Two-stage fixed-bed catalytic process for converting pyrolysis oil into BTX

Abstract

A method for reforming pyrolysis oil comprises the steps of: contacting pyrolysis oil feedstock with hydrogen in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor, wherein the pyrolysis oil feedstock comprises a polycyclic aromatic compound having 16 or more carbon atoms; contacting the pyrolysis oil feedstock with hydrogen in the presence of a mixed metal oxide catalyst in the first fixed-bed reactor to convert at least a portion of the polycyclic aromatic compound in the pyrolysis oil feedstock into a bicyclic aromatic compound, a tricyclic aromatic compound, or both; and sending an intermediate stream containing the bicyclic aromatic compound, a tricyclic aromatic compound, or both to a second fixed-bed reactor located downstream of the first fixed-bed reactor; and contacting this intermediate stream with hydrogen in the presence of a mesoporous supported metal catalyst in the second fixed-bed reactor.

Description

Description of related applications

[0001] This application claims priority to U.S. Patent Application No. 18 / 355789, filed on July 20, 2023, the full disclosure of which is incorporated herein by reference. [Technical Field]

[0002] This disclosure broadly relates to methods and systems for modifying pyrolysis oils, and more particularly to methods and systems for modifying pyrolysis oils into light aromatic compounds using a two-stage fixed-bed catalytic process. [Background technology]

[0003] Crude oil can be converted into valuable chemical intermediates and products through one or more refining processes. These processes may include vapor cracking, which breaks down larger hydrocarbons in crude oil to produce smaller hydrocarbons. For example, naphtha flows separated from crude oil or gas condensate two-phase flows can be vapor-cracked to produce higher-value products and intermediates. Light hydrocarbon gases can also be vapor-cracked to produce high-value products and intermediates, such as olefins, but are not limited to these. Vapor cracking units produce a bottom flow called pyrolysis oil. This pyrolysis oil may contain aromatic compounds at increased concentrations compared to the raw crude oil. In many crude oil processing facilities, this pyrolysis oil is burned as fuel. However, aromatic compounds in pyrolysis oil can be converted into high-value chemical products and intermediates, which can be used as basic components in chemical synthesis processes. For example, aromatic compounds derived from pyrolysis oil can be converted into xylene, which can be an initial basic component in the production of terephthalic acid, which can then be used in the production of polyesters. Aromatic compounds in pyrolysis oils can be modified into many other high-value aromatic products and intermediates. Market demand for these high-value aromatic compounds continues to expand. [Overview of the project] [Problems that the invention aims to solve]

[0004] Polycyclic aromatic compounds in pyrolysis oils can be converted to light aromatic compounds (including benzene, toluene, ethylbenzene, xylene (BTEX), other aromatic compounds, or combinations thereof) through various reactions such as hydrogenation, ring-opening, disproportionation, dealkylation, transalkylation, decomposition, or decomposition of aromatic compounds, but are not limited to those listed below. In general, combinations of these reactions make it possible to convert some of the polycyclic aromatic compounds in pyrolysis oils to light aromatic compounds in a single step. However, carrying out multiple reactions in a single process can be complex, and the yield may be insufficient to meet the demand for BTEX. Furthermore, it would be difficult to carry out combinations of reactions without employing harsh conditions.

[0005] Therefore, there is still a need for improved systems and methods for modifying pyrolysis oil to produce light aromatic compounds and increase BTEX yield using mild processing conditions. [Means for solving the problem]

[0006] Embodiments of the present disclosure satisfy this requirement by providing a two-stage catalytic process that can modify pyrolysis oil into BTEX in a single process by using two fixed-bed reactors in series. The first fixed-bed reactor may include a mixed metal oxide catalyst configured for use in a fixed-bed reactor. The first fixed-bed reactor may be configured to convert at least a portion of the polycyclic compounds in the pyrolysis oil into intermediate aromatic compounds, such as bicyclic aromatic compounds. The second fixed-bed reactor may include a mesoporous supported metal catalyst and may be configured to convert at least a portion of the intermediate aromatic compounds into BTEX. The method and system can convert a portion of the polycyclic aromatic compounds in pyrolysis oil into BTEX in a two-stage fixed-bed catalytic process without the need for subsequent chemical reaction steps. Furthermore, the method and system can increase the yield of BTEX by modifying pyrolysis oil under milder conditions compared to conventional methods that use harsher reaction conditions.

[0007] According to one or more aspects of this disclosure, a method for reforming pyrolysis oil may include contacting pyrolysis oil feedstock with hydrogen in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor, and contacting an intermediate flow with hydrogen in the presence of a mesoporous supported metal catalyst in a second fixed-bed reactor. The mesoporous supported metal catalyst may include nickel and tungsten impregnated in a mesoporous support comprising large-pore alumina, a binder, and at least one zeolite. By contacting pyrolysis oil feedstock with hydrogen in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor, at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock may react to produce an intermediate flow containing bicyclic aromatic compounds, tricyclic aromatic compounds, or combinations thereof. By contacting the intermediate flow with hydrogen in the presence of a mesoporous supported metal catalyst, at least a portion of the bicyclic aromatic compounds and / or tricyclic aromatic compounds in the intermediate flow may react to produce a second reactor effluent containing aromatic compounds having 6 to 8 carbon atoms. The pyrolysis oil feedstock may contain polycyclic aromatic compounds having 16 or more carbon atoms. The mixed metal oxide catalyst may contain multiple MMO particles, each of which contains Fe2O3, ZrO2, CeO2, and Al2O3.

[0008] According to one or more aspects of the present disclosure, a system for reforming pyrolysis oil may comprise a first fixed-bed reactor containing a mixed metal oxide catalyst, and a second fixed-bed reactor located downstream of the first fixed-bed reactor and containing a mesoporous supported metal catalyst. The first fixed-bed reactor may be configured to contact pyrolysis oil feedstock with hydrogen in the presence of the mixed metal oxide catalyst to produce an intermediate flow containing a bicyclic aromatic compound, a tricyclic aromatic compound, or both. The mixed metal oxide catalyst may comprise a plurality of catalyst particles, each of which may include Fe2O3, ZrO2, CeO2, and Al2O3. The second fixed-bed reactor may be configured to contact the intermediate flow with hydrogen in the presence of the mesoporous supported metal catalyst to produce a second reactor effluent containing an aromatic compound having 6 to 8 carbon atoms. The mesoporous supported metal catalyst may comprise nickel and tungsten impregnated in a mesoporous support containing alumina and at least one zeolite.

