A catalytic conversion process and system for producing ethylene and propylene

Abstract

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

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and in particular to a catalytic conversion method and system for producing ethylene and propylene. Background Art

[0002] Ethylene, propylene, and other low-carbon olefins are essential chemical raw materials, currently primarily derived from processes such as steam cracking and catalytic cracking. Steam cracking generally uses light raw materials, while catalytic cracking can use heavy raw materials.

[0003] For example, CN1031834A discloses a catalytic conversion method for producing light olefins. This method uses petroleum fractions, residual oil or crude oil of different boiling ranges as raw materials, a mixture containing Y zeolite and pentacyclic high-silicon zeolite as catalyst, and a fluidized bed or moving bed as a reactor. The reaction conditions are: temperature 500-650°C, pressure 0.15-0.30 MPa, and weight hourly space velocity 0.2-20 h / min. -1 The catalyst-oil ratio is 2 to 12. The catalyst after the reaction is burned and regenerated and then returned to the reactor for recycling.

[0004] However, the yield of light olefins in the existing catalytic cracking process is not high and it is difficult to meet the demand. Therefore, it is necessary to further improve the yield of light olefins prepared by catalytic cracking. Summary of the Invention

[0005] The purpose of the present invention is to further improve the yield of light olefins prepared by catalytic cracking.

[0006] In order to achieve the above-mentioned object, the present invention provides a catalytic conversion method for producing ethylene and propylene, which comprises the following steps: S1, contacting a heavy feedstock oil with a first catalyst in a first fast bed 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 second fast 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, introducing the second oil-agent mixture into a catalyst separation device for separation to obtain a first spent catalyst and a third oil-agent mixture; S4, further subjecting the third oil-agent mixture to gas-solid separation to obtain an oil and gas product and a second spent catalyst; S5, subjecting the first spent catalyst to a first stripping and 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 stripping and a second regeneration, and then returning it 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 first fast bed reactor, a second fast bed reactor, a settler and a regenerator; the upper end of the first fast bed reactor is connected to the lower end of the second fast bed reactor; the settler is provided with a settler partition and a catalyst separator, and the settler partition separates the settler into a first settling zone and a second settling zone; the material inlet of the catalyst separator is connected to the upper end of the second fast bed reactor, and the catalyst separator further has a first material outlet opened in the first settling zone and a second material outlet opened in the second settling zone; the lower part of the first settling zone is provided with a first stripper, and the second A second stripper is provided outside the settling zone; 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 to be regenerated is connected to the first stripper and the first regeneration zone; a second catalyst to be regenerated is connected to the second stripper and the second regeneration zone; a first regenerated catalyst is connected to the first regeneration zone and the first fast bed reactor; a second regenerated catalyst is connected to the second regeneration zone and the second fast bed reactor; a first stripper is provided at the lower part of the first settling zone, and a second stripper is provided in the second catalyst to be regenerated connection.

[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-First fast bed reactor 2-Second fast bed reactor 3-First settling zone

[0015] 4-First stripper 5-Second settling zone 6-Second stripper

[0016] 7-First regeneration zone 8-Second regeneration zone

[0017] 11-Heavy raw material 12-Pre-lift gas 13-Oil agent mixture delivery pipe

[0018] 14-Catalyst separator 15-Settler baffle 16, 21-Stripping gas

[0019] 17, 22- baffles 19, 23- stripping oil and gas

[0020] 18-First catalyst delivery pipe

[0021] 20, 27- Second catalyst delivery pipe

[0022] 24, 32- cyclone separator 25, 33- gas collecting chamber

[0023] 26-reaction oil and gas 28-main air 29-first regeneration agent delivery pipe

[0024] 30-Second regeneration agent delivery pipe 31-Regenerator partition 34-Regeneration flue gas DETAILED DESCRIPTION

[0025] 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.

