Method for producing high-octane gasoline through hydrocarbon catalytic cracking and reaction system thereof

Abstract

The invention relates to a method for producing high-octane gasoline through hydrocarbon catalytic cracking and a reaction system thereof, and the method comprises the following steps: in a constant linear velocity fluidized bed reactor, diesel oil and other light petroleum hydrocarbons are contacted with a high silica-alumina ratio catalytic cracking catalyst, and self-heat balance is maintained through regeneration flue gas circulation to produce liquefied gas and high-octane gasoline. According to the method disclosed by the invention, heavy oil such as naphtha, wax oil and residual oil can be processed while light hydrocarbon such as diesel oil is processed, the conversion rate of the diesel oil is high, self-heating balance can be realized, the problem of excessive diesel oil production capacity of a refinery plant is solved, and the processing benefit of crude oil is also improved.

Description

Technical Field

[0001] The invention relates to the field of catalytic cracking of petroleum hydrocarbons, and in particular to a method and a reaction system for producing high-octane gasoline. Background Art

[0002] In recent years, the diesel-to-gasoline ratio in the refined oil market has been decreasing. After reaching a peak of 176Mt in 2014, diesel consumption has experienced zero or negative growth. According to statistics, the unit mileage emissions of a heavy-duty diesel vehicle are about 150 times that of a light-duty gasoline vehicle at the same stage, and the annual emissions are about 750 times that of a light-duty gasoline vehicle at the same stage. This pollution situation further restricts the development of diesel vehicles. It is expected that by 2025, diesel consumption will be reduced to 168Mt, and the diesel-to-gasoline ratio will be reduced from the current 1.4 to less than 1. This will mean that there will be a surplus of hundreds of millions of tons of gasoline and diesel products, and the high particulate matter emissions of diesel engines will further restrict the use of diesel, and there will be a surplus of millions of tons of diesel for vehicles in tens of millions of tons of refineries. Reducing the diesel-to-gasoline ratio of refinery products and finding a way out for diesel have become urgent issues to be solved. Straight-run diesel accounts for about 50% of the total diesel volume. Reducing the output of straight-run diesel or converting it into other high-value-added products to adapt to future changes in diesel demand is of great significance to ensuring the balance of supply and demand in my country's refined oil market.

[0003] For the conversion of straight-run diesel, usually less than 10% of light diesel can be blended into ethylene cracking raw materials. However, compared with other light raw materials, the steam cracking olefin yield of straight-run diesel is lower and the decoking cycle is short. In addition, hydrocracking can process straight-run diesel, with a hydrogen consumption of 2.5%, a naphtha yield of 50% to 60%, and a liquefied gas yield of 4% to 5%. In recent years, domestic refineries have also adopted conventional catalytic cracking units to blend straight-run diesel in order to reduce the diesel-gasoline ratio. For example, the conventional catalytic cracking unit of Sinopec Hainan Refining and Chemical Co., Ltd. blends the three-line straight-run diesel, with a gasoline yield of 41%, but the volume fraction of propylene in the liquefied gas decreases by 0.52 percentage points and the volume fraction of isobutylene decreases by 0.12 percentage points, which is not conducive to increasing the production of low-carbon olefins.

[0004] The technology of catalytic cracking or catalytic cracking of straight-run diesel has been progressing slowly. On the one hand, straight-run diesel has always been of high value as a high-cetane number vehicle fuel, with large usage and limited resources. On the other hand, the yield of catalytic cracking of straight-run diesel to produce gasoline or chemical materials such as ethylene and propylene is low. In addition, the coke production of catalytic cracking of straight-run diesel is low, which is not enough to maintain the conventional fluidized bed catalytic cracking of autothermal equilibrium, and catalytic cracking requires a relatively high temperature.

[0005] Existing research at home and abroad has mainly focused on improving conversion rate and compensating for heat balance. For example, China National Petroleum Corporation's patent CN111607425A discloses a method for cracking straight-run diesel, that is, straight-run diesel with alkaline nitrogen removed by dihydrogen phosphate and inert gases such as nitrogen enter a fixed bed or moving bed reactor equipped with activated pretreated ZSM-5 nanomolecular sieve for catalytic cracking, while patent CN111718751A discloses a method for preparing a ZSM-5 nanomolecular sieve catalyst modified by a transition metal. As described in the two patents, straight-run diesel uses a fixed bed reactor to heat the reaction temperature up to 600°C to achieve a diesel conversion rate of up to 80.16% and a light olefin yield of 34.13%; however, its one-way cycle is as short as 47 hours, and the short reaction cycle requires frequent switching of reactors, while the one-way cycle of a moving bed reactor is extended to 78 hours, but the operation is difficult.

[0006] Sinopec's patents CN104418685B and CN104418686A both disclose a method for catalytic cracking of straight-run diesel in a riser reactor with methane as a diluent and the spent catalyst exchanging heat with flue gas. Patent CN104418686A also discloses a technology for extracting aromatics from cracked gasoline and steam cracking of C2-C4 alkanes. As described in the two patents, the use of mature fluidized bed technology can achieve continuous reaction-regeneration and solve the heat balance problem by setting up a spent catalyst and flue gas heat exchanger. At a reaction temperature of up to 630°C and a catalyst / oil mass ratio of 18, the diesel conversion rate of up to 83.83% and the ethylene and propylene yields of 16.52% and 35.19% were achieved through C4 recycling; however, the heat exchange between the spent catalyst and flue gas requires the addition of a heat exchanger, which is complex in process, high in equipment investment, and low in heat exchange efficiency. In addition, the flue gas contains a certain amount of oxygen and the spent catalyst is not fully burned, which is prone to tail combustion and other hidden dangers.

