Catalytic cracking method and system

Abstract

The present invention relates to a catalytic conversion method and system. The method comprises the following steps: bringing a heavy hydrocarbon raw material into contact with a first regenerated catalyst in a first reactor so as to undergo a first catalytic conversion reaction, and performing first separation on a first material obtained after the first catalytic conversion reaction, so as to obtain a first catalyst to be regenerated and a first reaction oil gas; feeding a fresh second catalyst into a second reactor, bringing a light hydrocarbon raw material into contact with the second catalyst in the second reactor to undergo a second catalytic conversion reaction, so as to obtain a second material containing the second catalyst and a reaction product, and performing second separation on the second material, so as to obtain a second catalyst to be regenerated and a second reaction oil gas; feeding the first catalyst to be regenerated into a first regenerator to undergo regeneration and feeding the fresh first catalyst into the first regenerator, so as to obtain the first regenerated catalyst, and returning same to the first reactor; and introducing at least part of the second catalyst to be regenerated into the first reactor. The method of the present invention can improve the yields of ethylene and propylene.

Description

Catalytic cracking method and system Technical Field

[0001] The present invention belongs to the field of petroleum processing, and in particular relates to a catalytic cracking method and system for producing more ethylene and propylene. Background Art

[0002] The downstream products of ethylene and propylene involve all areas of the manufacturing industry and play an irreplaceable role in production and life. At present, the main sources of ethylene are steam cracking and catalytic cracking of hydrocarbon oils, while propylene is mainly produced by naphtha cracking. Heavy oil catalytic cracking is an important method for producing light olefins such as ethylene, propylene and butene. Typical processes for producing light olefins by catalytic cracking of heavy oil include the DCC process, CPP process, Maxofin process and PetroFCC process. These processes convert heavy hydrocarbons at a reaction temperature of 500-600°C, while recycling the intermediate C4 component and light hydrocarbons such as pyrolysis gasoline in the secondary reactor, and further cracking at a higher reaction temperature than the heavy hydrocarbon conversion to increase the production of light olefins.

[0003] CN100448954C discloses a catalytic conversion method for increasing propylene production, which first cracks heavy, macromolecular feedstocks in a main riser to produce products such as gasoline, diesel, and liquefied gas; then, the liquefied gas intermediate product, after propylene is separated, is injected into an auxiliary riser reactor and contacted with a hot catalyst, where olefin polymerization, cracking of the polymerization product, and alkane dehydrogenation reactions are successively carried out, and the liquefied gas product after de-propyleneing can be further converted into propylene. CN102690682A discloses a catalytic cracking method for producing propylene, which contacts heavy feedstocks with a first catalytic cracking catalyst containing Y-type zeolite as a primary active component in a first riser reactor for a first reaction, contacts light hydrocarbons with a second catalytic cracking catalyst containing shape-selective zeolite with a pore size of less than 0.7 nm as a primary active component in a second riser reactor for a second reaction, and introduces the oil, gas, and catalyst after the second reaction into a fluidized bed reactor connected in series with the second riser reactor for reaction.

[0004] Although there are catalytic conversion methods for increasing the production of light olefins such as propylene in the prior art, the method of producing ethylene and propylene by catalytic cracking of heavy hydrocarbons still has the problem of low ethylene and propylene yields. Summary of the Invention

[0005] The object of the present invention is to solve the problem of low yield of ethylene and propylene in a method for preparing ethylene and propylene by catalytic conversion of heavy hydrocarbons.

[0006] In order to achieve the above object, a first aspect of the present invention provides a catalytic cracking method, which comprises the following steps:

[0007] The heavy hydrocarbon feedstock is contacted with the first regenerated catalyst in the first reactor to perform a first catalytic conversion reaction, and the first material obtained after the first catalytic conversion reaction is subjected to a first separation to obtain a first spent catalyst and a first reaction oil gas;

[0008] feeding a fresh second catalyst into a second reactor and contacting the light hydrocarbon feedstock with the second catalyst in the second reactor to perform a second catalytic conversion reaction to obtain a second material comprising the second catalyst and a reaction product, and performing a second separation on the second material to obtain a second spent catalyst and a second reaction oil and gas; wherein the fresh second catalyst contains 10 to 80 weight percent of a zeolite having an MFI structure;

[0009] sending the first spent catalyst into a first regenerator for regeneration after stripping and sending a fresh first catalyst into the first regenerator to obtain a first regenerated catalyst and return it to the first reactor; wherein the fresh first catalyst contains 10 to 70 weight percent of Y series zeolite; and

[0010] At least a portion of the second regenerated catalyst is introduced into the first reactor, wherein the mass ratio of the second catalyst introduced into the first reactor to the fresh first catalyst fed into the first regenerator is (1-10):1, preferably (1-6):1.

[0011] Optionally, the method of the first aspect also includes: sending the second catalyst to be regenerated together with the first catalyst to be regenerated into the first regenerator for regeneration to obtain the first regenerated catalyst, and returning the first regenerated catalyst to the first reactor; preferably, the second catalyst to be regenerated together with the first catalyst to be regenerated are stripped in a heavy hydrocarbon stripper, and the stripped second catalyst to be regenerated together with the first catalyst to be regenerated are sent into the first regenerator for regeneration to obtain the first regenerated catalyst, and returning the first regenerated catalyst to the first reactor.

[0012] Optionally, the method of the first aspect further comprises discharging a portion of the second catalyst through a catalyst outlet pipe provided at the lower portion of the second reactor.

[0013] Optionally, in the method of the first aspect, the second reactor is a dense phase fluidized bed.

[0014] Optionally, in the method of the first aspect, the first reactor is a combined riser and fluidized bed reactor, and the method further comprises: feeding the second spent catalyst into the fluidized bed of the first reactor.

[0015] Optionally, the method of the first aspect also includes: sending the second spent catalyst into a light hydrocarbon stripper for stripping to obtain a stripped second catalyst, and sending at least a portion of the stripped second catalyst into the first reactor, and optionally outputting the remaining stripped second catalyst through a catalyst output pipe provided at the lower part of the light hydrocarbon stripper, preferably returning the remaining stripped second catalyst to the second reactor.

[0016] Optionally, in the method of the first aspect, the first reactor is a combined riser and fluidized bed reactor, and the method further includes: sending the second spent catalyst into a light hydrocarbon stripper for stripping to obtain a stripped second catalyst, and sending at least a portion of the stripped second catalyst into the riser of the first reactor, and optionally outputting the remaining stripped second catalyst through a catalyst output pipe provided at the lower part of the light hydrocarbon stripper, and preferably returning the remaining stripped second catalyst to the second reactor.

[0017] Optionally, in the method of the first aspect, the feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second reactor, and the method also includes: feeding the second catalyst to be regenerated into a second regenerator (i.e., a light hydrocarbon regenerator) for regeneration to obtain a regenerated second catalyst, and feeding at least a portion of the regenerated second catalyst into the first reactor, and optionally returning the remaining portion of the regenerated second catalyst to the second reactor.

[0018] Optionally, in the method of the first aspect, the feeding of the fresh second catalyst into the second reactor includes feeding the fresh second catalyst directly into the second regenerator, and the method also includes: feeding the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, and feeding a portion of the regenerated second catalyst into the first reactor, and returning a portion of the regenerated second catalyst to the second reactor.

[0019] Optionally, in the method of the first aspect, the first reactor is a combined riser and fluidized bed reactor, and the feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second reactor, and the method further includes: feeding the second catalyst to be regenerated into a second regenerator for regeneration to obtain a regenerated second catalyst, and feeding at least a portion of the regenerated second catalyst into the riser of the first reactor, and optionally returning the remaining portion of the regenerated second catalyst to the second reactor.

[0020] Optionally, in the method of the first aspect, the first reactor is a combined riser and fluidized bed reactor, and the feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second regenerator, and the method further includes: feeding the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, and feeding a portion of the regenerated second catalyst into the riser of the first reactor, and returning a portion of the regenerated second catalyst to the second reactor.

[0021] Optionally, in the method of the first aspect, the regeneration temperature in the second regenerator is 400-650°C, preferably 450-600°C.

[0022] Optionally, in the method of the first aspect, the carbon mass content on the second spent catalyst is A, the mass ratio of the feed amount of the fresh second catalyst to the feed amount of the light hydrocarbon feedstock is R, and A and R satisfy the following relationship:

[0023] 0.2 / (1+6B) <R / A<10 / (1+2B)

[0024] Wherein, B is the mass content of olefins in the light hydrocarbon feedstock.

[0025] Optionally, the method of the first aspect further comprises detecting the values ​​of A and B over time and adjusting the value of R according to the detected values ​​of A and B so that R / A still satisfies the above relationship.

[0026] Optionally, the method of the first aspect further comprises separating the first reaction oil gas and the second reaction oil gas, and optionally using one or more components obtained by separation as the light hydrocarbon feedstock.

[0027] Optionally, in the method of the first aspect, the regeneration temperature in the first regenerator is 550-750°C, preferably 600-720°C.

[0028] Optionally, the first reactor in the method of the first aspect is selected from one or more of a riser, a fluidized bed, a fast bed and a downcomer; and / or the second reactor is selected from a fluidized bed, preferably a dense phase fluidized bed.

[0029] Optionally, the first reactor in the method of the first aspect is a combined riser and fluidized bed reactor, and the second reactor is a dense phase fluidized bed reactor.

[0030] Optionally, in the method of the first aspect, the mass ratio of the fresh first catalyst feed amount to the heavy hydrocarbon feed amount is (0.0001-0.1):1, preferably (0.0005-0.005):1.

[0031] Optionally, in the method of the first aspect, the mass ratio R of the fresh second catalyst feed amount to the light hydrocarbon feed amount is (0.0004-0.2):1, preferably (0.001-0.1):1.

[0032] Optionally, the fresh first catalyst in the method of the first aspect contains 15 to 70 weight % of the first clay, 15 to 70 weight % of the first inorganic oxide and 10 to 70 weight % of the Y series zeolite; preferably, the fresh first catalyst contains 20 to 70 weight % of the first clay, 20 to 70 weight % of the first inorganic oxide and 10 to 60 weight % of the Y series zeolite.

[0033] Optionally, the fresh second catalyst in the method of the first aspect contains 10 to 80 weight % of a second clay, 10 to 80 weight % of a second inorganic oxide and 10 to 80 weight % of a zeolite having an MFI structure, such as a ZSM series zeolite; preferably, the fresh second catalyst contains 15 to 70 weight % of a second clay, 15 to 70 weight % of a second inorganic oxide and 20 to 70 weight % of a zeolite having an MFI structure, such as a ZSM series zeolite.

[0034] Optionally, in the method of the first aspect, the zeolite having an MFI structure is selected from ZSM series zeolites and ZSP zeolites.

[0035] Preferably, the first clay and the second clay are independently selected from at least one of kaolin, halloysite, sepiolite, attapulgite, montmorillonite and rectorite, preferably kaolin and / or halloysite. Preferably, the first inorganic oxide and the second inorganic oxide are independently selected from at least one of alumina, silica, amorphous silica-alumina and phosphate-alumina sol, preferably silica and / or aluminum oxide. Preferably, the zeolite having an MFI structure is selected from ZSP zeolite or from ZSM series zeolites; more preferably, the ZSM series zeolite includes modified or unmodified ZSM zeolite, such as at least one of modified or unmodified ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38 and ZSM-48. In some embodiments, preferably, the ZSM series zeolite includes ZSM-5 zeolite. Preferably, the Y series zeolite comprises at least one of rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultrastable Y-type zeolite and high silica Y-type zeolite. Optionally, the first catalyst and / or the second catalyst further comprises beta zeolite.

