Catalytic conversion method and system for producing ethylene and propylene from heavy hydrocarbon oil

Abstract

The invention relates to a catalytic conversion method and system for producing ethylene and propylene from heavy hydrocarbon oil, and the catalytic conversion method comprises the following steps: carrying out deasphalting treatment on the heavy hydrocarbon oil to respectively obtain light deasphalted oil, heavy deasphalted oil and deoiled asphalt; introducing the light deasphalted oil into the bottom of a first riser reactor, contacting the light deasphalted oil with a first catalyst to carry out a first catalytic conversion reaction, and feeding an obtained first oil agent mixture into a separation device for separation; introducing the heavy deasphalted oil into the bottom of a second riser reactor, and contacting the heavy deasphalted oil with a second catalyst for a second catalytic conversion reaction to obtain a second oiling agent mixture; the second oil agent mixture is introduced into a fluidized bed reactor for a third catalytic conversion reaction, and the reaction material flow is separated; the method provided by the invention can reduce green coke and improve the yield of ethylene and propylene.

Description

Technical Field

[0001] This invention relates to the field of petrochemicals, specifically to a catalytic conversion method and system for producing ethylene and propylene from heavy hydrocarbon oils. Background Technology

[0002] Ethylene and propylene are important basic chemical raw materials. Currently, the production of ethylene and propylene mainly relies on the steam cracking of light hydrocarbon oils.

[0003] As crude oil becomes increasingly heavier, the supply of light petroleum hydrocarbons can no longer meet the demand for steam cracking. Therefore, the technology of producing low-carbon olefins such as ethylene and propylene using heavy petroleum hydrocarbons is receiving increasing attention. For example, CN1218786A discloses a catalytic thermal cracking method for producing ethylene and propylene. In a riser or downflow reactor, heavy petroleum hydrocarbons are reacted with a catalyst containing layered column clay molecular sieves and / or five-membered ring high-silica molecular sieves modified with phosphorus and aluminum or magnesium or calcium. By adjusting the reaction conditions, the yields of ethylene and propylene in the products both exceed 18% by weight.

[0004] CN1393510A discloses a method for catalytic conversion of heavy petroleum hydrocarbons to increase the production of ethylene and propylene. The method involves contacting and reacting the petroleum hydrocarbon feedstock with a catalyst containing a five-membered ring high-silica molecular sieve in a riser or fluidized bed reactor. Water vapor is injected in stages as the oil-agent mixture moves upward along the reactor. This method can also alleviate the hydrothermal deactivation of the catalyst to some extent.

[0005] CN102443423A discloses a method for catalytic conversion of petroleum hydrocarbons to produce high yields of ethylene, propylene, and light aromatics. Preheated petroleum hydrocarbon feedstock and a pyrolysis catalyst are introduced into the bottom of a fluidized bed reactor. The mixture of the petroleum hydrocarbon feedstock and the pyrolysis catalyst passes sequentially from bottom to top through a pre-lifting zone, a first reaction zone, a quenching zone, and a second reaction zone of the fluidized bed reactor under the action of a lifting medium. The reaction occurs in the first reaction zone, the quenching zone, and the second reaction zone under catalytic pyrolysis conditions. By controlling the reaction temperature in each reaction zone, and by controlling the reaction temperature in the first reaction zone to be 20-150°C higher than that in the second reaction zone, higher yields of ethylene, propylene, and light aromatics can be obtained.

[0006] CN102899078A discloses a catalytic cracking method for producing propylene, comprising: in a first riser reactor, contacting a heavy feedstock with a first catalyst containing shape-selective zeolite with an average pore size of less than 0.7 nm for cracking reaction; then separating the oil and catalyst, introducing the oil and gas into a product separation system, and introducing the catalyst into a stripper or fluidized bed reactor; in a second riser reactor, contacting recycled cracked heavy oil with a second catalyst containing shape-selective zeolite with an average pore size of less than 0.7 nm for cracking reaction, then contacting the resulting oil-catalyst mixture with light hydrocarbons introduced into the second riser reactor for reaction, then introducing the reaction mixture into a fluidized bed combined reactor for reaction, introducing the reacted oil and gas into a product separation system, and introducing the reacted catalyst into a stripper. This method is used for heavy oil catalytic cracking, achieving high heavy oil conversion and high yields of propylene and butene.

[0007] In summary, existing technologies typically employ catalysts containing shape-selective zeolites or heat carriers, as well as multi-reaction-zone reactors, in order to achieve both heavy hydrocarbon conversion and increased ethylene and propylene production. However, heavy hydrocarbons contain high levels of asphaltenes and residual carbon, resulting in harsh reaction conditions and a need for further improvement in ethylene and propylene yields. Summary of the Invention

[0008] The purpose of this invention is to improve the production capacity of ethylene and propylene from heavy hydrocarbon oils, further increase the yield of ethylene and propylene, and reduce the generation of coke.