[0009] Additional features and advantages of the technology described herein are set forth in the following detailed description, some of which will be readily apparent to those skilled in the art from that description, or will be recognized by carrying out the technology as described herein, including in the following detailed description, claims, and accompanying drawings. [Brief explanation of the drawing]

[0010] The following detailed description of specific embodiments of this disclosure will be best understood when read in conjunction with the following drawings, which have similar structures and are numbered similarly. [Figure 1] A generalized flowchart of a system for modifying pyrolysis oil according to one or more embodiments shown and described in this disclosure. [Figure 2] A generalized flowchart of a system for providing pyrolysis oil raw materials according to one or more embodiments shown and described in this disclosure. [Figure 3]A generalized flowchart of a system for providing pyrolysis oil raw materials according to one or more embodiments shown and described in this disclosure. [Figure 4] Graph showing the components of heavy pyrolysis oil. [Figure 5] A generalized flowchart of a system for modifying pyrolysis oil according to one or more embodiments shown and described in this disclosure. [Figure 6] A generalized flowchart of a system for modifying pyrolysis oil according to one or more embodiments shown and described in this disclosure. [Modes for carrying out the invention]

[0011] For the purpose of describing the simplified schematic diagrams and descriptions in Figures 1-3 and 5, numerous valves, temperature sensors, electronic control devices, etc., which are used and well known to those skilled in the art of specific chemical processing operations, are not included in the drawings. Furthermore, ancillary components often included in chemical processing operations, such as air supply devices, heat exchangers, surge tanks, catalyst hoppers, or other related systems, are not shown. These components will be found to be included in the spirit and scope of the disclosed embodiments. However, operating components such as those described in this disclosure may be added to the embodiments described in this disclosure.

[0012] Furthermore, it should be noted that arrows in the drawings may indicate process flows. However, these arrows may also equally indicate transfer lines that move process flows between two or more system components. In addition, arrows connected to system components define inlets or outlets at each given system component. The direction of the arrows generally coincides with the main direction of movement of the material in the flow contained within the physical transfer line indicated by the arrow. Furthermore, arrows not connected to two or more system components indicate product flows discharged from the illustrated system, or system inlets flowing into the illustrated system. Product flows may be further processed in an accompanying chemical processing system or commercialized as final products. System inlets may be flows transferred from an accompanying chemical processing system or unprocessed raw material flows. Some arrows may represent recirculation flows, which are discharge flows from system components that are recycled back into the system. However, it should be understood that in some embodiments, the indicated recirculation flows may be replaceable by system inlets of the same material, and a portion of the recirculation flow may be discharged from the system as system products.

[0013] In addition, arrows in the diagram may schematically represent process steps that transport fluid flow from one system component to another. For example, an arrow pointing from one system component to another may represent "passing" the discharge of one system component to the other, which may include the "discharge" or "removal" of the contents of the process flow from one system component and the "introduction" of the contents of the resulting product flow into the other system component.

[0014] In the schematic flowcharts of Figures 1-3 and Figure 5, where two or more lines intersect, it should be understood that two or more process flows are “mixed” or “merged.” Mixing or merging may also include mixing by directly introducing both fluid flows into a similar reactor, separator, or other system component. For example, where it is shown that two fluid flows are directly merged just before entering a separator or reactor, it should be understood that in some embodiments, the fluid flows may be introduced equally into the separator or reactor and mixed within the reactor.

[0015] Various embodiments of this disclosure are described in more detail below. Some of these embodiments are shown in the accompanying drawings. Wherever possible, the same reference numerals are used throughout the drawings to refer to identical or similar parts.

[0016] Embodiments of the present disclosure relate to methods and systems for reforming pyrolysis oil in a two-stage fixed-bed catalytic process. Referring hereto to Figure 1, the system 100 for reforming pyrolysis oil may comprise a first fixed-bed reactor 110 and a second fixed-bed reactor 120 located downstream of the first fixed-bed reactor 110. The first fixed-bed reactor 110 may include a mixed metal oxide catalyst 112. The first fixed-bed reactor 110 may be configured to contact pyrolysis oil feedstock 102 with hydrogen 116 in the presence of the mixed metal oxide catalyst 112 to produce an intermediate flow 118 containing a bicyclic aromatic compound, a tricyclic aromatic compound, or a combination thereof. The mixed metal oxide catalyst 112 may include a plurality of catalyst particles, each of which may include iron oxide (Fe2O3), zirconium oxide (ZrO2), cerium oxide (CeO2), and alumina (Al2O3). A second fixed-bed reactor 120 located downstream of the first fixed-bed reactor 110 may include a mesoporous supported metal catalyst 122. The second fixed-bed reactor 120 may be configured to contact an intermediate flow 118 with hydrogen in the presence of the mesoporous supported metal catalyst 122 to produce a second reactor effluent 130 containing an aromatic compound having 6 to 8 carbon atoms. The mesoporous supported metal catalyst 122 may include nickel and tungsten impregnated in a mesoporous support containing alumina and at least one zeolite.

[0017] Referring further to Figure 1, the method for reforming pyrolysis oil includes the step of contacting pyrolysis oil feedstock 102 with hydrogen 116 in the presence of a mixed metal oxide catalyst 112 in a first fixed-bed reactor 110. The pyrolysis oil feedstock 102 may include polycyclic aromatic compounds having 16 or more carbon atoms. The mixed metal oxide catalyst 112 may include a plurality of catalyst particles, each of which may include Fe2O3, ZrO2, CeO2, and Al2O3. When the pyrolysis oil feedstock 102 is contacted with hydrogen 116 in the presence of the mixed metal oxide catalyst 112 in the first fixed-bed reactor 110, at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock 102 may react to produce an intermediate flow containing a bicyclic aromatic compound, a tricyclic aromatic compound, or both. This method may further include the step of contacting the intermediate flow 118 with hydrogen 124 in the presence of a mesoporous supported metal catalyst 122 in a second fixed-bed reactor 120. The mesoporous supported metal catalyst 122 may include nickel and tungsten impregnated in a mesoporous support containing alumina and at least one zeolite. When the intermediate flow 118 is brought into contact with hydrogen 124 in the presence of the mesoporous supported metal catalyst 122, at least a portion of the bicyclic aromatic compounds, tricyclic aromatic compounds, or combinations thereof in the intermediate flow 118 can react to produce a second reactor effluent 130 containing aromatic compounds having 6 to 8 carbon atoms.

[0018] This system and method improve the performance of a fixed-bed catalytic process in converting raw material pyrolysis oil into a high-value aromatic compound stream. The total yield of monocyclic aromatic compounds can be significantly higher than with conventional systems. Furthermore, this process can achieve its yield using a heavy pyrolysis oil feed stream and a fixed-bed system. The use of a fixed-bed system eliminates the need to separate the solid catalyst from the reactor effluent in a separate process.