[0036] Optionally, in the process of the first aspect, the zeolite having an MFI structure accounts for at least 80 wt%, preferably at least 90 wt%, of all zeolites contained in the fresh second catalyst.

[0037] Optionally, in the method of the first aspect, the mass ratio of the zeolite with MFI structure to the Y series zeolite contained in the second spent catalyst introduced into the first reactor and the fresh first catalyst sent to the first regenerator is (1-15):1, preferably (2-10):1.

[0038] Optionally, in the method of the first aspect, the micro-reaction activity of the first regenerated catalyst is 40-80%, preferably 50-70%; and / or the micro-reaction activity of the fresh first catalyst is 70-95%, preferably 75-90%; and / or the micro-reaction activity of the fresh second catalyst is 50-95%, preferably 55-85%.

[0039] Optionally, in the method of the first aspect, the conditions for the first catalytic conversion reaction include: a temperature of 450 to 700° C., preferably 520 to 650° C.; a pressure of 0.05 to 0.2 MPa, preferably 0.08 to 0.15 MPa; a mass ratio of the heavy hydrocarbon feedstock to the first regenerated catalyst of 1:(3 to 100), preferably 1:(4 to 40); a mass ratio of the heavy hydrocarbon feedstock to water vapor of 1:(0.05 to 5), preferably 1:(0.2 to 2); and an oil and gas residence time of 0.1 to 100 seconds, preferably 0.5 to 20 seconds; and / or the conditions for the second catalytic conversion reaction include: a temperature of 500 to 750° C., preferably 550 to 700° C.; a pressure of 0.05 to 0.2 MPa, preferably 0.08 to 0.15 MPa; a weight hourly space velocity of 0.1 to 50 h -1 , preferably 0.2 to 10 hours -1 ; and the weight ratio of the light hydrocarbon feedstock to water vapor is 1: (0.1 to 5), preferably 1: (0.2 to 3).

[0040] Optionally, in the method of the first aspect, the heavy hydrocarbon feedstock is selected from one or more of petroleum hydrocarbons, mineral oils, synthetic oils, animal fats and vegetable oils; and / or the light hydrocarbon feedstock is selected from one or more of C4 to C10 hydrocarbons. Preferably, the petroleum hydrocarbons are selected from one or more of crude oil, atmospheric wax oil, vacuum wax oil, atmospheric residue oil, vacuum residue oil, deasphalted oil, hydrogenated heavy oil, coker wax oil, diesel and naphtha; and the mineral oil is selected from one or more of coal liquefaction oil, oil sands oil and shale oil. Preferably, the C4 to C10 hydrocarbons are selected from one or more of C4, C5, C6, C7, C8, C9 and C10 alkanes, cycloalkanes, olefins and aromatics.

[0041] A second aspect of the present invention provides a system for the method of the first aspect of the present invention, comprising a heavy hydrocarbon reactor (i.e., a first reactor), a heavy hydrocarbon stripper coaxially arranged with the heavy hydrocarbon reactor, a light hydrocarbon reactor (i.e., a second reactor), a first gas-solid separation device, a second gas-solid separation device, and a first regenerator; and the system comprises a mechanism for introducing at least a portion of the second regenerated catalyst into the first reactor;

[0042] The first reactor comprises a riser reactor and a fluidized bed reactor directly connected to the outlet of the riser reactor; the bottom of the riser reactor is provided with a first catalyst inlet for introducing a first regenerated catalyst, and the lower part is provided with a heavy hydrocarbon inlet; and the top of the fluidized bed reactor is provided with a first reaction material outlet;

[0043] The inlet of the heavy hydrocarbon stripper is communicated with the outlet of the catalyst to be regenerated of the first gas-solid separation device, and the outlet of the heavy hydrocarbon stripper is communicated with the first inlet of the catalyst to be regenerated of the first regenerator;

[0044] The second reactor is provided with a light hydrocarbon inlet at the bottom, a second reaction material outlet at the top, and a fresh second catalyst inlet at the lower part of the second reactor; preferably, the second reactor is a dense phase fluidized bed reactor;

[0045] The first regenerator is provided with a flue gas outlet at the top, a first regenerated catalyst outlet at the upper part, a first catalyst inlet to be regenerated and a fresh first catalyst inlet at the lower part, and a first regeneration gas inlet at the bottom;

[0046] The first reaction material outlet of the fluidized bed reactor is connected to the inlet of the first gas-solid separation device;

[0047] The catalyst outlet of the first regenerator is in communication with the first catalyst inlet of the first reactor; and

[0048] The second reaction material outlet of the second reactor is communicated with the inlet of the second gas-solid separation device.

[0049] Optionally, in the system of the second aspect, the spent catalyst outlet of the second gas-solid separation device is connected to the inlet of the heavy hydrocarbon stripper. Optionally, in the system of the second aspect, a catalyst output pipe is provided at the lower portion of the light hydrocarbon reactor.

[0050] Optionally, the system of the second aspect further comprises a light hydrocarbon stripper coaxially arranged with the second reactor; a material outlet is provided at the top of the second gas-solid separation device; the light hydrocarbon stripper is provided with a catalyst outlet after stripping; a second catalyst inlet is provided at the bottom of the riser reactor; the inlet of the light hydrocarbon stripper is connected to the outlet of the catalyst to be regenerated of the second gas-solid separation device; and the catalyst outlet after stripping of the light hydrocarbon stripper is connected to the second catalyst inlet of the riser reactor; optionally, the light hydrocarbon stripper further comprises a catalyst output pipe arranged at the lower part of the light hydrocarbon stripper, which is optionally connected to the second reactor.

[0051] Optionally, the system of the second aspect also includes a light hydrocarbon stripper coaxially arranged with the light hydrocarbon reactor; and the system also includes a light hydrocarbon stripper coaxially arranged with the second reactor; and the system also includes a second regenerator; the top of the second gas-solid separation device is provided with a material outlet, and the light hydrocarbon stripper is provided with a stripped catalyst outlet; the top of the second regenerator is provided with a flue gas outlet, the upper part is provided with a first outlet for regenerating the second catalyst, the lower part is provided with a second inlet for the catalyst to be regenerated, and the bottom is provided with a second regeneration gas inlet; the inlet of the light hydrocarbon stripper is connected to the outlet of the catalyst to be regenerated of the second gas-solid separation device; the outlet of the stripped catalyst of the light hydrocarbon stripper is connected to the second inlet of the catalyst to be regenerated of the second regenerator; the bottom of the riser reactor is provided with a second catalyst inlet; the first outlet of the regenerated second catalyst of the second regenerator is connected to the second catalyst inlet of the riser reactor; and optionally, the upper part of the second regenerator is provided with a second outlet for regenerating the second catalyst, which is connected to the second reactor.

[0052] Through the above technical solution, the present invention makes full use of the high acid density and strong acid center of the fresh second catalyst, significantly improving the yield of ethylene and propylene in the catalytic conversion products of light hydrocarbon feedstocks; at the same time, the catalyst filling method of directly adding fresh second catalyst to the second reactor and replenishing fresh first catalyst in the first regenerator can simultaneously meet the different requirements for molecular sieves in the catalytic cracking process of heavy hydrocarbon feedstocks and light hydrocarbon feedstocks, further increasing the yield of ethylene and propylene. In some embodiments, by directly introducing the (carbonized) second catalyst after the reaction and stripping of the light hydrocarbon feedstock into the first reactor, the oil-agent contact temperature of the heavy oil is reduced, thereby reducing the yield of low value-added products. In some embodiments, by using a separate regenerator to regenerate the second catalyst, the regeneration temperature can be adjusted and the activity of the second catalyst can be appropriately adjusted, thereby increasing the yield of ethylene and propylene.

[0053] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] 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:

[0055] FIG1 is a process flow chart of the catalytic conversion of hydrocarbons to produce more ethylene and propylene provided by the present invention.

[0056] FIG2 is a process flow chart of the catalytic conversion of hydrocarbons to produce more ethylene and propylene provided by the present invention.

[0057] FIG3 is a process flow chart of the catalytic conversion of hydrocarbons to produce more ethylene and propylene provided by the present invention.

[0058] FIG4 is a process flow chart of the catalytic conversion of hydrocarbons to produce more ethylene and propylene provided by the present invention.

[0059] Explanation of the markings in Figure 1: 1. Riser reactor; 11. Heavy hydrocarbon feed nozzle; 2. Fluidized bed reactor; 3. Second reactor; 31. Light hydrocarbon feed line; 32. Feed distributor; 33. Fresh second catalyst delivery pipe; 34. Carbon deposited catalyst output pipe; 35. Second reaction oil delivery pipe; 4. Settler; 41. Cyclone separator; 42. Oil and gas output pipe; 5. Stripper; 51. Stripping steam delivery pipe; 52. Regenerated catalyst delivery pipe; 6. Regenerator; 61. Air delivery pipe; 62. Regenerated flue gas delivery pipe; 63. Regenerated catalyst delivery pipe; 64. Fresh first catalyst delivery pipe.

[0060] Explanation of the markings in Figure 2: 1. Riser reactor; 11. Heavy hydrocarbon feed nozzle; 2. Fluidized bed reactor; 3. Second reactor; 31. Light hydrocarbon feed pipeline; 32. Feed distributor; 33. Fresh second catalyst delivery pipe; 34. Second reaction oil delivery pipe; 4. Heavy hydrocarbon settler; 41. First cyclone separator; 42. First reaction oil and gas output pipe; 5. Heavy hydrocarbon stripper; 51. First stripping steam delivery pipe; 52. Regenerated catalyst delivery pipe; 6. Regenerator; 61. Air delivery pipe; 62. Regenerated flue gas delivery pipe; 63. Regenerated catalyst delivery pipe; 64. Fresh first catalyst delivery pipe; 7. Light hydrocarbon settler; 71. Second cyclone separator; 72. Second reaction oil and gas output pipe; 8. Light hydrocarbon stripper; 81. Second stripping steam delivery pipe; 82. Second carbonized catalyst delivery pipe; 83. Second carbonized catalyst output pipe.

[0061] Explanation of the markings in Figure 3: 1. Riser reactor; 11. Heavy hydrocarbon feed nozzle; 2. Fluidized bed reactor; 3. Second reactor; 31. Light hydrocarbon feed line; 32. Feed distributor; 33. Fresh second catalyst delivery pipe; 34. Second reaction oil delivery pipe; 4. Heavy hydrocarbon settler; 41. First cyclone separator; 42. First reaction oil and gas output pipe; 5. Heavy hydrocarbon stripper; 51. First stripping steam delivery pipe; 52. Regenerated catalyst delivery pipe; 6. Regenerator; 61. Air delivery pipe; 62. Regenerated flue gas delivery pipe; 63. Regenerated catalyst delivery pipe; 64. Fresh second catalyst delivery pipe; 7. Light hydrocarbon settler; 71. Second cyclone separator; 72. Second reaction oil and gas output pipe; 8. Light hydrocarbon stripper; 81. Second stripping steam delivery pipe; 82. Second carbonized catalyst delivery pipe; 83. Second carbonized catalyst return pipe.