[0009] To achieve the above objectives, a first aspect of the present invention provides a catalytic conversion method for producing ethylene and propylene from heavy hydrocarbon oil, the catalytic conversion method comprising: Heavy hydrocarbon oil is deasphalted to obtain light deasphalted oil, heavy deasphalted oil and deoiled asphalt, respectively. The light deasphalted oil is introduced into the bottom of the first riser reactor and comes into contact with the first catalyst to carry out the first catalytic conversion reaction, resulting in a first oil-agent mixture; the first oil-agent mixture is then subjected to a first separation to obtain a first reaction oil-gas and a first catalyst to be generated. The deasphalted oil is introduced into the bottom of the second riser reactor and comes into contact with the second catalyst to carry out the second catalytic conversion reaction, thereby obtaining the second oil-agent mixture; The second oil-agent mixture is introduced into a fluidized bed reactor for a third catalytic conversion reaction, and the reaction stream is separated to obtain a second reaction oil-gas and a second catalyst to be generated. The first and second reaction oil and gas are separated to obtain dry gas, liquefied gas, gasoline, diesel and oil slurry; The light deasphalted oil has an initial boiling point of any temperature between 280-320℃ and a final boiling point of any temperature between 640-680℃; the heavy deasphalted oil has an initial boiling point of any temperature between 300-340℃ and a final boiling point of any temperature between 680-720℃; the first catalyst and the second catalyst comprise MPZ multi-level porous molecular sieves.

[0010] Optionally, the initial boiling point of the light deasphalted oil is any temperature between 290-310℃, and the final boiling point is any temperature between 650-670℃; and / or the asphaltene content in the light deasphalted oil is 0.01-0.2% by weight, preferably 0.01-0.1% by weight; and / or the carbon residue content in the light deasphalted oil is 0.1-2.0% by weight, preferably 0.1-1.0% by weight.

[0011] Optionally, the initial boiling point of the heavy deasphalting oil is any temperature between 310-330℃, and the final boiling point is any temperature between 690-710℃; and / or the asphaltene content in the heavy deasphalting oil is 0.05-0.5% by weight, preferably 0.05-0.2% by weight; and / or the carbon residue content in the heavy deasphalting oil is 0.5-4.0% by weight, preferably 0.5-2.0% by weight.

[0012] Optionally, the conditions for the first catalytic conversion reaction include: a reaction temperature of 600-660 ℃, preferably 620-640 ℃; a catalyst-to-oil ratio of 5-50, preferably 10-40; an oil-gas residence time of 0.5-1.5 s, preferably 0.5-1.0 s; and a reaction pressure of 0.15-0.30 MPa, preferably 0.15-0.20 MPa. The conditions for the second catalytic conversion reaction include: a reaction temperature of 580-640 ℃, preferably 600-620 ℃; a catalyst-to-oil ratio of 5-25, preferably 10-20; an oil-gas residence time of 0.5-1.5 s, preferably 0.5-1.0 s; and a reaction pressure of 0.15-0.30 MPa, preferably 0.15-0.20 MPa. The conditions for the third catalytic conversion reaction include: a reaction temperature of 560-640 ℃, preferably 580-620 ℃. ℃; weight hourly space velocity is 1-30 h -1 Preferably 3-20 h -1 The reaction pressure is 0.15-0.30 MPa, preferably 0.15-0.20 MPa.

[0013] Optionally, the first catalyst and the second catalyst each independently comprise a molecular sieve mixture, a heat-resistant inorganic oxide, and clay; based on the weight of each of the first catalyst and the second catalyst, each of the first catalyst and the second catalyst independently contains 1-60% by weight of the molecular sieve mixture, 5-99% by weight of the heat-resistant inorganic oxide, and 0-70% by weight of clay, and the sum of the weight contents of each component is 100%; based on the total weight of the molecular sieve mixture, the molecular sieve mixture contains 80-100% by weight of the MPZ hierarchical porous molecular sieve.

[0014] Optionally, in the surface XPS elemental analysis of the MPZ hierarchical porous molecular sieve, n1 / n2 is less than or equal to 0.08, where n1 represents the number of moles of phosphorus in the MPZ hierarchical porous molecular sieve, and n2 represents the total number of moles of silicon and aluminum in the MPZ hierarchical porous molecular sieve; preferably, after hydrothermal aging at 800 ℃, 100% water vapor conditions, and 17 h, the proportion of the area of ​​strong acid central peaks with desorption temperatures above 200 ℃ in the NH3-TPD spectrum is greater than or equal to 45% of the total area of ​​acid central peaks.

[0015] Optionally, the deasphalting treatment includes the following steps: subjecting the heavy hydrocarbon oil to a first supercritical extraction to obtain a deasphalted oil solution and deasphalted asphalt; subjecting the deasphalted oil solution to a second supercritical extraction to obtain a light deasphalted oil solution and heavy deasphalted oil; and recovering the solvent from the light deasphalted oil solution to obtain an extractant and light deasphalted oil; wherein the extractant is selected from one or more of C4-C6 alkanes; the content of gums in the heavy hydrocarbon oil is 5.0-20.0% by weight, and the content of asphaltene is 0.5-5.0% by weight; optionally, the heavy hydrocarbon oil is selected from one or a mixture of several of vacuum gas oil, atmospheric residue, vacuum residue, hydrotreated vacuum gas oil, and hydrotreated atmospheric residue.

