Preparation method for preparing BTX and co-producing light olefins and system thereof

Abstract

The present invention relates to a preparation method for preparing BTX and co-producing light olefins and a system thereof, and more specifically, to a preparation method for preparing BTX and co-producing light olefins using bio-based feedstock oil, and a system for implementing the preparation method. In the present invention, by subjecting the bio-based feedstock oil to a catalytic conversion reaction, the bio-based feedstock oil can be converted into bio-derived BTX aromatics at a high yield, and light olefins are co-produced.

Description

A method and system for preparing BTX that also produces low-carbon olefins Technical Field

[0001] This invention belongs to the field of renewable energy, specifically, it relates to a method and system for preparing BTX that also produces low-carbon olefins, and more specifically, it relates to a method for preparing BTX that also produces low-carbon olefins using bio-based oil and a system for implementing the preparation method. Background Technology

[0002] Benzene, toluene, and xylene (abbreviated as BTX, or BTX aromatics) are basic chemical raw materials for the production of resins, plastics, and synthetic pharmaceuticals, and are also excellent organic solvents. For example, benzene has a high energy density and can reduce combustion knocking, so it is used as a gasoline additive. It can also serve as a raw material for the production of important chemical intermediates such as styrene, phenol, and cyclohexane. Toluene is not only used as a solvent and high-octane gasoline additive, but it can also be used to produce benzene and xylene. Xylene and para-xylene are mainly used to produce terephthalic acid, which is then used to synthesize polyester resin (PET), synthetic fibers, plasticizers, and other important industrial raw materials.

[0003] Currently, BTX aromatics are mainly obtained through two processes in the petroleum route: catalytic reforming of naphtha and steam cracking. With the depletion of fossil fuels, the need for the continued development of the BTX aromatics industry, which is highly dependent on fossil fuels, is becoming increasingly urgent. Bio-based BTX aromatics, due to their structural identicality to mineral BTX aromatics, hold the potential to completely replace mineral oil BTX aromatics, and their importance is increasingly prominent. At the same time, low-carbon olefins (ethylene, propylene, butene), as crucial basic chemical monomer feedstocks, have also seen strong market demand in recent years.

[0004] Therefore, developing and utilizing renewable and alternative raw materials to produce green BTX aromatics and low-carbon olefins will become a future development trend. CN105175205A discloses a method for preparing aromatics from biomass oil by catalytic aromatization of methyl carboxylate. This method involves introducing biomass oil into a fixed-bed reaction tube, mixing it with a solid acid catalyst and methanol, first esterifying it to obtain methyl carboxylate, and then contacting it with a modified molecular sieve to carry out an aromatization reaction to obtain biomass aromatics.

[0005] CN109575978A discloses a method for processing bio-oils, the method comprising: feeding a bio-oil-containing raw material into a catalytic cracking reactor to contact with a catalytic cracking catalyst and carry out a catalytic cracking reaction; wherein the catalytic cracking catalyst contains a molecular sieve and a metal oxide with adsorption function; the metal in the metal oxide with adsorption function includes at least one selected from alkali metals, alkaline earth metals and transition metals; on a dry basis and based on the total weight of the catalytic cracking catalyst, the catalytic cracking catalyst contains 0.5 to 20% by weight of the metal oxide with adsorption function.

[0006] However, in existing technologies for the catalytic conversion of biomass feedstocks to produce BTX aromatics, the yield of BTX is relatively low, and the yield of low-carbon olefins needs to be further improved. Summary of the Invention

[0007] In response to the technical problems in the prior art, the inventors of this invention conducted in-depth research and discovered that by adopting the specific method of this invention, the yield of BTX prepared from biomass raw materials can be significantly improved, and at the same time, the yield of low-carbon olefins is also improved.

[0008] To achieve the above-mentioned objectives, this invention provides a method for preparing BTX that also produces low-carbon olefins, characterized by comprising the following steps:

[0009] S0, bringing fossil feedstock into contact with the catalytic conversion catalyst in the first catalytic conversion zone to carry out the first catalytic conversion reaction;

[0010] S1. The bio-based feedstock oil and the reactants from the first catalytic conversion zone are reacted in the second catalytic conversion zone to undergo a second catalytic conversion reaction, yielding reacted oil and gas and a catalyst to be generated.

[0011] S2. Separate the reaction oil and gas from the second catalytic conversion zone to obtain dry gas, liquefied gas, and residual distillate;

[0012] S3. Low-carbon olefins are separated from the liquefied gas, and BTX and residual oil are separated from the residual fraction.

[0013] Furthermore, the present invention also provides a system for preparing BTX and producing low-carbon olefins, characterized in that the system comprises the following units:

[0014] The first catalytic conversion unit, wherein fossil feedstock oil is brought into contact with a catalytic conversion catalyst in the first catalytic conversion unit to carry out a first catalytic conversion reaction;

[0015] The second catalytic conversion unit is connected downstream of the first catalytic conversion unit and is equipped with a bio-based oil inlet. In the second catalytic conversion unit, the bio-based oil and the reactants from the first catalytic conversion unit undergo a second catalytic conversion reaction to separate the reactant oil and gas and the catalyst to be generated.

[0016] A separation unit, connected downstream of the second catalytic conversion unit, separates the reaction oil and gas from the second catalytic conversion unit to obtain dry gas, liquefied gas, and residual distillate.

[0017] A low-carbon olefin separation unit, connected downstream of the separation unit, wherein low-carbon olefins are separated from the liquefied gas; and

[0018] The BTX separation unit, connected downstream of the separation unit, separates BTX and residual oil from the residual fraction.

[0019] This invention introduces biomass feedstock into a catalytic conversion reactor for catalytic conversion, enabling a greater conversion of biomass feedstock components into bio-derived BTX aromatics while maintaining a high yield of bio-derived BTX aromatics and simultaneously producing low-carbon olefins. Furthermore, this invention couples the biomass feedstock catalytic conversion with aromatics extraction, recycling the raffinate as residual oil (fossil feedstock oil) for further catalytic conversion, thereby increasing the yield of both bio-derived BTX aromatics and low-carbon olefins.

[0020] The inventors of this invention have discovered that by employing the method of this invention, in which fossil feedstock oil is brought into contact with a catalyst in a first catalytic conversion zone to carry out a first catalytic conversion reaction, and then the resulting reaction stream is introduced into a second catalytic conversion zone, and simultaneously biomass feedstock, especially bio-feedstock oil, is introduced into the second catalytic conversion zone to carry out a second catalytic conversion reaction, thereby significantly increasing the yield of BTX, and at the same time, significantly increasing the yield of low-carbon olefins.

[0021] In this invention, the raffinate oil after BTX extraction can also be used as residual oil for reprocessing, so that the raffinate oil, as a fossil feedstock, undergoes a first catalytic conversion reaction in the first catalytic conversion zone, thereby significantly improving the utilization rate of bio-feedstock oil.

[0022] Furthermore, in this invention, by introducing oxygen-containing organic compounds into the second catalytic conversion zone, the yield of low-carbon olefins can be adjusted, thereby allowing for flexible adjustment of the product yield and proportion as needed.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] 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:

[0025] Figure 1 is a schematic flowchart of one embodiment of the preparation method for BTX and low-carbon olefins provided by the present invention.

[0026] Explanation of reference numerals in the attached diagram: Ⅰ-First catalytic conversion zone; ⅠⅠ-Second catalytic conversion zone; 1. Pipeline; 2. Pipeline; 3. Pipeline; 4. Pipeline; 5. Stripping section; 6. Gas collection chamber; 7. Settling chamber; 8. Pipeline; 9. Regenerator; 10. Pipeline; 11. Pipeline; 12. Pipeline; 13. Pipeline; 14. Product separation unit; 15. Pipeline; 16. Pipeline; 17. Pipeline; 18. Pipeline; 19. Aromatics extraction unit; 20. Pipeline; 21. Pipeline; 22. Pipeline; 23. Pipeline Detailed Implementation

[0027] The present invention will be described in detail with reference to specific embodiments. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0030] When this specification uses the prefixes "known to those skilled in the art," "prior art," or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application's filing, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0031] In the context of this specification, except where expressly stated, any matters or issues not mentioned herein shall apply directly to those known in the art without any modification. Furthermore, any implementation described herein may be freely combined with one or more other implementations described herein, and any resulting technical solutions or concepts shall be considered part of the original disclosure or original record of this invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider such combination to be clearly unreasonable.

[0032] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight, unless being based on weight would not be in accordance with the common understanding of those skilled in the art.

[0033] In the context of this invention, unless otherwise specified, the physical properties of substances (such as boiling point) are measured at room temperature (25°C) and normal pressure (101325 Pa).

[0034] In the context of this invention, "rich" may mean that the amount of one or a class of compounds in the stream is typically at least 50 mol% or at least 65 mol%, preferably 90 mol%. More broadly, "rich" means the fact that the stream from the unit outlet has a greater percentage of a certain component than is present in the unit inlet feed.