[0019] As used herein, the term “catalyst” refers to any substance that increases the rate of a particular chemical reaction. The catalysts and catalytic components described herein, but are not limited to, can be used to facilitate a variety of reactions, including but are not limited to selective hydrogenation, ring opening, disproportionation, dealkylation, hydrogenated dealkylation, transalkylation, decomposition, decomposition of aromatic compounds, other chemical reactions, or combinations thereof.

[0020] As used in this disclosure, the term “cracking” refers to a chemical reaction in which a molecule having a carbon-carbon bond is broken down into multiple molecules by the cleavage of one or more carbon-carbon bonds; a chemical reaction in which a molecule containing one or more cyclic parts, such as aromatic compounds, undergoes a reaction that opens one or more of its cyclic parts; or a chemical reaction in which a molecule having a carbon-carbon double bond is broken down into a carbon-carbon single bond. Some catalysts may have multiple catalytic activities, and naming a catalyst by a particular function does not mean that the catalyst may not have catalytic activity for other functions. As used in this disclosure, the term “hydrocracking” refers to decomposition in the presence of hydrogen.

[0021] As used in this disclosure, the term “aromatic compound” refers to a compound having one or more aromatic ring structures. The term “light aromatic compound” refers to a compound having an aromatic ring with or without substituents and having 6 to 8 carbon atoms. The term “BTEX” refers to one or any combination of benzene, toluene, ethylbenzene, paraxylene, metaxylene, and orthoxylene.

[0022] As used in this disclosure, the term "xylene," unless accompanied by a prefix designating an isomer such as para, meta, or ortho, refers to one or more of metaxylene, orthoxylene, paraxylene, and mixtures thereof of these xylene isomers.

[0023] Throughout this disclosure, the terms “boiling point temperature” or “boiling temperature” refer to the boiling point temperature at atmospheric pressure unless otherwise specified.

[0024] As used in this disclosure, the term “initial boiling point” or “IBP” of a composition refers to the temperature at which the component with the lowest boiling point in the composition begins to transition from the liquid phase to the gas phase.

[0025] As used in this disclosure, the term “endpoint” or “FBP” of a composition refers to the temperature at which the component with the highest boiling point in the composition transitions from the liquid phase to the gas phase.

[0026] As used in this disclosure, the term “outer surface” refers to the outer surface of a catalyst or catalyst support (e.g., a mesoporous support).

[0027] As used in this disclosure, the term “pore surface” refers to the inner surface of pores in a catalyst or catalyst support, the pores including at least pores that are in fluid communication with the outer surface of the catalyst or catalyst support and are accessible to reactants.

[0028] As used in this disclosure, the term “average pore size” of a catalyst or catalyst support refers to the average pore size determined by Barrett-Joyner-Hallenda (BJH) analysis. BJH analysis measures the amount of gas (argon) desorbed from a material, such as a mesoporous support, at 87 Kelvin (approximately -186°C) over a certain pressure range. Using the Kelvin equation, the average pore size of the material is calculated using the amount of argon adsorbate removed from the pores of the material and the relative pressure of the system.

[0029] As used in this disclosure, the term “fixed-bed reactor” refers to a reactor in which a catalyst is housed and which maintains the catalyst in a fixed position within it. The fixed-bed reactors used in this disclosure may have multiple material inlets but have a single outlet.

[0030] As used in this disclosure, “separation unit” refers to any separation apparatus that separates one or more chemical substances in a mixture from each other, at least partially. For example, a separation unit can selectively separate different chemical species from each other to form one or more chemical fractions. Examples of separation units include, without limitation, distillation columns, fractionation units, flash drums, knockout drums, knockout pots, centrifuges, filters, traps, scrubbers, expansion units, membranes, solvent extractors, high-pressure separators, and low-pressure separators. It should be understood that the separation processes described in this disclosure may not completely separate all of one chemical component from all of another. It should be understood that the separation processes described in this disclosure separate different chemical components from each other “at least partially,” and that separation may include only partial separation, even if not explicitly stated. As used in this disclosure, one or more chemical components may be “separated” from a process flow to form a new process flow. Generally, a process flow may enter a separation unit and be divided, i.e., separated, into two or more process flows having a desired composition.

[0031] As used in this disclosure, the terms “upstream” and “downstream” refer to the relative position of a unit operation with respect to the direction of process flow. A first unit operation in a system is considered “upstream” of a second unit operation if the process flow through the system encounters the first unit operation before encountering the second unit operation. Similarly, a second unit operation is considered “downstream” of a first unit operation if the process flow through the system encounters the first unit operation before encountering the second unit operation.

[0032] As used in this disclosure, passing a fluid flow or effluent "directly" from one unit to another means passing the fluid flow or effluent from a first unit to a second unit without passing it through an intermediate reaction system or separation system that substantially alters its composition. Heat transfer devices such as heat exchangers, preheaters, coolers, condensers, or other heat transfer equipment, and pressure devices such as pumps, pressure regulators, compressors, or other pressure devices are not considered intermediate systems that alter the composition of a fluid flow or effluent. Mixing two fluid flows or effluents upstream of a process unit is also not considered to constitute an intermediate system that alters the composition of one or both of the fluid flows or effluents being mixed. Simply splitting a fluid flow into two fluid flows of the same composition is also not considered to constitute an intermediate system that alters the composition of a fluid flow.

[0033] As used in this disclosure, the term “effluent” refers to the fluid flow discharged from a reactor, reaction zone, or separation device after a particular reaction or separation process. Generally, effluent has a different composition from the fluid flow that entered the separation device, reactor, or reaction zone. It should be understood that if effluent is sent to another system unit, only a portion of that system's fluid flow may be sent. For example, a slip flow (having the same composition) may carry away some of the effluent, meaning that only a portion of the effluent may enter a downstream system unit. The term “reaction effluent” is used more specifically to refer to the fluid flow discharged from a reactor or reaction zone.

[0034] Furthermore, it should be understood that fluid flows can be named based on their components, and that the components from which the name of a fluid flow is derived may be the main components of that fluid flow (for example, including 50 mass percent (mass%), 70 mass percent, 90 mass percent, 95 mass percent, 99 mass percent, 99.5 mass percent, and even 99.9 mass percent to 100 mass percent of the contents of the fluid flow, without considering inert gases or diluents added to the fluid flow). Also, if a component of a fluid flow is disclosed as a fluid flow containing that component flowing from one system component to another, it should be understood that the component is disclosed as flowing from that system component to another. For example, a “hydrogen flow” disclosed as flowing into a first system component or flowing from a first system component to a second system component should be understood as equivalently disclosing “hydrogen” flowing into a first system component or flowing from a first system component to a second system component.