[0016] Optionally, the method further includes: regenerating the first and second spent catalysts by coking to obtain a regenerated catalyst; dividing the regenerated catalyst into at least two streams and returning them to the first and second riser reactors for recycling, respectively; optionally, the conditions for coking regeneration include: a temperature of 650-750 ℃ ​​and a pressure of 0.15-0.30 MPa.

[0017] Optionally, the method further includes: introducing the deoiled asphalt into the upper part of the second riser reactor for reaction; and / or hydrogenating the deoiled asphalt to obtain a hydrogenated product, and introducing the hydrogenated product into the upper part of the second riser reactor for reaction.

[0018] A second aspect of the present invention provides a system for the catalytic conversion method described in the first aspect of the present invention. The system includes a first riser reactor, a second riser reactor, a fluidized bed reactor, a settling tank, a stripper, and an oil-to-fuel separation device. The first riser reactor and the second riser reactor are arranged side-by-side. The outlet of the second riser reactor is connected to any position of the fluidized bed reactor. The settling tank is located above the fluidized bed reactor. The stripper is located below the fluidized bed reactor. The stripper is arranged around the second riser reactor, coaxial with the fluidized bed reactor, and directly below the fluidized bed reactor. The first riser reactor is located outside the stripper, passes through the interior of the settling tank, and communicates with the oil-to-fuel separation device.

[0019] Through the above technical solution, the present invention has the following beneficial effects: (1) The present invention removes most of the asphalt and some of the gum from the heavy hydrocarbon oil by deasphalting the heavy hydrocarbon oil, thereby reducing coking and increasing the yield of ethylene and propylene. (2) By sending the light deasphalted oil and heavy deasphalted oil obtained from the deasphalting treatment of heavy hydrocarbon oil into different reactors for catalytic conversion, it is beneficial to control the reaction conditions separately, which is beneficial to increase the yield of ethylene and propylene and reduce the yield of coke. (3) By using MPZ molecular sieve catalyst to catalytically convert the above-mentioned modified heavy hydrocarbon oil, the selectivity of ethylene and propylene can be improved and the coking rate can be significantly reduced.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating a specific embodiment of the catalytic conversion method of the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. First riser reactor; 11. First pre-rise gas pipe; 12. Light deasphalted oil feed pipe; 13. First regenerator conveying pipe; 2. Second riser reactor; 21. Second pre-rise gas pipe; 22. Heavy deasphalted oil feed pipe; 23. Second regenerator conveying pipe; 24. Hydrogenated deoiled asphalt feed pipe; 3. Stripper; 31. Stripping gas pipe; 32. Stripping baffle; 33. Catalyst conveying pipe; 4. Fluidized bed reactor; 5. Settler; 51. Cyclone separator; 52. Gas collection chamber; 53. Reaction oil and gas pipeline; 6. Regenerator; 61. Main air inlet pipe; 62. Cyclone separator; 63. Gas collection chamber; 64. Flue gas pipeline. Detailed Implementation

[0023] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0024] In this invention, unless otherwise specified, pressure refers to absolute pressure.

[0025] A first aspect of the present invention provides a catalytic conversion method for producing ethylene and propylene from heavy hydrocarbon oil, the catalytic conversion method comprising: Heavy hydrocarbon oil is deasphalted to obtain light deasphalted oil, heavy deasphalted oil and deoiled asphalt, respectively. The light deasphalted oil is introduced into the bottom of the first riser reactor and comes into contact with the first catalyst to carry out the first catalytic conversion reaction, resulting in a first oil-agent mixture; the first oil-agent mixture is then subjected to a first separation to obtain a first reaction oil-gas and a first catalyst to be generated. The deasphalted oil is introduced into the bottom of the second riser reactor and comes into contact with the second catalyst to carry out the second catalytic conversion reaction, thereby obtaining the second oil-agent mixture; The second oil-agent mixture is introduced into a fluidized bed reactor for a third catalytic conversion reaction, and the reaction stream is separated to obtain a second reaction oil-gas and a second catalyst to be generated. The first and second reaction oil and gas are separated to obtain dry gas, liquefied gas, gasoline, diesel and oil slurry; The light deasphalted oil has an initial boiling point of any temperature between 280-320℃ and a final boiling point of any temperature between 640-680℃; the heavy deasphalted oil has an initial boiling point of any temperature between 300-340℃ and a final boiling point of any temperature between 680-720℃; the first catalyst and the second catalyst comprise MPZ multi-level porous molecular sieves.

[0026] Through the above technical solution, the present invention removes most of the asphalt and some of the gum from the heavy hydrocarbon oil by deasphalting the heavy hydrocarbon oil, thereby reducing coking and increasing the yield of ethylene and propylene. At the same time, the present invention improves the selectivity of ethylene and propylene and significantly reduces coking by using MPZ molecular sieve catalyst to catalytically convert the above-mentioned modified heavy hydrocarbon oil.

[0027] Furthermore, by feeding the light deasphalted oil and heavy deasphalted oil obtained from the deasphalting of heavy hydrocarbon oil into different reactors for catalytic conversion, it is beneficial to control the reaction conditions separately, which can help increase the yield of ethylene and propylene and reduce the yield of coke.