[0035] [Method for preparing BTX with the co-production of low-carbon olefins]

[0036] This invention provides a method for preparing BTX that also produces low-carbon olefins, characterized by comprising the following steps:

[0037] S0, bringing fossil feedstock into contact with the catalytic conversion catalyst in the first catalytic conversion zone to carry out the first catalytic conversion reaction;

[0038] S1. The bio-feed oil and the reactants from the first catalytic conversion zone are reacted in the second catalytic conversion zone to carry out the second catalytic conversion reaction, and the reactant oil and gas and the catalyst to be generated are separated.

[0039] S2. Separate the reaction oil and gas from the second catalytic conversion zone to obtain dry gas, liquefied gas, and residual distillate;

[0040] S3. Low-carbon olefins are separated from the liquefied gas, and BTX and residual oil are separated from the residual fraction.

[0041] In one embodiment of the present invention, there is no limitation on the fossil feedstock oil, and any oil known in the art that can be used for catalytic conversion, especially heavy feedstock oil, can be used, such as crude oil, atmospheric residue, vacuum residue, vacuum wax oil, heavy oil, oil sands asphalt, catalytic cracking slurry oil, asphalt, wax oil, Fischer-Tropsch synthetic oil and coal liquefaction oil, but is not limited thereto.

[0042] In one embodiment of the present invention, the fossil feedstock oil at least comprises the residual oil obtained after separating BTX from the residual fraction, wherein the residual oil is the heavy oil fraction (raffinate) remaining after BTX extraction. In another embodiment of the present invention, the fossil feedstock oil optionally further comprises at least one selected from crude oil, atmospheric residue, vacuum residue, vacuum wax oil, heavy oil, oil sands bitumen, catalytic cracking slurry oil, bitumen, wax oil, Fischer-Tropsch synthetic oil, and coal liquefaction oil.

[0043] The catalytic conversion catalyst of the present invention is used in the first catalytic conversion reaction in step S0, and the reaction stream containing the catalyst after the first catalytic conversion enters the second catalytic conversion zone to carry out the second catalytic conversion reaction. That is, in the present invention, the fresh catalyst / regenerated catalyst first participates in the first catalytic conversion reaction, and the catalyst after the first catalytic conversion reaction is contained in the first reaction stream, which then participates in the second catalytic conversion reaction.

[0044] In one embodiment of the invention, the catalyst comprises zeolite, inorganic oxide, and optionally clay, wherein the zeolite comprises mesoporous zeolite and optionally macroporous zeolite. In another embodiment of the invention, the mesoporous zeolite content is 51% to 100% by weight, and the macroporous zeolite content is 0% to 49% by weight, based on the weight of the zeolite.

[0045] In one embodiment of the present invention, the catalyst comprises 1% to 50% by weight of zeolite, 5% to 99% by weight of inorganic oxides, and 0% to 70% by weight of clay, based on the weight of the catalyst.

[0046] In one embodiment of the present invention, the molar ratio of SiO2 to Al2O3 in the mesoporous zeolite is 50 or more, preferably 80 or more, and the molar ratio of SiO2 to Al2O3 does not exceed 300, preferably not more than 280.

[0047] In this invention, due to the limitation of the catalyst pore structure, long-chain molecules in bio-based oil undergo deoxygenation and cracking simultaneously or sequentially on the catalyst, and undergo isomerization, cyclization and addition reactions under the acidic action of the catalyst, promoting the conversion of bio-derived BTX, and also producing low-carbon olefins.

[0048] In one embodiment of the present invention, the mesoporous zeolite is selected from at least one of ZSM series zeolites, ZRP zeolite, and mordenite.

[0049] In one embodiment of the present invention, the macroporous zeolite is selected from at least one of rare earth Y-type zeolite, rare earth HY-type zeolite, ultrastable Y-type zeolite, high-silica Y-type zeolite, and β-type zeolite.

[0050] In one embodiment of the present invention, the conditions of the first catalytic conversion zone include: a reaction temperature of 580–700°C, preferably 600–650°C.

[0051] In one embodiment of the present invention, the conditions of the first catalytic conversion zone include: a reaction pressure of 0.01 to 1 MPa, preferably 0.1 to 0.9 MPa.

[0052] In one embodiment of the present invention, the conditions of the first catalytic conversion zone include: a weight hourly space velocity of 1 to 150 h⁻¹. -1 Preferably 10-100h -1 .

[0053] In one embodiment of the present invention, the conditions of the first catalytic conversion zone include: a reaction time of 0.01 to 200 seconds, preferably 0.1 to 80 seconds.

[0054] In one embodiment of the present invention, the conditions of the first catalytic conversion zone include: the weight ratio of the catalyst to the fossil feedstock oil is (1-90):1, preferably (3-80):1.

[0055] In one embodiment of the present invention, the reaction temperature of the first catalytic conversion zone is 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, 660°C, 670°C, 680°C, 690°C, or 700°C.

[0056] In step S0 of this invention, fossil feedstock oil comes into contact with a catalytic conversion catalyst to undergo a first catalytic conversion reaction. The resulting reaction stream includes the reaction oil and gas obtained from the first catalytic conversion reaction and the catalyst remaining after the first catalytic conversion reaction. This reaction stream is not subjected to gas-solid separation treatment and is entirely fed into the second catalytic conversion zone of step S1.

[0057] In this invention, in step S1, the reaction stream from the first catalytic conversion in step S0 is fed into the second catalytic conversion zone, and at the same time, the bio-based oil is fed into the second catalytic conversion zone to carry out the second catalytic conversion reaction.

[0058] In one embodiment of the present invention, there is no limitation on the biological raw material oil, and examples include vegetable oils, animal oils, microbial oils, waste cooking oils, and oil refinery by-products. In one embodiment of the present invention, the vegetable oils may include soybean oil, rapeseed oil, palm oil, sunflower seed oil, corn oil, peanut oil, cottonseed oil, flaxseed oil, castor oil, coconut oil, olive oil, jatropha oil, tung oil, jatropha oil, rice bran oil, etc. In one embodiment of the present invention, the animal oils may include tallow, lard, mutton fat, chicken fat, fish oil, etc. In one embodiment of the present invention, the microbial oils may include algae oil (microalgae oil), yeast oil, fungal oil, etc. In one embodiment of the present invention, the waste cooking oils may include gutter oil, acidified oil, and waste frying oil, etc. In one embodiment of the present invention, the oil refinery by-products may include acidified oil, etc. In one embodiment of the present invention, the oil refinery by-products refer to by-products generated during the refining of vegetable oils and animal oils. The method of this invention can convert more biomass feedstock oil into bio-derived BTX aromatics, improving the high-value utilization of biomass feedstocks. Furthermore, due to the small amount of hydrogen generated during fatty acid ester deoxygenation and catalytic conversion, less coke is produced.

[0059] In one embodiment of the present invention, the bio-based feedstock oil is selected from fatty acid esters with 14 to 20 carbon atoms, such as, but not limited to, palmitate (C16), stearate (C18), oleate (C18), and linoleate (C18). In another embodiment of the present invention, the content of unsaturated fatty acid esters in the bio-based feedstock oil is 10% to 80% by weight. In the present invention, biomass feedstocks with an unsaturated fatty acid ester content of 10% to 80% by weight undergo catalytic conversion reactions at the acidic sites of the catalyst, which can simultaneously produce low-carbon olefins while generating multiple bio-source BTX aromatics. For example, the unsaturated sites enhance the breaking of carbon-carbon double bonds, promoting the formation of butene, or propylene can be generated through catalytic conversion.

[0060] In one embodiment of the present invention, the bio-based oil may be at least one selected from triglycerides, diglycerides, monoglycerides, fatty acid esters, fatty acid methyl esters, phospholipids, and fatty acid derivatives. For example, methyl esters, ethyl esters, monoglycerides, and triglycerides of various fatty acids can be listed.

[0061] In one embodiment of the present invention, the conditions of the second catalytic conversion zone include: a reaction temperature of 450–580°C, preferably 500–550°C.

[0062] In one embodiment of the present invention, the conditions of the second catalytic conversion zone include: a reaction pressure of 0.01 to 1 MPa, preferably 0.1 to 0.9 MPa.

[0063] In one embodiment of the present invention, the conditions of the second catalytic conversion zone include: a weight hourly space velocity of 1 to 150 h⁻¹. -1 Preferably 10-100h -1 .

[0064] In one embodiment of the present invention, the conditions of the second catalytic conversion zone include: a reaction time of 0.01 to 200 seconds, preferably 0.1 to 80 seconds.

[0065] In one embodiment of the present invention, the reaction temperature of the second catalytic conversion zone is 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, or 580°C.

[0066] In one embodiment of the present invention, the conditions of the second catalytic conversion zone include: the weight ratio of the bio-feed oil to the reaction stream from the first catalytic conversion zone is (1-90):1, preferably (3-80):1.