[0026] refer to Figure 1 The present invention provides a catalytic conversion method for producing ethylene and propylene, which comprises the following steps: S1, contacting heavy feedstock oil with a first catalyst in a first fast bed 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 second fast 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, introducing the second oil-agent mixture into a catalyst separation device for separation to obtain a first spent catalyst and a third oil-agent mixture; S4, further performing gas-solid separation on the third oil-agent mixture to obtain an oil and gas product and a second spent catalyst; S5, performing a first stripping and a first regeneration on the first spent catalyst, and then returning it to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and performing a second stripping and a second regeneration on the second spent catalyst, and then returning it to step S2 as the second catalyst to participate in the second catalytic conversion reaction.

[0027] In the present application, the material (including the first catalyst and reaction oil gas and fluidization medium) that has undergone the first catalytic conversion in the first fast bed reactor is not separated and is all introduced into the second fast bed reactor to contact the second catalyst to perform the second catalytic conversion reaction, that is, the first catalytic conversion reaction and the second catalytic conversion reaction can be performed in succession.

[0028] 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 greater than the particle size and density of the second catalyst.

[0029] Optionally, the first catalyst contains 60-100% by mass of a heavy oil catalyst and 0-40% by mass of a light oil catalyst; and the second catalyst contains 0-40% by mass of a heavy oil catalyst and 60-100% by mass of a light oil catalyst.

[0030] Preferably, the first catalyst contains 80-100% by mass of a heavy oil catalyst and 0-20% by mass of a light oil catalyst; and the second catalyst contains 0-20% by mass of a heavy oil catalyst and 80-100% by mass of a light oil catalyst.

[0031] Optionally, the heavy oil catalyst contains unmodified Y-type molecular sieve or modified Y-type molecular sieve, clay and binder. The content of the unmodified Y-type molecular sieve or modified Y-type molecular sieve is 10-80%, preferably 30-60%, the content of the clay is 10-80%, preferably 15-60%, and the content of the binder is 10-30%, preferably 10-20%, based on the total weight of the heavy oil catalyst. The particle size of the heavy oil catalyst is 60-250 μm, preferably 80-200 μm, and the particle density is 1200-1600 kg / m 3 , preferably 1300-1500 kg / m 3 . The unmodified Y-type molecular sieve or modified Y-type molecular sieve can be selected from one or more of HY, USY, REUSY, REY, REHY, DASY, REDASY, or Y-type molecular sieve treated with various metal oxides. 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 two or a mixture of three of silica sol, alumina sol and pseudo-boehmite, and the preferred binder is a double aluminum binder of alumina sol and pseudo-boehmite.

[0032] Optionally, the light oil catalyst contains unmodified ZSM-5 molecular sieve or modified ZSM-5 molecular sieve, clay and binder.

[0033] 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.

[0034] 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 .

[0035] Among them, optionally, the first regeneration and the second regeneration are carried out in the first regeneration zone and the second regeneration zone of the regenerator respectively; 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.

[0036] 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.

[0037] 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.

[0038] Optionally, the reaction temperature of the first fast bed 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 first fast bed reactor through a nozzle.

[0039] Wherein, optionally, the reaction temperature of the second fast bed reactor is 540-640°C, preferably 560-620°C, the catalyst-oil ratio is 3-30, preferably 5-25; and the reaction time is 1-10 seconds, preferably 2-8 seconds.

[0040] 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.

[0041] Optionally, the method further comprises introducing a pre-lift gas into the bottom of the first fast bed reactor, wherein the pre-lift gas can be selected from one or more of water vapor, nitrogen, and dry gas, preferably water vapor.

[0042] The present invention also provides a catalytic conversion system, which includes a first fast bed reactor, a second fast bed reactor, a settler and a regenerator; the upper end of the first fast bed reactor is connected to the lower end of the second fast bed reactor; the settler is provided with a settler partition and a catalyst separator, and the settler partition separates the settler into a first settling zone and a second settling zone; the material inlet of the catalyst separator is connected to the upper end of the second fast bed reactor, and the catalyst separator further has a first material outlet opened in the first settling zone and a second material outlet opened in the second settling zone; the lower part of the first settling zone is provided with a first stripper, and the second A second stripper is provided outside the settling zone; 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 to be regenerated is connected to the first stripper and the first regeneration zone; a second catalyst to be regenerated is connected to the second stripper and the second regeneration zone; a first regenerated catalyst is connected to the first regeneration zone and the first fast bed reactor; a second regenerated catalyst is connected to the second regeneration zone and the second fast bed reactor; a first stripper is provided at the lower part of the first settling zone, and a second stripper is provided in the second catalyst to be regenerated connection.

