovery device is connected to the inlet of the flue gas purification device so that the regenerated flue gas 16 can enter the flue gas purification device for flue gas purification.

[0057] The flue gas energy recovery device and flue gas purification device used in this disclosure are conventional choices in the art, and this application does not make any special requirements. For example, the flue gas energy recovery device includes one or more of the following: flue gas turbine, waste heat boiler, flue gas-main air heat exchanger, and flue gas-hot water heater; the flue gas purification device includes a flue gas desulfurization module, a flue gas denitrification module, and a flue gas dust removal module, wherein the desulfurization module can be one or more of the following: wet desulfurization system, semi-dry desulfurization system, and dry desulfurization system; the denitrification module can be one or more of the following: SCR denitrification system, SNCR denitrification system, ozone oxidation denitrification system, and oxygen plasma denitrification system; and the dust removal module can be one or more of the following: wet scrubbing dust removal, bag filter dust removal, filtration dust removal, and electrostatic precipitator.

[0058] In the above embodiment, the flue gas energy recovery device can recover the pressure energy and heat in the regenerated flue gas 16; the flue gas purification device can remove pollutants such as NOx, SOx and dust from the regenerated flue gas 16 to obtain purified flue gas 17. In addition, in order to reduce the carbon content of the exhaust flue gas, the purified flue gas 17 is sent to a carbon dioxide capture device.

[0059] In one implementation, such as Figure 1As shown, the methods for converting light hydrocarbon oils into low-carbon olefins and aromatics include:

[0060] After the light hydrocarbon oil feedstock 12 is preheated to 100~700℃, it enters from the bottom of the riser reactor in reaction unit 1 and comes into contact with the catalytic conversion catalyst. The catalytic conversion reaction is carried out under the operating conditions of reaction temperature 650~680℃, reaction time 0.4~0.8s, weight ratio of catalytic conversion catalyst to light hydrocarbon oil feedstock 12 of 30~40, and weight ratio of water vapor to light hydrocarbon oil feedstock 12 of 0.25~0.35, to obtain the first reaction oil gas 15.

[0061] The first reaction oil and gas 15 and the catalyst 14 are separated by a cyclone separator at the reactor outlet of the riser and a two-stage cyclone separator in the reaction settling tank. The catalyst 14 enters the stripping section downwards, and the first reaction oil and gas 15 enters the oil and gas quencher at the top of the reaction settling tank. The first reaction oil and gas 15 is cooled to 200~400℃ by the heat-extracted oil slurry (250℃~300℃) from the bottom of the fractionation tower and enters the oil and gas separation unit 4. The separated components are methane hydrogen gas 18, ethylene 19, ethane 24, propylene 20, propane 25, mixed C4 26, mixed C5 27, cracked naphtha 23, cracked light oil 21, and cracked heavy oil 22.

[0062] The spent catalyst 14 enters the regeneration unit 2 and comes into contact with the main air 11 for coking and regeneration, resulting in a high-temperature regenerated catalyst 13 and regenerated flue gas 16. The high-temperature regenerated catalyst 13 is returned to the reaction unit 1. The regenerated flue gas 16 enters the flue gas treatment unit 3 to recover pressure energy and heat energy, and after removing pollutants such as NOx, SOx and dust, it becomes purified flue gas 17 and is discharged.

[0063] The cracked naphtha 23 enters the aromatics processing unit 5, where it undergoes a first hydrogenation treatment by contacting a first hydrogenation catalyst at a temperature of 40℃~150℃ and a reaction pressure of 1.0~6.0 MPaG. Then, it undergoes a second hydrogenation treatment by contacting a second hydrogenation catalyst at a temperature of 300℃~400℃ and a reaction pressure of 1.0~6.0 MPaG. Finally, aromatics are extracted using a solvent-liquid extraction method to obtain light aromatics 29 and naphtha component 30.