[0007] Therefore, in order to meet the growing demand for low-carbon olefins and high-octane clean gasoline and solve the problem of excess diesel, it is necessary to develop a production method for converting diesel into gasoline and liquefied gas. Summary of the invention

[0008] The object of the present invention is to provide a method for producing gasoline by catalytic cracking of hydrocarbons and a reaction system thereof, which has a high diesel conversion rate and can achieve self-heating balance.

[0009] A first aspect of the present invention provides a method for producing high-octane gasoline by catalytic cracking of hydrocarbons, the method comprising:

[0010] (1) in a constant linear velocity fluidized bed reactor, subjecting a light hydrocarbon feedstock to catalytic cracking in the presence of a catalyst to obtain a first mixed material comprising a first spent catalyst and a first oil gas;

[0011] (2) separating the first mixed material in a cyclone separator, and allowing the separated oil and gas to enter an oil-gas separation system for product separation to obtain high-octane gasoline;

[0012] (3) the separated catalyst to be regenerated enters the regenerator for oxygen-containing regeneration, and the regenerated catalyst is circulated back to the isolinear fluidized bed reactor, wherein part or all of the flue gas after regeneration is circulated back to the regenerator;

[0013] The catalyst at least comprises a mesoporous molecular sieve having a ten-membered ring structure with an average pore size of 0.5 to 0.6 nm, which accounts for 5 to 10 weight percent of the total amount of the catalyst.

[0014] According to the method described in the first aspect of the present invention, in the isolinear fluidized bed reactor, the reaction temperature is 500-560°C, the reaction pressure is 0.1-0.3 MPa, the weight ratio of catalyst to crude oil is 5-8:1, and the reaction time is 2.0-7.0 seconds.

[0015] According to the method of the first aspect of the present invention, the reaction section of the isolinear fluidized bed reactor is a variable diameter whose diameter gradually increases from bottom to top;

[0016] Preferably, in the isolinear fluidized bed reactor, the oil and gas linear velocity is 1.0 to 2.0 m / s, and the catalyst circulation rate is 150 to 200 kg / m 2 ·Second).

[0017] According to the method of the first aspect of the present invention, the atmosphere of oxygen-containing regeneration is an oxygen-rich and / or pure oxygen atmosphere;

[0018] The temperature of the regenerator is 580-680°C and the pressure is 0.2-0.6MPa; and / or

[0019] The flue gas temperature of the circulating regenerator is 380-530°C.

[0020] According to the method of the first aspect of the present invention, the catalyst comprises medium-pore zeolite and large-pore zeolite, an inorganic oxide and optional clay, wherein the large-pore zeolite is a twelve-membered ring structure molecular sieve with an average pore diameter of 0.74 nm, and the total silicon-aluminum ratio of the large-pore zeolite is higher than 5.0, accounting for 20 to 50% by weight of the total amount of the catalyst;

[0021] Preferably, the average particle size of the catalyst is 40 to 150 microns;

[0022] More preferably, the catalyst is modified with one or more metal and / or non-metal oxides selected from Group IA, Group IIA, Group VA, Group VIA, Group VIIA, Group IB, Group IIB or transition metal elements, and the oxide accounts for 0.5 to 5.0 weight % of the total catalyst.

[0023] According to the method of the first aspect of the present invention, the light hydrocarbon feedstock oil is diesel;

[0024] Preferably, the diesel comprises straight-run diesel, catalytic cracking diesel and / or hydrogenated diesel; the boiling point of the diesel is 180-380°C and the density is not more than 900kg / m 3 .

[0025] According to the method of the first aspect of the present invention, the light hydrocarbon feedstock oil is preheated before entering the reactor, and the preheating temperature is 120 to 300° C., preferably 160 to 260° C.; and / or

[0026] The fluidizing medium of the isolinear fluidized bed reactor is water vapor. Preferably, the mass ratio of the water vapor to the feedstock oil is 0.04 to 0.08.

[0027] According to the method of the first aspect of the present invention, the method further comprises feeding heavy oil into the isolinear fluidized bed reactor, wherein the feeding position of the heavy oil is located above the feeding position of the light hydrocarbon feedstock oil;

[0028] The heavy oil is wax oil, residual oil and / or oil slurry separated by the oil-gas separation system in step (2).

[0029] According to the method of the first aspect of the present invention, the method further comprises: subjecting the heavy oil and / or the oil slurry separated by the oil-gas separation system to a second catalytic cracking reaction in a second reactor to obtain a second mixed material comprising second oil and gas and a second spent catalyst;

[0030] Separating the second mixed material in a cyclone separator;

[0031] Preferably, the second reactor is a riser reactor or a variable diameter riser reactor.

[0032] The second aspect of the present invention provides a reaction system for producing high-octane gasoline by catalytic cracking, the reaction system comprising:

[0033] The isolinear fluidized bed reaction system comprises:

[0034] - isolinear fluidized bed reactor,

[0035] - a cyclone separator, and

[0036] - stripper,

[0037] The cyclone separator is arranged at the top of the isolinear fluidized bed reactor and is connected to the stripper, so that the spent catalyst separated by the cyclone separator is stripped in the stripper;

[0038] Regenerator,

[0039] The stripper is connected to the regenerator, so that the catalyst to be regenerated after being stripped by the stripper enters the regenerator for regeneration; the regenerator is also connected to the constant linear velocity fluidized bed reactor, so that the regenerated catalyst after being regenerated by the regenerator is circulated back to the constant linear velocity fluidized bed reactor; the regenerator also includes a flue gas circulation system, and part or all of the regenerated flue gas is circulated back to the regenerator;

[0040] An oil-gas separation system, the oil-gas separation system being in communication with the oil-gas outlet of the isolinear fluidized bed reactor;

[0041] Preferably, the isolinear fluidized bed reactor is provided with a light hydrocarbon feedstock oil inlet and a heavy oil inlet, and the heavy oil inlet is provided above the light hydrocarbon feedstock oil inlet;

[0042] More preferably, the heavy oil inlet is communicated with the oil slurry outlet of the oil-gas separation system.