[0028] In this invention, the reaction oil and gas are introduced into the product separation unit for separation. The resulting dry gas contains ethylene, and the liquefied gas contains propylene. The coke yield is calculated by the concentration of carbon monoxide and carbon dioxide in the regenerated flue gas and the main air flow rate.

[0029] In this invention, the method for deasphalting heavy hydrocarbon oil is a common method in the field, and for details, please refer to CN114426861A.

[0030] In some embodiments of the present invention, the deasphalting treatment includes the following steps: Heavy hydrocarbon oil is subjected to first supercritical extraction to obtain deasphalted oil solution and deoiled asphalt; The deasphalted oil solution is subjected to a second supercritical extraction to obtain a light deasphalted oil solution and a heavy deasphalted oil. The solvent in the lightly deasphalted oil solution is recovered to obtain the extractant and the lightly deasphalted oil. The extractant is selected from one or more of C4-C6 alkanes; The content of gums in the heavy hydrocarbon oil can be 5.0-20.0% by weight, and the content of asphaltenes can be 0.5-5.0% by weight.

[0031] The heavy hydrocarbon oil may be selected from one or a mixture of several of the following: vacuum gas oil, atmospheric residue oil, vacuum residue oil, hydrotreated vacuum gas oil, and hydrotreated atmospheric residue oil.

[0032] In some embodiments of the present invention, after the above-mentioned deasphalting treatment, the yield of the lightly deasphalted oil is 50-80%, preferably 60-70%; the yield of the heavily deasphalted oil is 10-40%, preferably 20-30%; and the yield of the deasphalted asphalt is 10-50%, preferably 10-40%.

[0033] In some embodiments of the present invention, the asphalt removal rate of the lightly deasphalted oil is greater than 90%, and the asphalt removal rate of the heavily deasphalted oil is greater than 80%.

[0034] In some embodiments of the present invention, the carbon removal rate of the lightly deasphalted oil is greater than 80%, and the carbon removal rate of the heavily deasphalted oil is greater than 60%.

[0035] In some embodiments of the present invention, the initial boiling point of the light deasphalted oil is any temperature between 290-310°C, and the final boiling point is any temperature between 650-670°C.

[0036] In some embodiments of the present invention, the asphalt content in the light deasphalted oil is 0.01-0.2% by weight, preferably 0.01-0.1% by weight.

[0037] In some embodiments of the present invention, the carbon residue content in the light deasphalted oil is 0.1-2.0% by weight, preferably 0.1-1.0% by weight.

[0038] In some embodiments of the present invention, the initial boiling point of the deasphalted oil is any temperature between 310-330°C, and the final boiling point is any temperature between 690-710°C.

[0039] In some embodiments of the present invention, the asphalt content in the deasphalted oil is 0.05-0.5% by weight, preferably 0.05-0.2% by weight.

[0040] In some embodiments of the present invention, the residual carbon content in the deasphalted oil is 0.5-4.0% by weight, preferably 0.5-2.0% by weight.

[0041] In this process, the light deasphalted oil and a catalyst rich in MPZ molecular sieves undergo a catalytic conversion reaction in the first riser reactor to convert the light deasphalted oil, which has a stronger cracking capacity, into small molecule hydrocarbons. The oil-agent mixture at the outlet of the first riser reactor is then directly introduced into a separation device for separation. Specifically, the conditions for the first catalytic conversion reaction may include: a reaction temperature of 600-660 ℃, preferably 620-640 ℃; an oil-agent ratio of 5-50, preferably 10-40; an oil-gas residence time of 0.5-1.5 s, preferably 0.5-1.0 s; and a reaction pressure of 0.15-0.30 MPa, preferably 0.15-0.20 MPa.

[0042] In this process, the deasphalted oil and a catalyst rich in MPZ molecular sieves undergo catalytic cracking in a second riser reactor. By controlling the reaction conditions, the deasphalted oil reacts at a relatively lower reaction temperature and with a longer contact time, which is beneficial for the full conversion of the feedstock. Specifically, the conditions for the second catalytic conversion reaction may include: a reaction temperature of 580-640 ℃, preferably 600-620 ℃; a catalyst-to-oil ratio of 5-25, preferably 10-20; an oil-gas residence time of 0.5-1.5 s, preferably 0.5-1.0 s; and a reaction pressure of 0.15-0.30 MPa, preferably 0.15-0.20 MPa.

[0043] The oil-agent mixture obtained from the second riser reactor is introduced into a fluidized bed reactor for further reaction, thereby enhancing the catalytic conversion of heavy deasphalted oil and further improving the selectivity of ethylene and propylene. Specifically, the conditions for the third catalytic conversion reaction include: a reaction temperature of 560-640 °C, preferably 580-620 °C; and a heavy hourly space velocity of 1-30 h⁻¹. -1 Preferably 3-20 h -1 The reaction pressure is 0.15-0.30 MPa, preferably 0.15-0.20 MPa.

[0044] In some embodiments of the present invention, the first catalyst and the second catalyst each independently comprise a molecular sieve mixture, a heat-resistant inorganic oxide, and clay; based on the weight of each of the first catalyst and the second catalyst, each of the first catalyst and the second catalyst independently contains 1-60% by weight of the molecular sieve mixture, 5-99% by weight of the heat-resistant inorganic oxide, and 0-70% by weight of clay, and the sum of the weight contents of each component is 100%; based on the total weight of the molecular sieve mixture, the molecular sieve mixture contains 80-100% by weight of the MPZ hierarchical porous molecular sieve.