[0064] The fractionation and light hydrocarbon separation unit produces mixed C4 26 and mixed C5 27, which are sent to reaction unit 1 for catalytic conversion. Ethane 24 and propane 25 are sent to the cracking furnace for reprocessing. The resulting second reaction oil and gas 28 is mixed with the first reaction oil and gas 15 and then enters the oil and gas separation unit 4 for further separation.

[0065] A second aspect of this disclosure provides a system for converting light hydrocarbon oil into low-carbon olefins and aromatics. The system includes: a reaction unit 1, a regeneration unit 2, an oil-gas separation unit 4, an aromatics processing unit 5, and an alkane reprocessing unit 6. The reaction unit 1 includes a light hydrocarbon oil feedstock inlet, a regeneration catalyst inlet, a mixed C4 inlet, a mixed C5 inlet, a spent catalyst outlet, and a first reaction oil-gas outlet. The regeneration unit 2 includes a main air inlet, a regeneration flue gas outlet, a regeneration catalyst outlet, and a spent catalyst inlet. The oil-gas separation unit 4 includes a first reaction oil-gas inlet, a second reaction oil-gas inlet, and a methane hydrogen gas outlet. The reactor includes an ethylene outlet, a propylene outlet, a cracked light oil outlet, a cracked heavy oil outlet, a cracked naphtha outlet, a mixed C4 outlet, a mixed C5 outlet, an ethane outlet, and a propane outlet; the aromatics processing unit 5 includes a cracked naphtha inlet, a light aromatics outlet, and a naphtha component outlet; the alkane reprocessing unit 6 includes an ethane inlet, a propane inlet, and a second reaction oil and gas outlet; the regenerated catalyst inlet of the reaction unit 1 is connected to the regenerated catalyst outlet of the regeneration unit 2, and the spent catalyst outlet of the reaction unit 1 is connected to the spent catalyst inlet of the regeneration unit 2, so that the spent catalyst 14 in the reaction unit 1 can... After coke regeneration in regeneration unit 2, the oil and gas return to reaction unit 1 for catalytic conversion. The first reaction oil and gas outlet of reaction unit 1 is connected to the first reaction oil and gas inlet of oil and gas separation unit 4, so that the first reaction oil and gas 15 can enter oil and gas separation unit 4 for separation. The second reaction oil and gas outlet of alkane reprocessing unit 6 is connected to the second reaction oil and gas inlet of oil and gas separation unit 4, so that the second reaction oil and gas 28 can enter oil and gas separation unit 4 for further separation. The mixed C4 outlet of oil and gas separation unit 4 is connected to the mixed C4 inlet of reaction unit 1. The mixed C5 outlet of Unit 4 is connected to the mixed C5 inlet of the reaction unit 1, so that the mixed C4 and mixed C5 27 can be returned to the reaction unit 1 for reprocessing; the ethane outlet of the oil-gas separation unit 4 is connected to the ethane inlet of the alkane reprocessing unit 6, and the propane outlet of the oil-gas separation unit 4 is connected to the propane inlet of the alkane reprocessing unit 6, so that ethane and propane can enter the alkane reprocessing unit 6 for reprocessing; the cracked naphtha outlet of the oil-gas separation unit 4 is connected to the cracked naphtha inlet of the aromatics processing unit 5, so that cracked naphtha 23 can enter the aromatics processing unit 5 for processing.

[0066] In one embodiment, the reaction unit 1 includes a fluidized bed reactor, a settling tank, and a reaction oil-gas quencher; the settling tank is a hollow cylinder and is disposed on the upper part of the fluidized bed reactor; the reaction oil-gas quencher is disposed inside the fluidized bed reactor; the reaction oil-gas quencher is located above the settling tank, or the reaction oil-gas quencher is located on the outlet pipeline of the first reaction oil-gas of the reaction unit 1; the inlet of the reaction oil-gas quencher is connected to the outlet of the settling tank, and the outlet of the reaction oil-gas quencher is connected to the inlet of the outlet pipeline of the first reaction oil-gas, so that the reaction oil-gas can be cooled by passing through the reaction oil-gas quencher; or, the inlet of the reaction oil-gas quencher is connected to the outlet of the first reaction oil-gas of the reaction unit 1; the outlet of the reaction oil-gas quencher is connected to the inlet of the first reaction oil-gas of the oil-gas separation unit 4, so that the first reaction oil-gas 15 can be cooled by passing through the reaction oil-gas quencher on the outlet pipeline of the reaction unit 1.