[0043] According to the reaction system of the second aspect of the present invention, the reaction system further comprises a second reactor, the second reactor is a heavy oil catalytic cracking reactor, the outlet of the second reactor is connected to the outlet section of the isolinear fluidized bed reactor, and the second mixed material containing the second oil gas and the second spent catalyst obtained after the second catalytic cracking reaction in the second reactor is separated in a cyclone separator;

[0044] Preferably, the second reactor is a riser reactor or a variable diameter riser reactor;

[0045] More preferably, the inlet of the second reactor is communicated with the oil slurry outlet of the oil-gas separation system.

[0046] Compared with the prior art, the present invention has the following technical effects:

[0047] (1) Compared with fixed bed and moving bed reactors, isolinear fluidized bed reactors do not require external heating and can produce continuously. Compared with conventional riser reactors, the oil-agent contact is sufficient, the diesel conversion rate is high, and the dry gas and coke yields are low, which is more suitable for catalytic cracking of light hydrocarbons.

[0048] (2) Regeneration in an oxygen-enriched and / or pure oxygen atmosphere, compared with conventional air regeneration, has less heat to heat up the air, higher charring intensity, and higher regeneration temperature, which can maintain a higher regeneration agent temperature.

[0049] (3) After regeneration, part or all of the high-temperature flue gas is returned to the regenerator, which not only fully utilizes the oxygen in the flue gas, but also solves the problem of the flue gas carrying heat out of the reaction regeneration system, and reduces the emission of waste gases such as carbon dioxide, thus significantly saving energy and reducing emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of a process flow of an embodiment of the present invention, used to illustrate the linear velocity fluidized bed catalytic cracking process of light hydrocarbon feedstock oil.

[0051] Figure 2 It is a schematic diagram of a process flow of an embodiment of the present invention, used to illustrate the catalytic cracking process of coupling a light hydrocarbon feedstock isolinear fluidized bed with a heavy feedstock riser.

[0052] Description of reference numerals:

[0053] I. Reactor pre-lifting section; II. Reactor reaction section; III. Reactor outlet section; IV. Settler; IV-1. Cyclone separator; IV-2. Catalyst settling section; 1. Constant linear velocity fluidized bed reactor; 2. Light hydrocarbon feedstock oil; 3. Atomizing steam; 4. Fluidizing medium I; 5. Reaction oil and gas pipeline; 6. Oil and gas separation system; 7. Dry gas; 8. Liquefied gas; 9. Gasoline; 10. Circulating oil; 11. Oil slurry; 12. Heavy feedstock oil; 13. Atomizing steam; 14. Stripping medium; 15. Regenerated agent delivery pipeline; 16. Regenerator; 17. Oxygen-containing regeneration gas; 18. Regeneration agent delivery pipeline I; 19. Flue gas; 20. Flue gas circulation system; 21. Riser reactor; 22. Fluidizing medium II; 23. Regeneration agent delivery pipeline II. DETAILED DESCRIPTION

[0054] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0055] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0056] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0057] Before describing the technical solution of the present invention, the terms used in this article are defined as follows:

[0058] The term "BTX" refers to: light aromatics, a mixture of benzene, toluene and xylenes.

[0059] The present invention provides a method for producing high-octane gasoline by catalytic cracking of hydrocarbons, comprising:

[0060] (1) in a constant linear velocity fluidized bed reactor, subjecting a light hydrocarbon feedstock to catalytic cracking in the presence of a catalyst to obtain a first mixed material comprising a first spent catalyst and a first oil gas;

[0061] (2) separating the first mixed material in a cyclone separator, and allowing the separated oil and gas to enter an oil-gas separation system for product separation to obtain high-octane gasoline;

[0062] (3) the separated catalyst to be regenerated enters the regenerator for oxygen-containing regeneration, and the regenerated catalyst is circulated back to the isolinear fluidized bed reactor, wherein part or all of the flue gas after regeneration is circulated back to the regenerator;

[0063] Wherein, the catalyst at least comprises a mesoporous molecular sieve having a ten-membered ring structure with an average pore size of 0.5 to 0.6 nm, accounting for 5 to 10 weight % of the total amount of the catalyst.

[0064] The constant linear velocity fluidized bed reactor of the present invention refers to the catalytic cracking reaction oil and gas in the fluidized bed reactor to maintain a relatively uniform linear velocity. Because the catalytic cracking reaction is a reaction of rapid volume expansion, the reaction section of the constant linear velocity fluidized bed reactor is a variable diameter with a diameter gradually enlarged from bottom to top; preferably, in the constant linear velocity fluidized bed reactor, the oil and gas linear velocity is 1.0-2.0 m / s, the catalyst circulation rate is 150-200 kg / (m 2 · seconds). Compared with a common fluidized bed with uniform diameter, the oil and gas in the constant linear velocity fluidized bed reactor contact the catalyst in a plug flow state at a uniform linear velocity, the catalyst density is high, and the oil and gas contact is more complete.

[0065] The present invention utilizes a constant linear velocity fluidized bed reactor to catalytically crack light hydrocarbon feedstock oil to produce high-octane gasoline. Compared with fixed bed and moving bed reactors, it does not require external heating and can produce continuously. Compared with conventional riser reactors, the oil agent is fully contacted, the diesel conversion rate is high, and the dry gas and coke yields are low, which is more suitable for catalytic cracking of light hydrocarbons.