[0067] In one embodiment of the present invention, the conditions of the second catalytic conversion zone include: the weight ratio of the catalyst entering the first catalytic conversion zone to the bio-based oil is (1-90):1, preferably (3-80):1.

[0068] In this invention, no new catalyst is introduced in the second catalytic conversion reaction in step S1; the catalyst is the catalyst from the first catalytic conversion reaction in step S0.

[0069] In one embodiment of the present invention, in step S1, an oxygen-containing organic compound is further introduced into the second catalytic conversion zone. In another embodiment of the present invention, in step S1, the weight ratio of the oxygen-containing organic compound introduced into the second catalytic conversion zone to the bio-based feedstock oil is (0.01–0.8):1, preferably (0.02–0.4):1. Therefore, the bio-based feedstock oil and the oxygen-containing organic compound can undergo catalytic conversion under suitable conditions, thereby increasing the yield of BTX and low-carbon olefins.

[0070] In one embodiment of the present invention, the oxygen-containing organic compound introduced in step S1 is at least one selected from alcohols, ketones and ethers having 4 or fewer carbon atoms, preferably one or more selected from methanol, ethanol, dimethyl ketone, dimethyl ether and diethyl ether.

[0071] In one embodiment of the present invention, the oxygen-containing organic compound can be mixed with the bio-based oil and then introduced into the second catalytic conversion zone, or it can be introduced into the second catalytic conversion zone separately, or it can be introduced into the second catalytic conversion zone in multiple streams.

[0072] In one embodiment of the present invention, the oxygen-containing organic compound is injected into the second catalytic conversion zone upstream of the bio-feed oil inlet. Specifically, the distance between the inlet for injecting the oxygen-containing organic compound and the inlet for introducing the bio-feed oil is 0.05 to 0.45 of the axial height of the second catalytic conversion zone.

[0073] In step S1 of the present invention, in the second catalytic conversion zone, the reaction stream from the first catalytic conversion reaction in step S0 and the bio-based feedstock oil undergo a second catalytic conversion reaction together. At this time, an oxygen-containing organic compound may optionally be introduced, thereby obtaining a reaction stream in the second catalytic conversion zone, which includes the reaction oil and gas obtained from the second catalytic conversion reaction and the catalyst to be generated.

[0074] In step S1 of the present invention, the reaction stream after the second catalytic conversion reaction is separated to obtain reaction oil and gas and the catalyst to be generated.

[0075] In one embodiment of the present invention, in step S1, the reactant stream from the second catalytic conversion zone is fed into the settling section for separation of the catalyst to be generated and the reactant oil and gas.

[0076] In one embodiment of the present invention, in step S1, the catalyst to be generated is stripped to recover residual reaction oil and gas. The separated reaction oil and gas is then collected in a gas collection chamber and discharged for further separation.

[0077] In step S2 of the present invention, the reaction oil and gas from the second catalytic conversion zone are separated to obtain dry gas, liquefied gas and residual distillate.

[0078] In one embodiment of the present invention, in step S2, the means of separating the reaction oil and gas after the second catalytic conversion reaction are not particularly limited, and conventional means such as fractionation and distillation in the art can be used.

[0079] In this invention, in step S3, the means of separating low-carbon olefins from the liquefied gas obtained in step S2 is not particularly limited, as long as low-carbon olefins can be separated from the liquefied gas, such as distillation, adsorption separation, membrane separation, etc.

[0080] In this invention, in step S3, the means of separating BTX and residual oil from the residual fraction obtained in step S2 is not particularly limited, as long as BTX can be separated.

[0081] In one embodiment of the present invention, in step S3, the residual fraction is subjected to aromatic extraction to obtain raffinate oil as residual oil and aromatic extract oil. BTX is separated from the aromatic extract oil, and the raffinate oil can be refluxed to the first catalytic conversion zone as residual oil.

[0082] In one embodiment of the present invention, the extraction conditions for aromatic hydrocarbon extraction are not particularly limited, as long as the BTX-containing components can be separated.

[0083] In one embodiment of the present invention, the conditions for aromatic hydrocarbon extraction in step S3 include: the extraction solvent is selected from one or more of N-methylpyrrolidone, sulfolane, dimethyl sulfoxide, N-methylformamide, ethylene glycol, furfural, monoethanolamine and 1,2-propanediol.

[0084] In one embodiment of the present invention, the conditions for aromatic hydrocarbon extraction in step S3 include an extraction temperature of 30–120°C.

[0085] In one embodiment of the present invention, the conditions for aromatic extraction in step S3 include: the volume ratio of the residual fraction to the extraction solvent is (0.5-8.0):1.

[0086] In one embodiment of the present invention, the conditions for aromatic extraction in step S3 include: extraction pressure of 0.3 to 1.0 MPa.

[0087] In one embodiment of the present invention, step S3, in which aromatics are extracted from the residual fraction, further includes step S4, wherein at least a portion of the obtained raffinate is introduced as at least a portion of the fossil feedstock (preferably the fossil feedstock is the raffinate) into the first catalytic conversion zone of step S0 to carry out a first catalytic conversion reaction.

[0088] In one embodiment of the present invention, in step S4, 1% to 95% by weight, more preferably 10% to 90% by weight, of the raffinate oil is returned to the first catalytic conversion zone of step S0.

[0089] In one embodiment of the present invention, in step S3, when aromatics are extracted from the residual fraction, in step S1, at least a portion of the bio-feed oil, the reaction stream from the first catalytic conversion zone, and optionally at least a portion of the raffinate oil are subjected to a second catalytic conversion reaction in the second catalytic conversion zone to separate the reaction oil gas and the catalyst to be generated. Preferably, the conditions of the second catalytic conversion zone include: a reaction time of 0.01 to 150 seconds, preferably 0.1 to 100 seconds, and further optionally including: a weight ratio of the bio-feed oil to the raffinate oil entering the second catalytic conversion zone of (1 to 90):1, preferably (3 to 80):1.

[0090] Therefore, in this invention, by returning at least a portion of the raffinate oil as fossil feedstock to the first catalytic conversion zone of step S0 and optionally to the second catalytic conversion reaction of step S1, the efficient utilization of bio-feedstock oil can be achieved, by reducing byproducts and increasing the yield of BTX and low-carbon olefins. On the other hand, the ratio of BTX to low-carbon olefins can be adjusted as needed by adjusting the ratio of the raffinate oil returned to the first catalytic conversion zone of step S0 and the raffinate oil of the optional second catalytic conversion reaction of step S1, thereby maximizing the economic benefits of the product.

[0091] In one embodiment of the present invention, in step S2, the reaction oil and gas from the second catalytic conversion zone are separated to obtain dry gas, liquefied gas, light fraction containing BTX and heavy fraction oil. At this time, conventional fractionation, distillation and other methods in the art can be used.

[0092] In one embodiment of the present invention, if dry gas, liquefied petroleum gas, light fraction containing BTX, and heavy distillate oil are separated in step S2, then in step S3, low-carbon olefins are separated from the liquefied petroleum gas, and the process further includes the following steps:

[0093] S3-1. The light fraction containing BTX is subjected to a first extraction under the first extraction conditions to obtain a first aromatic extract oil and a first raffinate oil; the heavy fraction oil is subjected to a second extraction under the second extraction conditions to obtain a second aromatic extract oil and a second raffinate oil.

[0094] S3-2. Combine the first aromatic extract oil and the second aromatic extract oil to obtain an aromatic extract oil, from which BTX is separated. Combine the first raffinate oil and the second raffinate oil to obtain a raffinate oil, which is used as the residual oil.

[0095] In one embodiment of the present invention, the first extraction conditions include: an extraction temperature of 30–120°C, a volume ratio of the BTX-containing light fraction to the extraction solvent of (0.5–5):1, and an extraction pressure of 0.3–1.0 MPa. Preferably, the solvent for the first extraction is N-methylpyrrolidone.

[0096] In one embodiment of the present invention, the second extraction conditions include: an extraction temperature of 30–120°C, a volume ratio of heavy distillate oil to the extraction solvent of (0.5–5):1, and an extraction pressure of 0.3–1.0 MPa. Preferably, the solvent for the second extraction is sulfolane.

[0097] In one embodiment of the present invention, when a light fraction containing BTX is obtained by more fine fractionation of the reaction oil and gas in step S2, the distillation range of the light fraction containing BTX is 25 to 230°C, preferably 55 to 200°C.

[0098] In one embodiment of the present invention, the initial boiling point of the BTX-containing light fraction is any temperature between 25 and 55°C, and the final boiling point is any temperature between 170 and 230°C, preferably any temperature between 170 and 200°C.

[0099] In one embodiment of the present invention, the initial boiling point of the BTX-containing light fraction is 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, or 55°C.

[0100] In one embodiment of the present invention, the final boiling point of the BTX-containing light fraction is any temperature between 170 and 230°C, preferably any temperature between 170 and 200°C.

[0101] In one embodiment of the present invention, the final boiling point of the BTX-containing light fraction is 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, or 230°C.