[0067] In one embodiment, the regeneration unit 2 includes a fluidized bed regenerator and a reheating device; the fluidized bed regenerator includes a regenerated flue gas outlet, a reheating medium inlet disposed at the lower part of the fluidized bed regenerator, and a reheating medium outlet disposed at the upper part of the fluidized bed regenerator; the reheating device includes a reheating medium inlet and a reheating medium outlet; the reheating medium inlet of the fluidized bed regenerator is connected to the reheating medium outlet of the reheating device, and the reheating medium outlet of the fluidized bed regenerator is connected to the reheating medium inlet of the reheating device, so that the catalyst to be regenerated 14 enters the regenerator and contacts the main air 11 for regeneration treatment, thereby obtaining regenerated flue gas 16 and the regenerated catalyst 13, and the regenerated catalyst 13 enters the reheating device for heating and then returns to the regenerator to mix with the catalyst to be regenerated 14.

[0068] In one embodiment, the system further includes a flue gas treatment unit 3; the flue gas treatment unit 3 includes a flue gas energy recovery device and a flue gas purification device; the regenerated flue gas outlet of the fluidized bed regenerator is connected to the inlet of the flue gas energy recovery device; the outlet of the flue gas energy recovery device is connected to the inlet of the flue gas purification device, so that the regenerated flue gas 16 passes through the flue gas energy recovery device and the flue gas purification device in sequence to recover energy and purify the flue gas.

[0069] The method provided by the present invention will be further described below through specific embodiments, but this does not limit the present invention.

[0070] The light alkane feedstocks used in the embodiments and comparative examples of this disclosure are straight-run naphtha, straight-run kerosene, and coking naphtha, the specific properties of which are shown in Table 1. The composition and content of the catalytic conversion catalyst are based on the total weight of the catalytic conversion catalyst, with the content of inorganic oxides such as SiO2 and Al2O3 being 20-40% by weight, the clay content being 20-40% by weight, and the zeolite content as the active component being 40-50% by weight, of which mesoporous zeolite accounts for 20-40% by weight of the total zeolite, mesoporous zeolite accounts for 40-60% by weight of the total zeolite, and macroporous zeolite accounts for 10-20% by weight of the total zeolite. The properties of the catalytic conversion catalyst are shown in Table 2. The first hydrogenation catalyst is a Pd-based catalyst, and the second hydrogenation catalyst is a Co-Mo-Ni-based catalyst. The extraction solvent for aromatic hydrocarbon extraction is sulfolane.

[0071] Table 1 Properties of light alkane feedstocks

[0072]

[0073] Table 2 Catalyst Properties

[0074]

[0075] Example 1

[0076] The light hydrocarbon oil feedstock 12, which is preheated from 300°C to 450°C, enters from the bottom of the riser reactor in reaction unit 1 and comes into contact with the catalytic conversion catalyst. The catalytic conversion reaction is carried out under the following operating conditions: reaction temperature of 675°C, reaction pressure of 0.1 MPaG, reaction time of 0.5 s, weight ratio of catalytic conversion catalyst to light hydrocarbon oil feedstock 12 of 35, and weight ratio of water vapor to light hydrocarbon oil feedstock 12 of 30, to obtain the first reaction oil gas 15 at 670°C.

