A catalytic conversion process and system for producing low carbon olefins

Abstract

The application provides a catalytic conversion method for producing low-carbon olefins, comprising: S1, contacting heavy feed oil with a first catalyst in a riser reactor to perform a first catalytic conversion reaction, and obtaining a first oil catalyst mixture; S2, introducing the first oil catalyst mixture into a fluidized bed reactor to contact with a second catalyst to perform a second catalytic conversion reaction, and obtaining a second oil catalyst mixture; S3, performing gas-solid separation and stripping on the second oil catalyst mixture in a settler, and obtaining an oil gas product and a mixed spent catalyst; S4, introducing the mixed spent catalyst into a catalyst separation device to perform separation, and obtaining a first spent catalyst and a second spent catalyst. The application also provides a catalytic conversion system. Through the above technical scheme, the application improves the yield of low-carbon olefins such as ethylene and propylene prepared by catalytic cracking of heavy feedstock.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of petrochemical industry, in particular to a catalytic conversion method and system for producing low-carbon olefins. BACKGROUND

[0002] Low-carbon olefins such as ethylene and propylene are basic chemical raw materials, which are currently mainly derived from steam cracking and catalytic cracking processes. The raw materials for steam cracking are generally light raw materials, and the raw materials for catalytic cracking can use heavy raw materials.

[0003] For example, CN107828443A discloses a fluid catalytic cracking process and apparatus for maximizing light olefin yield and other applications, which feeds hydrocarbons, a first catalyst and a second catalyst into a reactor, wherein the first catalyst has a smaller average particle size and is less dense than the second catalyst. A first portion of the second catalyst is recovered as a reactor bottom product, and a cracking hydrocarbon effluent, a second portion of the second catalyst and the first catalyst are recovered as a reactor top product, the top product is separated in a separation system to obtain a first stream comprising the first catalyst and the hydrocarbon effluent and a second stream comprising the second catalyst, and the separated second catalyst in the second stream is returned to the reactor.

[0004] However, the yield of low-carbon olefins in the existing catalytic cracking process is not high, and it is difficult to meet the demand, so it is necessary to further improve the yield of low-carbon olefins prepared by catalytic cracking. SUMMARY

[0005] The purpose of the present application is to further improve the yield of low-carbon olefins prepared by catalytic cracking.

[0006] In order to achieve the above-mentioned purpose, the present application provides a catalytic conversion method for producing low-carbon olefins, which comprises the following steps: S1, contacting a heavy raw oil with a first catalyst in a riser reactor to perform a first catalytic conversion reaction, to obtain a first oil-catalyst mixture; S2, introducing the first oil-catalyst mixture into a fluidized bed reactor to contact with a second catalyst to perform a second catalytic conversion reaction, to obtain a second oil-catalyst mixture; S3, performing gas-solid separation and stripping of the second oil-catalyst mixture in a settler to obtain an oil-gas product and a mixed spent catalyst; S4, introducing the mixed spent catalyst into a catalyst separation device for separation to obtain a first spent catalyst and a second spent catalyst, wherein the catalyst separation device comprises a primary catalyst separator and a secondary catalyst separator; S5, returning the first spent catalyst after first regeneration to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and returning the second spent catalyst after second regeneration to step S2 as the second catalyst to participate in the second catalytic conversion reaction.

[0007] The present invention also provides a catalytic conversion system, which includes a riser reactor, a fluidized bed reactor, a settler, a stripper, a catalyst separator and a regenerator; the upper end of the riser reactor is connected to the lower end of the fluidized bed reactor; the upper end of the fluidized bed reactor is connected to the lower end of the settler; the settler is also provided with a gas-solid separation device; the lower end of the fluidized bed reactor is also connected to a stripper; the solid material outlet of the gas-solid separation device is provided in the stripper or at the upper part of the stripper; the lower part of the stripper has an outlet for mixed catalyst to be regenerated; the catalyst separation device includes a primary catalyst separator and a secondary catalyst separator, the primary catalyst separator has a material outlet connected to the outlet of the mixed catalyst to be regenerated inlet, a first catalyst outlet to be regenerated and a gas-solid mixture outlet, the secondary catalyst separator has a logistics inlet connected to the gas-solid mixture outlet of the first catalyst separator, a second catalyst outlet to be regenerated and an oil and gas delivery outlet; a regenerator partition is provided in the regenerator, and the regenerator partition separates the regenerator into a first regeneration zone and a second regeneration zone; a first catalyst delivery connection is provided between the first catalyst outlet to be regenerated and the first regeneration zone; a second catalyst delivery connection is provided between the second catalyst outlet to be regenerated and the second regeneration zone; a first regenerated catalyst delivery connection is provided between the first regeneration zone and the riser reactor; a second regenerated catalyst delivery connection is provided between the second regeneration zone and the fluidized bed reactor.