[0035] Referring again to Figure 1, a system 100 for modifying the pyrolysis oil feedstock 102 is schematically shown. The system 100 for modifying the pyrolysis oil feedstock 102 may comprise a first fixed-bed reactor 110 and a second fixed-bed reactor 120 located downstream of the first fixed-bed reactor 110. The first fixed-bed reactor 110 may comprise one or more fixed-bed reactors and may be configured to contact the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of a mixed metal oxide catalyst 112 to produce an intermediate flow 118. The intermediate flow 118 may include a bicyclic aromatic compound, a tricyclic aromatic compound, or both. The second fixed-bed reactor 120 may be configured to contact the intermediate flow 118 with hydrogen 124 in the presence of a mesoporous supported metal catalyst 122 to produce a second reactor effluent 130 containing an aromatic compound having 6 to 8 carbon atoms.

[0036] This system and method improve the performance of reforming raw material pyrolysis oil into a high-value aromatic compound stream (including relatively high concentrations of monocyclic aromatic compounds) in a single process. By using a fixed-bed reactor, the catalyst / product separation and catalyst recirculation steps can be eliminated.

[0037] Referring here to Figures 2 and 3, the pyrolysis oil feedstock 102 may include heavy pyrolysis oil 250. In embodiments, the pyrolysis oil feedstock 102 may also include diluents such as light pyrolysis oil, toluene, other light aromatic compounds, or combinations thereof, but are not limited to these. The heavy pyrolysis oil 250 may be a fluid flow from a hydrocarbon processing facility, rich in aromatic compounds such as polycyclic aromatic compounds. In embodiments, the heavy pyrolysis oil 250 of the pyrolysis oil feedstock 102 may be a bottom flow from a liquid vapor cracking process, such as a naphtha vapor cracking system 200. As used in this disclosure, “bottom flow” may refer to the residual oil or fraction of feedstock (such as feedstock to a vapor cracking process) containing the least volatile components that have not been separately recovered as condensed vapor.

[0038] The heavy pyrolysis oil 250 of the pyrolysis oil raw material 102 may contain monocyclic aromatic compounds and polycyclic aromatic compounds. Polycyclic aromatic compounds may contain aromatic compounds having 2, 3, 4, 5, 6, 7, 8, or more than 8 aromatic ring structures. Polycyclic aromatic compounds may contain aromatic compounds having 16 or more carbon atoms. The heavy pyrolysis oil 250 of the pyrolysis oil raw material 102 may also contain other components such as saturated hydrocarbons, but is not limited to the above. Referring to Figure 4, an example of a typical embodiment of the composition of heavy pyrolysis oil 250 that can be used as pyrolysis oil raw material 102 is shown graphically. The heavy pyrolysis oil 250 given in Figure 4 is pyrolysis oil produced from steam cracked naphtha. As shown in Figure 4, the heavy pyrolysis oil 250 of the pyrolysis oil raw material 102 may contain monocyclic aromatic compounds, dicyclic aromatic compounds, tricyclic aromatic compounds, tetracyclic aromatic compounds, pentacyclic aromatic compounds, hexacyclic aromatic compounds, and aromatic compounds having six or more aromatic rings (six-aromatic compounds in Figure 4). The heavy pyrolysis oil 250 of the pyrolysis oil raw material 102 may contain dicyclic aromatic compounds and aromatic compounds having six or more aromatic rings in high concentrations, as shown in Figure 4. In the embodiment, the heavy pyrolysis oil 250 of the pyrolysis oil raw material 102, which is rich in polycyclic aromatic compounds, may contain 50% by mass or more of polycyclic aromatic compounds, for example, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, and even 80% by mass or more of polycyclic aromatic compounds, based on the unit mass of the heavy pyrolysis oil 250 in the pyrolysis oil raw material 102.

[0039] Most of the heavy pyrolysis oil 250 in the pyrolysis oil feedstock 102 may be polycyclic aromatic compounds having more than 16 carbon atoms or 4 or more aromatic rings. The heavy pyrolysis oil 250 may contain 30 mass% or more of polycyclic aromatic compounds having 16 or more carbon atoms, for example, 35 mass% or more, 40 mass% or more, or even 45 mass% or more of the polycyclic aromatic compounds having 16 or more carbon atoms, and the mass percentages are based on the unit mass of the heavy pyrolysis oil 250 in the pyrolysis oil feedstock 102. The heavy pyrolysis oil 250 may contain 30 mass% or more of polycyclic aromatic compounds having a boiling point temperature of 750 degrees Fahrenheit (°F) (399°C) or higher, for example, 35 mass% or more, 40 mass% or more, or even 45 mass% or more of the polycyclic aromatic compounds having a boiling point temperature of 399°C or higher, and the mass percentages are based on the unit mass of the heavy pyrolysis oil 250 in the pyrolysis oil feedstock 102.

[0040] In the embodiment, the heavy pyrolysis oil 250 may have a density of 1.00 gram per cubic centimeter (g / cm 3 ) or more, for example, 1.02 g / cm 3 or more, 1.00 g / cm 3 to 1.20 g / cm 3 , 1.01 g / cm 3 to 1.10 g / cm 3 , or 1.02 g / cm 3 to 1.10 g / cm 3 at 15°C, which is determined according to the test method of ASTM D5002. In the embodiment, the heavy pyrolysis oil 250 may have a dynamic viscosity of 10 millipascal seconds (mPa * s), for example, 10 mPa * s to 20 mPa * s, or 12 mPa * s to 15 mPa * s at 60°C, and the dynamic viscosity is determined according to the test method of ASTM D7042. In the embodiment, the heavy pyrolysis oil 250 may have a kinematic viscosity of 10 square millimeters per second (mm 2 / s) or more, for example, 12 mm 2 / s or more, 10 mm 2 / s to 20mm 2 / s, 10mm 2 / s to 15mm 2 / s, 12mm 2 / s to 20mm 2 / s, or 12mm 2 / s to 15mm 2 It can have a kinematic viscosity of / s at 60°C.

[0041] In the embodiment, the heavy pyrolysis oil 250 may have an initial boiling point temperature (IBP) of 150°C or higher, for example, 150°C to 200°C or 150°C to 180°C, as determined according to the test method of ASTM D2887. In the embodiment, the heavy pyrolysis oil 250 may have a final boiling point temperature (FBP) of 500°C or higher, for example, 600°C or higher, 650°C or higher, 700°C or higher, 500°C to 1000°C, 500°C to 900°C, 500°C to 800°C, 600°C to 1000°C, 600°C to 900°C, 600°C to 800°C, 650°C to 1000°C, 650°C to 900°C, 650°C to 800°C, 700°C to 1000°C, 700°C to 900°C, or 700°C to 800°C, as determined according to the ASTM D2887 test method and the ISO test method EN15199-1-3. In the embodiment, the heavy pyrolysis oil 250 may have a 50% distillation temperature of 300°C to 500°C, for example, 300°C to 450°C, 300°C to 400°C, 300°C to 380°C, 325°C to 500°C, 325°C to 450°C, 325°C to 400°C, 325°C to 380°C, 350°C to 500°C, 350°C to 450°C, 350°C to 400°C, or 350°C to 380°C, as determined according to the test method of ASTM D2887.