[0062] FIG4 shows the symbols: 1. Riser reactor; 11. Heavy hydrocarbon feed nozzle; 2. Fluidized bed reactor; 3. First settler; 31. First cyclone separator; 32. First reaction oil and gas output pipe; 4. First stripper; 41. First stripping steam delivery pipe; 42. First catalyst delivery pipe to be regenerated; 5. First regenerator; 51. First air delivery pipe; 52. First regeneration flue gas delivery pipe; 53. First regenerated catalyst delivery pipe; 54. Fresh first catalyst delivery pipe; 6. Second reactor; 61. Light hydrocarbon feed pipeline; 62. Feed distributor; 63. Second reaction oil agent delivery pipe; 7. Second settler; 71. Second cyclone separator; 72. Second reaction oil and gas output pipe; 8. Second stripper; 81. Second stripping steam delivery pipe; 82. Second catalyst delivery pipe to be regenerated; 9. Second regenerator; 91. Second air delivery pipe; 92. Second regeneration flue gas delivery pipe; 93. Regenerated second catalyst delivery pipe; 94. Regenerated second catalyst delivery pipe; 95. Fresh second catalyst delivery pipe. DETAILED DESCRIPTION

[0063] 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.

[0064] A first aspect of the present invention provides a catalytic cracking method, characterized in that the method comprises the following steps:

[0065] The heavy hydrocarbon feedstock is contacted with the first regenerated catalyst in the first reactor to perform a first catalytic conversion reaction, and the first material obtained after the first catalytic conversion reaction is subjected to a first separation to obtain a first spent catalyst and a first reaction oil gas;

[0066] feeding a fresh second catalyst into a second reactor and contacting the light hydrocarbon feedstock with the second catalyst in the second reactor to perform a second catalytic conversion reaction to obtain a second material comprising the second catalyst and a reaction product, and performing a second separation on the second material to obtain a second spent catalyst and a second reaction oil and gas; the fresh second catalyst contains 10 to 80 weight percent of a zeolite having an MFI structure, such as a ZSM series zeolite; and

[0067] sending the first spent catalyst into a first regenerator for regeneration after stripping and sending a fresh first catalyst into the first regenerator to obtain a first regenerated catalyst and return it to the first reactor; the fresh first catalyst contains 10 to 70 weight percent of Y series zeolite; and

[0068] At least a portion of the second regenerated catalyst is introduced into the first reactor, wherein the mass ratio of the second catalyst introduced into the first reactor to the fresh first catalyst fed into the first regenerator is (1-10):1, preferably (1-6):1.

[0069] The method of the present invention fully utilizes the high acid density and strong acid centers of the fresh second catalyst, significantly improving the yield of ethylene and propylene in the catalytic conversion products of the light hydrocarbon feedstock; at the same time, the catalyst filling method of directly adding the fresh second catalyst to the second reactor and replenishing the fresh first catalyst in the first regenerator can simultaneously meet the different requirements for molecular sieves in the catalytic cracking process of heavy hydrocarbon feedstock and light hydrocarbon feedstock, further increasing the yield of ethylene and propylene.

[0070] In the present invention, introducing at least a portion of the second spent catalyst into the first reactor can be performed in various ways. In some embodiments of the present invention, the entire second spent catalyst can be introduced into the first reactor. For example, the amount of the second spent catalyst introduced into the first reactor can be determined based on the ratio of the first catalyst to the second catalyst required for the first regenerated catalyst used in the first reactor.

[0071] Specifically, in some embodiments, in the method of the present invention, the second catalyst to be regenerated can be sent together with the first catalyst to be regenerated (for example, after mixing) to the first regenerator for regeneration to obtain a first regenerated catalyst, and then part or all of the first regenerated catalyst can be introduced into the first reactor for recycling. Preferably, the second catalyst to be regenerated can be stripped together with the first catalyst to be regenerated in a heavy hydrocarbon stripper, and the stripped second catalyst to be regenerated can be sent together with the first catalyst to the first regenerator for regeneration to obtain the first regenerated catalyst, and the first regenerated catalyst can be returned to the first reactor; for example, as shown in Figure 1.

[0072] In some embodiments, the method may further include discharging a portion of the second catalyst through a (carbon deposited) catalyst outlet pipe disposed at the lower portion of the second reactor.

[0073] In some embodiments, in the method of the present invention, the first reactor is a combined riser and fluidized bed reactor, and the method further comprises: introducing the second spent catalyst into the fluidized bed of the first reactor. In this case, the second spent catalyst is mixed with the reaction mixture in the first reactor and becomes part of the first feed.

[0074] Alternatively, in some embodiments, in the method of the present invention, the second spent catalyst can be sent to a light hydrocarbon stripper for stripping to obtain a stripped second catalyst, at least a portion of the stripped second catalyst is sent to the first reactor, and the remaining stripped second catalyst is optionally discharged through a catalyst outlet pipe provided at the lower part of the light hydrocarbon stripper, and preferably the remaining stripped second catalyst is returned to the second reactor (if the stripped second catalyst is not all sent to the first reactor, for example, through a catalyst outlet pipe provided at the lower part of the light hydrocarbon stripper).

[0075] Alternatively, in some embodiments, in the process of the present invention, the first reactor is a combined riser and fluidized bed reactor. Therefore, in the process, the second spent catalyst can be introduced into a light hydrocarbon stripper for stripping to produce a stripped second catalyst, at least a portion of which is introduced into the riser of the first reactor, and the remaining stripped second catalyst is optionally discharged through a catalyst outlet pipe disposed at the bottom of the light hydrocarbon stripper, preferably returned to the second reactor; for example, as shown in FIG2 or 3. In this case, the temperature of the stripped second catalyst is lower than the regeneration temperature of the first regenerator, for example, by 20 to 200°C lower. By introducing the stripped second catalyst directly into the first reactor without regeneration, the oil-agent contact temperature during the heavy hydrocarbon reaction in the first reactor can be reduced, further increasing the yields of ethylene and propylene.

[0076] Alternatively, in some embodiments, in the method of the present invention, the fresh second catalyst may be sent into the second reactor and the fresh second catalyst may be directly sent into the second reactor, and the method further includes: sending the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, and sending at least a portion of the regenerated second catalyst into the first reactor, and optionally returning the remaining portion of the regenerated second catalyst to the second reactor; or the fresh second catalyst may be sent into the second reactor and the fresh second catalyst may be directly sent into the second regenerator, and the method further includes: sending the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, and a portion of the regenerated second catalyst is sent into the first reactor, and a portion of the regenerated second catalyst is returned to the second reactor. As understood by those skilled in the art, when the fresh second catalyst is directly sent into the second regenerator, the fresh second catalyst mixes with the second catalyst to be regenerated in the second regenerator and undergoes regeneration treatment to obtain a regenerated second catalyst.

[0077] Alternatively, in some embodiments, in the method of the present invention, the first reactor is a combined riser and fluidized bed reactor, and the feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second reactor, and the method further includes: feeding the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, and feeding at least a portion of the regenerated second catalyst into the riser of the first reactor, and optionally returning the remaining portion of the regenerated second catalyst to the second reactor; or the feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second regenerator, and the method further includes: feeding the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, and feeding a portion of the regenerated second catalyst into the riser of the first reactor, and returning the remaining portion of the regenerated second catalyst to the second reactor; for example, as shown in Figure 4.

[0078] In some embodiments, in the method of the present invention, the regeneration temperature in the second regenerator may be 400-650° C., preferably 450-600° C., more preferably 500-600° C. or 510-590° C. For example, the regeneration temperature in the second regenerator may be 510° C., 520° C., 530° C., 540° C., 550° C., 560° C., 570° C., 580° C., 590° C., or a range consisting of any two of the foregoing values.

[0079] In some specific embodiments of the present invention, the first separation comprises gas-solid separation after catalytic cracking of heavy hydrocarbons. The heavy hydrocarbon gas-solid separation can be performed by a heavy hydrocarbon gas-solid separation device. After gas-solid separation in the heavy hydrocarbon gas-solid separation device, a first spent catalyst is obtained. The first spent catalyst is optionally stripped and then fed to the first regenerator for regeneration, such as char regeneration. Specifically, the heavy hydrocarbon gas-solid separation device can include a settler and a cyclone separator.

[0080] In some embodiments of the present invention, the second separation comprises gas-solid separation after catalytic cracking of light hydrocarbons. The light hydrocarbon gas-solid separation can be performed by a light hydrocarbon gas-solid separation device, and the second spent catalyst is obtained after gas-solid separation in the light hydrocarbon gas-solid separation device. Specifically, the light hydrocarbon gas-solid separator can include a settler and a cyclone separator. In some embodiments, the light hydrocarbon gas-solid separator can share a settler with the heavy hydrocarbon gas-solid separator.

[0081] In some embodiments of the present invention, the second separation may further include discharging a portion of the second catalyst through a (carbon deposited) catalyst outlet pipe disposed at the lower portion of the second reactor.

[0082] In the present invention, the amount of the second catalyst entering the first reactor can be controlled to meet the requirements of the catalytic conversion reaction of the heavy hydrocarbon feedstock, while reasonably utilizing the highly active second catalyst containing zeolite with MFI structure, such as ZSM series zeolite.

[0083] In some embodiments of the present invention, the second reactor is a fluidized bed reactor, preferably a dense phase fluidized bed reactor. In the present invention, for a dense phase fluidized bed, the catalyst density can be 100 to 1000 kg / m 3 , preferably 150~600kg / m 3 . In the present invention, the average linear velocity of the oil and gas in the second reactor is 0.01 to 10 m / s, preferably 0.1 to 5 m / s. For example, in the present invention, the average linear velocity of the oil and gas in the second reactor can be 0.01 m / s, 0.02 m / s, 0.04 m / s, 0.06 m / s, 0.08 m / s, 0.1 m / s, 0.12 m / s, 0.14 m / s, 0.16 m / s, 0.18 m / s, 0.2 m / s, 0.4 m / s, 0.6 m / s, 0.8 m / s, 1 m / s, 2 m / s, 3 m / s, 4 m / s, 5 m / s, or a range consisting of any two of the above values. Specifically, in some embodiments of the present invention, the second reactor can be selected from one or more of a constant diameter fluidized bed, a constant linear velocity fluidized bed and a variable diameter fluidized bed.

[0084] In some embodiments of the present invention, preferably, the carbon mass content on the second spent catalyst is A, and the mass ratio of the feed amount of the fresh second catalyst to the feed amount of the light hydrocarbon is R, then A and R satisfy the following relationship:

[0085] 0.2 / (1+6B) <R / A<10 / (1+2B)

[0086] Wherein, B is the mass content of olefins in the light hydrocarbon feedstock.

[0087] In the present invention, the carbon mass content on the catalyst is determined by the following test method: the catalyst is placed in a furnace, oxygen is introduced and burned at high temperature to convert carbon into CO2; the gas after combustion flows through an infrared detector to measure the CO2 concentration, and the carbon mass content on the catalyst is obtained by calculation.

[0088] In some embodiments of the present invention, the method further comprises detecting the values ​​of A and B over time and adjusting the value of R based on the detected values ​​of A and B so that R / A still satisfies the above relationship. For example, adjusting the value of R may comprise adjusting the rate of addition of the fresh second catalyst and / or the rate of feeding the light hydrocarbons. For example, the rate of addition of the fresh second catalyst and / or the rate of feeding the light hydrocarbons may be increased or decreased to increase or decrease the value of R.