[0066] The high-temperature flue gas after regeneration is partially or completely returned to the regenerator, which not only fully utilizes the oxygen in the flue gas, but also maintains a high regeneration temperature of the regenerator and a high regeneration agent temperature. It not only solves the problem of flue gas carrying heat out of the reaction regeneration system, but also reduces the emission of waste gas such as carbon dioxide, thus significantly saving energy and reducing emissions.

[0067] The reaction oil and gas are separated into products through a separation system to obtain dry gas, liquefied gas, gasoline and other products as well as naphthalene-containing aromatic oil and other products.

[0068] The reactor and the regenerator can be arranged in parallel or overlapped, and the fluidized bed and the settler can be internal or external; the catalyst is lifted by media such as air and / or water vapor so that it circulates between the reactor and the regenerator.

[0069] In one embodiment, in the isolinear fluidized bed reactor, the reaction temperature is 500-560° C., the reaction pressure is 0.1-0.3 MPa, the weight ratio of catalyst to feedstock oil is 5-8:1, and the reaction time is 2.0-7.0 seconds.

[0070] The catalyst in the reactor may flow in an upward direction or in a downward direction; preferably, the catalyst flows in an upward direction.

[0071] In one embodiment, the reaction section of the isolinear fluidized bed reactor is a variable diameter whose diameter gradually increases from bottom to top;

[0072] Preferably, in the isolinear fluidized bed reactor, the oil and gas linear velocity is 1.0 to 2.0 m / s, and the catalyst circulation rate is 150 to 200 kg / m 2 ·Second).

[0073] In one embodiment, the oxygen-containing regeneration atmosphere is an oxygen-rich and / or pure oxygen atmosphere;

[0074] The temperature of the regenerator is 580-680°C and the pressure is 0.2-0.6MPa; and / or

[0075] The flue gas temperature of the circulating regenerator is 380-530°C.

[0076] The present invention adopts oxygen-enriched and / or pure oxygen atmosphere regeneration. Compared with conventional air regeneration, the air heating heat is less, the charring intensity is high, the regeneration temperature is also high, and a higher regeneration agent temperature can be maintained, thereby ensuring the regeneration efficiency.

[0077] In one embodiment, the catalyst comprises medium-pore zeolite and large-pore zeolite, an inorganic oxide and optional clay, wherein the large-pore zeolite is a twelve-membered ring structure molecular sieve with an average pore diameter of 0.74 nm, and the total silicon-aluminum ratio of the large-pore zeolite is higher than 5.0, accounting for 20 to 50 weight percent of the total amount of the catalyst;

[0078] Preferably, the average particle size of the catalyst is 40 to 150 microns;

[0079] More preferably, the catalyst is modified with one or more metal and / or non-metal oxides selected from Group IA, Group IIA, Group VA, Group VIA, Group VIIA, Group IB, Group IIB or transition metal elements, and the oxide accounts for 0.5 to 5.0 weight % of the total catalyst.

[0080] In a specific embodiment, based on the weight of the catalyst, the catalyst includes 20-50 wt% of large-pore zeolite molecular sieve, 5.0-10 wt% of medium-pore zeolite molecular sieve, 15-35 wt% of inorganic oxide, 20-40 wt% of clay and 0.5-5.0 wt% of metal oxide.

[0081] In a specific embodiment, the large-pore zeolite is one or more selected from REY zeolite, HY zeolite, REHY zeolite, ultrastable Y zeolite, high-silicon Y zeolite and β zeolite, preferably high-silicon-aluminum ratio ultrastable Y zeolite, whose total silicon-aluminum ratio is higher than 5.0; the medium-pore zeolite is one or more selected from ZSM-5 zeolite, ZSM-11 zeolite, ZSM-12 zeolite, ZSM-23 zeolite, ZSM-35 zeolite, ZSM-38 zeolite, ZSM-48 zeolite and ZRP zeolite; the inorganic oxide is a heat-resistant inorganic oxide, preferably a binder such as silicon oxide and / or aluminum oxide; the clay is one or more selected from silica, kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite.

[0082] In a specific embodiment, the catalyst is a composite of USY series large-pore zeolite and ZSM series medium-pore zeolite, binders such as alumina and silica, and optional natural porous carrier materials such as clay, wherein the large-pore molecular sieve accounts for 20 to 50% by weight of the total catalyst, and its total silicon-aluminum ratio is higher than 5.0, while the medium-pore molecular sieve accounts for 5.0 to 10% by weight of the total catalyst.

[0083] In one embodiment, the light hydrocarbon feedstock oil is diesel;

[0084] Preferably, the diesel comprises straight-run diesel, catalytic cracking diesel and / or hydrogenated diesel; the boiling point of the diesel is 180-380°C and the density is not more than 900kg / m 3 .

[0085] In one embodiment, the light hydrocarbon feedstock oil is preheated before entering the reactor, and the preheating temperature is 120 to 300° C., preferably 160 to 260° C.; and / or

[0086] The fluidizing medium of the isolinear fluidized bed reactor is water vapor. Preferably, the mass ratio of the water vapor to the feedstock oil is 0.04 to 0.08.

[0087] The raw materials can be preheated by heating in a heating furnace or by exchanging heat with the product to the preheating temperature.

[0088] In one embodiment, the method further comprises feeding heavy oil into the isolinear fluidized bed reactor, wherein the feeding position of the heavy oil is located above the feeding position of the light hydrocarbon feedstock oil;

[0089] The heavy oil is wax oil, residual oil and / or oil slurry separated by the oil-gas separation system in step (2).

[0090] In one embodiment, the method further comprises: subjecting the heavy oil and / or the oil slurry separated by the oil-gas separation system to a second catalytic cracking reaction in a second reactor to obtain a second mixed material comprising second oil and gas and a second spent catalyst;

[0091] Separating the second mixed material in a cyclone separator;

[0092] Preferably, the second reactor is a riser reactor or a variable diameter riser reactor.