[0042] The heavy pyrolysis oil 250 of the pyrolysis oil raw material 102 may also contain sulfur and sulfur compounds at low concentrations. The heavy pyrolysis oil 250 of the pyrolysis oil raw material 102 may contain sulfur and sulfur-containing compounds at concentrations of 1000 ppm (ppmw) or less by mass, for example, 500 ppmw or less, 400 ppmw or less, and even 300 ppmw or less, as determined according to the test method of ASTM D2622. In the embodiment, the heavy pyrolysis oil 250 may contain sulfur and sulfur compounds at concentrations from greater than 0 ppmw to 1000 ppmw, for example, from 300 ppmw to 1000 ppmw, or from 300 ppmw to 500 ppmw. In the embodiment, the heavy pyrolysis oil 250 may contain iron, nickel, or both at concentrations of 100 ppmw or less, 50 ppmw or less, or 20 ppmw or less, as determined according to the ASTM D2622 test method. The properties of an exemplary embodiment of the heavy pyrolysis oil 250 obtained by the vapor cracking of naphtha are given in Table 1.

[0043] [Table 1]

[0044] As mentioned earlier, in the embodiment, the pyrolysis oil raw material 102 may include a diluent 104 (such as a light aromatic compound flow). The heavy pyrolysis oil 250 has high viscosity (dynamic viscosity > 10 mPa). * s or kinematic viscosity > 10 mm 2 Because of the fluidity of the pyrolysis oil raw material 102 ( / s), a diluent 104 can be added to increase the fluidity of the pyrolysis oil raw material 102. By including the diluent 104 in the pyrolysis oil raw material 102, the contact of the pyrolysis oil raw material 102 with the surface of the mixed metal oxide catalyst 112 can be increased in the first fixed-bed reactor 110. The diluent 104 may include, but is not limited to, light pyrolysis oil, benzene, mixed xylene, toluene, ethylbenzene, or a combination thereof. As shown in Figure 3, in the embodiment, the diluent 104 may include light pyrolysis oil 350 derived from the bottom flow of the hydrocarbon gas vapor cracking unit.

[0045] The properties of one embodiment of diluent 104 containing light pyrolysis oil 350 from a hydrocarbon gas vapor cracking system are given in Table 1. In this embodiment, the light pyrolysis oil 350 is 0.98 g / cm³, determined according to the ASTM D5002 test method. 3 Less than, for example, 0.97 g / cm³ 3 Below, 0.96g / cm 3 Below, 0.92g / cm 3 From 0.978 g / cm³ 3 , or 0.92 g / cm³ 3 From 0.97 g / cm³ 3 It can have a density at 15°C. In the embodiment, the light pyrolysis oil 350 has a density of 5 millipascal seconds (mPa * s) For example, 4 mPa * s or less, 0.5mPa * s to 5 mPa * s, 1 mPa * s to 4 mPa * s, or 1 mPa * s to 2 mPa * It can have a dynamic viscosity of s at 60°C, and the dynamic viscosity is determined according to the test method of ASTM D7042. In the embodiment, the light pyrolysis oil 350 has a dynamic viscosity of 5 square millimeters per second (mm) as determined according to the test method of ASTM D7042. 2 / s) or less, for example, 4mm 2 / s or less, 2mm 2 / s or less, 0.5mm 2 / s to 5mm 2 / s, 0.5mm 2 / s to 4mm 2 / s, 1mm 2 / s to 5mm 2 / s, or 1mm 2 / s to 2mm 2 It can have a kinematic viscosity of / s at 60°C.

[0046] In the embodiment, the light pyrolysis oil 350 may have an initial boiling point temperature (IBP) of 120°C or less, for example, 100°C or less, 40°C to 120°C, or 50°C to 100°C, as determined according to the test method of ASTM D2887. In the embodiment, the light pyrolysis oil 350 may have a final boiling point temperature (FBP) of less than 500°C, for example, 450°C or less, 400°C or less, 250°C to 500°C, 250°C to 450°C, 250°C to 400°C, 300°C to less than 500°C, 300°C to 475°C, 300°C to 450°C, or 300°C to 400°C, as determined according to the test method of ASTM D2887. In the embodiment, the light pyrolysis oil 350 may have a 50% distillation temperature of less than 230°C, as determined according to the test method of ASTM D2887, for example, 150°C to 230°C, 150°C to 225°C, 150°C to 200°C, 175°C to 230°C, 175°C to 225°C, 175°C to 200°C, 180°C to 230°C, 180°C to 225°C, or 180°C to 200°C.

[0047] The light pyrolysis oil 350 of the pyrolysis oil raw material 102 may also contain sulfur and sulfur compounds at low concentrations. The light pyrolysis oil 350 may contain sulfur and sulfur-containing compounds at concentrations of 500 ppm (ppmw) or less by mass, for example, 400 ppmw or less, or even 300 ppmw or less, as determined according to the test method of ASTM D2622. In the embodiment, the light pyrolysis oil 350 may contain sulfur and sulfur compounds at concentrations from greater than 0 ppmw to 500 ppmw, for example, from 1 ppmw to 500 ppmw, from 1 ppmw to 400 ppmw, or from 1 ppmw to 300 ppmw. In the embodiment, the light pyrolysis oil 350 may contain iron, nickel, or both at concentrations of 100 ppmw or less, 50 ppmw or less, 20 ppmw or less, and even 10 ppmw or less, for example, from 0 ppmw to 100 ppmw, as determined according to the ASTM D2622 test method. The properties of an exemplary embodiment of the light pyrolysis oil 350 obtained by vapor decomposition of a light hydrocarbon gas stream are given in Table 1.