[0043] 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.

[0044] Optionally, a light feedstock oil inlet is further provided at the lower portion of the second fast 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 first fast bed reactor, a first catalyst inlet is further provided at the lower portion of the first fast bed reactor. 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 second fast bed reactor, a second catalyst inlet is further provided at the lower portion of the second fast bed reactor. The second catalyst inlet can be used to introduce fresh second catalyst or regenerated second catalyst.

[0045] 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 arranged in each of the settlers is one or more; and the multiple catalyst separators are connected in series and / or in parallel.

[0046] As a particularly preferred embodiment of the present invention, the catalytic conversion system includes a first fast bed reactor 1, a second fast bed reactor 2, a settler, and a regenerator; the settler is provided with a first settling zone 3 and a second settling zone 5. The outlet of the first fast bed reactor 1 is connected to the inlet of the second fast bed reactor 2, which is connected to the catalyst separator 14 within the settler. The inlet of the cyclone separator 24 is located above the second settling zone 5. The catalyst outlet of the cyclone separator 24 is positioned so that the catalyst therein can enter the second settling zone 5. The oil and gas outlet of the cyclone separator 24 is connected to the oil and gas separation system. The catalyst separator 14 is located inside the settler, and the settler is divided into a first settling zone 3 and a second settling zone 5 by a settler partition 15. The first outlet for the regenerated catalyst of the catalyst separator 14 is located in the first settling zone 3, and the second outlet for the regenerated catalyst is located in the second settling zone 5. The first settling zone 3 is connected to the first stripping zone 4, so that the first regenerated catalyst is stripped in the first stripping zone 4 and then introduced into the first regeneration zone 7 through the first regenerated catalyst delivery pipe 18 for regeneration. The second settling zone 5 is connected to the second stripping zone 6, so that the second regenerated catalyst is stripped in the second stripping zone 6 and then introduced into the second regeneration zone 8 through the second regenerated catalyst delivery pipe 27 for regeneration. A cyclone separator 24 is also provided inside the settler for separating the catalyst entrained in the reaction oil and gas, and the resulting reaction oil and gas 26 is led out of the device. The catalyst delivery speed can be adjusted by a valve on the catalyst delivery pipe. The catalytic conversion system also includes a first regeneration zone 7 and a second regeneration zone 8, which are arranged in series with a regenerator partition 31 disposed therebetween. The incompletely regenerated flue gas generated in the first regeneration zone 7 is introduced into the second regeneration zone 8 for further regeneration. The resulting regenerated flue gas 34 is separated from the catalyst carried by a cyclone separator 32 and then drawn out through a gas collection chamber 33 to enter a subsequent flue gas treatment system. The first regeneration agent outlet of the first regeneration zone 7 is connected to the bottom of the first fast bed reactor 1 via a first regeneration agent delivery pipe 29, and the second regeneration agent outlet of the second regeneration zone 8 is connected to the bottom of the second fast bed reactor 2 via a second regeneration agent delivery pipe 30. The catalyst delivery rate can be adjusted using valves on the catalyst delivery pipes.