[0102] In one embodiment of the present invention, when a heavy distillate is obtained by further fractionating the reaction oil and gas in step S2, the distillation range of the heavy distillate is 230–550°C, preferably 250–500°C.

[0103] In one embodiment of the present invention, the initial boiling point of the heavy distillate oil is any temperature between 230 and 350°C, and the final boiling point is any temperature between 450 and 550°C, preferably any temperature between 450 and 500°C.

[0104] In one embodiment of the present invention, the initial boiling point of the heavy distillate oil is 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, or 350°C.

[0105] In one embodiment of the present invention, the final boiling point of the heavy distillate oil is 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, or 550°C.

[0106] In one embodiment of the present invention, the content of BTX aromatics in the BTX-containing light fraction is 50% by weight or more, preferably 70% by weight or more.

[0107] In one embodiment of the present invention, the aromatic content of the heavy distillate oil is 5% to 85% by weight.

[0108] In one embodiment of the present invention, the content of BTX aromatics in the heavy distillate oil is 15% to 50% by weight, preferably 20% to 45% by weight.

[0109] That is, in this invention, by performing more refined fractionation of the reaction oil and gas in step S2, the residual distillate is separated into light distillate and heavy distillate oil containing BTX. By extracting the light distillate and heavy distillate oil under different conditions, BTX can be recovered better.

[0110] In one embodiment of the present invention, after the first aromatic extract oil and the second aromatic extract oil obtained by the first extraction conditions and the second extraction conditions are combined, BTX is separated from them.

[0111] In one embodiment of the present invention, the first raffinate oil and the second raffinate oil obtained by the first extraction conditions and the second extraction conditions are combined as residual oil (fossil feedstock oil), and at least a portion of it is returned to the first catalytic conversion zone of step S0, and optionally at least a portion of it is returned to the second catalytic conversion reaction of step S1.

[0112] In one embodiment of the present invention, the method further includes the following steps:

[0113] S5. The spent catalyst obtained in step S1 is regenerated by coking to obtain a regenerated catalyst, and the regenerated catalyst is returned to step S0 for recycling in the first catalytic conversion zone.

[0114] There are no restrictions on the conditions for regenerating the catalyst; it can be the coking temperature and coking atmosphere conventional in the field for catalyst regeneration.

[0115] In one embodiment of the present invention, the coke regeneration is carried out in the presence of oxygen-containing gas; the conditions for coke regeneration include: a regeneration temperature of 580–750°C, preferably 600–700°C; a bed pressure of 0.1–0.6 MPa, preferably 0.12–0.40 MPa; a residence time of oxygen-containing gas of 0.1–300 seconds, preferably 1–240 seconds; and an oxygen content of 20–100% by volume in the oxygen-containing gas.

[0116] In one embodiment of the present invention, a method for preparing BTX that also produces low-carbon olefins is provided, comprising the following steps:

[0117] S0. The raffinate from step S4 is used as a fossil feedstock and contacted with a catalytic conversion catalyst in the first catalytic conversion zone to carry out a first catalytic conversion reaction. The conditions of the first catalytic conversion zone include: a reaction temperature of 580–700°C, preferably 600–650°C; a reaction pressure of 0.01–1 MPa, preferably 0.1–0.9 MPa; and a weight hourly space velocity of 1–150 h⁻¹. -1 Preferably 10-100h -1The reaction time is 0.01 to 200 seconds, preferably 0.1 to 80 seconds;

[0118] S1. The bio-based feedstock oil, reactant stream from the first catalytic conversion zone, optionally raffinate from step S4 below, and optionally oxygen-containing organic compounds are subjected to a second catalytic conversion reaction in a second catalytic conversion zone, and the reactant oil gas and the catalyst to be generated are separated. The conditions of the second catalytic conversion zone include: a reaction temperature of 450–580°C, preferably 500–550°C; a reaction pressure of 0.01–1 MPa, preferably 0.1–0.9 MPa; and a weight hourly space velocity of 1–150 h⁻¹. -1 Preferably 10-100h -1 The reaction time is 0.01 to 200 seconds, preferably 0.1 to 80 seconds;

[0119] S2. Separate the reaction oil and gas from the second catalytic conversion zone to obtain dry gas, liquefied gas, light distillate containing BTX, and heavy distillate oil; the initial boiling point of the light distillate containing BTX is any temperature between 25 and 55°C, and the final boiling point is any temperature between 170 and 230°C, preferably any temperature between 170 and 200°C; the final boiling point of the heavy distillate oil is any temperature between 450 and 550°C, preferably any temperature between 450 and 500°C.

[0120] In step S3, low-carbon olefins are separated from the liquefied gas, and the process further includes the following steps:

[0121] S3-1. The light fraction containing BTX is subjected to a first extraction under a first extraction condition to obtain a first aromatic extract oil and a first raffinate oil; the heavy fraction oil is subjected to a second extraction under a second extraction condition to obtain a second aromatic extract oil and a second raffinate oil; the first extraction conditions include: an extraction temperature of 30-120°C, a volume ratio of the light fraction containing BTX to the extraction solvent of (0.5-5):1, and an extraction pressure of 0.3-1.0 MPa; the second extraction conditions include: an extraction temperature of 30-120°C, a volume ratio of the heavy fraction oil to the extraction solvent of (0.5-5):1, and an extraction pressure of 0.3-1.0 MPa.

[0122] S3-2. Combine the first aromatic extract oil and the second aromatic extract oil to obtain an aromatic extract oil, from which BTX is separated. Combine the first raffinate oil and the second raffinate oil to obtain a raffinate oil, which is used as the residual oil.

[0123] S4. At least a portion of the raffinate (preferably 1% to 95% by weight, more preferably 10% to 90% by weight) is introduced as at least a portion of the fossil feedstock (preferably the raffinate) into the first catalytic conversion zone for a first catalytic conversion reaction, and optionally at least a portion of the raffinate is introduced into the second catalytic conversion zone for a second catalytic conversion reaction; and

[0124] S5. The spent catalyst obtained in step S1 is regenerated by coking to obtain a regenerated catalyst, and the regenerated catalyst is returned to step S0 for recycling in the first catalytic conversion zone.

[0125] [System for preparing BTX and producing low-carbon olefins]

[0126] The present invention further provides a system for preparing BTX and producing low-carbon olefins, characterized in that the system comprises the following units:

[0127] The first catalytic conversion unit is provided with a fossil feedstock oil inlet and a catalyst inlet, wherein the fossil feedstock oil is brought into contact with the catalytic conversion catalyst in the first catalytic conversion unit to carry out the first catalytic conversion reaction;

[0128] The second catalytic conversion unit is connected downstream of the first catalytic conversion unit and is equipped with a bio-based oil inlet. In the second catalytic conversion unit, the bio-based oil and the reactants from the first catalytic conversion unit undergo a second catalytic conversion reaction to separate the reactant oil and gas and the catalyst to be generated.

[0129] A separation unit, connected downstream of the second catalytic conversion unit, separates the reaction oil and gas from the second catalytic conversion unit to obtain dry gas, liquefied gas, and residual distillate.

[0130] A low-carbon olefin separation unit, connected downstream of the separation unit, wherein low-carbon olefins are separated from the liquefied gas; and

[0131] The BTX separation unit, connected downstream of the separation unit, separates BTX and residual oil from the residual fraction.

[0132] In one embodiment of the present invention, the first catalytic conversion unit is provided with a fossil feedstock inlet and a catalyst inlet, wherein step S0 of the preparation method of BTX and low-carbon olefins of the present invention is carried out.

[0133] In one embodiment of the present invention, the second catalytic conversion unit is connected downstream of the first catalytic conversion unit and is provided with a bio-based oil inlet, wherein step S1 of the preparation method of BTX and low-carbon olefins of the present invention is carried out.

[0134] In one embodiment of the present invention, the second catalytic conversion unit is optionally provided with a raffinate inlet and optionally with an oxygen-containing organic compound inlet.

[0135] In one embodiment of the present invention, the second catalytic conversion unit is provided with a reaction zone for performing the second catalytic conversion, a stripping section located downstream of the reaction zone, a settling section located downstream of the stripping section, and a gas collection chamber located downstream of the settling section, and the bottom of the stripping section is connected to a catalyst regeneration unit.

[0136] In one embodiment of the present invention, the separation unit is connected downstream of the second catalytic conversion unit, wherein step S2 of the method for preparing BTX and producing low-carbon olefins according to the present invention is performed. In one embodiment of the present invention, the separation unit may be a distillation tower or similar device.

[0137] In one embodiment of the present invention, the low-carbon olefin separation unit is connected downstream of the separation unit, wherein low-carbon olefins are separated from the liquefied gas.

[0138] In one embodiment of the present invention, the BTX separation unit is connected downstream of the separation unit to separate BTX and residual oil from the residual fraction.

[0139] In one embodiment of the present invention, the BTX separation unit includes an extraction unit, wherein the residual fraction is subjected to aromatic extraction to obtain raffinate oil as residual oil and aromatic-containing extracted oil. The BTX separation unit is connected to the fossil feedstock inlet of the first catalytic conversion unit and is used to feed the raffinate oil as fossil feedstock oil into the first catalytic conversion unit.