[0008] Through the above technical scheme, the present invention first performs a primary cracking reaction on the heavy raw material with a first catalyst rich in heavy oil catalyst, and then performs a secondary cracking reaction on the generated intermediate product with a second catalyst rich in light oil catalyst, thereby realizing the relay of the primary cracking reaction and the secondary cracking reaction of the heavy raw material, thereby improving the yield of light olefins such as ethylene and propylene.

[0009] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0011] Figure 1 This is a schematic structural diagram of a catalytic conversion system according to one embodiment of the present invention.

[0012] Description of Reference Numerals

[0013] Figure 1 In the figure, the reference numerals are described as follows:

[0014] 1-Riser reactor 2-Stripper 3-Fluidized bed reactor

[0015] 4-settler 5-first regeneration zone 6-second regeneration zone

[0016] 11-Heavy raw material 12-Pre-lift gas 13-Stripping gas

[0017] 14-stripping baffle 15-mixed spent catalyst delivery pipe 16-first-stage catalyst separator

[0018] 17-First spent catalyst delivery pipe 18-Gas-solid mixture delivery pipe 19-Secondary catalyst separator

[0019] 20-Second spent catalyst delivery pipe 21-Oil and gas delivery pipe 22-Cyclone separator

[0020] 23-Gas collecting chamber 24-Reaction oil and gas 25-Main air

[0021] 26-first regenerant delivery pipe 27-second regenerant delivery pipe 28-regenerator partition

[0022] 29- cyclone separator 30- gas collecting chamber 31- regeneration flue gas DETAILED DESCRIPTION

[0023] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0024] refer to Figure 1 The present invention provides a catalytic conversion method for producing light olefins, which comprises the following steps: S1, contacting heavy feedstock oil with a first catalyst in a riser reactor to carry out a first catalytic conversion reaction to obtain a first oil-agent mixture; S2, introducing the first oil-agent mixture into a fluidized bed reactor to contact it with a second catalyst to carry out a second catalytic conversion reaction to obtain a second oil-agent mixture; S3, subjecting the second oil-agent mixture to gas-solid separation and steam stripping in a settler to obtain an oil and gas product and a mixed spent catalyst; S4, introducing the mixed spent catalyst into a catalyst separation device for separation to obtain a first spent catalyst and a second spent catalyst, the catalyst separation device comprising a primary catalyst separator and a secondary catalyst separator; S5, subjecting the first spent catalyst to a first regeneration and then returning it to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and subjecting the second spent catalyst to a second regeneration and then returning it to step S2 as the second catalyst to participate in the second catalytic conversion reaction.

[0025] In the present invention, the materials that have undergone the first catalytic conversion in the riser reactor (including the first catalyst, reaction oil and gas, and fluidized medium) all enter the fluidized bed reactor without separation and contact with the second catalyst to undergo the second catalytic conversion reaction, that is, the first catalytic conversion reaction and the second catalytic conversion reaction can be carried out in relay.

[0026] Wherein, optionally, in order to facilitate the separation of the first spent catalyst and the second spent catalyst, the particle size and density of the first catalyst are both larger than the particle size and density of the second catalyst.

[0027] Optionally, the first catalyst contains 60-100% by mass of heavy oil catalyst and 0-40% by mass of light oil catalyst; the second catalyst contains 0-40% by mass of heavy oil catalyst and 60-100% by mass of light oil catalyst.

[0028] Preferably, the first catalyst contains 80-100 mass % of heavy oil catalyst and 0-20 mass % of light oil catalyst; the second catalyst contains 0-20 mass % of heavy oil catalyst and 80-100 mass % of light oil catalyst.

[0029] Wherein, optionally, the heavy oil catalyst comprises unmodified Y-type molecular sieve or modified Y-type molecular sieve, clay and binder. Wherein, based on the total weight of the heavy oil catalyst, the content of unmodified Y-type molecular sieve or modified Y-type molecular sieve is 10-80%, preferably 30-60%, the content of clay is 10-80%, preferably 15-60%, and the content of binder is 10-30%, preferably 10-20%. The particle size range of the heavy oil catalyst is 60-250 μm, preferably 80-200 μm, and the particle density is 1200-1600 kg / m 3 , preferably 1300~1500kg / m 3 The unmodified Y-type molecular sieve or modified Y-type molecular sieve may be selected from one or more of HY, USY, REUSY, REY, REHY, DASY, and REDASY, or a Y-type molecular sieve treated with various metal oxides. The clay may be selected from various clays that can be used as catalyst components, such as kaolin, montmorillonite, and bentonite. The binder may be selected from one or a mixture of two or three of silica sol, alumina sol, and pseudo-boehmite, wherein the preferred binder is a bialuminum binder of alumina sol and pseudo-boehmite.