[0089] In the present invention, when detecting over time, the values ​​of A and B can be detected at intervals of, for example, 1 hour to several days. For example, the detection can be performed at intervals of 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 28 hours, 32 hours, 36 hours, 48 ​​hours, 60 hours, 72 hours, 84 hours, 96 hours, 120 hours, 144 hours, 168 hours, etc. Those skilled in the art can select and determine the appropriate detection time interval according to operational needs.

[0090] In some embodiments of the present invention, the first reactor may be selected from one or more of a riser, a fluidized bed, a fast bed, and a downcomer. For example, in some embodiments of the present invention, the first reactor may be a reactor in a DCC process. In some embodiments of the present invention, preferably, the first reactor is a combination riser and fluidized bed reactor.

[0091] In some embodiments of the present invention, preferably, the first reactor is a combined riser and fluidized bed reactor, and the second reactor is a dense phase fluidized bed reactor.

[0092] In some embodiments of the present invention, the mass ratio of the second spent catalyst introduced into the first reactor to the fresh first catalyst introduced into the first regenerator may be (1-10):1, preferably (1-6):1. For example, the mass ratio of the second spent catalyst introduced into the first reactor to the fresh first catalyst introduced into the first regenerator may be 1:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or any range consisting of two of the above ratios, for example, (1.5-6):1.

[0093] The method of the present invention further includes separating the first reaction oil gas and the second reaction oil gas. For example, the first reaction oil gas and the second reaction oil gas can be combined and then separated, or the first reaction oil gas and the second reaction oil gas can be separated separately. The separation can be carried out using methods commonly known in the field of catalytic cracking to obtain the desired product. For example, the separation operation in the DCC process can be used. In some embodiments, the method can include using one or more components obtained by separation as the light hydrocarbon feedstock. For example, one or more of the C4 to C10 hydrocarbon components can be used as the light hydrocarbon feedstock.

[0094] In the present invention, the regeneration temperature in the first regenerator may be 550-750° C., preferably 600-720° C. For example, the regeneration temperature in the first regenerator may be 610° C., 620° C., 630° C., 640° C., 650° C., 660° C., 670° C., 680° C., 690° C., 700° C., 710° C., 720° C., 730° C., 740° C., 750° C., or a range consisting of any two of the foregoing values, for example, 610-750° C.

[0095] In some embodiments of the present invention, the regeneration temperature in the first regenerator is higher than the regeneration temperature in the second regenerator, for example, 20 to 200° C. higher, for example, 20° C., 40° C., 60° C., 80° C., 100° C., 120° C., 140° C., 160° C., 180° C., 200° C., or a range consisting of any two of the foregoing values, for example, 40 to 160° C. When at least a portion of the regenerated second catalyst is fed into the first reactor, for example, into the riser of the first reactor, the oil-solvent contact temperature during the reaction of the heavy hydrocarbon feedstock can be reduced, which can further increase the yields of ethylene and propylene.

[0096] In the present invention, by introducing at least a portion of the second regenerated catalyst into the first reactor and controlling the ratio of the introduced second catalyst to the fresh first catalyst, the requirements for different molecular sieves during the catalytic conversion of heavy hydrocarbons can be met. Specifically, the ZSM series zeolite is a medium-pore zeolite, and the Y series zeolite is a large-pore zeolite. The first regenerated catalyst introduced into the first reactor contains both the highly active ZSM series zeolite and the Y series zeolite, which facilitates the catalytic conversion of heavy hydrocarbons and the catalytic conversion of intermediates from the catalytic cracking of heavy hydrocarbons to increase the production of ethylene and propylene. In some embodiments, this also improves the conversion rate of heavy hydrocarbons.

[0097] In some embodiments of the present invention, the mass ratio of the fresh first catalyst feed amount to the heavy hydrocarbon feed amount may be (0.0001-0.1):1, preferably (0.0005-0.005):1. Specifically, the mass ratio of the fresh first catalyst feed amount to the heavy hydrocarbon feed amount may be 0.0001:1, 0.0005:1, 0.0007:1, 0.001:1, 0.003:1, 0.005:1, 0.008:1, 0.01:1, 0.05:1, 0.1:1, or a range consisting of any two of the foregoing values, for example, (0.0005-0.05):1.

[0098] In some embodiments of the present invention, the mass ratio R of the fresh second catalyst feed amount to the light hydrocarbon feed amount may be (0.0004-0.2):1, preferably (0.001-0.1):1. Specifically, the mass ratio R of the fresh second catalyst feed amount to the light hydrocarbon feed amount may be 0.0004, 0.0008, 0.001, 0.002, 0.004, 0.006, 0.008, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, or a range consisting of any two of the foregoing values, for example, (0.002-0.1):1.

[0099] In the method of the present invention, fresh first catalyst is supplemented in the first regenerator, and the activity of the supplemented fresh first catalyst is used to further improve the selectivity of catalytic conversion of heavy hydrocarbons into ethylene and propylene.

[0100] In some embodiments of the present invention, the fresh second catalyst contains 10 to 80 weight % of the second clay, 10 to 80 weight % of the second inorganic oxide, and 10 to 80 weight % of the zeolite having an MFI structure.

[0101] In the present invention, the fresh second catalyst may contain 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt% of zeolite having an MFI structure, or may contain a range of any two of the above values ​​consisting of zeolite having an MFI structure.

[0102] In the present invention, preferably, the zeolite with an MFI structure may be selected from ZSM series zeolites and ZSP zeolites. In the present invention, preferably, in some embodiments, the zeolite with an MFI structure may be selected from ZSP zeolites. In the present invention, the ZSM series zeolite may include modified or unmodified ZSM zeolites, for example, at least one of modified or unmodified ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38 and ZSM-48. Optionally, the above-mentioned zeolite may be modified with non-metallic elements such as phosphorus and / or metallic elements such as iron, cobalt, nickel, and rare earth elements.

[0103] In some preferred embodiments of the present invention, the fresh second catalyst contains 15-70 wt% of a second clay, 15-70 wt% of a second inorganic oxide, and 20-70 wt% of a zeolite having an MFI structure, such as a ZSM series zeolite.

[0104] In some embodiments of the present invention, the second clay may be selected from at least one of kaolin, halloysite, sepiolite, attapulgite, montmorillonite and rectorite, preferably kaolin and / or halloysite; and / or the second inorganic oxide may be selected from at least one of alumina, silica, amorphous silica-alumina and phosphate-alumina sol, preferably silica and / or alumina.

[0105] In some embodiments of the present invention, the fresh first catalyst contains 15 to 70 weight percent of a first clay, 15 to 70 weight percent of a first inorganic oxide, and 10 to 70 weight percent of a Y series zeolite; preferably, the fresh first catalyst contains 20 to 70 weight percent of a clay, 20 to 70 weight percent of an inorganic oxide, and 10 to 60 weight percent of a Y series zeolite.

[0106] In the present invention, the fresh second catalyst may contain 15 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt% of Y series zeolite, or may contain a range of any two of the above values ​​of Y series zeolite.

[0107] In some embodiments of the present invention, preferably, the Y series zeolite contains at least one of rare earth Y-type zeolite (REY), rare earth hydrogen Y-type zeolite (REHY), ultrastable Y-type zeolite (USY) and high silica Y-type zeolite.

[0108] In some embodiments of the present invention, the first clay may be selected from at least one of kaolin, halloysite, sepiolite, attapulgite, montmorillonite and rectorite, preferably kaolin and / or halloysite; and / or the first inorganic oxide may be selected from at least one of alumina, silica, amorphous silica-alumina and phosphate-alumina sol, preferably silica and / or alumina.

[0109] Optionally, the first catalyst and / or the second catalyst may further contain beta zeolite.

[0110] In the present invention, the (fresh) second catalyst may optionally contain other zeolites in addition to the zeolite having an MFI structure, such as a ZSM series zeolite. However, in the (fresh) second catalyst, the zeolite having an MFI structure accounts for at least 80% by weight of all the zeolites contained in the (fresh) second catalyst, preferably at least 90% by weight, preferably at least 95% by weight, and even more preferably at least 99% by weight. In some embodiments, the (fresh) second catalyst may not contain zeolites other than the zeolite having an MFI structure, such as a ZSM series zeolite and a ZSP zeolite.

[0111] ZSP molecular sieve is disclosed, for example, in CN1176020C; USY molecular sieve is disclosed, for example, in CN1127161A. In the present invention, fresh catalyst can be prepared according to methods well known in the art, for example, by mixing and slurrying the molecular sieve, kaolin, and an Al2O3 binder, followed by spray drying, washing, filtering, and drying.

[0112] In some embodiments of the present invention, the mass ratio of the zeolite having an MFI structure to the Y series zeolite contained in the second spent catalyst introduced into the first reactor and the fresh first catalyst fed into the first regenerator may be (1-15):1, preferably (2-10):1. For example, the mass ratio may be 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, or a range consisting of any two of the above ratios, for example, (2.5-10):1.

[0113] In the present invention, the (fresh) first catalyst and the (fresh) second catalyst can be of shapes and sizes generally known in the art, for example, they can be powders or particles, preferably spherical particles. In the present invention, in some embodiments, the average particle size of the (fresh) first catalyst and the (fresh) second catalyst can be 50 to 85 μm. In the present invention, in some embodiments, the average particle size of the (fresh) first catalyst and the (fresh) second catalyst can be the same or substantially the same. In the present invention, there is no particular limitation on the specific surface area and pore volume of the (fresh) first catalyst and the (fresh) second catalyst, for example, the specific surface area and pore volume generally used in the art can be used.

[0114] In some preferred embodiments of the present invention, the micro-reaction activity of the first regenerated catalyst is 40-80%, preferably 50-70%.

[0115] In some preferred embodiments of the present invention, the micro-reaction activity of the fresh first catalyst is 70-95%, preferably 75-90%.

[0116] In some preferred embodiments of the present invention, the micro-reaction activity of the fresh second catalyst is 50-95%, preferably 55-85%.

[0117] In the present invention, the micro-reaction activity is measured using the RIPP 92-90 Micro-reaction Activity Test Method for Catalytic Cracking Industrial Equilibrium Catalyst (Petrochemical Analytical Methods (RIPP Test Method), edited by Yang Cuiding et al., 1990 edition). In the present invention, fresh catalyst refers to a commercially available catalyst or a catalyst that has not been used since its preparation.

[0118] The present invention employs different fresh catalyst injection methods for heavy hydrocarbon feedstocks and light hydrocarbon feedstocks. The catalytic cracking of light hydrocarbons utilizes a fresh catalyst containing ZSM series zeolites, leveraging the fresh catalyst's high acid density and strong acid centers to catalytically crack the light hydrocarbon feedstock to produce ethylene and propylene. The catalytic cracking of heavy hydrocarbons utilizes a combination of a ZSM series zeolite catalyst and a Y-type zeolite catalyst to meet the requirements for catalytic cracking of the heavy hydrocarbon feedstock. The method of the present invention significantly increases the yield of ethylene and propylene. In some embodiments, the method of the present invention can also improve the conversion rate of the heavy hydrocarbon feedstock.