[0140] In one embodiment of the present invention, the second catalytic conversion unit is further provided with a raffinate inlet, which is connected to the BTX separation unit and is used to feed at least a portion of the raffinate.

[0141] In one embodiment of the present invention, the separation unit is connected downstream of the second catalytic conversion unit, wherein the reaction oil and gas from the second catalytic conversion unit are separated to obtain dry gas, liquefied gas, light fraction containing BTX, and heavy fraction oil.

[0142] In one embodiment of the present invention, the BTX separation unit includes a first extraction unit and a second extraction unit. The first extraction unit is used to extract light fractions containing BTX to obtain a first aromatic extract oil and a first raffinate oil. The second extraction unit is used to extract heavy fraction oil to obtain a second aromatic extract oil and a second raffinate oil. The first aromatic extract oil and the second aromatic extract oil are combined to obtain an aromatic extract oil from which BTX is separated. The first raffinate oil and the second raffinate oil are combined to obtain a raffinate oil, which is used as residual oil.

[0143] In one embodiment of the present invention, the BTX separation unit is connected to the fossil feedstock inlet of the first catalytic conversion unit, and is used to feed the raffinate oil as fossil feedstock into the first catalytic conversion unit.

[0144] In one embodiment of the present invention, the second catalytic conversion unit is further provided with a raffinate inlet, which is connected to the BTX separation unit and is used to feed at least a portion of the raffinate.

[0145] In one embodiment of the present invention, the second catalytic conversion unit is further provided with an oxygen-containing organic compound inlet, thereby introducing oxygen-containing organic compounds into the second catalytic conversion unit.

[0146] In one embodiment of the present invention, the oxygen-containing organic compound is injected into the second catalytic conversion unit upstream of the bio-feed oil inlet. Specifically, the distance between the inlet for injecting the oxygen-containing organic compound and the inlet for introducing the bio-feed oil is 0.05 to 0.45 of the axial height of the second catalytic conversion zone.

[0147] In one embodiment of the present invention, the system further includes a catalyst regeneration unit connected downstream of the second catalytic conversion unit, which regenerates the spent catalyst from the second catalytic conversion unit by coking to obtain a regenerated catalyst, and is connected to the catalyst inlet of the first catalytic conversion unit to feed the regenerated catalyst into the first catalytic conversion unit for recycling.

[0148] In one embodiment of the present invention, the first catalytic conversion unit is a combination of one or more selected from fluidized bed reactors, fixed bed reactors, moving bed reactors and slurry bed reactors; the fluidized bed reactor is a combination of one or more selected from risers, constant velocity fluidized beds, constant diameter fluidized beds, upward conveying lines and downward conveying lines.

[0149] In one embodiment of the present invention, the second catalytic conversion unit is a combination of one or more selected from fluidized bed reactors, fixed bed reactors, moving bed reactors and slurry bed reactors; the fluidized bed reactor is a combination of one or more selected from risers, constant velocity fluidized beds, constant diameter fluidized beds, upward conveying lines and downward conveying lines.

[0150] In one embodiment of the present invention, the first catalytic conversion unit and the second catalytic conversion unit can be a variable diameter riser reactor. Specifically, the variable diameter riser includes, from bottom to top along the axial direction, a first riser section, an expanding section, a dense phase fluidization section, a narrowing section, and a second riser section. The expanding section has a continuously increasing diameter from bottom to top along the axial direction, and the angle between the sidewall of the expanding section and the axis can be 5–60°. The ratio of the diameter to the height of the dense phase fluidization section can be (1–20):1. The narrowing section has a continuously decreasing diameter from bottom to top along the axial direction, and the angle between the sidewall of the narrowing section and the axis can be 5–60°. A material distributor is also provided at the starting head of the dense phase fluidization section. Furthermore, the radial cross-section of the variable diameter riser reactor is approximately circular.

[0151] In one embodiment of the present invention, the first catalytic conversion unit and the second catalytic conversion unit may be two independent reactors connected upstream and downstream.

[0152] In one embodiment of the present invention, the first catalytic conversion unit and the second catalytic conversion unit may be two different reaction zones in a reactor.

[0153] The following describes a preferred embodiment of the present invention with reference to the flowchart shown in Figure 1. As shown in Figure 1, the regenerated catalyst from regenerator 9 is introduced into the lower part of the fluidized bed reactor via pipeline 12. The catalyst moves upward along the fluidized bed reactor under the influence of pre-lift steam from pipeline 1. Simultaneously, preheated raffinate oil is introduced into the bottom of the fluidized bed reactor via pipeline 22. The raffinate oil and the catalyst undergo a first catalytic conversion reaction in the first catalytic conversion zone (region I) of the fluidized bed reactor, yielding the first catalytic conversion reaction stream. Then, the first catalytic conversion reaction stream enters the bottom of the second catalytic conversion zone of the fluidized bed reactor, where it contacts the preheated bio-feedback oil from pipeline 2 and the preheated oxygenated organic compounds from pipeline 3, undergoing a second catalytic conversion reaction in the second catalytic conversion zone (region I) of the fluidized bed reactor, yielding the second catalytic conversion reaction stream. The reaction stream enters the cyclone separator in the settling tank 7 for gas-solid separation, yielding the regenerated catalyst and reaction oil-gas. The reaction oil-gas enters the gas collection chamber 6, while the catalyst fine powder returns to the settling tank 7 via the feed leg. The spent catalyst in settling tank 7 flows to stripping section 5, where it comes into contact with stripping steam from pipeline 4 for stripping. After stripping, the spent catalyst enters regenerator 9 via spent catalyst inclined tube 8, where, under the condition of main air supplied via pipeline 10, the coke on the spent catalyst is burned off, regenerating the deactivated spent catalyst. The flue gas enters the flue gas fan via pipeline 11, and the regenerated catalyst obtained from the regeneration is returned to the fluidized bed reactor for recycling via pipeline 12.

[0154] The oil and gas extracted from the catalyst enter the gas collection chamber 6 via a cyclone separator. After mixing with the reaction oil and gas, it enters the subsequent product separation unit 14 via pipeline 13. The separated dry gas is led out via pipeline 15, the liquefied gas via pipeline 16, the light fraction containing BTX via pipeline 17, and the heavy distillate oil via pipeline 18. The light fraction containing BTX and the heavy distillate oil are each introduced into the aromatics extraction unit 19, where they come into contact with the extraction solvent introduced via pipeline 20. Aromatics extraction is carried out in the first extraction unit (not shown) and the second extraction unit (not shown), respectively, to separate the raffinate oil and the aromatics-containing extracted oil. The aromatics-containing extracted oil is led out via pipeline 21, and the raffinate oil continues to be circulated to the bottom of the fluidized bed reactor via pipeline 22 for the first catalytic conversion reaction to further convert and prepare BTX and low-carbon olefins.

[0155] In one embodiment of the present invention, the following solution is provided:

[0156] Solution 1. A method for producing bio-based BTX and simultaneously generating low-carbon olefins, characterized in that the method comprises the following steps:

[0157] (1) The biomass feedstock is brought into contact with the molecular sieve catalyst in the catalytic conversion reactor to carry out the catalytic conversion reaction, and the reacted oil and gas and the catalyst to be generated are obtained.

[0158] (2) The reaction oil and gas are separated to obtain dry gas, liquefied gas, naphtha fraction rich in bio-BTX and heavy distillate oil;

[0159] (3) The naphtha fraction and the heavy distillate oil are introduced into the aromatic extraction device and contacted with the extraction solvent to extract aromatics, thereby obtaining raffinate oil and aromatic-rich extracted oil; the raffinate oil is recycled back to the catalytic conversion reactor for catalytic conversion reaction;

[0160] Option 2. The method according to Option 1, wherein the biomass raw material is derived from one or more of vegetable oils, animal oils, microbial oils, and waste cooking oils;

[0161] Option 3. The method according to Option 1, wherein the molecular sieve catalyst comprises zeolite, inorganic oxide and optionally clay;

[0162] Based on the weight of the molecular sieve catalyst, the molecular sieve catalyst comprises 1-50% by weight of zeolite, 5-99% by weight of inorganic oxides and 0-70% by weight of clay.

[0163] The zeolite includes mesoporous zeolite and optional macroporous zeolite; based on the weight of the zeolite, the content of mesoporous zeolite is 51-100% by weight, and the content of macroporous zeolite is 0-49% by weight.

[0164] The molar ratio of SiO2 to Al2O3 in the mesoporous zeolite is greater than or equal to 50, preferably greater than or equal to 80.