[0030] Optionally, the light oil catalyst comprises unmodified ZSM-5 molecular sieve or modified ZSM-5 molecular sieve, clay and a binder.

[0031] Optionally, based on the total weight of the catalyst, the content of unmodified ZSM-5 molecular sieve or modified ZSM-5 molecular sieve is 10-60%, preferably 20-50%, the content of clay is 10-80%, preferably 20-70%, and the content of binder is 10-30%, preferably 10-20%. The modified ZSM-5 molecular sieve is, for example, selected from one or more of ZRP zeolite, phosphorus-containing ZRP zeolite, rare earth-containing ZRP zeolite, phosphorus- and rare earth-containing ZRP zeolite, phosphorus- and alkaline earth metal-containing ZRP zeolite, and phosphorus- and transition metal-containing ZRP zeolite, preferably phosphorus- and rare earth-containing ZRP zeolite. The clay is selected from various clays that can be used as catalyst components, such as kaolin, montmorillonite, bentonite, etc. The binder is selected from one or a mixture of two or three of silica sol, alumina sol, and pseudo-boehmite, wherein the preferred binder is a bialuminum binder of alumina sol and pseudo-boehmite.

[0032] Optionally, the particle size of the light oil catalyst is in the range of 10 to 100 μm, preferably 30 to 80 μm, and the particle density is 800 to 1200 kg / m 3 , preferably 900~1100kg / m 3 .

[0033] Among them, optionally, the first regeneration zone and the second regeneration zone are arranged in series, the first regeneration zone adopts incomplete regeneration, and the second regeneration zone adopts complete regeneration, and the incompletely regenerated flue gas generated in the first regeneration zone is introduced into the second regeneration zone to continue the regeneration reaction.

[0034] Optionally, the regeneration temperature of the first regeneration zone is 640-700°C, preferably 660-680°C, and the catalyst distribution density is 50-400 kg / m 3 , preferably 100~300kg / m 3 The main wind residence time is 0.5 to 20 seconds, preferably 2 to 10 seconds.

[0035] Optionally, the regeneration temperature of the second regeneration zone is 670-730°C, preferably 690-710°C, and the catalyst distribution density is 30-350 kg / m 3 , preferably 80~250kg / m 3 The main wind residence time is 0.5 to 15 seconds, preferably 2 to 10 seconds.

[0036] Optionally, the reaction temperature of the riser reactor is 520-620°C, preferably 540-600°C; the catalyst-oil ratio is 2-25, preferably 3-20; and the reaction time is 1-15 seconds, preferably 2-10 seconds. The heavy feedstock 11 can be preheated to 180-340°C and then sprayed into the riser reactor through a nozzle.

[0037] Optionally, the reaction temperature of the fluidized bed reactor is 540-640°C, preferably 560-620°C, and the catalyst distribution density is 20-300 kg / m 3 , preferably 100-200 kg / m 3 , airspeed is 2~15h -1 , preferably 5 to 10 hours -1 ; The oil and gas residence time is 0.2 to 8 seconds, preferably 1 to 4 seconds.

[0038] Among them, optionally, the heavy raw material is selected from one or a mixture of vacuum wax oil, atmospheric residue oil, vacuum residue oil, coker wax oil, deasphalted oil, furfural refined raffinate oil, coal liquefaction oil, oil sands oil, shale oil, Fischer-Tropsch synthesis distillate oil, animal oil and vegetable oil.

[0039] Optionally, the method further comprises introducing a pre-lift gas into the bottom of the riser reactor, wherein the pre-lift gas may be selected from one or more of water vapor, nitrogen, and dry gas, preferably water vapor.