[0119] In the present invention, the conditions of the first catalytic conversion reaction may include: a temperature of 450 to 700°C, preferably 520 to 650°C; a pressure of 0.05 to 0.2 MPa, preferably 0.08 to 0.15 MPa, for example, the pressure can be 0.1 to 0.2 MPa, preferably 0.1 to 0.15 MPa; the mass ratio of the heavy hydrocarbon feedstock to the first regenerated catalyst is 1:(3 to 100), preferably 1:(4 to 40), for example, preferably 1:(8 to 40); and an oil and gas residence time of 0.1 to 100 seconds, preferably 0.5 to 20 seconds.

[0120] In the first catalytic conversion reaction, the heavy hydrocarbon feedstock and water vapor are contacted with the first regenerated catalyst to react. The weight ratio of the heavy hydrocarbon feedstock to the water vapor can be 1:(0.05-5), preferably 1:(0.2-2).

[0121] In the present invention, the conditions of the second catalytic conversion reaction may include: a temperature of 500-750°C, preferably 550-700°C; a pressure of 0.05-0.2 MPa, preferably 0.08-0.15 MPa, for example, the pressure may be 0.1-0.2 MPa, preferably 0.1-0.15 MPa; and a weight hourly space velocity of 0.1-50 h -1 , preferably 0.2 to 10 hours -1 .

[0122] In the second catalytic conversion reaction, the light hydrocarbon feedstock and water vapor are contacted with the first catalyst to react. The weight ratio of the light hydrocarbon feedstock to the water vapor can be 1:(0.1-5), preferably 1:(0.2-3).

[0123] In the present invention, the heavy hydrocarbon feedstock is not particularly limited, and any heavy hydrocarbon feedstock commonly used for catalytic cracking can be used. For example, the heavy hydrocarbon feedstock can be selected from one or more of petroleum hydrocarbons, mineral oils, synthetic oils, animal fats, and vegetable oils. In some embodiments, the petroleum hydrocarbons can be selected from one or more of crude oil, atmospheric gas oil, vacuum gas oil, atmospheric residue, vacuum residue, deasphalted oil, hydrogenated heavy oil, coker gas oil, diesel, and naphtha; and the mineral oil can be selected from one or more of coal liquefaction oil, oil sands oil, and shale oil. For example, the heavy hydrocarbon feedstock can be a feedstock that can be used in a DCC process.

[0124] In the present invention, there is no particular limitation on the light hydrocarbon feedstock, and light hydrocarbon feedstocks commonly used for catalytic cracking can be used. In some embodiments of the present invention, the light hydrocarbon feedstock can be selected from C4-C10 hydrocarbons. For example, the light hydrocarbons can be part or all of the fractions of the C4-C10 hydrocarbons. In some embodiments, preferably, the C4-C10 hydrocarbons can be selected from one or more of C4, C5, C6, C7, C8, C9 and C10 alkanes, cycloalkanes, olefins and aromatics. For example, the light hydrocarbon feedstock can be light gasoline. Specifically, the light hydrocarbons can come from a catalytic cracking unit, a steam cracking unit, a hydrocracking unit, a coking unit, a reforming unit, an aromatics extraction unit or an atmospheric tower. The catalytic cracking unit can be, for example, the catalytic cracking system disclosed in this application. In some embodiments of the present invention, the light hydrocarbon components separated from the first reaction oil gas and / or the second reaction oil gas can be used as the light hydrocarbon feedstock, and optionally, light hydrocarbon components from other processes or devices can also be used as the light hydrocarbon feedstock.

[0125] In the method of the present invention, the weight ratio of the heavy hydrocarbon feedstock to the light hydrocarbon feedstock can be adjusted according to actual conditions, for example, it can be 1 to 100:1, preferably 1 to 30:1. In some embodiments, the light hydrocarbon feedstock can only include the components that can be used as the light hydrocarbon feedstock after separation of the first oil and gas and the second oil and gas.

[0126] In the present invention, when fresh catalyst is added, it can be added in a continuous feed manner. Alternatively, fresh catalyst can be added in an intermittent manner, for example, adding a fixed amount of fresh catalyst at fixed intervals. Those skilled in the art can appropriately determine the method of adding fresh catalyst to eliminate or minimize the impact of the addition method on the operation of the method of the present invention.

[0127] In the method of the present invention, in some embodiments, preferably, only the second catalyst is used in the light hydrocarbon reactor (ie, the second reactor).

[0128] A second aspect of the present invention provides a system for the method of the first aspect of the present invention, comprising a heavy hydrocarbon reactor (i.e., a first reactor), a heavy hydrocarbon stripper coaxially arranged with the heavy hydrocarbon reactor, a light hydrocarbon reactor (i.e., a second reactor), a first gas-solid separation device, a second gas-solid separation device, and a first regenerator; and the system comprises a mechanism for introducing at least a portion of the second regenerated catalyst into the first reactor;

[0129] The first reactor comprises a riser reactor and a fluidized bed reactor directly connected to the outlet of the riser reactor; the bottom of the riser reactor is provided with a first catalyst inlet for introducing a first regenerated catalyst, and the lower part is provided with a heavy hydrocarbon inlet; and the top of the fluidized bed reactor is provided with a first reaction material outlet;

[0130] The inlet of the heavy hydrocarbon stripper is communicated with the outlet of the catalyst to be regenerated of the first gas-solid separation device, and the outlet of the heavy hydrocarbon stripper is communicated with the first inlet of the catalyst to be regenerated of the first regenerator;

[0131] The second reactor is provided with a light hydrocarbon inlet at the bottom, a second reaction material outlet at the top, and a fresh second catalyst inlet at the lower part of the second reactor; preferably, the second reactor is a dense phase fluidized bed reactor;

[0132] The first regenerator is provided with a flue gas outlet at the top, a first regenerated catalyst outlet at the upper part, a first catalyst inlet to be regenerated and a fresh first catalyst inlet at the lower part, and a first regeneration gas inlet at the bottom;

[0133] The first reaction material outlet of the fluidized bed reactor is connected to the inlet of the first gas-solid separation device;

[0134] The catalyst outlet of the first regenerator is in communication with the first catalyst inlet of the first reactor; and

[0135] The second reaction material outlet of the second reactor is communicated with the inlet of the second gas-solid separation device.

[0136] In the present invention, the mechanism for introducing at least a portion of the second spent catalyst into the heavy hydrocarbon reactor may be any mechanism capable of achieving catalyst transfer, including but not limited to a pipeline, equipment, device, or a combination thereof. As understood by those skilled in the art, introducing at least a portion of the second spent catalyst from the light hydrocarbon reactor into the heavy hydrocarbon reactor may include directly introducing the second spent catalyst into the heavy hydrocarbon reactor, or may include indirectly introducing the second spent catalyst into the heavy hydrocarbon reactor, for example, first introducing the second spent catalyst into a stripper or regenerator, and then introducing it into the heavy hydrocarbon reactor.

[0137] In some embodiments, for the system of the second aspect of the present invention, the spent catalyst outlet of the second gas-solid separation device is connected to the inlet of the heavy hydrocarbon stripper. In some embodiments, a catalyst outlet pipe is optionally provided at the lower portion of the light hydrocarbon reactor, as shown, for example, in FIG1 .

[0138] In some embodiments, the system of the second aspect of the present invention further comprises a light hydrocarbon stripper coaxially arranged with the light hydrocarbon reactor; a material outlet is provided at the top of the second gas-solid separation device; the light hydrocarbon stripper is provided with an outlet for stripped catalyst; a second catalyst inlet is provided at the bottom of the riser reactor; the inlet of the light hydrocarbon stripper is connected to the outlet of the regenerated catalyst of the second gas-solid separation device; and the outlet of the stripped catalyst of the light hydrocarbon stripper is connected to the second catalyst inlet of the riser reactor; optionally, the light hydrocarbon stripper further comprises a catalyst outlet pipe provided at the bottom of the light hydrocarbon stripper, which is optionally connected to the second reactor, as shown in Figure 2 or Figure 3.

[0139] In some embodiments, the system of the second aspect of the present invention further comprises a light hydrocarbon stripper coaxially arranged with the light hydrocarbon reactor; and the system further comprises a second regenerator; the top of the second gas-solid separation device is provided with a material outlet, and the light hydrocarbon stripper is provided with a stripped catalyst outlet; the top of the second regenerator is provided with a flue gas outlet, the upper part is provided with a first outlet for regenerating the second catalyst, the lower part is provided with a second inlet for the catalyst to be regenerated, and the bottom is provided with a second regeneration gas inlet; the inlet of the light hydrocarbon stripper is connected to the outlet of the catalyst to be regenerated of the second gas-solid separation device; the outlet of the stripped catalyst of the light hydrocarbon stripper is connected to the second inlet of the catalyst to be regenerated of the second regenerator; the bottom of the riser reactor is provided with a second catalyst inlet; the first outlet of the regenerated second catalyst of the second regenerator is connected to the second catalyst inlet of the riser reactor; and optionally, the upper part of the second regenerator is provided with a second outlet for regenerating the second catalyst, which is connected to the second reactor. For example, as shown in Figure 4.

[0140] Some specific embodiments of the present invention are provided below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

[0141] Figure 1 illustrates a flow chart of a method for catalytic conversion of high-yield ethylene and propylene according to the present invention. Referring to Figure 1 , the first reactor comprises a riser reactor 1 and a fluidized bed reactor 2 coaxially arranged with the riser reactor 1. The second reactor is a fluidized bed reactor 3 arranged in parallel with the riser reactor 1. A first regenerated catalyst is introduced into the bottom of the riser reactor 1 via a regenerated catalyst delivery pipe 63, where it flows upward under the action of a pre-lifting medium, such as steam. Heavy hydrocarbon feedstock and steam are sprayed into the riser reactor 1 via a heavy hydrocarbon feed nozzle 11, where they contact the first regenerated catalyst and undergo a catalytic cracking reaction. The oil then flows upward to continue the catalytic cracking reaction within the fluidized bed reactor 2. The reacted first oil undergoes heavy hydrocarbon gas-solid separation within a settler 4, yielding a first spent catalyst and a first reaction oil gas. The spent catalyst then enters a stripper 5, where it is stripped of adsorbed hydrocarbon products and transported via a spent catalyst delivery pipe 52 to a regenerator 6 for regeneration. The regenerated catalyst is returned to the riser reactor 1 for recycling. Fresh second catalyst is added to the second reactor 3 via the fresh second catalyst delivery pipe 33. Light hydrocarbon feedstock and water vapor enter the second reactor 3 via the light hydrocarbon feed line 31, where they contact the second catalyst for a catalytic cracking reaction, yielding a second material. Light hydrocarbon gas-solid separation is then performed in the settler 4, yielding a second spent catalyst and a second reaction oil and gas. The first reaction oil and gas enter the product separation system. Light hydrocarbon gas-solid separation is performed in the cyclone separator 41, and the cyclone's feed leg extends into the stripper 5, allowing the solid material obtained from the light hydrocarbon gas-solid separation to be steam-stripped to remove hydrocarbons from the spent catalyst before being transferred to the regenerator 6 for regeneration. In the flow chart shown in FIG1 , fresh first catalyst is added to the regenerator 6 via the fresh first catalyst delivery pipe 64, where the fresh first catalyst contacts the regeneration gas and is then introduced into the riser reactor 1 via the regenerated catalyst delivery pipe 63.