[0165] The mesoporous zeolite is selected from at least one of ZSM series zeolites, ZRP zeolite and mordenite;

[0166] The macroporous zeolite is selected from at least one of rare earth Y-type zeolite, rare earth HY-type zeolite, ultra-stable Y-type zeolite, high-silica Y-type zeolite and β-type zeolite;

[0167] Option 4. According to the method described in Option 1, the conditions for the catalytic conversion reaction include: a reaction temperature of 450–700°C, preferably 500–650°C; a reaction pressure of 0.01–1 MPa, preferably 0.03–1 MPa; and a weight hourly space velocity of 1–95 h⁻¹. -1 Preferably 5-85h -1 The weight ratio of the molecular sieve catalyst to the biomass raw material is 3-25, preferably 5-20; the reaction time is 0.01-200 seconds, preferably 0.1-80 seconds.

[0168] Option 5. According to the method described in Option 1, wherein the catalytic conversion reactor is selected from one or more of the following: fluidized bed reactor, fixed bed reactor, moving bed reactor, and slurry bed reactor; the fluidized bed reactor is selected from one or more of the following: riser, constant velocity fluidized bed, constant diameter fluidized bed, upward conveyor line, and downward conveyor line, or two or more of the same type of reactor.

[0169] Option 6. According to the method described in Option 1, wherein the initial boiling point of the naphtha fraction is any temperature between 25 and 55°C, and the final boiling point is any temperature between 170 and 230°C.

[0170] Preferably, the final boiling point of the heavy distillate oil is any temperature between 450 and 550°C;

[0171] Scheme 7. The method according to Scheme 1, wherein the extraction solvent is selected from one or more of dimethyl sulfoxide, N-methylformamide, ethylene glycol, furfural, monoethanolamine and 1,2-propanediol;

[0172] Option 8. The method according to Option 1, wherein the conditions for aromatic extraction include: a temperature of 30–120°C; and a volume ratio of naphtha fraction to extraction solvent of (0.5–8.0):1.

[0173] Scheme 9. The method according to Scheme 1, wherein the method further comprises: introducing an oxygen-containing organic compound into the catalytic conversion reactor to co-convert with the biomass feedstock; the weight ratio of the oxygen-containing organic compound introduced into the catalytic conversion reactor to the biomass feedstock per unit time is (0.02~0.2):1;

[0174] The oxygen-containing organic compound is selected from at least one of alcohols and ethers with 4 or fewer carbon atoms, preferably one or more of methanol, ethanol, dimethyl ketone, dimethyl ether and diethyl ether;

[0175] Option 10. The method according to Option 1, wherein the method further includes: stripping and coking the spent catalyst to obtain a regenerated catalyst, and returning the regenerated catalyst to the catalytic conversion reactor for recycling;

[0176] The coke regeneration is carried out in the presence of oxygen-containing gas; the conditions for coke regeneration include: a regeneration temperature of 580–750°C, preferably 600–700°C; a bed pressure of 0.1–0.45 MPa, preferably 0.12–0.40 MPa; and a residence time of oxygen-containing gas of 0.1–300 seconds, preferably 1–240 seconds.

[0177] The oxygen content in the oxygen-containing gas is 20-100% by volume.

[0178] Example

[0179] The present invention will be further illustrated by the following examples, but these examples are not intended to limit the invention. All raw materials used in the examples are commercially available.

[0180] The properties of the bio-based feedstock oil and the vacuum gas oil (VGO) in the following examples and comparative examples are shown in Tables 1-1 and 1-2.

[0181] The molecular sieve catalyst used in the following examples and comparative examples is designated TCC-1, which contains 30% by weight of mesoporous zeolite ZSM-5, with the balance being an alumina support. The molar ratio of SiO2 to Al2O3 in the ZSM-5 zeolite is 170, and it was produced by Sinopec Catalyst Co., Ltd., Qilu Branch. The properties of the catalyst are listed in Table 2.

[0182] Table 1-1 Raw Material Properties

[0183] Table 1-2 Raw Material Properties

[0184] Table 2. Properties of Molecular Sieves Catalysts

[0185] Example 1

[0186] Example 1 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedstock oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0187] Preheated VGO is introduced into the bottom of the first catalytic conversion zone of the reactor via pipeline 23. Regenerated catalyst is introduced into the bottom of the fluidized bed reactor via pipeline 12. VGO and catalyst contact each other in the first catalytic conversion zone (region I) and react at the first catalytic conversion reaction temperature to obtain the first catalytic conversion reaction stream. Then, the first catalytic conversion reaction stream enters the bottom of the second catalytic conversion zone of the reactor and contacts the preheated bio-feed oil fed from pipeline 2. The second catalytic conversion reaction occurs in the second catalytic conversion zone (region ⅠⅠ) at the second catalytic conversion reaction temperature to obtain the second catalytic conversion reaction stream. The reaction oil and gas are separated from the second reaction stream and fractionated. Dry gas is drawn out via pipeline 15, liquefied petroleum gas (LPG) via pipeline 16, light fraction containing BTX is drawn out via pipeline 17, and heavy distillate oil is drawn out via pipeline 18. The distillation range of the BTX-containing light fraction is 55–230°C, and the distillation range of the heavy distillate oil is 230–550°C. The light and heavy distillate oils containing BTX are introduced into an aromatics extraction unit, where they are extracted under first and second extraction conditions, respectively, to separate the raffinate oil and the aromatics-containing extract oil.

[0188] The spent catalyst is introduced into the regenerator 9 via pipeline 8 for coke burn-off regeneration, and the regenerated catalyst is returned to the reactor for recycling via pipeline 12. The regeneration conditions for the spent catalyst include: oxygen-containing gas is air; regeneration temperature is 620℃; bed pressure is 0.5MPa; and oxygen-containing gas residence time is 180 seconds.

[0189] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0190] Example 2

[0191] Example 2 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedback oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0192] The difference from Example 1 is that raffinate oil is introduced at the bottom of the first catalytic conversion zone to replace VGO. The introduced raffinate oil is 100% by weight of the total amount of raffinate oil obtained from the first and second extractions. In addition, methanol is introduced into the second catalytic conversion zone (Region ⅠⅠ). The remaining operations are the same as in Example 1.

[0193] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0194] Example 3

[0195] Example 3 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedstock oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0196] The difference from Example 1 is that raffinate is introduced at the bottom of the first catalytic conversion zone, and the introduced raffinate is 60% by weight of the total amount of raffinate obtained from the first extraction and the second extraction. The remaining operations are the same as in Example 1.

[0197] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0198] Example 4

[0199] Example 4 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedstock oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0200] The difference from Example 1 is that raffinate is introduced at the bottom of the first catalytic conversion zone, and the introduced raffinate is 20% by weight of the total amount of raffinate obtained from the first extraction and the second extraction; otherwise, the remaining operations are performed in the same manner as in Example 1.

[0201] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0202] Example 5

[0203] Example 5 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedstock oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0204] The difference from Example 2 is that raffinate is introduced at the bottom of the first catalytic conversion zone, and the introduced raffinate is 30% by weight of the total amount of raffinate obtained from the first extraction and the second extraction. The remaining operations are the same as in Example 2.

[0205] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0206] Example 6

[0207] Example 6 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedstock oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0208] The difference from Example 2 is that raffinate is introduced at the bottom of the first catalytic conversion zone, and the introduced raffinate is 50% by weight of the total amount of raffinate obtained from the first extraction and the second extraction. The remaining operations are the same as in Example 2.

[0209] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0210] Example 7

[0211] Example 7 was conducted on the experimental setup shown in the flowchart in Figure 1. In this example, the bio-feedback oil was tested on a medium-sized catalytic conversion unit with a variable-diameter riser reactor.

[0212] The difference from Example 1 is that raffinate is introduced at the bottom of the first catalytic conversion zone, and the introduced raffinate is 70% by weight of the total amount of raffinate obtained from the first extraction and the second extraction. The remaining operations are the same as in Example 1.

[0213] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 3.

[0214] Comparative Example 1

[0215] Comparative Example 1 was conducted on the experimental setup shown in the flowchart in Figure 1. The first and second catalytic conversion zones were combined into a single reaction zone.

[0216] In this process, the preheated bio-based oil and the raffinate (90% by weight of the total amount of the raffinate obtained from the first extraction and the raffinate obtained from the second extraction) are introduced together into the bottom of the reactor. The regenerated catalyst is introduced into the bottom of the reactor through pipeline 12. In the presence of the catalyst, the catalytic conversion reaction is carried out at the first catalytic conversion reaction temperature to obtain the catalytic conversion reaction stream.

[0217] The reaction stream is introduced into a separation unit for further separation. Reaction oil and gas are separated from the reaction stream and fractionated. Dry gas is led out via pipeline 15, liquefied petroleum gas via pipeline 16, the light fraction containing BTX is led out via pipeline 17, and the heavy distillate oil is led out via pipeline 18. The boiling range of the BTX-containing light fraction is 55–230℃, and the boiling range of the heavy distillate oil is 230–550℃. The BTX-containing light fraction and heavy distillate oil are each introduced into an aromatics extraction unit and extracted under first and second extraction conditions, respectively, to separate raffinate oil and aromatics-containing extract oil.