[0040] The present invention also provides a catalytic conversion system, which is particularly suitable for implementing the method of the present invention as described above. The catalytic conversion system includes a riser reactor, a fluidized bed reactor, a settler, a stripper, a catalyst separation device and a regenerator; the upper end of the riser reactor is connected to the lower end of the fluidized bed reactor; the upper end of the fluidized bed reactor is connected to the lower end of the settler; a gas-solid separation device is also provided in the settler; the lower end of the fluidized bed reactor is also connected to a stripper; the solid material outlet of the gas-solid separation device is provided in the stripper or on the upper part of the stripper; the lower part of the stripper has an outlet for mixed catalyst to be regenerated; the catalyst separation device includes a primary catalyst separator and a secondary catalyst separator, the primary catalyst separator having a material inlet connected to the outlet of the mixed catalyst to be regenerated, a first catalyst inlet connected to the outlet of the mixed catalyst to be regenerated, and a second catalyst inlet connected to the outlet of the mixed catalyst to be regenerated. Catalyst outlet and gas-solid mixture outlet, the secondary catalyst separator has a logistics inlet connected to the gas-solid mixture outlet of the primary catalyst separator, a second catalyst outlet to be regenerated and an oil and gas delivery outlet; a regenerator partition is provided in the regenerator, and the regenerator partition separates the regenerator into a first regeneration zone and a second regeneration zone; a first catalyst delivery connection is provided between the first catalyst outlet to be regenerated and the first regeneration zone; a second catalyst delivery connection is provided between the second catalyst outlet to be regenerated and the second regeneration zone; a first regenerated catalyst delivery connection is provided between the first regeneration zone and the riser reactor; a second regenerated catalyst delivery connection is provided between the second regeneration zone and the fluidized bed reactor.

[0041] Optionally, the catalyst separation device separates the first catalyst from the second catalyst based on a difference between a particle size and a density of the first catalyst and a particle size and a density of the second catalyst.

[0042] Wherein, optionally, a light feedstock oil inlet is further provided at the lower portion of the fluidized bed reactor. The light feedstock oil inlet can be used to introduce light feedstock oil. As an embodiment in which a first regenerated catalyst is transported and connected between the first regeneration zone and the riser reactor, a first catalyst inlet is further provided at the lower portion of the riser reactor, and the first catalyst inlet can be used to introduce fresh first catalyst or regenerated first catalyst. As an embodiment in which a second regenerated catalyst is transported and connected between the second regeneration zone and the fluidized bed reactor, a second catalyst inlet is further provided at the lower portion of the fluidized bed reactor, and the second catalyst inlet can be used to introduce fresh second catalyst or regenerated second catalyst.

[0043] Among them, optionally, the catalyst separator is a combination of one or more of a cyclone type quick separator, a three-leaf quick separator, a catapult type quick separator, a U-tube type separator and a wall-cutting type quick separator, preferably a cyclone type quick separator; the number of the catalyst separators connected to the outside of each settler is one or more; and the multiple catalyst separators are connected in series and / or in parallel.

[0044] In one embodiment, reference Figure 1 The stripper is externally connected to a first-level catalyst separator, the lower part of the first-level catalyst separator is provided with an outlet for the first catalyst to be regenerated, and the upper part of the first-level catalyst separator is provided with an outlet for a mixed material; the outlet for the mixed material is connected to the material inlet of the second-level catalyst separator; the upper part of the second-level catalyst separator is provided with an outlet for residual reaction oil and gas, and the lower part of the second-level catalyst separator is provided with an outlet for a second catalyst to be regenerated.

[0045] In one embodiment, the catalytic conversion system includes a riser reactor 1, a stripper 2, a fluidized bed reactor 3, a settler 4, and a cyclone separator 22. The outlet of the riser reactor 1 is connected to the inlet of the fluidized bed reactor 3, the lower portion of the fluidized bed reactor 3 is connected to the stripper 2, and the upper portion of the fluidized bed reactor 3 is connected to the settler 4. The inlet of the cyclone separator 22 is located above the settler 4. The catalyst outlet of the cyclone separator 22 is positioned so that the catalyst therein can enter the stripper 2. The oil and gas outlet of the cyclone separator 22 is connected to the oil and gas separation system. The catalytic conversion system also includes a primary catalyst separator 16 and a secondary catalyst separator 19. The inlet of the primary catalyst separator 16 is connected to the stripper 2 via a spent catalyst delivery pipe 15. The first spent catalyst outlet of the primary catalyst separator 16 is connected to the first regeneration zone 5 via a first spent catalyst delivery pipe 17. The mixed material outlet of the primary catalyst separator 16 is connected to the inlet of the secondary catalyst separator 19 via an oil-agent mixture delivery pipe 18. The second spent catalyst outlet of the secondary catalyst separator 19 is connected to the second regeneration zone 6 via a second spent catalyst delivery pipe 20. The residual oil and gas outlet of the secondary catalyst separator 19 is connected to the settler 4 via an oil and gas delivery pipe 21. The catalyst delivery rate can be adjusted by valves on the catalyst delivery pipes. The catalytic converter also includes a first regeneration zone 5 and a second regeneration zone 6, which are arranged in series with a regenerator partition 28 disposed therebetween. The incompletely regenerated flue gas generated in the first regeneration zone 5 is introduced into the second regeneration zone 6 for continued regeneration. The resulting regenerated flue gas 31 is separated from the catalyst carried by a cyclone separator 29 and then drawn out through a gas collection chamber 30 into a subsequent flue gas treatment system. The first regeneration agent outlet of the first regeneration zone 5 is connected to the bottom of the riser reactor 1 via a first regeneration agent delivery pipe 26, while the second regeneration agent outlet of the second regeneration zone 6 is connected to the bottom of the fluidized bed reactor 2 via a second regeneration agent delivery pipe 27. The catalyst delivery rate can be adjusted using valves on the catalyst delivery pipes.