[0048] The pyrolysis oil raw material 102 may contain 10% to 90% by mass of diluent 104, based on the total mass of the pyrolysis oil raw material 102. The diluent 104 may contain at least 50% by mass, at least 60% by mass, at least 70% by mass, at least 80% by mass, at least 90% by mass, at least 95% by mass, and even at least 99% by mass of aromatic hydrocarbons having 6 to 8 carbon atoms, based on the total mass of hydrocarbons in the diluent 104. In the embodiment, the light aromatic compound stream consists substantially of aromatic hydrocarbons having 6 to 8 carbon atoms, such as benzene, toluene, xylene, and combinations thereof. The pyrolysis oil raw material 102 may contain diluent 104 in any subset thereof, based on the total mass of the pyrolysis oil raw material 102, ranging from 10% to 80% by mass, 10% to 70% by mass, 10% to 60% by mass, 10% to 40% by mass, 10% to 30% by mass, 10% to 20% by mass, 15% to 90% by mass, 15% to 75% by mass, 15% to 60% by mass, 15% to 45% by mass, 15% to 30% by mass, 15% to 25% by mass, or any subset thereof. In the embodiment, heavy pyrolysis oil 250 can be mixed with diluent 104 (such as light pyrolysis oil 350) in a mixing unit (not shown) upstream of the first fixed-bed reactor 110 to produce pyrolysis oil raw material 102, which can then be sent to the first fixed-bed reactor 110. In these embodiments, the pyrolysis oil raw material 102 may not contain diluents that can be added to the heavy pyrolysis oil 250 upstream of the first fixed-bed reactor 110. However, in these embodiments, the pyrolysis oil raw material 102 may still contain toluene, xylene, or benzene that may be carried throughout the process of producing the heavy pyrolysis oil 250.

[0049] In the embodiment, the pyrolysis oil raw material 102 may contain at least 50% by mass of heavy pyrolysis oil 250, for example, at least 60% by mass, at least 70% by mass, at least 80% by mass, at least 90% by mass, at least 95% by mass, at least 99% by mass, 10% to 100% by mass, 50% to 100% by mass, 50% to 99% by mass, 60% to 99% by mass, 75% to 99% by mass, 75% to 90% by mass, 75% to 85% by mass, or any subset thereof. In the embodiment, the pyrolysis oil raw material 102 may contain 75% to 85% by mass of heavy pyrolysis oil 250 and 15% to 25% by mass of diluent 104 (such as light pyrolysis oil 350). In the embodiment, the pyrolysis oil raw material 102 may contain 80% by mass of heavy pyrolysis oil 250 and 20% by mass of diluent 104, wherein the diluent 104 includes light pyrolysis oil 350, toluene, benzene, xylene, ethylbenzene, or a combination thereof. Based on the total mass of pyrolysis oil in the pyrolysis oil raw material, the pyrolysis oil raw material 102 may contain 30% by mass or more of polycyclic aromatic compounds having 16 or more carbon atoms, for example, 35% by mass or more, 40% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more.

[0050] In this embodiment, the pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, is determined according to the ASTM D5002 test method to be 0.98 g / cm³. 3 From 1.03 g / cm³ 3 For example, 0.98 g / cm³ 3 From 1.02 g / cm³ 3 , 1.00 g / cm³ 3 From 1.03 g / cm³ 3 , or 1.00 g / cm³ 3 From 1.02 g / cm³ 3 It can have a density at 15°C. In this embodiment, the pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, has a density of 5 mPa * s to 10 mPa * s, 5.0 mPa *s to 10.0 mPa * s less than, 5.0 mPa * s to 9.5 mPa * s, 5.0 mPa * s to 9.0 mPa * s, 5.5 mPa * s to 10.0 mPa * s, 5.5 mPa * s to 9.5 mPa * s, 5.5 mPa * s to 9.0 mPa * s, 6.0 mPa * s to 10.0 mPa * s, 6.0 mPa * s to 9.5 mPa * s, or 6.0 mPa * s to 9.0 mPa * s at 60°C, wherein the dynamic viscosity is determined in accordance with the test method of ASTM D7042. In embodiments, the pyrolysis oil feedstock 102 comprising a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as diluent 104 can have a dynamic viscosity of 5.0 mm as determined in accordance with the test method of ASTM D7042 2 / s to 10.0 mm 2 / s, for example, 5.0 mm 2 / s to 9.5 mm 2 / s, 5.0 mm 2 / s to 9.0 mm 2 / s, 5.5 mm 2 / s to 10 mm 2 / s, 5.5 mm 2 / s to 9.5 mm 2 / s, 5.5 mm 2 / s to 9.0 mm 2 / s, 6.0 mm 2 / s to 10.0 mm 2 / s, 6.0 mm 2 / s to 9.5 mm 2 / s, or 6.0 mm 2 / s to 9.0 mm 2 / s at 60°C.

[0051] In the embodiment, the pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, can have an initial boiling point temperature (IBP) of 120°C to 150°C, for example, 120°C to 145°C, 125°C to 150°C, or 125°C to 145°C, as determined according to the test method of ASTM D2887. In the embodiment, the pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, can have a final boiling point temperature (FBP) of 500°C or higher, for example, 600°C or higher, 650°C or higher, 700°C or higher, 500°C to 1000°C, 500°C to 900°C, 500°C to 800°C, 600°C to 1000°C, 600°C to 900°C, 600°C to 800°C, 650°C to 1000°C, 650°C to 900°C, 650°C to 800°C, 700°C to 1000°C, 700°C to 900°C, or 700°C to 800°C, as determined according to the test method of ASTM D2887. In the embodiment, the pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, can have a 50% distillation temperature of 200°C to 300°C, 200°C to 290°C, 200°C to 275°C, 225°C to 300°C, 225°C to 290°C, 225°C to 275°C, 240°C to 300°C, 240°C to 290°C, or 240°C to 275°C, as determined according to the test method of ASTM D2887.

[0052] The pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, may also contain sulfur and sulfur compounds at low concentrations. The pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, may contain sulfur and sulfur-containing compounds at concentrations of 500 ppm (ppmw) or less by mass, for example, 400 ppmw or less, and even 300 ppmw or less, as determined according to the ASTM D2622 test method. In the embodiment, the pyrolysis oil raw material 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, may contain sulfur and sulfur compounds at concentrations from greater than 0 ppmw to 500 ppmw, for example, from 1 ppmw to 500 ppmw, from 1 ppmw to 400 ppmw, or from 1 ppmw to 300 ppmw. In the embodiment, the pyrolysis oil feedstock 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, may contain iron, nickel, or both at concentrations of 100 ppmw or less, 50 ppmw or less, 20 ppmw or less, and even 10 ppmw or less, for example, between 0 ppmw and 100 ppmw, as determined according to the ASTM D2622 test method. The properties of the exemplary embodiment of the pyrolysis oil feedstock 102, which includes a mixture of heavy pyrolysis oil 250 and light pyrolysis oil 350 as a diluent 104, are given in Table 1. Referring again to Figure 1, in the embodiment, the pyrolysis oil feedstock 102 may further include a bottom recirculation flow 150 from a separation unit 140 located downstream of the second fixed-bed reactor 120.