[0077] The first reaction oil and gas 15 and the catalyst 14 are separated by a cyclone separator at the reactor outlet of the riser and a two-stage cyclone separator in the reaction settling tank. The catalyst 14 enters the stripping section downwards, and the first reaction oil and gas 15 enters the oil and gas quencher at the top of the reaction settling tank. The first reaction oil and gas 15 is cooled to 350°C by the heat-extracting oil slurry from the bottom of the fractionation tower and enters the oil and gas separation unit 4. The separation yields methane hydrogen gas 18, ethylene 19, ethane 24, propylene 20, propane 25, mixed C4 26, mixed C5 27, cracked naphtha 23, cracked light oil 21, and cracked heavy oil 22.

[0078] The spent catalyst 14 enters the regeneration unit 2 and is regenerated by contacting the main air 11 at 750°C and 0.13 MPaG, resulting in high-temperature regenerated catalyst 13 and regenerated flue gas 16. The high-temperature regenerated catalyst 13 is returned to the reaction unit 1. The apparent linear velocity of the gas in the regenerator is 1.4 m / s, and the average residence time of the catalyst is 0.2–0.4 min. The regenerated flue gas 16 enters the flue gas treatment unit 3 to recover pressure and heat energy, and removes NO. x SO x After being purified by pollutants such as dust, the flue gas 17 is discharged externally.

[0079] The cracked naphtha 23 enters the aromatics processing unit 5, where it undergoes a first hydrogenation treatment by contacting a first hydrogenation catalyst at a temperature of 90°C and a reaction pressure of 3 MPaG. Then, it undergoes a second hydrogenation treatment by contacting a second hydrogenation catalyst at a temperature of 350°C and a reaction pressure of 3 MPaG. Finally, aromatics are extracted using a solvent-liquid extraction method to obtain light aromatics 29 and naphtha component 30.

[0080] The fractionation and light hydrocarbon separation unit produces mixed C4 26 and mixed C5 27, which are sent to reaction unit 1 for catalytic conversion. Ethane 24 and propane 25 are sent to the cracking furnace for reprocessing. The resulting second reaction oil and gas 28 is mixed with the first reaction oil and gas 15 and then enters the oil and gas separation unit 4 for further separation. The reaction conditions in the cracking furnace include: a temperature of 850°C, a pressure of 0.15 MPaG, and a time of 0.1 s.

[0081] The product distribution is shown in Table 3.

[0082] Comparative Example 1

[0083] The method for converting light hydrocarbon oils to produce low-carbon olefins and aromatics is the same as in Example 1, except that ethane 24 and propane 25 are not recycled, and only mixed C4 26 is returned to reaction unit 1. The product distribution is shown in Table 3.

[0084] Table 3 Product Distribution

[0085]

[0086] As shown in Table 3, a comparison of the data in Example 1 and Comparative Example 1 shows that the method described in this disclosure can improve the yield of low-carbon olefins and light aromatics, and can reduce plant energy consumption and carbon emissions. The plant energy consumption and carbon emissions are calculated based on the total amount of chemicals produced per unit (ethylene, propylene and BTX).

[0087] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0088] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0089] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for converting light hydrocarbon oil into low-carbon olefins and aromatics, characterized in that, The method includes: Light hydrocarbon oil feedstock is introduced into the reaction unit (1) and comes into contact with the catalytic conversion catalyst to carry out the catalytic conversion reaction, so as to obtain the first reaction oil and gas and the catalyst to be generated; The first reaction oil and gas are introduced into the oil and gas separation unit (4) for the first separation process to obtain methane hydrogen gas, ethylene, propylene, ethane, propane, cracked light oil, cracked heavy oil, cracked naphtha, mixed C4 and mixed C5; the mixed C4 and the mixed C5 are returned to the reaction unit (1) for the catalytic conversion reaction; The cracked naphtha is fed into the aromatics processing unit (5) for hydrogenation separation to obtain light aromatics and naphtha components; The ethane and propane are fed into the alkane refining unit (6) for alkane refining to obtain the second reaction oil and gas, which is then returned to the oil and gas separation unit (4) for the first separation process. The spent catalyst is sent to the regeneration unit (2) for regeneration treatment to obtain a regenerated catalyst, and the regenerated catalyst is returned to the reaction unit (1) to carry out the catalytic conversion reaction; The method further includes cooling the first reaction oil and gas through a reaction oil and gas quencher before performing the first separation process. The temperature of the first reaction oil and gas after cooling is 200~400℃.