[0045] In this invention, the MPZ hierarchical porous molecular sieve is a phosphorus- and metal-containing hierarchical porous ZSM-5 molecular sieve, in which phosphorus is fully coordinated with the framework aluminum, which can fully protect the framework aluminum.

[0046] In some embodiments of the present invention, in the surface XPS elemental analysis of the MPZ hierarchical porous molecular sieve, n1 / n2 is less than or equal to 0.08, where n1 represents the number of moles of phosphorus in the MPZ hierarchical porous molecular sieve, and n2 represents the total number of moles of silicon and aluminum in the MPZ hierarchical porous molecular sieve.

[0047] In some embodiments of the present invention, the MPZ hierarchical porous molecular sieve exhibits good hydrothermal stability. Specifically, after hydrothermal aging at 800°C and 100% steam for 17 hours, the NH3-TPD spectrum of the MPZ hierarchical porous molecular sieve shows that the area of ​​strong acid centers with desorption temperatures above 200°C accounts for greater than or equal to 45% of the total area of ​​acid centers, preferably between 45% and 60%, indicating a high retention rate of strong acid centers. This molecular sieve can increase the production of liquefied petroleum gas, improve the yield of low-carbon olefins, and produce more high-value-added products. The preparation method of the MPZ hierarchical porous molecular sieve can be found in CN113526519A and CN14715911A.

[0048] In some embodiments of the present invention, the method further includes: regenerating the first spent catalyst and the second spent catalyst by coking to obtain a regenerated catalyst; and dividing the regenerated catalyst into at least two streams, which are then returned to the first riser reactor and the second riser reactor for recycling.

[0049] Specifically, the conditions for coke regeneration include: a temperature of 650-750 ℃ ​​and a pressure of 0.15-0.30 MPa.

[0050] In some embodiments of the present invention, the method further includes: introducing the deoiled asphalt into the upper part of the second riser reactor for reaction.

[0051] In another embodiment of the present invention, the method further includes: hydrogenating the deoiled asphalt to obtain a hydrogenated product, and introducing the hydrogenated product into the upper part of the second riser reactor for reaction. The conditions for the hydrogenation reaction of the deoiled asphalt can be conventionally chosen in the art, and the present invention does not limit them. Hydrogenation modification of deoiled asphalt can reduce the content of gums and asphaltenes, and contain more components that are easily catalytically cracked.

[0052] The present invention also provides a system for the above-described catalytic conversion method, the system comprising a first riser reactor, a second riser reactor, a fluidized bed reactor, a settling tank, a stripper, and an oil-to-agent separation device, wherein the first riser reactor and the second riser reactor are arranged side by side; the outlet of the second riser reactor is connected to any position of the fluidized bed reactor; the settling tank is located above the fluidized bed reactor; the stripper is located below the fluidized bed reactor; the stripper is arranged around the second riser reactor, coaxial with the fluidized bed reactor, and located directly below the fluidized bed reactor; the first riser reactor is located outside the stripper, passes through the interior of the settling tank, and is connected to the oil-to-agent separation device.

[0053] Among them, such as Figure 1As shown, the first riser reactor 1 can be equipped with a first pre-rise gas pipe 11 and a light deasphalted oil feed pipe 12. The second riser reactor can be equipped with a second pre-rise gas pipe 21, a heavy deasphalted oil feed pipe 22, and an optional hydrotreated deasphalted oil feed pipe 24. The pre-rise gas is selected from one or a mixture of several of water vapor, low-carbon alkanes, and nitrogen, preferably water vapor. The bottom of the stripper 3 can be equipped with a stripping gas pipe 31, and the stripping gas is usually water vapor. The regenerator 6 can be equipped with a main air inlet pipe 61.

[0054] The following is in conjunction with the appendix Figure 1 The method provided by the present invention will be further described, but this does not limit the present invention.

[0055] Figure 1 This illustration schematically shows a particularly preferred embodiment of the invention, such as... Figure 1 As shown, in this invention, heavy hydrocarbon oil is treated with deasphalting agents to obtain light deasphalted oil, heavy deasphalted oil, and deoiled asphalt, respectively.

[0056] The light deasphalted oil is preheated to 250-350℃ and injected into the lower part of the first riser reactor 1 through the nozzle via the light deasphalted oil feed pipe 12. It undergoes a first catalytic conversion reaction with the first catalyst introduced from the regenerator 6 through the first regenerator conveying pipe 13 to obtain a first oil-agent mixture. The first oil-agent mixture is introduced into the cyclone separator 51 in the settling tank 5 for separation. The separated reaction oil and gas enter the gas collection chamber 52 and are introduced into a further separation device via the reaction oil and gas pipeline 53. The first regenerated catalyst obtained after separation is introduced into the stripper 3 for stripping. The stripped first regenerated catalyst is introduced into the regenerator 6 for regeneration under the action of the stripping baffle 32 via the regenerated catalyst conveying pipe 33.