[0218] The spent catalyst is introduced into the regenerator 9 via pipeline 8 for coke burn-off regeneration, and the regenerated catalyst is returned to the reactor for recycling via pipeline 12. The regeneration conditions for the spent catalyst include: oxygen-containing gas is air; regeneration temperature is 620℃; bed pressure is 0.5MPa; and oxygen-containing gas residence time is 180 seconds.

[0219] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 4.

[0220] Comparative Example 2

[0221] Comparative Example 2 was conducted on the experimental setup shown in the flowchart in Figure 1. In this setup, the first and second catalytic conversion zones were combined into a single reaction zone.

[0222] In this process, the preheated bio-based oil and raffinate (60% by weight of the total amount of raffinate obtained from the first extraction and the second extraction) along with methanol are introduced into the bottom of the reactor. The regenerated catalyst is introduced into the bottom of the reactor via pipeline 12. In the presence of the catalyst, the catalytic conversion reaction is carried out at the second catalytic conversion reaction temperature to obtain the catalytic conversion reaction stream.

[0223] The reaction stream is then fed into a separation unit for further separation. The reaction oil and gas are separated from the reaction stream and fractionated. The dry gas is led out via pipeline 15, the liquefied petroleum gas (LPG) via pipeline 16, the BTX-containing light fraction via pipeline 17, and the heavy distillate oil via pipeline 18. The boiling range of the BTX-containing light fraction is 55–230°C, and the boiling range of the heavy distillate oil is 230–550°C. The BTX-containing light and heavy distillate oils are then separately introduced into an aromatics extraction unit, where they are extracted under first and second extraction conditions, respectively, to separate the raffinate oil and the aromatics-containing extract oil.

[0224] The spent catalyst is introduced into the regenerator 9 via pipeline 8 for coke burn-off regeneration, and the regenerated catalyst is returned to the reactor for recycling via pipeline 12. The regeneration conditions for the spent catalyst include: oxygen-containing gas is air; regeneration temperature is 620℃; bed pressure is 0.5MPa; and oxygen-containing gas residence time is 180 seconds.

[0225] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 4.

[0226] Comparative Example 3

[0227] Comparative Example 3 was conducted on the experimental setup shown in the flowchart in Figure 1. In this setup, the first and second catalytic conversion zones were combined into a single reaction zone.

[0228] In this process, the preheated bio-based oil and raffinate oil (40% by weight of the total amount of raffinate oil obtained from the first and second extractions) are introduced together into the bottom of the reactor. The regenerated catalyst is introduced into the bottom of the reactor via pipeline 12. In the presence of the catalyst, the catalytic conversion reaction is carried out at the second catalytic conversion reaction temperature to obtain the catalytic conversion reaction stream. The remaining operations are the same as in Comparative Example 1.

[0229] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 4.

[0230] Comparative Example 4

[0231] Comparative Example 4 was conducted on the experimental setup shown in the flowchart in Figure 1. In this setup, the first and second catalytic conversion zones were combined into a single reaction zone.

[0232] In this process, the preheated bio-based oil and the raffinate oil (30% by weight of the total amount of the raffinate oil obtained from the first and second extractions) are introduced together into the bottom of the reactor. The regenerated catalyst is introduced into the bottom of the reactor via pipeline 12. In the presence of the catalyst, the catalytic conversion reaction is carried out at the second catalytic conversion reaction temperature to obtain the catalytic conversion reaction stream. The remaining operations are the same as in Comparative Example 1.

[0233] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 4.

[0234] Comparative Example 5

[0235] Comparative Example 5 was conducted on the experimental setup shown in the flowchart in Figure 1. In this setup, the first and second catalytic conversion zones were combined into a single reaction zone.

[0236] In this process, preheated VGO, raffinate (40% by weight of the total amount of raffinate from the first and second extractions), and methanol are introduced together into the bottom of the reactor. Regenerated catalyst is introduced into the bottom of the reactor via pipeline 12. In the presence of the catalyst, a catalytic conversion reaction is carried out at the second catalytic conversion reaction temperature to obtain the catalytic conversion reaction stream. The remaining operations are the same as in Comparative Example 1.

[0237] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 4.

[0238] Comparative Example 6

[0239] Comparative Example 6 was conducted on the experimental setup shown in the flowchart in Figure 1. In this setup, the first and second catalytic conversion zones were combined into a single reaction zone.

[0240] In this process, preheated VGO, raffinate (40% by weight of the total amount of raffinate from the first and second extractions), and methanol are introduced together into the bottom of the reactor. Regenerated catalyst is introduced into the bottom of the reactor via pipeline 12. In the presence of the catalyst, a catalytic conversion reaction is carried out at the second catalytic conversion reaction temperature to obtain the catalytic conversion reaction stream. The remaining operations are the same as in Comparative Example 1.

[0241] The implementation conditions for catalytic conversion reaction and aromatic extraction, as well as the product distribution, are shown in Table 4.

[0242] As can be seen from the data in Tables 3 and 4, the method of the present invention, when using bio-based feedstock oil, yields higher BTX than that obtained by catalytic conversion of mineral-based middle distillate oil. At the same time, the method provided by the present invention significantly improves the yield of low-carbon olefins and significantly reduces the yield of coke.

[0243] Data from Examples 1-7 also show that introducing methanol during the catalytic conversion of bio-based oil further improves the yield of BTX and low-carbon olefins, and significantly increases the BTX content in naphtha fractions.

[0244] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of 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 protection scope of the present invention.

[0245] 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, the present invention will not describe the various possible combinations separately.

[0246] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing BTX that also produces low-carbon olefins, characterized in that, It includes the following steps: S0, bringing fossil feedstock into contact with the catalytic conversion catalyst in the first catalytic conversion zone to carry out the first catalytic conversion reaction; S1. The bio-feed oil and the reactants from the first catalytic conversion zone are reacted in the second catalytic conversion zone to carry out the second catalytic conversion reaction, and the reactant oil and gas and the catalyst to be generated are separated. S2. Separate the reaction oil and gas from the second catalytic conversion zone to obtain dry gas, liquefied gas, and residual distillate; S3. Low-carbon olefins are separated from the liquefied gas, and BTX and residual oil are separated from the residual fraction.

2. The preparation method according to claim 1, wherein at least one of the following conditions is satisfied: The fossil feedstock oil comprises at least the residual oil obtained after separating BTX from the residual fraction, and optionally further comprises at least one selected from crude oil, atmospheric residue, vacuum residue, vacuum wax oil, heavy oil, oil sands bitumen, catalytic cracking slurry oil, bitumen, wax oil, Fischer-Tropsch synthetic oil and coal liquefaction oil. The bio-based oil is derived from one or more of the following: vegetable oil, animal oil, microbial oil, waste cooking oil, and oil refinery by-products. Preferably, the bio-based oil is selected from fatty acid esters with 14 to 20 carbon atoms; Preferably, the content of unsaturated fatty acid esters in the bio-based oil is 10% to 80% by weight.

3. The preparation method according to claim 1 or 2, wherein, The catalyst includes zeolite, inorganic oxides, and optionally clay; Based on the weight of the catalyst, the catalyst comprises 1% to 50% by weight of zeolite, 5% to 99% by weight of inorganic oxides, and 0% to 70% by weight of clay; wherein the zeolite comprises mesoporous zeolite and optionally macroporous zeolite; based on the weight of the zeolite, the content of mesoporous zeolite is 51% to 100% by weight, and the content of macroporous zeolite is 0% to 49% by weight. The catalyst further satisfies at least one of the following conditions: The molar ratio of SiO2 to Al2O3 in the mesoporous zeolite is 50 or more, preferably 80 or more, and the molar ratio of SiO2 to Al2O3 does not exceed 300, preferably not more than 280. The mesoporous zeolite is selected from at least one of ZSM series zeolites, ZRP zeolite and mordenite; The macroporous zeolite is selected from at least one of rare earth Y-type zeolite, rare earth HY-type zeolite, ultra-stable Y-type zeolite, high-silica Y-type zeolite, and β-type zeolite.

4. The preparation method according to any one of claims 1-3, wherein, The conditions of the first catalytic conversion zone include: reaction temperature of 580-700°C, preferably 600-650°C; reaction pressure of 0.01-1 MPa, preferably 0.1-0.9 MPa; weight hourly space velocity of 1-150 h -1 , preferably 10-100 h -1 , reaction time of 0.01-200 seconds, preferably 0.1-80 seconds; The conditions in the second catalytic conversion zone include: a reaction temperature of 450–580°C, preferably 500–550°C; a reaction pressure of 0.01–1 MPa, preferably 0.1–0.9 MPa; and a weight hourly space velocity of 1–150 h⁻¹. -1 Preferably 10-100h -1 The reaction time is 0.01 to 200 seconds, preferably 0.1 to 80 seconds.