2. The method according to claim 1, characterized in that, The light hydrocarbon oil feedstock is selected from one or more of the following: catalytic cracking gasoline, catalytic pyrolysis gasoline, straight-run naphtha, coking naphtha, thermally cracked naphtha, thermally cracked naphtha, hydrotreated naphtha, reforming residue oil, straight-run kerosene, and hydrotreated kerosene. The catalytic conversion catalyst includes zeolite and inorganic oxide; the zeolite includes mesoporous zeolite and mesoporous zeolite.

3. The method according to claim 2, characterized in that, The catalytic conversion catalyst also includes clay; the zeolite also includes macroporous zeolite.

4. The method according to claim 3, characterized in that, Based on the total weight of the catalytic conversion catalyst, the zeolite content is 0.5-90% by weight, the inorganic oxide content is 1-99% by weight, and the clay content is 0-80% by weight. Based on the total weight of the zeolite, the content of mesoporous zeolite is 10-90% by weight, the content of mesoporous zeolite is 10-90% by weight, and the content of macroporous zeolite is 0-50% by weight.

5. The method according to claim 1, characterized in that, The reaction unit (1) includes a fluidized bed reactor; The method also includes mixing the light hydrocarbon oil feedstock with water vapor before feeding it into the fluidized bed reactor; The reaction conditions for the catalytic conversion reaction include: a reaction temperature of 400~800℃, a reaction time of 0.1~30s, and a reaction pressure of 0.01~1.0MPaG; the weight ratio of the catalytic conversion catalyst to the light hydrocarbon feedstock is 1~100; and the weight ratio of the water vapor to the light hydrocarbon feedstock is 0.05~2.

6. The method according to claim 1, characterized in that, The alkane remelting unit (6) includes a cracking furnace and a propane dehydrogenation unit; The method further includes feeding the ethane and propane into the cracking furnace for the remelting process; The reaction conditions of the cracking furnace include: a temperature of 700~1200℃, a pressure of 0.05~0.25 MPaG, and a time of 0.05~5s; the reaction conditions of the propane dehydrogenation unit include: a temperature of 400~700℃ and a pressure of 0.05~0.35 MPaG.

7. The method according to claim 6, characterized in that, The propane, after undergoing the remelting process, is then fed into the propane dehydrogenation unit.

8. The method according to claim 1, characterized in that, The hydrogenation separation process includes a first hydrogenation process, a second hydrogenation process, and an aromatics extraction process; The conditions for the first hydrogenation treatment include: a temperature of 40~150℃ and a pressure of 1.0~6.0 MPaG; The conditions for the second hydrogenation treatment include: a temperature of 300~400℃ and a pressure of 1.0~6.0 MPaG; The method for aromatic hydrocarbon extraction is selected from one or more of the following: solvent-liquid extraction, adsorption separation, and extraction distillation.

9. The method according to claim 1, characterized in that, The regeneration unit (2) includes a regenerator and a reheating device; The method further includes introducing the catalyst to be recycled into the regenerator to contact the main air for regeneration treatment, thereby obtaining regenerated flue gas and the regenerated catalyst; The regenerated catalyst is heated in the heating device and then returned to the regenerator to be mixed with the catalyst to be recycled. The regeneration conditions include: a temperature of 450~850℃, a pressure of 0.01~1.0MPaG, a gas apparent linear velocity of 0.5~3.5m / s in the regenerator, and an average catalyst residence time of 0.01~5.0min.