[0093] The present invention also provides a reaction system for producing high-octane gasoline by catalytic cracking, comprising:

[0094] The isolinear fluidized bed reaction system comprises:

[0095] - isolinear fluidized bed reactor,

[0096] - a cyclone separator, and

[0097] - stripper,

[0098] The cyclone separator is arranged at the top of the isolinear fluidized bed reactor and is connected to the stripper, so that the spent catalyst separated by the cyclone separator is stripped in the stripper;

[0099] Regenerator,

[0100] The stripper is connected to the regenerator, so that the catalyst to be regenerated after being stripped by the stripper enters the regenerator for regeneration; the regenerator is also connected to the constant linear velocity fluidized bed reactor, so that the regenerated catalyst after being regenerated by the regenerator is circulated back to the constant linear velocity fluidized bed reactor; the regenerator also includes a flue gas circulation system, and part or all of the regenerated flue gas is circulated back to the regenerator;

[0101] An oil-gas separation system, the oil-gas separation system being in communication with the oil-gas outlet of the isolinear fluidized bed reactor;

[0102] Preferably, the isolinear fluidized bed reactor is provided with a light hydrocarbon feedstock oil inlet and a heavy oil inlet, and the heavy oil inlet is provided above the light hydrocarbon feedstock oil inlet;

[0103] More preferably, the heavy oil inlet is communicated with the oil slurry outlet of the oil-gas separation system.

[0104] In one embodiment, the reaction system further comprises a second reactor, the second reactor is a heavy oil catalytic cracking reactor, the outlet of the second reactor is connected to the outlet section of the isolinear fluidized bed reactor, and the second mixed material containing the second oil gas and the second spent catalyst obtained after the second catalytic cracking reaction in the second reactor is separated in a cyclone separator;

[0105] Preferably, the second reactor is a riser reactor or a variable diameter riser reactor;

[0106] More preferably, the inlet of the second reactor is communicated with the oil slurry outlet of the oil-gas separation system.

[0107] In one embodiment, the reaction section of the isolinear fluidized bed reactor has a variable diameter with the diameter gradually increasing from bottom to top.

[0108] A specific embodiment of the present invention is as follows Figure 1 As shown, in this embodiment, an upward variable diameter constant linear velocity fluidized bed reactor 1 is used, and the light hydrocarbon feedstock oil 2 enters the reactor by bottom feeding to contact the regeneration agent for catalytic cracking reaction, and the spent catalyst after the reaction is separated from the oil and gas and then regenerated, and the flue gas after regeneration is partially circulated back to the regenerator 16. The process flow is as follows:

[0109] The light hydrocarbon feedstock oil 2 is atomized by the atomizing steam 3 and enters the bottom of the variable diameter reaction section II in the isolinear fluidized bed reactor 1, while the hot regenerated agent is introduced into the pre-lifting section I of the fluidized bed reactor through the regenerated agent delivery pipeline I18, and enters the reactor reaction section II upward under the fluidization of the fluidizing medium I4, and the light hydrocarbon feedstock oil 2 contacts the hot regenerated agent to carry out catalytic cracking reaction; after the reaction, the oil gas and the catalyst enter the cyclone separator IV-1 through the reactor outlet section III for oil-agent separation, and the separated catalyst settles to the stripping section IV-2 of the reactor, and is stripped by the stripping medium 14 and then passed through the regenerated agent to be regenerated. The transmission pipeline 15 enters the regenerator 16; the catalyst to be regenerated is regenerated in the oxygen-containing atmosphere in the regenerator 16, and the oxygen-containing regeneration gas 17 includes air, oxygen, etc. The regeneration temperature is 580-680°C, and the regenerated catalyst is recycled; the flue gas 19 after regeneration is partially circulated back to the regenerator 16 through the flue gas circulation system 20; the separated reaction oil and gas enter the oil and gas separation system 6 through the reaction oil and gas pipeline 5, and the product dry gas 7, liquefied gas 8, gasoline 9, circulating oil 10 and oil slurry 11 are separated, wherein the circulating oil 10 and oil slurry 11 can be recycled and / or not recycled according to production needs. In order to meet the needs of the device's self-heating balance, oil slurry recycling is preferred; the oil slurry recycling and / or the heavy raw oil 12 is atomized by the atomizing steam 13 and then enters the reactor, preferably entering the middle of the reaction section II of the variable diameter constant linear velocity fluidized bed reactor, that is, feeding at the upper part of the light hydrocarbon raw oil nozzle.

[0110] Figure 2This is a process flow diagram of another embodiment of the present invention. The light hydrocarbon feedstock uses a variable diameter constant linear velocity fluidized bed reactor 1 as in Example 1. The difference is that the oil slurry is recycled and / or the heavy feedstock 12 enters a conventional riser reactor. The conventional riser and the light hydrocarbon fluidized bed can each use a separate settler or share a settler. In this embodiment, both use a settler. The process flow is as follows:

[0111] The light hydrocarbon feedstock oil 2 is atomized by the atomizing steam 3 and enters the bottom of the variable diameter reactor reaction section II in the isolinear fluidized bed reactor 1, while the hot regenerated agent is introduced into the reactor pre-lift section I of the isolinear fluidized bed reactor 1 through the regenerated agent delivery pipeline 18, and ascends into the reaction section II under the fluidization of the fluidized medium I4, and the light hydrocarbon feedstock oil 2 contacts the hot regenerated agent for catalytic cracking reaction; the heavy feedstock oil 12 is atomized by the atomizing steam 13 and enters the lower part of the riser reactor 21, while the hot regenerated agent is introduced into the bottom of the riser reactor 21 through the regenerated agent delivery pipeline II23, and ascends under the fluidization of the fluidized medium II22, and the heavy feedstock oil 12 contacts the hot regenerated agent for catalytic cracking reaction; after the reaction of the light hydrocarbon feedstock oil 2 and the heavy feedstock oil 12, both oil and gas enter the cyclone separator IV-1 for oil-agent separation After the reaction, the oil gas and the catalyst enter the cyclone separator IV-1 through the reactor outlet section III for oil-agent separation, and the separated catalyst settles to the reactor stripping section IV-2, and enters the regenerator 16 through the regenerated catalyst conveying pipeline 15 after stripping by the stripping medium 14; the regenerated catalyst is regenerated in the oxygen-containing atmosphere in the regenerator 16, and the oxygen-containing regeneration gas 17 includes air, oxygen, etc., and the regeneration temperature is 500-800°C, and the regenerated catalyst is recycled; part of the regenerated flue gas 19 is circulated back to the regenerator 16 through the flue gas circulation system 20; the separated reaction oil gas enters the oil and gas separation system 6 through the reaction oil and gas pipeline 5, and is separated to obtain product dry gas 7, liquefied gas 8, gasoline 9, circulating oil 10 and oil slurry 11, among which the circulating oil 10 and oil slurry 11 can be selected to be recycled and / or not recycled according to production needs. The oil slurry 11 is recycled and can enter the middle of the variable diameter reactor reaction section II of the constant linear velocity fluidized bed reactor 1, and the heavy crude oil 12 is preferably atomized by the atomizing steam 13 and then enters the riser reactor 21 for catalytic cracking reaction.

[0112] The present invention is further described in detail by way of examples. The raw materials used in the examples can be obtained through commercial sources.

[0113] The following examples will further illustrate the method, but are not intended to limit the method.

[0114] The light hydrocarbon feedstock used in the embodiment is hydrogenated diesel produced by hydrogenating straight-run diesel and catalytic cracking diesel in a refinery at a mass ratio of 4:1, and the heavy feedstock oil is hydrogenated residue oil after hydrogenation of residue oil in a refinery. The properties of the two are shown in Table 1.

[0115] The catalysts used in the examples are the same, and their preparation methods are briefly described as follows:

[0116] 1) Dissolve 10 kg NH4Cl in 500 kg water, add 50 kg (dry basis) of crystallized DASY zeolite (produced by Sinopec Catalyst Qilu Branch, unit cell constant 2.445-2.455 nm, rare earth content RE2O3 = 8.0 wt%) to the solution, exchange at 90°C for 0.5 h, filter to obtain a filter cake; add 1.1 kg Fe(NO3)3·9H2O dissolved in 3.3 kg water, mix with the filter cake, soak and dry; then calcine at 550°C for 2 hours to obtain an iron-containing macroporous zeolite, whose elemental analysis chemical composition is 0.1 Na2O·5.1 Al2O3·1.0 Fe2O3·7.6 RE2O3·88.1 SiO2.

[0117] 2) Use 125kg of decationized water to slurry 18.8kg of halloysite (industrial product of Suzhou Clay Company, solid content 71.6m%), then add 13.7kg of pseudo-boehmite (industrial product of Shandong Aluminum Plant, solid content 63m%), adjust its pH to 2-4 with hydrochloric acid, stir evenly, stand and age at 60-70°C for 1 hour, keep the pH at 2-4, reduce the temperature to below 60°C, add 10.4Kg of aluminum sol (product of Sinopec Catalyst Qilu Branch, Al2O3 content is 21.7m%), stir for 40 minutes, and obtain a mixed slurry.

[0118] 3) Add the iron-containing macroporous zeolite (8.5 kg on dry basis) prepared in step 1) and the medium-pore ZRP-1 zeolite with MFI structure (industrial product of Sinopec Catalyst Qilu Branch, SiO2 / Al2O3=30, phosphorus content P2O5=3.5 wt%, dry basis 2.1 kg) to the mixed slurry obtained in step 2) and stir evenly. Put it in a bonding machine, add an appropriate amount of water, stir well, place it in the air for 4 hours, spray dry it, dry it in a drying oven at 120°C for 3 hours, and wash it with ammonium dihydrogen phosphate solution (phosphorus content is 1m%) to remove free Na + The catalyst was dried again at 120°C for 3 hours to obtain a catalyst named CAT-1. The catalyst comprises 24.0 wt% DASY zeolite, 0.3 wt% iron oxide, 6.0 wt% MFI structure medium pore zeolite, 24.7 wt% pseudo-boehmite, 6.5 wt% aluminum sol and 38.5% kaolin. Its properties are listed in Table 2.

[0119] Example 1

[0120] This embodiment follows Figure 1The test was carried out in a flow process, using hydrogenated diesel A in Table 1 as the raw material, and the test was carried out in an isolinear fluidized bed reactor using CAT-1 catalyst. The crude oil A is preheated at 260°C and enters the bottom of the reaction section of the isolinear fluidized bed reactor. At a reaction pressure of 0.24 MPa, water vapor is used as the fluidizing medium, and the mass ratio of atomized steam to crude oil is 0.05. As the fluidizing medium flows from bottom to top, a catalytic cracking reaction is carried out under the conditions of a reaction temperature (based on the reactor outlet, the same below) of 540°C, a weight ratio of catalyst to crude oil of 8.0, and a reaction time of 3.0 seconds. After the reaction, oil-agent separation is carried out, and the separated reaction oil and gas are separated into products by a separation system to obtain dry gas, liquefied gas, gasoline, circulating oil, oil slurry and other products, and the oil slurry is partially recycled. After the separation of the oil-agent, the catalyst to be regenerated is stripped with water vapor to remove the oil and gas adsorbed inside it, and then sent to a regenerator, using oxygen as the regeneration gas, and regenerated at a regeneration temperature of 580-680°C in contact with the catalyst to be regenerated. The regenerated regenerated agent is recycled, and the flue gas after regeneration is partially recycled. The circulating flue gas temperature is 400°C, and the regeneration dense phase temperature is maintained at 608°C. The operating conditions and product distribution are listed in Table 3.