[0046] According to a particularly preferred embodiment of the present invention, in the present invention, the heavy feedstock oil 11 is preheated to 180-340°C and then sprayed into the riser reactor 1 through a nozzle. The reaction temperature is 520-620°C, preferably 540-600°C; the catalyst-oil ratio is 2-25, preferably 3-20; and the reaction time is 1-15 seconds, preferably 2-10 seconds. The first catalyst-oil mixture is introduced into the bottom of the riser reactor 1 through the first regeneration agent delivery pipe 26 for reaction. The reacted first catalyst-oil mixture is introduced into the fluidized bed reactor 3 at a reaction temperature of 540-640°C, preferably 560-620°C, and a catalyst density of 20-300 kg / m 3 , preferably 100-200 kg / m 3 , airspeed is 2~15h -1 , preferably 5 to 10 hours-1 . The oil and gas residence time is 0.2 to 8 seconds, preferably 1 to 4 seconds, and is contacted with the second catalyst introduced into the fluidized bed reactor 3 through the second regeneration agent delivery pipe 27 for reaction. The second oil agent mixture after the reaction is separated by a cyclone separator 22, and the reaction oil and gas 24 obtained is collected by the gas collecting chamber 23 and introduced into the subsequent product separation system. The obtained regenerated agent is introduced into the stripper 2 for stripping, and the mixed regenerated catalyst after stripping is introduced into the primary catalyst separator 16 through the regenerated agent delivery pipe 15. The first regenerated agent obtained by separation is introduced into the first regeneration zone 5 through the first regenerated agent delivery pipe 17, and the regeneration temperature is 640 to 700 ° C, preferably 660 to 680 ° C, and the catalyst density is 50 to 400 kg / m 3 , preferably 100~300kg / m 3 The main air residence time is 0.5 to 20 seconds, preferably 2 to 10 seconds, and the main air 25 introduced into the first regeneration zone 5 is contacted to carry out regeneration reaction. Incomplete regeneration is carried out in the first reaction zone 5. The obtained incompletely regenerated flue gas is introduced into the second reaction zone 6 through the regeneration baffle 28. The obtained first regenerated agent is introduced into the bottom of the riser reactor 1 through the first regenerated agent delivery pipe 26 for recycling. The mixed material separated by the first catalyst separator 16 is introduced into the second catalyst separator 19 through the gas-solid mixture delivery pipe 18. The separated second spent agent is introduced into the second regeneration zone 6 through the second spent agent delivery pipe 20. The regeneration temperature is 670 to 730 ° C, preferably 690 to 710 ° C, and the catalyst density is 30 to 350 kg / m 3 , preferably 80~250kg / m 3 The main air residence time is 0.5 to 15 seconds, preferably 2 to 10 seconds, and the incompletely regenerated flue gas from the first regeneration zone 5 contacts and undergoes a regeneration reaction. Complete regeneration occurs in the second reaction zone 6. The resulting completely regenerated flue gas 31 is separated from the catalyst carried by the cyclone separator 29, collected by the gas collection chamber 30, and introduced into the regeneration flue gas treatment system. The resulting second regenerated agent is introduced into the bottom of the fluidized bed reactor 2 through the second regenerated agent delivery pipe 27 for recycling. The residual oil and gas separated by the secondary catalyst separator 19 is introduced into the settler 4 through the oil and gas delivery pipe 21, mixed with the reaction oil and gas 24, and introduced into the subsequent product separation system. The reaction oil and gas 24 enters the subsequent product separation system. In the product separation system, the catalytic cracking products are separated into dry gas, cracked gas, gasoline, light oil, and slurry oil. After subsequent product separation and refining, the cracked gas can produce a mixture of polymerization-grade propylene and C4-C8 hydrocarbons. The stripping steam in the stripper 2 can directly enter the settler 4, and after being separated together with other oil and gas by the cyclone separator 22, it is led out of the settler by the reaction oil and gas 24.