[0047] As a particularly preferred embodiment of the present invention, the heavy feedstock 11 is preheated to 180-340°C and then sprayed into the first fast bed 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 first fast bed reactor 1 through the first regeneration agent delivery pipe 29 for contact reaction. The reacted first oil-agent mixture is introduced into the second fast bed reactor 2 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 the second catalyst introduced into the second fast bed reactor 2 through the second regeneration agent delivery pipe 30 is contacted and reacted. The reacted second oil-agent mixture is introduced into the catalyst separator 14 and separated into the first spent catalyst and the third oil-agent mixture. The first spent catalyst is introduced into the first stripping zone 4 via the first settling zone 3 for stripping. The stripped first spent catalyst is introduced into the first regeneration zone 7 via the first spent catalyst delivery pipe 18 for regeneration. The regenerated first catalyst is introduced into the bottom of the first fast bed reactor 1 via the first catalyst delivery pipe 29. The third oil-agent mixture is separated in the cyclone separator 24 in the second settling zone 5 to produce an oil and gas product and a second spent catalyst. The second spent catalyst is introduced into the second stripping zone 6 via the second settling zone 5 for stripping. The stripped second spent catalyst is introduced into the second regeneration zone 8 via the second spent catalyst delivery pipe 27 for regeneration. The regenerated second catalyst is introduced into the bottom of the second fast bed reactor 2 via the second catalyst delivery pipe 30. The main air 28 is introduced into the first regeneration zone 7, and the regeneration temperature is 640-700°C, preferably 660-680°C, and the catalyst density is 50-400 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 is brought into contact with the first catalyst to be regenerated in the first regeneration zone 7 to carry out a regeneration reaction. Incomplete regeneration is carried out in the first regeneration zone 7, and the incompletely regenerated flue gas is introduced into the second regeneration zone 8 through the regeneration baffle 31. 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, under the condition that the main air residence time is 0.5 to 15 seconds, preferably 2 to 10 seconds, it contacts the second catalyst to be regenerated introduced into the second regeneration zone 8 and undergoes a regeneration reaction. The second regeneration zone 8 is fully regenerated, and the obtained fully regenerated flue gas 34 is separated from the carried catalyst by the cyclone separator 32, and then collected by the gas collecting chamber 33 and introduced into the regeneration flue gas treatment system. The reaction oil gas 26 enters the subsequent product separation system. In the product separation system, the catalytic cracking products are separated into products such as dry gas, cracked gas, gasoline, light oil and slurry. After subsequent product separation and refining, the cracked gas can obtain polymerization-grade ethylene product and propylene product and a mixture of C4 to C8 hydrocarbons. The stripping steam and residual oil gas in the first stripping zone 4 and the second stripping zone 6 can directly enter the second settling zone 5, and after being separated by the cyclone separator 24 together with other oil and gas, the reaction oil gas 26 is led out of the settler.

[0048] The present invention is further described in detail below through examples.

[0049] 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 25% 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.

[0050] Table 1 Composition and properties of catalysts

[0051] catalyst GOR-II RAG-6 DMMC-2 Chemical composition, % (w) <![CDATA[Al2O3]]> 57.5 51.2 48.1 SiO2 36.1 43.1 46 BET Full Analysis BET total area / (m 2 ·g -1 )]]> 181.000 197.000 102.491 <![CDATA[微孔面积 / (m 2 ·g -1 )]]> 104.000 98.000 49.601 Total pore volume / (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) 0-20μm 0.1 0.5 0.1 0-40μm 5.1 32.6 17 0-80μm 20.3 87.3 70.9 0-105μm 50.6 98.5 87.8 >105μm 49.4 1.5 12.2

[0052] Table 2 Composition and properties of wax oil

[0053]

[0054]

[0055] Example 1-2

[0056] The experiment Figure 1The reaction was carried out on the apparatus shown. The apparatus comprises two fast-bed reactors, each with a diameter of 40 mm and a length of 1500 mm. Preheated feedstock oil and a first catalyst enriched in GOR-II catalyst were introduced to the bottom of the first reaction zone, where they contacted and reacted. The resulting oil-agent mixture was introduced into the second reaction zone, where it contacted and continued to react with a second catalyst enriched in RAG-6 catalyst. The resulting oil-agent mixture was then introduced into a catalyst separator, where it was separated into a first, GOR-II-rich, spent catalyst and a second, RAG-6-rich, spent catalyst. The two spent catalysts were introduced into the first and second regeneration zones, respectively. The regenerated catalysts were returned to the first and second fast-bed reactors for recycling, and the oil and gas were introduced into a fractionation system for separation. Reaction conditions and results are shown in Table 3.