[0121] As can be seen from Table 3, in Example 1, the hydrogenated diesel was subjected to catalytic cracking reaction in a constant linear velocity fluidized bed reactor, and the yield of liquefied gas was 25.95% by weight, the yield of gasoline was 53.83% by weight, the yield of light olefins (ethylene + propylene + butene) was 12.32% by weight, the yield of BTX (benzene + toluene + xylene) was 11.15% by weight, and the octane number RON of gasoline reached 95.7.

[0122] Comparative Example 1

[0123] The catalytic cracking reaction was carried out by using the same feedstock oil, catalyst and process conditions as in Example 1, except that: 1) the riser reactor was used in Example 1; 2) air was used as the regeneration gas, and the flue gas was not circulated; 3) in order to maintain the same process conditions as in Example 1, it was necessary to spray combustion oil in the regenerator to provide heat. The operating conditions and product distribution are listed in Table 3.

[0124] As can be seen from Table 3, compared with Comparative Example 1 (riser reactor), Example 1 (constant linear velocity fluidized bed reactor) has a high gasoline yield, which is 2.60 percentage points higher than that of Comparative Example 1; a high light olefin yield, which is 1.05 percentage points higher than that of Comparative Example 1; and a slightly increased gasoline octane number, which is 0.4 units higher than that of Comparative Example 1.

[0125] Example 2

[0126] This embodiment follows Figure 2The process was tested, using hydrogenated diesel A and hydrogenated residue B in Table 1 as raw materials. The two were tested in an isolinear fluidized bed reactor and a riser reactor, respectively, using CAT-1 catalyst. The raw oil A was preheated at 200°C and entered the bottom of the reaction section of the isolinear fluidized bed reactor, and the raw oil B was preheated at 200°C and entered the bottom of the conventional riser reactor; both were at a reaction pressure of 0.22MPa, with water vapor as the fluidizing medium, and a mass ratio of atomized steam to raw oil of 0.05. As the fluidizing medium flows from bottom to top in different reactors, catalytic cracking reactions are carried out under the conditions of a reaction temperature (based on the reactor outlet) of 520°C, a weight ratio of catalyst to raw oil of 6.0, and a reaction time of 7.0 seconds; the oil and gas after the reaction of the raw oil B in the riser reactor and the catalyst are merged into the isolinear fluidized bed reactor The reactor is used to separate the oil agent from the oil agent after the reaction of the crude oil A; the reaction oil gas after the oil agent separation is separated by the separation system to obtain dry gas, liquefied gas, gasoline, circulating oil and oil slurry and other products, and the oil slurry is partially recycled; the catalyst to be regenerated after the oil agent separation is stripped by steam to remove the oil gas adsorbed inside it and then sent to the regenerator, using 20% ​​oxygen and 80% air enriched air as the regeneration gas, and regenerating it at a regeneration temperature of 580-680℃ in contact with the catalyst to be regenerated; the regenerated regenerated agent is recycled, and the flue gas after regeneration is partially recycled, the circulating flue gas temperature is 500℃, and the regeneration dense phase temperature is maintained at 664℃. The operating conditions and product distribution are listed in Table 3.

[0127] As can be seen from Table 3, in Example 2, the hydrogenated diesel was subjected to catalytic cracking reaction in the isolinear fluidized bed reactor and the hydrogenated residue was subjected to catalytic cracking reaction in the riser reactor at the same time, and the liquefied gas yield of the two was 18.98% by weight, the gasoline yield was 57.86% by weight, the light olefin (ethylene+propylene+butene) yield was 8.94% by weight, the BTX (benzene+toluene+xylene) yield was 9.98% by weight, and the gasoline octane number RON reached 94.1.

[0128] Comparative Example 2

[0129] The catalytic cracking reaction was carried out by using the same feedstock oil, catalyst and process conditions as in Example 2, except that: 1) both hydrogenated diesel A and hydrogenated residue B in Example 2 used riser reactors; 2) air was used as the regeneration gas, and the flue gas was not circulated; 3) in order to maintain the same process conditions as in Example 2 for the reverse regeneration system operation, it was necessary to spray combustion oil in the regenerator to provide heat. The operating conditions and product distribution are listed in Table 3.

[0130] As can be seen from Table 3, compared with Comparative Example 2 (riser reactor), Example 2 (constant linear velocity fluidized bed reactor) has a high gasoline yield, which is 1.08 percentage points higher than that of Comparative Example 2; the yields of liquefied gas and light olefins are high, which are 1.33 and 0.53 percentage points higher than those of Comparative Example 2, respectively; and the octane number of gasoline is slightly increased, which is 0.3 units higher than that of Comparative Example 2.

[0131] The present application has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, various replacements and improvements may be made to the present application, all of which fall within the scope of protection of the present application.