10. A system for converting light hydrocarbon oils into low-carbon olefins and aromatics using the method described in any one of claims 1-9, characterized in that, The system includes: a reaction unit (1), a regeneration unit (2), an oil-gas separation unit (4), an aromatics processing unit (5), and an alkane reprocessing unit (6). The reaction unit (1) includes a light hydrocarbon oil feedstock inlet, a regenerated catalyst inlet, a mixed C4 inlet, a mixed C5 inlet, a spent catalyst outlet, and a first reaction oil and gas outlet; The regeneration unit (2) includes a main air inlet, a regenerated flue gas outlet, a regenerated catalyst outlet, and a catalyst inlet to be generated; The oil-gas separation unit (4) includes a first reaction oil-gas inlet, a second reaction oil-gas inlet, a methane hydrogen gas outlet, an ethylene outlet, a propylene outlet, a cracked light oil outlet, a cracked heavy oil outlet, a cracked naphtha outlet, a mixed C4 outlet, a mixed C5 outlet, an ethane outlet, and a propane outlet. The aromatics processing unit (5) includes a cracked naphtha inlet, a light aromatics outlet, and naphtha components; The alkane reprocessing unit (6) includes an ethane inlet, a propane inlet, and a second reaction oil and gas outlet; The regenerated catalyst inlet of the reaction unit (1) is connected to the regenerated catalyst outlet of the regeneration unit (2), and the ungenerated catalyst outlet of the reaction unit (1) is connected to the ungenerated catalyst inlet of the regeneration unit (2); the first reaction oil and gas outlet of the reaction unit (1) is connected to the first reaction oil and gas inlet of the oil and gas separation unit (4); the second reaction oil and gas outlet of the alkane refining unit (6) is connected to the second reaction oil and gas inlet of the oil and gas separation unit (4); the mixed C4 outlet of the oil and gas separation unit (4) is connected to the mixed C4 inlet of the reaction unit (1), and the mixed C5 outlet of the oil and gas separation unit (4) is connected to the mixed C5 inlet of the reaction unit (1); the ethane outlet of the oil and gas separation unit (4) is connected to the ethane inlet of the alkane refining unit (6), and the propane outlet of the oil and gas separation unit (4) is connected to the propane inlet of the alkane refining unit (6); the cracked naphtha outlet of the oil and gas separation unit (4) is connected to the cracked naphtha inlet of the aromatics processing unit (5).

11. The system according to claim 10, characterized in that, The reaction unit (1) includes a fluidized bed reactor, a settling tank, and a reaction oil and gas quencher; The settling device is a hollow cylinder and is located at the top of the fluidized bed reactor; The reaction oil and gas quencher is installed inside the fluidized bed reactor; the reaction oil and gas quencher is located above the settling tank, or the reaction oil and gas quencher is located on the outlet pipeline of the first reaction oil and gas of the reaction unit (1). The inlet of the reaction oil-gas quencher is connected to the outlet of the settler, and the outlet of the reaction oil-gas quencher is connected to the inlet of the outlet pipeline of the first reaction oil-gas; or... The inlet of the reaction oil-gas quencher is connected to the first reaction oil-gas outlet of the reaction unit (1); the outlet of the reaction oil-gas quencher is connected to the first reaction oil-gas inlet of the oil-gas separation unit (4).

12. The system according to claim 10, characterized in that, The regeneration unit (2) includes a fluidized bed regenerator and a heating device; the fluidized bed regenerator includes a regenerated flue gas outlet, a heating medium inlet located at the lower part of the fluidized bed regenerator, and a heating medium outlet located at the upper part of the fluidized bed regenerator; the heating device includes a heating medium inlet and a heating medium outlet; the heating medium inlet of the fluidized bed regenerator is connected to the heating medium outlet of the heating device, and the heating medium outlet of the fluidized bed regenerator is connected to the heating medium inlet of the heating device; The system also includes a flue gas treatment unit (3); the flue gas treatment unit (3) includes a flue gas energy recovery device and a flue gas purification device; the regenerated flue gas outlet of the fluidized bed regenerator is connected to the inlet of the flue gas energy recovery device; the outlet of the flue gas energy recovery device is connected to the inlet of the flue gas purification device.

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