[0047] Three catalysts were used in the examples and comparative examples, namely GOR-II catalyst, RAG-6 catalyst and DMMC-2 catalyst, all of which are commercial catalysts produced by the Qilu Branch of Sinopec Catalyst Company. The specific properties of the three catalysts are shown in Table 1. Among them, GOR-II is a catalyst containing 40% by weight of Y molecular sieve, RAG-6 is a catalyst containing 35% by weight of ZSM-5 molecular sieve, and DMMC-2 is a catalyst containing 15% by weight of Y molecular sieve and 15% by weight of ZSM-5 molecular sieve. Before the test, the catalyst was aged for 17 hours at 800°C and 100% water vapor. The raw oil used in the examples and comparative examples is wax oil, and its specific properties are shown in Table 2.

[0048] Table 1 Composition and properties of catalysts

[0049] Catalyst GOR-II RAG-6 DMMC-2 Chemical composition, % (w) <![CDATA[Al2O3]]> 57.5 51.2 48.1 <![CDATA[SiO2]]> 36.1 43.1 46 BET total analysis <![CDATA[BET总面积 / (m 2 ·g -1 )]]> 181.000 197.000 102.491 Micropore area / (m 2 ·g -1 )]]> 104.000 98.000 49.601 <![CDATA[总孔体积 / (cm 3 ·g -1 )]]> 0.2240 0.1500 0.1057 <![CDATA[微孔体积 / (cm 3 ·g -1 )]]> 0.0340 0.0450 0.0259 <![CDATA[颗粒密度 / (kg·m -3 )]]> 1352 965 987 Particle size distribution, % (w) 0-20 μm 0.1 0.5 0.1 0-40 μm 5.1 32.6 17 0-80 μm 20.3 87.3 70.9 0-105 μm 50.6 98.5 87.8 > 105 μm 49.4 1.5 12.2

[0050] Table 2 Composition and properties of wax oil

[0051] Item Wax oil <![CDATA[密度(20℃) / (kg / m 3 )]]> 856.5 Residual carbon mass fraction, % 0.12 Elemental mass composition, % C 86.12 H 13.47 S 0.85 N 0.41 Mass group composition, % Saturated hydrocarbons 83.4 Aromatic hydrocarbons 14.7 Gel 1.9 Asphaltene <0.1 Mass metal composition, (mg / kg) Fe 1.9 Ni 8.0 V 9.5 Na 3.1 Ca 1.8 Distillation range, °C Initial boiling point 284 10％ 342 30％ 390 50％ 420 70％ 449 90％ 497 Final boiling point 526

[0052] Example 1-2

[0053] The test Figure 1 The process was carried out in the apparatus shown. This apparatus comprises a riser reactor and a fluidized bed reactor. The riser reactor has an inner diameter of 16 mm and a length of 3200 mm, while the fluidized bed reactor has an inner diameter of 64 mm and a height of 500 mm. Preheated feedstock oil and a first catalyst enriched in GOR-II catalyst are introduced into the bottom of the riser reactor, where they undergo contact and reaction. The resulting oil-catalyst mixture is then introduced into the fluidized bed reactor, where it contacts and reacts with a second catalyst enriched in RAG-6 catalyst. The reacted oil-catalyst mixture is separated in a cyclone separator, and the catalyst is stripped in a stripper before being introduced into a two-stage catalyst separator, where it is separated into a first spent catalyst enriched in GOR-II catalyst and a second spent catalyst enriched in RAG-6 catalyst. The two spent catalysts are introduced into the first and second regeneration zones, respectively. The regenerated catalysts are returned to the riser reactor and fluidized bed reactor for recycling, and the oil and gas are introduced into a fractionation system for separation. Reaction conditions and results are shown in Table 3.