[0057] After the deasphalted oil is preheated to 250-350℃, it is injected into the lower part of the second riser reactor 2 through the deasphalted oil feed pipe 22 and nozzle. There, it undergoes a second catalytic conversion reaction with the second catalyst introduced from the regenerator 6 via the second regenerator delivery pipe 23, yielding a second oil-agent mixture. This second oil-agent mixture is then introduced into the fluidized bed reactor 4 for a third catalytic conversion reaction. The reacted oil-agent mixture in the fluidized bed reactor is then introduced into the cyclone separator 51 for separation, yielding a second reaction oil-gas and a second spent catalyst. The second spent catalyst is then introduced into the stripper 3 for stripping, and the stripped second spent catalyst is introduced into the regenerator 6 for regeneration. The first and second spent catalysts are regenerated by coking in the regenerator 6. After regeneration, the spent catalyst is separated by the cyclone separator 62, and the regenerated flue gas enters the flue gas pipeline 64 through the gas collection chamber 63. The regenerated catalyst is divided into at least two streams, which are respectively introduced into the first riser reactor 1 and the second riser reactor 2 for recycling.

[0058] The first and second reaction oil and gas are further separated to obtain products such as dry gas, liquefied gas, gasoline, diesel, and oil slurry.

[0059] The present invention will be further described in detail below through examples. All raw materials used in the examples are commercially available.

[0060] In the embodiments and comparative examples of this invention, the gaseous products were tested using the RIPP 77-90 method for petrochemical analysis, the coke content was determined using the RIPP 107-90 method for petrochemical analysis, and the composition of the organic liquid products was determined using the SH / T0558-1993 method.

[0061] In the following embodiments, the product yield is calculated according to the following formula:

[0062] The RIPP petrochemical analysis method used in this invention is selected from "Petrochemical Analysis Methods (RIPP Test Methods)", edited by Yang Cuiding et al., Science Press, 1990.

[0063] In the method of this embodiment, the first reactor and the second reactor are riser reactors, and the first reactor and the second reactor are arranged in parallel. The outlet of the second reactor is connected to the fluidized bed reactor, and the outlet of the first reactor extends to the settler and is connected to the cyclone separator. The material leg of the cyclone separator extends into the stripping section.

[0064] The catalysts used in the examples and comparative examples were MPZ molecular sieve catalyst and Eplene-10 catalyst, both produced by Sinopec Catalyst Branch. Their composition and properties are shown in Table 1. Based on the total amount of MPZ molecular sieve catalyst, the MPZ molecular sieve catalyst contained 35 wt% MPZ molecular sieve (silicon-to-alumina ratio of 22), 40 wt% kaolin, and 25 wt% alumina binder. Both the MPZ molecular sieve catalyst and the Eplene-10 catalyst were aged at 800℃ under a 100% steam atmosphere for 17 h before use. After hydrothermal aging, in the NH3-TPD spectra, the proportions of the strong acid center peak area with a desorption temperature above 200℃ to the total acid center peak area were 55.7% and 42.9%, respectively.

[0065] The raw materials used in the examples and comparative examples were light deasphalted oil and heavy deasphalted oil, which were obtained by supercritical extraction deasphalting of heavy hydrocarbon oil. The yield of light deasphalted oil was 60.0% by weight, and the yield of heavy hydrocarbon oil in heavy deasphalted oil was 25.7% by weight. The composition and properties of heavy hydrocarbon oil, light deasphalted oil and heavy deasphalted oil are shown in Table 2.

[0066] Table 1. Composition and properties of catalysts

[0067] Table 2 Composition and properties of heavy hydrocarbon oil, light deasphalted oil and heavy deasphalted oil

[0068] Example 1 The experiment was conducted in Figure 1 The process is carried out on the medium-sized unit shown in the flowchart. The light deasphalted oil is preheated to 250°C and sprayed into the lower part of the first riser reactor through a nozzle, where it undergoes a first catalytic conversion reaction with the first catalyst from the regenerator to obtain a first oil-agent mixture. The first oil-agent mixture is introduced into a cyclone separator for separation, and the first prepared catalyst obtained after separation is introduced into a stripper for stripping. The stripped first prepared catalyst is then introduced into a regenerator for regeneration.

[0069] The deasphalted oil is preheated to 280°C and then sprayed into the lower part of the second riser reactor through a nozzle. It undergoes a second catalytic conversion reaction with the second catalyst from the regenerator to obtain a second oil-agent mixture. This second oil-agent mixture is then introduced into a fluidized bed reactor for a third catalytic conversion reaction. The reacted oil-agent mixture from the fluidized bed reactor is then introduced into a cyclone separator for separation, yielding a second reacted oil-gas and a second spent catalyst. The second spent catalyst is then introduced into a stripper for stripping, and the stripped second spent catalyst is introduced into the regenerator for regeneration. Both the first and second spent catalysts are regenerated by coking in the regenerator. The regenerated catalyst is divided into at least two streams, which are respectively introduced into the first and second riser reactors for recycling.

[0070] The first and second reaction oil and gas are further separated to obtain products such as dry gas, liquefied gas, gasoline, diesel, and oil slurry.