[0142] Figure 2 illustrates a process flow diagram of the catalytic conversion method for increasing the yield of ethylene and propylene according to the present invention. Referring to Figure 2 , the first reactor comprises a riser reactor 1 and a fluidized bed reactor 2 coaxially arranged with the riser reactor 1. The second reactor 3 is a fluidized bed reactor arranged in parallel with the riser reactor 1. A first regenerated catalyst is introduced into the bottom of the riser reactor 1 via a regenerated catalyst delivery pipe 63, where it flows upward under the action of a pre-lifting medium. Heavy hydrocarbon feedstock and water vapor are sprayed into the riser reactor 1 through a heavy hydrocarbon feed nozzle 11, where they contact the regenerated catalyst and undergo a catalytic cracking reaction. The oil then flows upward to continue the catalytic cracking reaction within the fluidized bed reactor 2. The reacted first oil undergoes heavy hydrocarbon gas-solid separation within the heavy hydrocarbon settler 4, yielding a first spent catalyst and a first reaction oil gas. The first spent catalyst enters the heavy hydrocarbon stripper 5, where it is stripped of adsorbed hydrocarbon products and then transported via the spent catalyst delivery pipe 52 to the regenerator 6 for regeneration. The regenerated catalyst is returned to the riser reactor 1 for recycling. Fresh second catalyst is added to the second reactor 3 via the fresh second catalyst delivery pipe 33. Light hydrocarbon feedstock and water vapor enter the second reactor 3 via the light hydrocarbon feed line 31, where they contact the second catalyst for a catalytic cracking reaction, producing a second material. Light hydrocarbon gas-solid separation is performed in the light hydrocarbon settler 7 to produce a second spent catalyst and a second reaction oil and gas. The first reaction oil and gas enter the product separation system. Light hydrocarbon gas-solid separation is performed in the second cyclone separator 71. The separated second spent catalyst is fed to the light hydrocarbon stripper 8 to strip adsorbed hydrocarbons. The catalyst is then introduced to the bottom of the riser reactor 1 via the second coked catalyst delivery pipe 82. Partially stripped coked catalyst can also be removed from the device via the second coked catalyst outlet pipe 83. In the flow chart shown in Figure 2, fresh first catalyst is added to the regenerator 6 via the fresh first catalyst delivery pipe 64. The fresh first catalyst is then contacted with the regeneration gas and introduced into the riser reactor 1 via the regenerated catalyst delivery pipe 63.

[0143] Figure 3 illustrates a process flow diagram of the catalytic conversion method for increasing the yield of ethylene and propylene according to the present invention. Referring to Figure 3 , the first reactor comprises a riser reactor 1 and a fluidized bed reactor 2 coaxially arranged with the riser reactor 1. The second reactor is a fluidized bed reactor 3 arranged in parallel with the riser reactor 1. A heavy hydrocarbon settler 4 is connected in series with the first reactor, in which a first cyclone separator 41 is located. The second reactor is connected in series with a light hydrocarbon settler 7, in which a second cyclone separator 71 is located. A second reaction oil and gas outlet pipe 72 is located at the top of the light hydrocarbon settler 7, and a light hydrocarbon stripper 8 is located below the light hydrocarbon settler 7. The first regenerated catalyst is introduced into the bottom of the riser reactor 1 through a regenerated catalyst delivery pipe 63, where it flows upward under the action of a pre-lifting medium. The heavy hydrocarbon feedstock and water vapor are injected into the riser reactor 1 through a heavy hydrocarbon feed nozzle 11, where they contact the first regenerated catalyst for a catalytic cracking reaction. The oil then flows upward to continue the catalytic cracking reaction within the fluidized bed reactor 2. The reacted first oil undergoes a first separation in the heavy hydrocarbon settler 4 to produce a first spent catalyst and a first reaction oil gas. Heavy hydrocarbon gas-solid separation is performed in the first cyclone separator 41. The spent catalyst enters the heavy hydrocarbon stripper 5, where it is stripped of adsorbed hydrocarbon products and then transported via the spent catalyst delivery line 52 to the regenerator 6 for regeneration. The regenerated catalyst is returned to the riser reactor 1 for recycling. Fresh second catalyst is added to the second reactor 3 via the fresh catalyst delivery line 33. Light hydrocarbon feedstock and water vapor enter the second reactor 3 via the light hydrocarbon feed line 31, where they contact the second catalyst for a catalytic cracking reaction, producing a second material. The second material undergoes a second separation in the light hydrocarbon settler 7 to produce a second spent catalyst and a second reaction oil gas. The first reaction oil gas and the second reaction oil gas enter the product separation system. Light hydrocarbon gas-solid separation is performed in the second cyclone separator 71. The separated second spent catalyst is fed to the light hydrocarbon stripper 8 to strip adsorbed hydrocarbons and then introduced to the bottom of the riser reactor 1 via the second carbonized catalyst delivery line 82. The partially stripped carbon deposited catalyst can also be introduced into the fluidized bed reactor 3 through the second carbon deposited catalyst outlet pipe 83 .

[0144] Figure 4 illustrates a process flow diagram for catalytic conversion of ethylene and propylene according to the present invention. Referring to Figure 4 , the first reactor comprises a riser reactor 1 and a fluidized bed reactor 2 coaxially arranged with the riser reactor 1. The second reactor is a fluidized bed reactor 6 arranged in parallel with the riser reactor 1. The first regenerated catalyst is introduced into the bottom of the riser reactor 1 via a first regenerated catalyst delivery pipe 53, where it flows upward under the action of a pre-lifting medium. Heavy hydrocarbon feedstock and water vapor are sprayed into the riser reactor 1 through a heavy hydrocarbon feed nozzle 11, where they contact the first regenerated catalyst for a catalytic cracking reaction. The oil then flows upward to continue the catalytic cracking reaction within the fluidized bed reactor 2. The reacted first oil undergoes heavy hydrocarbon gas-solid separation in the heavy hydrocarbon settler 3, yielding the first spent catalyst and the first reaction oil gas. This separation occurs in the first cyclone separator 31. The spent catalyst then enters the first stripper 4, where it is stripped of adsorbed hydrocarbon products and transported via the first spent catalyst delivery pipe 42 to the first regenerator 5 for regeneration. The regenerated catalyst is returned to the riser reactor 1 for recycling. Fresh second catalyst is added to the second regenerator 9 through the fresh second catalyst delivery pipe 95. Alternatively, fresh second catalyst can be directly added to the second reactor 6. Light hydrocarbon feedstock and water vapor pass through the light hydrocarbon feed pipeline 51 and the feed distributor 62 into the second reactor 6, where they come into contact with the second catalyst for a catalytic cracking reaction to obtain a second material. The second material undergoes light hydrocarbon gas-solid separation in the second settler 7 to obtain a second spent catalyst and a second reaction oil and gas. The second separation is carried out in the second cyclone separator 71. The separated second spent catalyst is sent to the second stripper 8 to strip out adsorbed hydrocarbons, and then introduced into the lower part of the second regenerator 9 through the second spent catalyst delivery pipe 82 for char regeneration. The regenerated catalyst can be divided into two streams, which are respectively sent to the riser reactor 1 through the regenerated second catalyst delivery pipe 94 and optionally sent to the second reactor 6 through the regenerated second catalyst delivery pipe 93 for recycling. Optionally, no regenerated catalyst is sent to the second reactor 6. 4 , the fresh first catalyst is added to the first regenerator 5 through the fresh first catalyst delivery pipe 54 and is introduced into the riser reactor 1 through the first regenerated catalyst delivery pipe 53 after the fresh first catalyst contacts the regeneration gas.

[0145] Example

[0146] The method provided by the present invention is further described in detail below by way of examples, but the present invention is not limited thereto.

[0147] The heavy hydrocarbon feedstock used in the examples of the present invention and the comparative examples is atmospheric residue oil, and the light hydrocarbon feedstock is light gasoline. The properties of the heavy hydrocarbon feedstock are shown in Table 1, and the composition (weight %) of the light hydrocarbon feedstock is shown in Table 2.

[0148] Table 1

[0149] Table 2

[0150] ZSP molecular sieve was prepared according to the method disclosed in CN1176020C; USY molecular sieve was prepared according to the method disclosed in CN1127161A. Fresh catalyst was prepared according to methods well known in the art, including mixing and slurrying the molecular sieve, kaolin, and Al2O3 binder, followed by spray drying, washing, filtering, and drying.

[0151] The properties of the fresh second catalyst, fresh first catalyst and first regenerated catalyst used in the examples and comparative examples of Group A of the present invention are shown in Table A3.

[0152] Table A3

[0153] Example A1

[0154] Tests were conducted using a medium-sized unit according to the process flowsheet shown in Figure 1. The heavy hydrocarbon feedstock used atmospheric residue (properties shown in Table 1) and the light hydrocarbon feedstock used light gasoline (properties shown in Table 2). The mass ratio of atmospheric residue to light gasoline was 20:3. The catalytic conversion reaction of the heavy hydrocarbon feedstock was carried out in the first reactor, which was a combined riser + fluidized bed reactor. The second reactor, used for the reaction of the light hydrocarbon feedstock, was a dense phase fluidized bed reactor.

[0155] During the experiment, atmospheric residue and steam were injected into the riser reactor through a heavy hydrocarbon feed nozzle, where they contacted the regenerated catalyst for a catalytic cracking reaction. The oil then ascended to continue the catalytic cracking reaction in the fluidized bed reactor. The reacted first oil was subjected to heavy hydrocarbon gas-solid separation in a settler, yielding the first spent catalyst and the first reaction oil gas. The first spent catalyst then entered a stripper, where it was stripped of adsorbed hydrocarbon products and then transported via a spent catalyst feed pipe to a regenerator for regeneration. The regenerated catalyst was returned to the riser reactor for recycling. Fresh second catalyst was added to the second reactor through a fresh second catalyst feed pipe. Light hydrocarbon feed and steam were then introduced into the second reactor through a light hydrocarbon feed line, where they contacted the second catalyst for a catalytic cracking reaction, yielding the second material. The second material then underwent light hydrocarbon gas-solid separation in the settler, yielding the second spent catalyst and the second reaction oil gas. The first reaction oil gas and the second reaction oil gas entered the product separation system. Light hydrocarbon gas-solid separation was performed in a cyclone separator. The solid material obtained from this separation was steam-stripped to remove hydrocarbons from the second spent catalyst and then transported to regenerator 6 for regeneration. Fresh first catalyst was added to the regenerator via a fresh first catalyst delivery pipe. The medium-sized unit used electric heating to maintain the reaction and regeneration system temperatures. The main operating conditions and results are shown in Table A4.

[0156] Example A2

[0157] This example used the same apparatus, raw materials, catalyst, and experimental procedures as in Example A1, except that the outlet temperature of the riser reactor was 600° C. The main operating conditions and results are shown in Table A4.

[0158] Example A3

[0159] This example used the same apparatus, raw materials, catalyst, and experimental procedures as in Example A1, except that the reaction temperature in the second reactor was 550° C. The main operating conditions and results are shown in Table A4.

[0160] Comparative Example A1A and Comparative Example A1B

[0161] Comparative Examples A1A and A1B used the same reaction apparatus, raw materials, catalysts, and major steps as Example A1. These examples differed from Example A1 in that fresh second catalyst was added directly to the regenerator, and the regenerated catalyst was contacted with light gasoline for catalytic cracking (i.e., the first and second reactors used the same regenerated catalyst, which comprised both the first and second catalysts). The main operating conditions and results are shown in Table A4.