[0053] Referring again to Figure 2, the naphtha vapor cracking system 200 may include a naphtha vapor cracking unit 210 located upstream of the first fixed-bed reactor of system 100. The naphtha vapor cracking unit 210 can provide at least a portion of the pyrolysis oil feedstock 102. In this embodiment, a naphtha feed stream 204 can be fed into the naphtha vapor cracking unit 210. The naphtha feed stream 204 may contain hydrocarbons having boiling points in the range of 30°C to 225°C, which are classified as naphtha. The naphtha feed stream 204 may contain hydrocarbons having 5 to 12 carbon atoms. Figure 2 shows one embodiment of the naphtha vapor cracking unit 210, but other configurations of the vapor cracking unit are also possible. The naphtha vapor cracking unit 210 may include a convection zone 220 and a pyrolysis zone 222. The naphtha feed stream 204 can be introduced into the convection zone 220 together with the vapor 206. In the convection zone 220, a mixture containing naphtha and vapor can be preheated to a desired temperature. The contents of the convection zone 220 can then be sent to the pyrolysis zone 222, where hydrocarbons from the naphtha feed stream 204 are vapor-decomposed. The vapor-decomposed naphtha effluent 230 can exit the naphtha vapor-decomposition unit 210 and be sent to the separation unit 240. The vapor-decomposed naphtha effluent 230 may contain a mixture of decomposed hydrocarbon materials, which can be separated into one or more petrochemical products contained in one or more system product streams. The separation unit 240 may be any unit operation or a set of unit operations capable of separating the heavy pyrolysis oil 250 from the gas stream 242. In some embodiments, the separation unit 240 may be further configured to separate at least one olefin product stream 244 from the gas stream 242 and the heavy pyrolysis oil 250. The heavy pyrolysis oil 250 may form all or part of the pyrolysis oil feedstock 102.

[0054] According to the embodiment, the pyrolysis zone 222 can be operated at a temperature of 750°C to 1000°C or 800°C to 950°C. The pyrolysis zone 222 can be operated with a residence time of 0.05 seconds to 2 seconds. The mass ratio of steam 206 to naphtha feed stream 204 may be about 0.3:1 to about 2:1.

[0055] Referring here to Figure 3, heavy pyrolysis oil 250 from the naphtha vapor cracking system 200 can be mixed with light pyrolysis oil 350 from the gaseous raw material vapor cracking system 300 located upstream of system 100. The naphtha vapor cracking system 200 and the gaseous raw material vapor cracking system 300 can be operated in parallel, and both can be located upstream of the first fixed-bed reactor of system 100. The naphtha vapor cracking system 200 may have any of the features or properties previously described in this disclosure with respect to the naphtha vapor cracking system 200. The gaseous raw material vapor cracking system 300 may comprise a gaseous raw material vapor cracking unit 310. In the embodiment, a gaseous raw material feed stream 304 can be supplied to the gaseous raw material vapor cracking unit 310. The gaseous raw material feed stream 304 may contain hydrocarbons having a boiling point temperature of 50°C or less, or 30°C or less. The gaseous raw material feed stream 304 may contain hydrocarbons having 5 or fewer carbon atoms, or 4 or fewer carbon atoms. The gaseous raw material vapor cracking unit 310 may include a convection zone 320 and a pyrolysis zone 322. The gaseous raw material feed stream 304 can be introduced into the convection zone 320 together with the steam 306. In the convection zone 320, the mixture containing the gaseous raw material feed stream 304 and the steam 306 can be preheated to a desired temperature. The contents of the convection zone 320 can then be sent to the pyrolysis zone 322, where they are vapor-cracked. The gaseous raw material vapor cracking unit outlet stream 330 can exit the gaseous raw material vapor cracking unit 310 and be sent to a separation unit 340. The gaseous raw material vapor cracking unit outlet stream 330 may contain a mixture of cracked hydrocarbon materials, which can be separated into one or more petrochemical products contained in one or more system product streams. The separation unit 340 may be any unit operation or a set of unit operations capable of separating the gaseous raw material vapor cracking unit outlet stream 330 into a light gas stream 342, at least one product stream 344, and a light pyrolysis oil 350. In this embodiment, at least one of the product streams 344 may be an olefin product stream. The light pyrolysis oil 350 can be mixed with the heavy pyrolysis oil 250 to form the pyrolysis oil raw material 102.

[0056] According to one or more embodiments, the pyrolysis zone 322 can be operated at temperatures from 750°C to 1000°C or from 800°C to 950°C. The pyrolysis zone 322 can be operated with residence times from 0.05 seconds to 2 seconds. The mass ratio of steam 306 to gaseous feed stream 304 may be from about 0.3:1 to about 2:1. Figures 2 and 3 show several embodiments of the naphtha vapor cracking system 200 and the gaseous feed stream vapor cracking system 300, but other configurations of the vapor cracking unit for producing heavy pyrolysis oil 250, light pyrolysis oil 350, or combinations thereof are also possible, including, but are not limited to, vapor cracking systems for vapor cracking crude oil, light hydrocarbon gas streams, gas condensate, atmospheric residue, vacuum distillation residue, vacuum diesel, or other heavy oils.

[0057] Referring again to Figure 1, the pyrolysis oil feedstock 102 can be sent to the first fixed-bed reactor 110. The first fixed-bed reactor 110 can be configured to contact the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of a mixed metal oxide catalyst 112 to generate an intermediate flow 118. Contacting the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of the mixed metal oxide catalyst 112 can convert at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock 102 into bicyclic aromatic compounds, tricyclic aromatic compounds, or both. The hydrogen 116 may include a recirculated hydrogen flow or supplemental hydrogen from an external hydrogen source located inside or outside the refinery's equipment boundary. The hydrogen 116 may be sent directly to the first fixed-bed reactor 110 or mixed with the pyrolysis oil feedstock 102 upstream of the first fixed-bed reactor 110. The hydrogen 116 can be used to pressurize the first fixed-bed reactor 110 to operating pressure.

[0058] The first fixed-bed reactor 110 is a fixed-bed reactor. The fixed-bed reactor may include a packed bed of mixed metal oxide catalyst 112. Hydrogen can flow in parallel or in the reverse flow with the pyrolysis oil feedstock 102. In the embodiment, it can flow in parallel with the pyrolysis oil feedstock 102. For example, hydrogen can be entrained with the flowing pyrolysis oil feedstock 102, or it can permeate through the reaction bed or rise as bubbles as the pyrolysis oil feedstock 102 flows downward through the reaction bed. The fixed-bed reactor can be a continuous reactor. In the embodiment, the first fixed-bed reactor 110 may include one or more fixed-bed reactors. If the first fixed-bed reactor 110 includes a plurality of fixed-bed reactors, the plurality of fixed-bed reactors can be operated in series, in parallel, or in a combination thereof. In the embodiment, the first fixed-bed reactor 110 may include a plurality of fixed-bed reactors in parallel.