[0071] The reaction conditions and results are shown in Table 3.

[0072] Example 2-3 The catalytic conversion methods in Examples 2-3 are basically similar to those in Example 1, except that the reaction conditions in the first riser reactor and the second riser reactor are different; the reaction conditions and results are shown in Table 3.

[0073] Comparative Example 1 The method in Comparative Example 1 is basically similar to that in Example 1, except that: heavy hydrocarbon oil (properties shown in Table 2) is introduced into the second riser reactor to react with catalyst Eplene-10 (properties shown in Table 1). The oil-catalyst mixture obtained from the second riser reactor is introduced into a fluidized bed reactor for further reaction. The reaction stream is then introduced into a cyclone separator for separation. The separated catalyst is stripped and then introduced into a regenerator for regeneration. The regenerated catalyst is returned to the second riser reactor for recycling. The reaction conditions and results are shown in Table 3.

[0074] Comparative Example 2 The method in Comparative Example 2 is basically similar to that in Comparative Example 1, except that the catalyst used is an MPZ molecular sieve catalyst. The reaction conditions and results are shown in Table 3.

[0075] Table 3. Reaction conditions and results of Examples 1-3 and Comparative Examples 1-2

[0076] As shown in Table 3, the method and apparatus provided by the present invention can increase the yield of ethylene and propylene and reduce the yield of coke.

[0077] Compared with Comparative Example 1, the present invention significantly improves the yields of ethylene and propylene by using MPZ molecular sieve catalyst to separate heavy hydrocarbon oil into light deasphalted oil and heavy deasphalted oil for catalytic conversion.

[0078] Compared with Comparative Example 2, the method provided by the present invention deasphalts the heavy hydrocarbon oil, which is beneficial to promoting the catalytic conversion of heavy oil to generate more propylene and reducing the coke yield.

[0079] Example 4 The catalytic conversion method in Example 4 is basically similar to that in Example 1, except that: it also includes introducing the hydrogenation product of deoiled bitumen into the upper part of the second riser reactor, and the distance between the introduction position and the outlet pipe of the second riser reactor is 1 / 3 of the height of the second riser; the hydrogenation product of deoiled bitumen accounts for 5% by weight of the total stream of the second riser reactor; wherein, the composition and properties of the hydrogenated deoiled bitumen are shown in Table 4.

[0080] The reaction conditions and results are shown in Table 5.

[0081] Table 4 Properties of Hydrode-oiled Asphalt

[0082] Example 5 The catalytic conversion method in Example 5 is basically similar to that in Example 4, except that the reaction conditions in the first riser reactor and the second riser reactor are different; the reaction conditions and results are shown in Table 5.

[0083] Comparative Example 3 The method in Comparative Example 3 is basically similar to that in Comparative Example 1, except that it also includes introducing heavy hydrocarbon oil into the lower part of the first riser reactor; the reaction conditions and results are shown in Table 5.

[0084] Comparative Example 4 The method in Comparative Example 4 is basically similar to that in Comparative Example 1, except that it also includes introducing the hydrogenation product of heavy hydrocarbon oil into the lower part of the first riser reactor; the reaction conditions and results are shown in Table 5.

[0085] Table 5. Reverse conditions and results of Examples 4-5 and Comparative Examples 3-4

[0086] As can be seen from the table above, by introducing the hydrotreated asphalt into the second riser reactor for reaction, the conversion rate of the feedstock and the selectivity of ethylene and propylene can be further improved.

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

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

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

Claims

1. A catalytic conversion method for producing ethylene and propylene from heavy hydrocarbon oil, characterized in that, The catalytic conversion method includes: Heavy hydrocarbon oil is deasphalted to obtain light deasphalted oil, heavy deasphalted oil and deoiled asphalt, respectively. The light deasphalted oil is introduced into the bottom of the first riser reactor and comes into contact with the first catalyst to carry out the first catalytic conversion reaction, resulting in a first oil-agent mixture; the first oil-agent mixture is then subjected to a first separation to obtain a first reaction oil-gas and a first catalyst to be generated. The deasphalted oil is introduced into the bottom of the second riser reactor and comes into contact with the second catalyst to carry out the second catalytic conversion reaction, thereby obtaining the second oil-agent mixture; The second oil-agent mixture is introduced into a fluidized bed reactor for a third catalytic conversion reaction, and the reaction stream is separated to obtain a second reaction oil-gas and a second catalyst to be generated. The first and second reaction oil and gas are separated to obtain dry gas, liquefied gas, gasoline, diesel and oil slurry; The light deasphalted oil has an initial boiling point of any temperature between 280-320℃ and a final boiling point of any temperature between 640-680℃; the heavy deasphalted oil has an initial boiling point of any temperature between 300-340℃ and a final boiling point of any temperature between 680-720℃; the first catalyst and the second catalyst comprise MPZ multi-level porous molecular sieves.

2. The catalytic conversion method according to claim 1, wherein, The light deasphalted oil has an initial boiling point of any temperature between 290-310℃ and a final boiling point of any temperature between 650-670℃; and / or The asphalt content in the lightly deasphalted oil is 0.01-0.2% by weight, preferably 0.01-0.1% by weight; and / or The residual carbon content in the light deasphalted oil is 0.1-2.0% by weight, preferably 0.1-1.0% by weight.