[0162] Comparative Example A2A and Comparative Example A2B

[0163] Comparative Examples A2A and A2B used the same reaction apparatus, raw materials, catalysts, and major steps as in Example A1. The difference from Example A1 was that no fresh first catalyst was added to the regenerator (i.e., the first reactor used regenerated catalyst, which contained only the second catalyst). The main operating conditions and results are shown in Table A4.

[0164] Comparative Example A3

[0165] This comparative example employed the same reaction apparatus, raw materials, catalyst, and major steps as in Example A1, differing from Example A1 in that the second reactor was a riser reactor. The major operating conditions and results are shown in Table A4.

[0166] Comparative Example A4

[0167] This comparative example employed the same reaction apparatus, raw materials, catalyst, and major steps as in Example A1, differing from Example A1 in that the mass ratio of fresh second catalyst added to light gasoline was 0.09. The major operating conditions and results are shown in Table A4.

[0168] Comparative Example A5

[0169] This comparative example employed the same reaction apparatus as in Example A1, along with the same raw materials, catalyst, and major steps as in Example A1. The differences from Example A1 were that the mass ratio of the second fresh catalyst added to the light gasoline was 0.003, and the mass ratio of the second catalyst introduced into the first reaction to the fresh first catalyst was 0.64. The main operating conditions and results are shown in Table A4.

[0170] Table A4

[0171] The properties of the catalysts used in the Examples and Comparative Examples of Group B of the present invention are shown in Table B3.

[0172] Table B3

[0173] Example B1

[0174] Tests were conducted using a medium-sized unit according to the process flowsheet shown in Figure 2. The heavy hydrocarbon feedstock used atmospheric residue (properties shown in Table 1), the light hydrocarbon feedstock used light gasoline (composition shown in Table 2), and the catalyst properties are shown in Table B3. The mass ratio of atmospheric residue to light gasoline was 5:1. The catalytic conversion reaction of the heavy hydrocarbon feedstock was carried out in the first reactor, a riser + fluidized bed combination reactor. The second reactor, used for the reaction of the light hydrocarbon feedstock, was a dense phase fluidized bed reactor.

[0175] During the test, hot regenerated catalyst was introduced to the bottom of the riser reactor. Atmospheric residue oil and steam were sprayed into the bottom of the riser reactor through nozzles, where they contacted the regenerated catalyst for a catalytic conversion reaction. The oil then ascended to continue the primary catalytic conversion reaction within the fluidized bed reactor. The reacted oil was introduced into the primary oil separation system. The separated primary reaction oil vapor entered the subsequent product separation system. The separated primary spent catalyst was stripped and then introduced into the regenerator for char regeneration. The regenerated catalyst was returned to the riser reactor for recycling. Light gasoline and steam were introduced into the secondary reactor, where they contacted fresh secondary catalyst for a secondary catalytic conversion reaction. The reacted oil was introduced into the secondary oil separation system. The separated secondary reaction oil vapor entered the subsequent product separation system. The separated secondary spent catalyst was stripped in the light hydrocarbon stripper and then introduced into the bottom of the riser reactor for a further reaction with the atmospheric residue oil. Fresh primary catalyst was added to the regenerator via a fresh primary catalyst delivery line.

[0176] The medium-sized unit uses electric heating to maintain the temperature of the reaction and regeneration systems. The main operating conditions and results are shown in Table B4.

[0177] Example B2

[0178] This example used the same apparatus, raw materials, catalyst, and experimental procedures as in Example B1, with the exception of the riser reactor outlet temperature. The main operating conditions and results are shown in Table B4.

[0179] Example B3

[0180] This example used the same apparatus, raw materials, catalyst, and experimental procedures as in Example B1, except that the reaction temperature in the second reactor was different. The main operating conditions and results are shown in Table B4.

[0181] Comparative Example B1

[0182] This comparative example employed the same reaction apparatus, raw materials, catalyst, and major steps as in Example B1. The difference from Example B1 was that fresh second catalyst was directly added to the regenerator for regeneration, and a portion of the regenerated catalyst was fed to the second reactor for contact with light gasoline for catalytic cracking (i.e., the first and second reactors used the same regenerated catalyst, wherein the regenerated catalyst comprised both the first and second catalysts). The main operating conditions and results are listed in Table B4.

[0183] Comparative Example B2

[0184] This comparative example employed the same reaction apparatus as Example B1, and the same raw materials, catalyst, and major steps were employed. This comparative example differed from Example B1 in that no fresh first catalyst was added to the regenerator (i.e., the first reactor used regenerated catalyst, which contained only the second catalyst). The main operating conditions and results are listed in Table B4.

[0185] Table B4

[0186] The properties of the catalysts used in the Examples and Comparative Examples of Group C of the present invention are shown in Table C3.

[0187] Table C3

[0188] Example C1

[0189] Tests were conducted using a medium-sized unit according to the process flow sheet shown in FIG4 . The heavy hydrocarbon feedstock used atmospheric residue (properties shown in Table 1) and the light hydrocarbon feedstock used light gasoline (composition shown in Table 2). The mass ratio of atmospheric residue to light gasoline was 5:1. The catalytic conversion reaction of the heavy hydrocarbon feedstock was carried out in the first reactor, which was a combined riser + fluidized bed reactor. The second reactor, used for the reaction of the light hydrocarbon feedstock, was a dense phase fluidized bed reactor.

[0190] During the test, hot regenerated catalyst was introduced into the bottom of the riser reactor. Atmospheric residue oil and water vapor were sprayed into the bottom of the riser reactor through a nozzle, where they came into contact with the regenerated catalyst for a catalytic conversion reaction. The oil then ascended to continue the first catalytic conversion reaction in the fluidized bed reactor. The reacted oil was introduced into the first oil separation system. The separated first reaction oil gas entered the subsequent product separation system. The separated first spent catalyst was stripped and introduced into the first regenerator (heavy hydrocarbon regenerator) for char regeneration. The regenerated regenerated catalyst was returned to the riser reactor for recycling. Light gasoline and water vapor entered the second reactor, where they came into contact with the second catalyst for a second catalytic conversion reaction. The reacted oil was introduced into the second oil separation system. The separated second reaction oil gas entered the subsequent product separation system. The separated second spent catalyst was stripped and introduced into the light hydrocarbon regenerator for regeneration. The fresh second catalyst was directly delivered to the second regenerator (light hydrocarbon regenerator) through the second fresh catalyst delivery pipe. A regenerated second catalyst is obtained in the light hydrocarbon regenerator, and a portion of the regenerated second catalyst is returned to the second reactor for recycling, and a portion of the regenerated second catalyst is sent to the bottom of the riser reactor to continue to contact and react with the atmospheric residue.

[0191] The medium-sized unit uses electric heating to maintain the temperature of the reaction and regeneration systems. The main operating conditions and results are shown in Table C4.

[0192] Example C2

[0193] This example used the same apparatus, raw materials, catalyst, and experimental procedures as Example C1, except that the outlet temperature of the riser reactor was 640° C. The main operating conditions and results are shown in Table C4.

[0194] Example C3

[0195] This example used the same apparatus, raw materials, catalyst, and experimental procedures as Example C1, except that the reaction temperature in the second reactor was 550° C. The main operating conditions and results are shown in Table C4.

[0196] Comparative Example C1

[0197] This comparative example employed the same reaction apparatus, raw materials, catalyst, and major steps as Example C1. The difference from Example C1 was that a second fresh catalyst was added to the second regenerator, and the regeneration temperature of the second regenerator was 680°C. The main operating conditions and results are listed in Table C4.

[0198] Example C4

[0199] This example used the same reaction apparatus as Example C1, and the same raw materials, catalyst, and main steps were employed. The difference from Example C1 was that the fresh second catalyst was added directly to the second reactor. The main operating conditions and results are listed in Table C4.

[0200] Table C4

[0201] As shown in Tables A4 and B4, the method provided by the present invention can significantly increase the yields of ethylene and propylene in the product and improve the conversion rate of heavy hydrocarbons. As shown in Table C4, the method provided by the present invention can promote the catalytic conversion of feedstocks to produce light olefins, significantly increasing the yields of ethylene and propylene.

[0202] 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.

[0203] 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.

[0204] 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 cracking method, characterized in that: The method comprises the following steps: The heavy hydrocarbon feedstock is contacted with the first regenerated catalyst in the first reactor to perform a first catalytic conversion reaction, and the first material obtained after the first catalytic conversion reaction is subjected to a first separation to obtain a first spent catalyst and a first reaction oil gas; feeding a fresh second catalyst into a second reactor and contacting the light hydrocarbon feedstock with the second catalyst in the second reactor to perform a second catalytic conversion reaction to obtain a second material comprising the second catalyst and a reaction product, and performing a second separation on the second material to obtain a second spent catalyst and a second reaction oil and gas; wherein the fresh second catalyst contains 10 to 80 weight percent of a zeolite having an MFI structure; The first spent catalyst is stripped and then fed into a first regenerator for regeneration, and a fresh first catalyst is fed into the first regenerator to obtain a first regenerated catalyst and returned to the first reactor; wherein the fresh first catalyst contains 10 to 70 weight percent of Y series zeolite; and At least a portion of the second spent catalyst is introduced into the first reactor, wherein the mass ratio of the second spent catalyst introduced into the first reactor to the fresh first catalyst fed into the first regenerator is (1-10):1, preferably (1-6):

1.

2. The method according to claim 1, wherein The method further comprises: feeding the second catalyst to be regenerated together with the first catalyst to be regenerated into the first regenerator for regeneration to obtain the first regenerated catalyst, and returning the first regenerated catalyst to the first reactor; preferably, stripping the second catalyst to be regenerated together with the first catalyst to be regenerated in a heavy hydrocarbon stripper, and feeding the stripped second catalyst to be regenerated together with the first catalyst to be regenerated into the first regenerator for regeneration to obtain the first regenerated catalyst, and returning the first regenerated catalyst to the first reactor; and / or The method further includes discharging a portion of the second catalyst through a catalyst outlet pipe disposed at the lower portion of the second reactor.

3. The method according to claim 1, wherein The first reactor is a riser and fluidized bed combined reactor, and the method further comprises: feeding the second spent catalyst into the fluidized bed of the first reactor.

4. The method according to claim 1, wherein The method also includes: sending the second spent catalyst into a light hydrocarbon stripper for stripping to obtain a stripped second catalyst, sending at least a portion of the stripped second catalyst into the first reactor, and optionally outputting the remaining stripped second catalyst through a catalyst output pipe provided at the lower part of the light hydrocarbon stripper, preferably returning the remaining stripped second catalyst to the second reactor.

5. The method according to claim 1, wherein The first reactor is a combined riser and fluidized bed reactor, and the method further includes: sending the second spent catalyst into a light hydrocarbon stripper for stripping to obtain a stripped second catalyst, and sending at least a portion of the stripped second catalyst into the riser of the first reactor, and optionally outputting the remaining stripped second catalyst through a catalyst output pipe provided at the lower part of the light hydrocarbon stripper, and preferably returning the remaining stripped second catalyst to the second reactor.