[0057] Comparative Example 1

[0058] The apparatus used in this comparative example included two fast-bed reactors, each with a diameter of 40 mm and a length of 1500 mm. Preheated feedstock oil and DMMC-2 catalyst were introduced into the bottom of the first fast-bed reactor, where they contacted and reacted. The resulting oil-agent mixture was then introduced into a second fast-bed reactor for further reaction, with additional DMMC-2 catalyst added. The resulting oil-agent mixture was separated in a cyclone separator, and the catalyst then passed through a stripper and then a regenerator for regeneration. The regenerated catalyst was returned to the first fast-bed 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.

[0059] Comparative Example 2

[0060] The device used in this comparative example includes two fast bed reactors, each with a diameter of 40 mm and a length of 1500 mm. The preheated feedstock oil and a mixed catalyst of a GOR-II catalyst and a RAG-6 catalyst in a mass ratio of 1:1 are introduced into the bottom of the first fast bed reactor. The two are contacted and reacted in the first fast bed reactor. The oil mixture after the reaction is introduced into the second fast bed reactor to continue the reaction and the mixed catalyst is added. The oil mixture after the reaction is separated by a cyclone separator. The catalyst enters the stripper and then enters the regenerator for regeneration. The regenerated catalyst returns to the first fast bed reactor for recycling, and the oil and gas are introduced into the fractionation system for separation. Reaction conditions and results are shown in Table 3.

[0061] Table 3 Reaction conditions and results of Examples 1-2 and Comparative Examples 1-2

[0062]

[0063]

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 ethylene and propylene, characterized in that: The catalytic conversion method comprises the following steps: S1. contacting a heavy crude oil with a first catalyst in a first fast bed reactor to perform a first catalytic conversion reaction to obtain a first oil mixture; S2. introducing the first oil mixture into a second fast bed reactor to contact with a second catalyst to perform a second catalytic conversion reaction to obtain a second oil mixture; S3, introducing the second oil agent mixture into a catalyst separation device for separation to obtain a first spent catalyst and a third oil agent mixture; S4, performing gas-solid separation on the third oil mixture to obtain an oil and gas product and a second spent catalyst; S5, performing a first stripping and a first regeneration on the first spent catalyst, and then returning to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and performing a second stripping and a second regeneration on the second spent catalyst, and then returning to step S2 as the second catalyst to participate in the second catalytic conversion reaction; the first regeneration and the second regeneration are respectively performed in the first regeneration zone and the second regeneration zone of the regenerator; 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%. The particle size and density of the first catalyst are both larger than those of the second catalyst.

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 1, 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 first fast bed 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 second fast bed reactor is 540-640° C., the catalyst-oil ratio is 3-30, and the reaction time is 1-10 seconds.

11. The catalytic conversion method according to claim 10, wherein: The reaction temperature of the first fast bed 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 second fast bed reactor is 560-620° C., the catalyst-oil ratio is 5-25, and the reaction time is 2-8 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 producing ethylene and propylene used in the catalytic conversion method according to any one of claims 1 to 12, characterized in that: The catalytic conversion system includes a first fast bed reactor, a second fast bed reactor, a settler and a regenerator; the upper end of the first fast bed reactor is connected to the lower end of the second fast bed reactor; The settler is provided with a settler partition and a catalyst separator, wherein the settler partition divides the settler into a first settling zone and a second settling zone; the material inlet of the catalyst separator is connected to the upper end of the second fast bed reactor, and the catalyst separator further has a first material outlet opened in the first settling zone and a second material outlet opened in the second settling zone; A first stripper is provided at the lower part of the first settling zone, and a second stripper is provided outside the second settling zone; The regenerator is provided with a regenerator partition, which divides the regenerator into a first regeneration zone and a second regeneration zone; a first catalyst to be regenerated is transported and connected between the first stripper and the first regeneration zone; a second catalyst to be regenerated is transported and connected between the second stripper and the second regeneration zone; a first regenerated catalyst is transported and connected between the first regeneration zone and the first fast bed reactor; and a second regenerated catalyst is transported and connected between the second regeneration zone and the second fast bed reactor.

Images