5. The preparation method according to any one of claims 1-4, wherein, In step S3, low-carbon olefins are separated from the liquefied gas, and the residual fraction is subjected to aromatic extraction to obtain raffinate oil and aromatic extract oil. BTX is separated from the aromatic extract oil, and the process further includes the following steps: S4. At least a portion of the raffinate, preferably 1% to 95% by weight, more preferably 10% to 90% by weight, is introduced into the first catalytic conversion zone as at least a portion of the fossil feedstock oil, preferably the raffinate oil, to carry out the first catalytic conversion reaction.

6. The preparation method according to claim 5, wherein, In step S1, at least a portion of the bio-feed oil, the reaction stream from the first catalytic conversion zone, and optionally the raffinate oil are subjected to a second catalytic conversion reaction in the second catalytic conversion zone to separate the reaction oil and gas and the catalyst to be generated. Preferably, the conditions of the second catalytic conversion zone include: a reaction time of 0.01 to 150 seconds, preferably 0.1 to 100 seconds, and further optionally including: a weight ratio of the bio-feed oil to the raffinate oil entering the second catalytic conversion zone of (1 to 90):1, preferably (3 to 80):

1.

7. The preparation method according to any one of claims 1-6, wherein, At least one of the following conditions must be met: The conditions in the first catalytic conversion zone include: the weight ratio of the catalyst to the fossil feedstock is (1-90):1, preferably (3-80):1; The conditions for the second catalytic conversion zone include: the weight ratio of the catalyst entering the first catalytic conversion zone to the bio-based oil is (1-90):1, preferably (3-80):

1.

8. The preparation method according to claim 5, wherein, The extraction conditions in step S3 include: the extraction solvent is selected from one or more of N-methylpyrrolidone, sulfolane, dimethyl sulfoxide, N-methylformamide, ethylene glycol, furfural, monoethanolamine and 1,2-propanediol, preferably the extraction conditions further include: an extraction temperature of 30-120°C; a volume ratio of the residual fraction to the extraction solvent of (0.5-8.0):1; and an extraction pressure of 0.3-1.0 MPa.

9. The preparation method according to any one of claims 1-8, wherein, In step S1, an oxygen-containing organic compound is further introduced into the second catalytic conversion zone; preferably, the weight ratio of the oxygen-containing organic compound introduced into the second catalytic conversion zone to the bio-based oil is (0.01-0.8):1, more preferably (0.02-0.4):1; Preferably, the oxygen-containing organic compound is at least one selected from alcohols, ketones and ethers having 4 or fewer carbon atoms, and more preferably one or more selected from methanol, ethanol, dimethyl ketone, dimethyl ether and diethyl ether.

10. The preparation method according to any one of claims 1-9, wherein, Further steps include: S5. The spent catalyst obtained in step S1 is regenerated by coking to obtain a regenerated catalyst, and the regenerated catalyst is returned to step S0 for recycling in the first catalytic conversion zone. Preferably, the coke regeneration is carried out in the presence of oxygen-containing gas; the conditions for coke regeneration include: a regeneration temperature of 580–750°C, preferably 600–700°C; a bed pressure of 0.1–0.6 MPa, preferably 0.12–0.40 MPa; a residence time of oxygen-containing gas of 0.1–300 seconds, preferably 1–240 seconds; and an oxygen content of 20–100% by volume in the oxygen-containing gas.

11. The preparation method according to any one of claims 1-4 or 9-10, wherein, In step S2, the reaction oil and gas from the second catalytic conversion zone are separated to obtain dry gas, liquefied gas, light fraction containing BTX, and heavy fraction oil. In step S3, low-carbon olefins are separated from the liquefied gas, and the process further includes the following steps: S3-1. The light fraction containing BTX is subjected to a first extraction under the first extraction conditions to obtain a first aromatic extract oil and a first raffinate oil; the heavy fraction oil is subjected to a second extraction under the second extraction conditions to obtain a second aromatic extract oil and a second raffinate oil. S3-2. Combine the first aromatic extract oil and the second aromatic extract oil to obtain an aromatic extract oil, from which BTX is separated. Combine the first raffinate oil and the second raffinate oil to obtain a raffinate oil, which is used as the residual oil.

12. The preparation method according to claim 11, wherein, At least one of the following conditions must be met: The distillation range of the BTX-containing light fraction is 25–230°C, preferably 55–200°C. The initial boiling point of the BTX-containing light fraction is any temperature between 25 and 55°C, and the final boiling point is any temperature between 170 and 230°C, preferably any temperature between 170 and 200°C. The heavy distillate oil has a distillation range of 230–550°C, preferably 250–500°C. The initial boiling point of the heavy fraction containing BTX is any temperature between 230 and 350°C, and the final boiling point is any temperature between 450 and 550°C, preferably any temperature between 450 and 500°C. The first extraction conditions include: an extraction temperature of 30–120°C, a volume ratio of BTX-containing light fraction to the extraction solvent of (0.5–5):1, and an extraction pressure of 0.3–1.0 MPa. The second extraction conditions include: an extraction temperature of 30–120°C, a volume ratio of heavy distillate oil to extraction solvent of (0.5–5):1, and an extraction pressure of 0.3–1.0 MPa.

13. A system for preparing BTX and simultaneously producing low-carbon olefins, characterized in that, The system includes the following units: The first catalytic conversion unit is provided with a fossil feedstock inlet and a catalyst inlet, wherein the fossil feedstock is brought into contact with the catalytic conversion catalyst in the first catalytic conversion unit to carry out the first catalytic conversion reaction; The second catalytic conversion unit is connected downstream of the first catalytic conversion unit and is equipped with a bio-based oil inlet. In the second catalytic conversion unit, the bio-based oil and the reactants from the first catalytic conversion unit undergo a second catalytic conversion reaction to separate the reactant oil and gas and the catalyst to be generated. A separation unit, connected downstream of the second catalytic conversion unit, separates the reaction oil and gas from the second catalytic conversion unit to obtain dry gas, liquefied gas, and residual distillate. A low-carbon olefin separation unit, connected downstream of the separation unit, wherein low-carbon olefins are separated from the liquefied gas; and The BTX separation unit, connected downstream of the separation unit, separates BTX and residual oil from the residual fraction.

14. The system according to claim 13, wherein, The BTX separation unit includes an extraction unit, wherein the residual fraction is subjected to aromatic extraction to obtain raffinate oil as residual oil and aromatic-containing extracted oil. The BTX separation unit is connected to the fossil feedstock inlet of the first catalytic conversion unit and is used to feed the raffinate oil into the first catalytic conversion unit. Optionally, the second catalytic conversion unit is further provided with a raffinate inlet, which is connected to the BTX separation unit and is used to feed at least a portion of the raffinate.

15. The system according to claim 13, wherein, In the separation unit, the reaction oil and gas from the second catalytic conversion unit are separated to obtain dry gas, liquefied gas, light fraction containing BTX, and heavy distillate oil. The BTX separation unit includes a first extraction unit and a second extraction unit. The first extraction unit is used to extract light fractions containing BTX to obtain a first aromatic extract oil and a first raffinate oil. The second extraction unit is used to extract heavy fraction oil to obtain a second aromatic extract oil and a second raffinate oil. The first aromatic extract oil and the second aromatic extract oil are combined to obtain an aromatic extract oil, from which BTX is separated. The first raffinate oil and the second raffinate oil are combined to obtain a raffinate oil, which is used as residual oil. The BTX separation unit is connected to the fossil feedstock inlet of the first catalytic conversion unit and is used to feed the raffinate oil into the first catalytic conversion unit. Optionally, the second catalytic conversion unit is further provided with a raffinate inlet, which is connected to the BTX separation unit and is used to feed at least a portion of the raffinate.

16. The system according to claim 13, wherein it satisfies at least one of the following conditions: The second catalytic conversion unit is further provided with an oxygen-containing organic compound inlet, thereby introducing oxygen-containing organic compounds into the second catalytic conversion unit; The system further includes a catalyst regeneration unit connected downstream of the second catalytic conversion unit, which regenerates the spent catalyst from the second catalytic conversion unit by coking to obtain a regenerated catalyst. The regenerated catalyst is then fed into the first catalytic conversion unit for recycling.

17. The system according to claims 13-16, wherein, The second catalytic conversion unit includes a reaction zone for carrying out the second catalytic conversion, a stripping section located downstream of the reaction zone, a settling section located downstream of the stripping section, and a gas collection chamber located downstream of the settling section. The bottom of the stripping section is connected to the catalyst regeneration unit.

18. The system according to claims 13-17, wherein, It satisfies at least one of the following conditions: The first catalytic conversion unit is selected from one or more of fluidized bed reactors, fixed bed reactors, moving bed reactors and slurry bed reactors; the fluidized bed reactor is selected from one or more of risers, constant velocity fluidized beds, constant diameter fluidized beds, upward conveying lines and downward conveying lines; The second catalytic conversion unit is selected from one or more of the following: fluidized bed reactor, fixed bed reactor, moving bed reactor, and slurry bed reactor; the fluidized bed reactor is selected from one or more of the following: riser, constant velocity fluidized bed, constant diameter fluidized bed, upward conveyor line, and downward conveyor line.

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