[0132] Table 1

[0133] Raw oil name Hydrogenated diesel Heavy crude oil Crude oil number A B <![CDATA[Density at 20°C, kg / m 3 > 844.0 929.6 Sulfur content, weight % 0.0009 0.22 Nitrogen content, weight % 0.0001 0.21 Four components Saturated hydrocarbons, weight % 81.8 56.9 Aromatics, weight % 18.2 29.8 Gel, weight% - 12.7 Asphaltene, weight % - 0.6 ASTM D86 distillation range, ℃ Initial distillation point 220 283.3 10％ 248 371.3 50％ 303 517.2 90％ 361 - Final distillation point 373 -

[0134] Table 2

[0135]

[0136]

[0137] Table 3

[0138]

[0139]

Claims

1. A method for producing high-octane gasoline by catalytic cracking of hydrocarbons, characterized in that: The method comprises: (1) in a constant linear velocity fluidized bed reactor, subjecting a light hydrocarbon feedstock to catalytic cracking in the presence of a catalyst to obtain a first mixed material comprising a first spent catalyst and a first oil gas; (2) separating the first mixed material in a cyclone separator, and allowing the separated oil and gas to enter an oil-gas separation system for product separation to obtain high-octane gasoline; (3) the separated catalyst to be regenerated enters the regenerator for oxygen-containing regeneration, and the regenerated catalyst is circulated back to the isolinear fluidized bed reactor, wherein part or all of the flue gas after regeneration is circulated back to the regenerator; The catalyst at least comprises a mesoporous molecular sieve having a ten-membered ring structure with an average pore size of 0.5 to 0.6 nm, which accounts for 5 to 10 weight percent of the total amount of the catalyst.

2. The method according to claim 1, characterized in that In the isolinear fluidized bed reactor, the reaction temperature is 500-560° C., the reaction pressure is 0.1-0.3 MPa, the weight ratio of catalyst to crude oil is 5-8:1, and the reaction time is 2.0-7.0 seconds.

3. The method according to claim 1, characterized in that The reaction section of the isolinear fluidized bed reactor has a variable diameter with the diameter gradually increasing from bottom to top; Preferably, in the isolinear fluidized bed reactor, the oil and gas linear velocity is 1.0 to 2.0 m / s, and the catalyst circulation rate is 150 to 200 kg / m 2 ·Second).

4. The method according to claim 1, characterized in that The oxygen-containing regeneration atmosphere is an oxygen-rich and / or pure oxygen atmosphere; The temperature of the regenerator is 580-680°C and the pressure is 0.2-0.6MPa; and / or The flue gas temperature of the circulating regenerator is 380-530°C.

5. The method according to claim 1, characterized in that: The catalyst comprises medium-pore zeolite and large-pore zeolite, inorganic oxides and optional clay, wherein the large-pore zeolite is a twelve-membered ring structure molecular sieve with an average pore diameter of 0.74 nm, and the total silicon-aluminum ratio of the large-pore zeolite is higher than 5.0, accounting for 20-50 weight percent of the total amount of the catalyst; Preferably, the average particle size of the catalyst is 40 to 150 microns; More preferably, the catalyst is modified with one or more metal and / or non-metal oxides selected from Group IA, Group IIA, Group VA, Group VIA, Group VIIA, Group IB, Group IIB or transition metal elements, and the oxide accounts for 0.1 to 5.0 weight % of the total catalyst.

6. The method according to claim 1, characterized in that The light hydrocarbon feedstock oil is diesel; Preferably, the diesel comprises straight-run diesel, catalytic cracking diesel and / or hydrogenated diesel; the boiling point of the diesel is 180-380°C and the density is not more than 900kg / m 3 .

7. The method according to claim 1, characterized in that The light hydrocarbon feedstock oil is preheated before entering the reactor, the preheating temperature is 120-300° C., preferably 160-260° C.; and / or The fluidizing medium of the isolinear fluidized bed reactor is water vapor. Preferably, the mass ratio of the water vapor to the feedstock oil is 0.04 to 0.

08.

8. The method according to claim 1, characterized in that: The method further comprises feeding heavy oil into the isolinear fluidized bed reactor, wherein the feeding position of the heavy oil is located above the feeding position of the light hydrocarbon feedstock oil; The heavy oil is wax oil, residual oil and / or oil slurry separated by the oil-gas separation system in step (2).

9. The method according to claim 1, characterized in that: The method further comprises: subjecting the heavy oil and / or the oil slurry separated by the oil-gas separation system to a second catalytic cracking reaction in a second reactor to obtain a second mixed material comprising second oil and gas and a second spent catalyst; Separating the second mixed material in a cyclone separator; Preferably, the second reactor is a riser reactor or a variable diameter riser reactor.

10. A reaction system for producing high-octane gasoline by catalytic cracking, characterized in that: The reaction system comprises: The isolinear fluidized bed reaction system comprises: - isolinear fluidized bed reactor, - a cyclone separator, and - stripper, The cyclone separator is arranged at the top of the isolinear fluidized bed reactor and is connected to the stripper, so that the spent catalyst separated by the cyclone separator is stripped in the stripper; Regenerator, The stripper is connected to the regenerator, so that the catalyst to be regenerated after being stripped by the stripper enters the regenerator for regeneration; the regenerator is also connected to the constant linear velocity fluidized bed reactor, so that the regenerated catalyst after being regenerated by the regenerator is circulated back to the constant linear velocity fluidized bed reactor; the regenerator also includes a flue gas circulation system, and part or all of the regenerated flue gas is circulated back to the regenerator; An oil-gas separation system, the oil-gas separation system being in communication with the oil-gas outlet of the isolinear fluidized bed reactor; Preferably, the isolinear fluidized bed reactor is provided with a light hydrocarbon feedstock oil inlet and a heavy oil inlet, and the heavy oil inlet is provided above the light hydrocarbon feedstock oil inlet; More preferably, the heavy oil inlet is communicated with the oil slurry outlet of the oil-gas separation system.

11. The reaction system according to claim 10, characterized in that: The reaction system further includes a second reactor, which is a heavy oil catalytic cracking reactor, wherein the outlet of the second reactor is connected to the outlet section of the isolinear fluidized bed reactor, and the second mixed material containing the second oil gas and the second spent catalyst obtained after the second catalytic cracking reaction in the second reactor is separated in a cyclone separator; Preferably, the second reactor is a riser reactor or a variable diameter riser reactor; More preferably, the inlet of the second reactor is communicated with the oil slurry outlet of the oil-gas separation system.

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