[0054] Comparative Example 1

[0055] The experimental apparatus used in this comparative example included a riser reactor and a fluidized bed reactor. The riser reactor had an inner diameter of 16 mm and a length of 3200 mm, while the fluidized bed reactor had an inner diameter of 64 mm and a height of 500 mm. Preheated crude oil and DMMC-2 catalyst were introduced into the bottom of the riser reactor, where they contacted and reacted. The resulting oil-agent mixture was then introduced into the fluidized bed reactor for further reaction. The oil-agent mixture was separated in a cyclone separator, and the catalyst then entered a stripper and a regenerator for regeneration. The regenerated catalyst was returned to the riser reactor for recycling, and the oil and gas were introduced into a fractionation system for separation. Reaction conditions and results are shown in Table 3.

[0056] Comparative Example 2

[0057] The experimental apparatus used in this comparative example includes a riser reactor and a fluidized bed reactor. The riser reactor has an inner diameter of 16 mm and a length of 3200 mm, while the fluidized bed reactor has an inner diameter of 64 mm and a height of 500 mm. The preheated feedstock oil and a mixed catalyst of GOR-II catalyst and RAG-6 catalyst in a mass ratio of 1:1 are introduced into the bottom of the riser reactor. The two are contacted and reacted in the riser reactor. The oil-agent mixture after the reaction is introduced into the fluidized bed reactor for further reaction. The oil-agent mixture after the reaction is separated by a cyclone separator. The catalyst enters the stripper and then the regenerator for regeneration. The regenerated catalyst is returned to the riser reactor for recycling, and the oil and gas are introduced into the fractionation system for separation. The reaction conditions and results are shown in Table 3.

[0058] Table 3 Reaction conditions and results of Examples 1-2 and Comparative Examples 1-2

[0059]

[0060]

[0061] As can be seen from Table 3, the method and apparatus provided by the present invention can increase the yield of light olefins such as ethylene and propylene.

[0062] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0063] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0064] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A catalytic conversion method for producing light olefins, characterized in that: The catalytic conversion method comprises the following steps: S1. contacting the heavy feedstock with a first catalyst in a riser reactor to perform a first catalytic conversion reaction to obtain a first oil agent mixture; S2. introducing the first oil mixture into a fluidized bed reactor to contact with a second catalyst to perform a second catalytic conversion reaction to obtain a second oil mixture; S3, subjecting the second oil agent mixture to gas-solid separation and stripping in a settler to obtain an oil and gas product and a mixed spent catalyst; S4, introducing the mixed spent catalyst into a catalyst separation device for separation to obtain a first spent catalyst and a second spent catalyst, wherein the catalyst separation device includes a primary catalyst separator and a secondary catalyst separator; S5, introducing the first catalyst to be regenerated into the first regeneration zone for the first regeneration and then returning to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and introducing the second catalyst to be regenerated into the second regeneration zone for the second regeneration and then returning to step S2 as the second catalyst to participate in the second catalytic conversion reaction; The particle size and density of the first catalyst are both greater than the particle size and density of the second catalyst; The first catalyst contains 60-100% by mass of heavy oil catalyst and 0-40% by mass of light oil catalyst; the second catalyst contains 0-40% by mass of heavy oil catalyst and 60-100% by mass of light oil catalyst; The heavy oil catalyst comprises an unmodified Y-type molecular sieve or a modified Y-type molecular sieve, clay, and a binder; based on the total weight of the heavy oil catalyst, the content of the unmodified Y-type molecular sieve or the modified Y-type molecular sieve is 10-80%, the content of the clay is 10-80%, and the content of the binder is 10-30%; The light oil catalyst comprises unmodified ZSM-5 molecular sieve or modified ZSM-5 molecular sieve, clay and a binder; based on the total weight of the light oil catalyst, the content of the unmodified ZSM-5 molecular sieve or modified ZSM-5 molecular sieve is 10-60%, the content of the clay is 10-80%, and the content of the binder is 10-30%.

2. The catalytic conversion method according to claim 1, wherein: The first catalyst contains 80-100% by mass of heavy oil catalyst and 0-20% by mass of light oil catalyst; the second catalyst contains 0-20% by mass of heavy oil catalyst and 80-100% by mass of light oil catalyst.

3. The catalytic conversion method according to claim 2, wherein: Based on the total weight of the heavy oil catalyst, the content of unmodified Y-type molecular sieve or modified Y-type molecular sieve is 30-60%, the content of clay is 15-60%, and the content of binder is 10-20%; The particle size of the heavy oil catalyst is in the range of 60 to 250 μm, and the particle density is in the range of 1200 to 1600 kg / m 3 .

4. The catalytic conversion method according to claim 3, wherein: The particle size of the heavy oil catalyst is in the range of 80 to 200 μm, and the particle density is in the range of 1300 to 1500 kg / m 3 .