3. The catalytic conversion method according to claim 1, wherein, The initial boiling point of the re-deasphalted oil is any temperature between 310-330℃, and the final boiling point is any temperature between 690-710℃; and / or The asphalt content in the re-deasphalted oil is 0.05-0.5% by weight, preferably 0.05-0.2% by weight; and / or The residual carbon content in the deasphalted oil is 0.5-4.0% by weight, preferably 0.5-2.0% by weight.

4. The catalytic conversion method according to claim 1, wherein, The conditions for the first catalytic conversion reaction include: a reaction temperature of 600-660 ℃, preferably 620-640 ℃; a catalyst-to-oil ratio of 5-50, preferably 10-40; an oil-gas residence time of 0.5-1.5 s, preferably 0.5-1.0 s; and a reaction pressure of 0.15-0.30 MPa, preferably 0.15-0.20 MPa. The conditions for the second catalytic conversion reaction include: a reaction temperature of 580-640 ℃, preferably 600-620 ℃; a catalyst-to-oil ratio of 5-25, preferably 10-20; an oil-gas residence time of 0.5-1.5 s, preferably 0.5-1.0 s; and a reaction pressure of 0.15-0.30 MPa, preferably 0.15-0.20 MPa. The conditions for the third catalytic conversion reaction include: a reaction temperature of 560-640 °C, preferably 580-620 °C; and a weight hourly space velocity of 1-30 h⁻¹. -1 Preferably 3-20 h -1 The reaction pressure is 0.15-0.30 MPa, preferably 0.15-0.20 MPa.

5. The catalytic conversion method according to claim 1, wherein, The first catalyst and the second catalyst each independently comprise a mixture of molecular sieves, heat-resistant inorganic oxides, and clay; Based on the respective weights of the first catalyst or the second catalyst, each of the first catalyst or the second catalyst independently contains 1-60% by weight of a molecular sieve mixture, 5-99% by weight of a heat-resistant inorganic oxide, and 0-70% by weight of clay, and the sum of the weight contents of each component is 100%. Based on the total weight of the molecular sieve mixture, the molecular sieve mixture contains 80-100% by weight of the MPZ multi-level porous molecular sieve.

6. The catalytic conversion method according to claim 1 or 5, wherein, In the surface XPS elemental analysis of the MPZ multi-level porous molecular sieve, n1 / n2 is less than or equal to 0.08, where n1 represents the number of moles of phosphorus in the MPZ multi-level porous molecular sieve, and n2 represents the total number of moles of silicon and aluminum in the MPZ multi-level porous molecular sieve. Preferably, after hydrothermal aging at 800 °C and 100% steam for 17 h, the area of ​​strong acid center peaks with desorption temperatures above 200 °C in the NH3-TPD spectrum accounts for more than or equal to 45% of the total area of ​​acid center peaks.

7. The catalytic conversion method according to claim 1, wherein, The deasphalting treatment includes the following steps: Heavy hydrocarbon oil is subjected to first supercritical extraction to obtain deasphalted oil solution and deoiled asphalt; The deasphalted oil solution is subjected to a second supercritical extraction to obtain a light deasphalted oil solution and a heavy deasphalted oil. The solvent in the lightly deasphalted oil solution is recovered to obtain the extractant and the lightly deasphalted oil. The extractant is selected from one or more of C4-C6 alkanes; The heavy hydrocarbon oil contains 5.0-20.0% by weight of gum and 0.5-5.0% by weight of asphaltene. Optionally, the heavy hydrocarbon oil is selected from one or a mixture of several of vacuum gas oil, atmospheric residue, vacuum residue, hydrotreated vacuum gas oil, and hydrotreated atmospheric residue.

8. The catalytic conversion method according to claim 1, wherein, The method further includes: regenerating the first spent catalyst and the second spent catalyst by coking to obtain a regenerated catalyst; The regenerated catalyst is divided into at least two streams and returned to the first riser reactor and the second riser reactor for recycling, respectively. Optionally, the conditions for coke regeneration include: a temperature of 650-750 ℃ ​​and a pressure of 0.15-0.30 MPa.

9. The catalytic conversion method according to claim 1, wherein, The method further includes: introducing the deoiled asphalt into the upper part of the second riser reactor for reaction; and / or The deoiled bitumen is hydrogenated to obtain a hydrogenated product, which is then introduced into the upper part of the second riser reactor for reaction.

10. A system for the catalytic conversion method according to any one of claims 1-9, characterized in that, The system includes a first riser reactor, a second riser reactor, a fluidized bed reactor, a settler, a stripper, and an oil-solvent separation device, wherein the first riser reactor and the second riser reactor are arranged side by side; the outlet of the second riser reactor is connected to any position of the fluidized bed reactor, and the settler is located above the fluidized bed reactor; The stripper is located below the fluidized bed reactor; the stripper is arranged around the second riser reactor, coaxial with the fluidized bed reactor, and located directly below the fluidized bed reactor; the first riser reactor is located outside the stripper, passes through the interior of the settling tank, and communicates with the oil-solvent separation device.

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