6. The method according to claim 1, wherein The feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second reactor, and the method further includes: feeding the second catalyst to be regenerated into a second regenerator for regeneration to obtain a regenerated second catalyst, and feeding at least a portion of the regenerated second catalyst into the first reactor, and optionally returning the remaining portion of the regenerated second catalyst to the second reactor; or The feeding of the fresh second catalyst into the second reactor includes directly feeding the fresh second catalyst into the second regenerator, and the method further includes: feeding the second catalyst to be regenerated into the second regenerator for regeneration to obtain a regenerated second catalyst, feeding a portion of the regenerated second catalyst into the first reactor, and returning a portion of the regenerated second catalyst to the second reactor; Preferably, the regeneration temperature in the second regenerator is 400-650°C, preferably 450-600°C.

7. The process according to claim 1, wherein the first reactor is a riser and fluidized bed combination reactor, and Said feeding of the fresh second catalyst into the second reactor comprises feeding the fresh second catalyst directly into the second reactor, and the method further comprises: feeding the second catalyst to be spent into a second regenerator for regeneration to obtain a regenerated second catalyst, and feeding at least a portion of the regenerated second catalyst into the riser of the first reactor, and optionally returning the remaining portion of the regenerated second catalyst to the second reactor; or said feeding of the fresh second catalyst into the second reactor comprises feeding the fresh second catalyst directly into the second regenerator, and the method further comprises: feeding the second catalyst to be spent into the second regenerator for regeneration to obtain a regenerated second catalyst, and feeding a portion of the regenerated second catalyst into the riser of the first reactor, and returning the remaining portion of the regenerated second catalyst to the second reactor; Preferably, the regeneration temperature in the second regenerator is 400-650°C, preferably 450-600°C.

8. The method according to any one of claims 1 to 7, wherein: The carbon mass content on the second spent catalyst is A, the mass ratio of the feed amount of the fresh second catalyst to the feed amount of the light hydrocarbon feedstock is R, and A and R satisfy the following relationship: 0.2 / (1+6B) <R / A<10 / (1+2B) Wherein, B is the mass content of olefins in the light hydrocarbon feedstock; Preferably, the method further comprises detecting the values ​​of A and B over time and adjusting the value of R according to the detected values ​​of A and B so that R / A still satisfies the above relationship.

9. The method according to any one of claims 1 to 8, wherein: The method further comprises separating the first reaction oil gas and the second reaction oil gas, and optionally using one or more components obtained by separation as the light hydrocarbon feedstock; and / or The regeneration temperature in the first regenerator is 550-750°C, preferably 600-720°C; and / or The regeneration temperature in the first regenerator is 20 to 200° C. higher than the regeneration temperature in the second regenerator, preferably 40 to 160° C. higher; and / or The mass ratio of the fresh first catalyst feed amount to the heavy hydrocarbon feed amount is (0.0001-0.1):1, preferably (0.0005-0.005):1; and / or The mass ratio R of the fresh second catalyst feed amount to the light hydrocarbon feed amount is (0.0004-0.2):1, preferably (0.001-0.1):1; and / or The micro-reaction activity of the first regenerated catalyst is 40-80%, preferably 50-70%; and / or The micro-reaction activity of the fresh first catalyst is 70-95%, preferably 75-90%; and / or The micro-reaction activity of the fresh second catalyst is 50-95%, preferably 55-85%; and / or The average linear velocity of oil and gas in the second reactor is 0.01 to 10 m / s, preferably 0.1 to 5 m / s; and / or Only the second catalyst is used in the second reactor.

10. The method according to any one of claims 1 to 9, wherein: The first reactor is selected from one or more of a riser, a fluidized bed, a fast bed and a downcomer; and / or the second reactor is selected from a fluidized bed, preferably a dense fluidized bed; preferably, the first reactor is a riser and fluidized bed combined reactor, and the second reactor is a dense fluidized bed reactor.

11. The method according to any one of claims 1 to 10, wherein: The fresh first catalyst contains 15-70 wt% of the first clay, 15-70 wt% of the first inorganic oxide and 10-70 wt% of the Y series zeolite; preferably, the fresh first catalyst contains 20-70 wt% of the first clay, 20-70 wt% of the first inorganic oxide and 10-60 wt% of the Y series zeolite; and / or The fresh second catalyst contains 10-80 wt% of the second clay, 10-80 wt% of the second inorganic oxide, and 10-80 wt% of the zeolite having an MFI structure; preferably, the fresh second catalyst contains 15-70 wt% of the second clay, 15-70 wt% of the second inorganic oxide, and 20-70 wt% of the zeolite having an MFI structure; Preferably, the zeolite having an MFI structure is selected from ZSM series zeolites and ZSP zeolites.

12. The method according to claim 11, wherein The first clay and the second clay are independently selected from at least one of kaolin, halloysite, sepiolite, attapulgite, montmorillonite and rectorite, preferably kaolin and / or halloysite; and / or The first inorganic oxide and the second inorganic oxide are independently selected from at least one of aluminum oxide, silicon oxide, amorphous silicon aluminum and phosphorus aluminum sol, preferably silicon dioxide and / or aluminum oxide; and / or The zeolite having an MFI structure is selected from ZSM series zeolites and ZSP zeolites; preferably, the ZSM series zeolites include modified or unmodified ZSM zeolites, preferably at least one of modified or unmodified ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38 and ZSM-48; and / or The Y series zeolite includes at least one of rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultrastable Y-type zeolite and high silicon Y-type zeolite; and / or The first catalyst and / or the second catalyst may further optionally contain beta zeolite.

13. The method according to any one of claims 1 to 12, wherein: The zeolite having the MFI structure constitutes at least 80% by weight, preferably at least 90% by weight, of all the zeolites contained in the fresh second catalyst; and / or The mass ratio of the zeolite with MFI structure to the Y series zeolite contained in the second spent catalyst introduced into the first reactor and the fresh first catalyst sent to the first regenerator is (1-15):1, preferably (2-10):

1.

14. The method according to any one of claims 1 to 13, wherein: The conditions of the first catalytic conversion reaction include: a temperature of 450 to 700° C., preferably 520 to 650° C.; a pressure of 0.05 to 0.2 MPa, preferably 0.08 to 0.15 MPa; a mass ratio of the heavy hydrocarbon feedstock to the first regenerated catalyst of 1:(3 to 100), preferably 1:(4 to 40); a mass ratio of the heavy hydrocarbon feedstock to water vapor of 1:(0.05 to 5), preferably 1:(0.2 to 2); and an oil and gas residence time of 0.1 to 100 seconds, preferably 0.5 to 20 seconds; and / or The conditions of the second catalytic conversion reaction include: temperature of 500-750°C, preferably 550-700°C; pressure of 0.05-0.2 MPa, preferably 0.08-0.15 MPa; weight hourly space velocity of 0.1-50 h -1 , preferably 0.2 to 10 hours -1 ; and the weight ratio of the light hydrocarbon feedstock to water vapor is 1: (0.1 to 5), preferably 1: (0.2 to 3).

15. The method according to any one of claims 1 to 14, wherein: The heavy hydrocarbon raw material is selected from one or more of petroleum hydrocarbons, mineral oils, synthetic oils, animal fats and vegetable fats; and / or the light hydrocarbon raw material is selected from one or more of C4 to C10 hydrocarbons; Preferably, the petroleum hydrocarbon is selected from one or more of crude oil, atmospheric wax oil, vacuum wax oil, atmospheric residue oil, vacuum residue oil, deasphalted oil, hydrogenated heavy oil, coker wax oil, diesel and naphtha; and the mineral oil is selected from one or more of coal liquefaction oil, oil sand oil and shale oil; and Preferably, the C4-C10 hydrocarbons are selected from one or more of C4, C5, C6, C7, C8, C9 and C10 alkanes, cycloalkanes, olefins and aromatics.

16. A system for the method according to any one of claims 1 and 8 to 15, characterized in that: The system comprises a first reactor, a heavy hydrocarbon stripper coaxially arranged with the first reactor, a second reactor, a first gas-solid separation device, a second gas-solid separation device, and a first regenerator; and the system comprises a mechanism for introducing at least a portion of the second regenerated catalyst into the first reactor; The first reactor comprises a riser reactor and a fluidized bed reactor directly connected to the outlet of the riser reactor; the bottom of the riser reactor is provided with a first catalyst inlet for introducing a first regenerated catalyst, and the lower part is provided with a heavy hydrocarbon inlet; and the top of the fluidized bed reactor is provided with a first reaction material outlet; The inlet of the heavy hydrocarbon stripper is communicated with the outlet of the catalyst to be regenerated of the first gas-solid separation device, and the outlet of the heavy hydrocarbon stripper is communicated with the first inlet of the catalyst to be regenerated of the first regenerator; The second reactor is provided with a light hydrocarbon inlet at the bottom, a second reaction material outlet at the top, and a fresh second catalyst inlet at the lower part of the second reactor; preferably, the second reactor is a dense phase fluidized bed reactor; The first regenerator is provided with a flue gas outlet at the top, a first regenerated catalyst outlet at the upper part, a first catalyst inlet to be regenerated and a fresh first catalyst inlet at the lower part, and a first regeneration gas inlet at the bottom; The first reaction material outlet of the fluidized bed reactor is connected to the inlet of the first gas-solid separation device; The catalyst outlet of the first regenerator is in communication with the first catalyst inlet of the first reactor; and The second reaction material outlet of the second reactor is communicated with the inlet of the second gas-solid separation device.

17. The system according to claim 16, wherein the system is used to implement the method according to claim 2 or 3, wherein the spent catalyst outlet of the second gas-solid separation device is connected to the inlet of the heavy hydrocarbon stripper; Optionally, a catalyst outlet pipe is provided at the lower portion of the second reactor.

18. The system according to claim 16, wherein the system is used to implement the method according to claim 4 or 5, wherein the system further comprises a light hydrocarbon stripper arranged coaxially with the second reactor; a material outlet is provided at the top of the second gas-solid separation device; and the light hydrocarbon stripper is provided with an outlet for the stripped catalyst; A second catalyst inlet is provided at the bottom of the riser reactor; The inlet of the light hydrocarbon stripper is connected to the outlet of the spent catalyst of the second gas-solid separation device; and The stripped catalyst outlet of the light hydrocarbon stripper is in communication with the second catalyst inlet of the riser reactor; Optionally, the light hydrocarbon stripper further comprises a catalyst outlet pipe provided at the lower portion of the light hydrocarbon stripper, which is optionally in communication with the second reactor.

19. The system according to claim 16, wherein the system is used to implement the method according to claim 6 or 7, wherein the system further comprises a light hydrocarbon stripper arranged coaxially with the second reactor; and the system further comprises a second regenerator; The top of the second gas-solid separation device is provided with a material outlet, and the light hydrocarbon stripper is provided with a catalyst outlet after stripping; The second regenerator is provided with a flue gas outlet at the top, a first outlet for regenerating the second catalyst at the upper part, an inlet for the second catalyst to be regenerated at the lower part, and a second regeneration gas inlet at the bottom; The inlet of the light hydrocarbon stripper is connected to the outlet of the spent catalyst of the second gas-solid separation device; The stripped catalyst outlet of the light hydrocarbon stripper is connected to the second catalyst inlet to be regenerated of the second regenerator; A second catalyst inlet is provided at the bottom of the riser reactor; The regenerated second catalyst first outlet of the second regenerator is in communication with the second catalyst inlet of the riser reactor; and Optionally, a second outlet for regenerating the second catalyst is provided at the upper portion of the second regenerator, which is communicated with the second reactor.

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