5. The catalytic conversion method according to claim 2 or 3, wherein: Based on the total weight of the light oil catalyst, the content of unmodified ZSM-5 molecular sieve or modified ZSM-5 molecular sieve is 20-50%, the content of clay is 20-70%, and the content of binder is 10-20%. The particle size of the light oil catalyst is in the range of 10 to 100 μm, and the particle density is in the range of 800 to 1200 kg / m 3 .

6. The catalytic conversion method according to claim 5, wherein: The particle size of the light oil catalyst is in the range of 30 to 80 μm, and the particle density is in the range of 900 to 1100 kg / m 3 .

7. The catalytic conversion method according to claim 1, wherein: The first regeneration zone and the second regeneration zone are arranged in series. The first regeneration zone adopts incomplete regeneration, and the second regeneration zone adopts complete regeneration. The incompletely regenerated flue gas generated in the first regeneration zone is introduced into the second regeneration zone to continue the regeneration reaction.

8. The catalytic conversion method according to claim 1, wherein: The regeneration temperature of the first regeneration zone is 640-700°C, and the catalyst distribution density is 50-400 kg / m 3 , the main wind stay time is 0.5~20s; The regeneration temperature of the second regeneration zone is 670-730°C, and the catalyst distribution density is 30-350 kg / m 3 , the main wind stay time is 0.5~15s.

9. The catalytic conversion method according to claim 8, wherein: The regeneration temperature of the first regeneration zone is 660-680°C, and the catalyst distribution density is 100-300 kg / m 3 , the main wind stay time is 2 to 10 seconds; The regeneration temperature of the second regeneration zone is 690-710°C, and the catalyst distribution density is 80-250 kg / m 3 , the main wind stay time is 2 to 10s.

10. The catalytic conversion method according to claim 1, wherein: The reaction temperature of the riser reactor is 520-620°C; the catalyst-oil ratio is 2-25; and the reaction time is 1-15 seconds. The reaction temperature of the fluidized bed reactor is 540-640°C, and the catalyst distribution density is 20-300 kg / m 3 , airspeed is 2~15h -1 ; The oil and gas residence time is 0.2 to 8 seconds.

11. The catalytic conversion method according to claim 10, wherein: The reaction temperature of the riser reactor is 540-600°C; the catalyst-oil ratio is 3-20; and the reaction time is 2-10 seconds. The reaction temperature of the fluidized bed reactor is 560-620°C, and the catalyst distribution density is 100-200 kg / m 3 , airspeed is 5~10h -1 ; The oil and gas residence time is 1 to 4 seconds.

12. The catalytic conversion method according to claim 1, wherein: The heavy raw material is selected from one or a mixture of two or more of vacuum wax oil, atmospheric residue oil, vacuum residue oil, coker wax oil, deasphalted oil, furfural refined raffinate oil, coal liquefaction oil, oil sand oil, shale oil, Fischer-Tropsch synthesis distillate oil, animal oil and vegetable oil.

13. A catalytic conversion system for the catalytic conversion method according to any one of claims 1 to 12, characterized in that: The catalytic conversion system comprises a riser reactor, a fluidized bed reactor, a settler, a stripper, a catalyst separation device and a regenerator; the upper end of the riser reactor is connected to the lower end of the fluidized bed reactor; The upper end of the fluidized bed reactor is connected to the lower end of the settler; the settler is also provided with a gas-solid separation device; The lower end of the fluidized bed reactor is also connected to a stripper; the solid material outlet of the gas-solid separation device is arranged in the stripper or on the upper part of the stripper; the lower part of the stripper has an outlet for mixed catalyst to be produced; The catalyst separation device includes a primary catalyst separator and a secondary catalyst separator, wherein the primary catalyst separator has a material inlet connected to the outlet of the mixed catalyst to be regenerated, a first catalyst outlet to be regenerated, and a gas-solid mixture outlet, and the secondary catalyst separator has a logistics inlet connected to the gas-solid mixture outlet of the primary catalyst separator, a second catalyst outlet to be regenerated, and an oil and gas delivery outlet; A regenerator partition is provided in the regenerator, which divides the regenerator into a first regeneration zone and a second regeneration zone; a first regenerated catalyst delivery connection is provided between the first regenerated catalyst outlet and the first regeneration zone; a second regenerated catalyst delivery connection is provided between the second regenerated catalyst outlet and the second regeneration zone; a first regenerated catalyst delivery connection is provided between the first regeneration zone and the riser reactor; and a second regenerated catalyst delivery connection is provided between the second regeneration zone and the fluidized bed reactor.

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