[0059] The mixed metal oxide catalyst 112 may have catalytic activity to convert polycyclic aromatic compounds having 16 or more carbon atoms in the pyrolysis oil raw material 102 into bicyclic aromatic compounds, tricyclic aromatic compounds, or combinations thereof. The mixed metal oxide catalyst 112 may contain a plurality of mixed metal oxide (MMO) particles. Each of the plurality of MMO particles may contain a plurality of different metal oxides. The plurality of metal oxides in the MMO particles may include oxides of metals in groups 3 to 13 of the International Union of Pure and Applied Chemistry (IUPAC) periodic table. In embodiments, the plurality of metal oxides in the MMO particles may include combinations of iron, zirconium, cerium, aluminum, tungsten, molybdenum, and titanium oxides. The MMO particles may also contain oxides of metalloids such as silicon oxide. MMO particles may consist of oxides of metals or metalloids selected from the group consisting of iron oxide (Fe2O3), zirconium oxide (ZrO2), cerium oxide (CeO2), aluminum oxide (alumina) (Al2O3), silica (SiO2), tungsten oxide (WO3), molybdenum oxide (MoO3), titanium oxide (TiO2), and combinations thereof.

[0060] The MMO particles of the mixed metal oxide catalyst 112 may contain iron oxide as one of the multiple metal oxides. In embodiments, the MMO particles may contain 60% to 95% by mass of iron oxide, for example, 70% to 90% by mass, 75% to 85% by mass, or 80% to 85% by mass of iron oxide. The MMO particles may contain zirconium oxide as one of the multiple metal oxides. In embodiments, the MMO particles may contain 1% to 20% by mass of zirconium oxide, for example, 1% to 15% by mass, 2.5% to 12.5% ​​by mass, or 5% to 10% by mass of zirconium oxide. The MMO particles may contain cerium oxide as one of the multiple metal oxides. In embodiments, the MMO particles may contain 0.1% to 10% by mass of cerium oxide, for example, 0.5% to 7.5% by mass, 0.5% to 5% by mass, or 1% to 5% by mass of cerium oxide. MMO particles may contain aluminum oxide (alumina) as one of several metal oxides. In embodiments, MMO particles may contain 1% to 20% by mass of aluminum oxide (alumina), for example, 2.5% to 15% by mass, 3% to 12.5% ​​by mass, or 5% to 10% by mass of aluminum oxide. The mass percentages of the several metal oxides in the MMO particles are based on the total mass of the MMO particles. MMO particles may consist of, or substantially consist of, 60% to 95% by mass of iron oxide, 1% to 20% by mass of zirconium oxide, 0.1% to 10% by mass of cerium oxide, and 1% to 20% by mass of aluminum oxide (alumina). In embodiments, MMO particles may contain 83% by mass of iron oxide, 7.5% by mass of zirconium oxide, 2.5% by mass of cerium oxide, and 7.0% by mass of aluminum oxide (alumina). In embodiments, MMO particles do not contain silica. In the embodiment, the MMO particles may be composed of a homogeneous solid mixture of metal oxides, rather than having one or more metal oxides deposited on the surface of the carrier material, by including multiple metal oxides that are mixed and fused or aggregated together.MMO particles can be prepared by a coprecipitation method, which produces MMO particles in which each of several different metal oxides is distributed within the MMO particles. After coprecipitation, the MMO particles can be pulverized to form a powder.

[0061] MMO particles may include nanoparticles having dimensions ranging from 20 nm to 200 nm, for example, 20 nm to 175 nm, 20 nm to 150 nm, 20 nm to 125 nm, 20 nm to 100 nm, 20 nm to 75 nm, 20 nm to 50 nm, 20 nm to 40 nm, 20 nm to 30 nm, 25 nm to 200 nm, 30 nm to 200 nm, 40 nm to 200 nm, 50 nm to 200 nm, 75 nm to 200 nm, 100 nm to 200 nm, 125 nm to 200 nm, 150 nm to 200 nm, 175 nm to 200 nm, 50 nm to 175 nm, 75 nm to 150 nm, 100 nm to 125 nm, or the maximum dimensions of any subset thereof. In embodiments, MMO particles may be nonporous. Although not theoretically limiting, it is assumed that hydrocarbons can only interact with the surface of MMO particles. Therefore, the increased surface area due to the nanoparticle properties of the mixed metal oxide catalyst will help achieve a sufficient reaction rate.

[0062] MMO particles in powder form can be mixed with other materials, such as a binder, extrusion aid, or other material, extruded, and calcined to form a mixed metal oxide catalyst 112 in the form of catalyst pellets, although this is not limited to the following. In the embodiment, MMO particles in powder form can be mixed with a binder and methylcellulose to produce a solid mixture.

[0063] The binder may include silica, alumina, silica-alumina, clay, or any combination thereof. Alumina may include acid-peptized alumina. Silica-alumina may include amorphous silica-alumina. Clays may include, but are not limited to, kaolin, montmorillonite, halloysite, bentonite, or combinations thereof. In embodiments, the binder may include bentonite, silica, or combinations thereof. In embodiments, the mixed metal oxide catalyst 112 may contain bentonite as a binder. Methylcellulose may be added to the solid mixture to facilitate extrusion, but will be burned off during calcination. Therefore, the mixed metal oxide catalyst 112 may consist of, or substantially consist of, MMO particles and a binder.

[0064] A solid mixture can be produced by thoroughly mixing the dry components—MMO particles, binder, and methylcellulose. In the embodiment, the solid mixture may contain 50% to 90% by mass of MMO particles based on the total mass of the solid mixture, for example, 50% to 85% by mass, 50% to 80% by mass, 60% to 90% by mass, 60% to 85% by mass, 60% to 80% by mass, 65% to 90% by mass, 65% to 85% by mass, 65% to 80% by mass, 70% to 90% by mass, 70% to 85% by mass, 70% to 80% by mass, or about 75% by mass of MMO particles based on the total mass of the dry solid mixture. In the embodiment, the solid mixture may contain about 10% to 50% by mass of binder based on the total mass of the dry solid mixture, for example, 10% to 49.9% by mass, 10% to 40% by mass, 10% to 35% by mass, 10% to 30% by mass, 10% to 25% by mass, 15% to 50% by mass, 15% to 49.9% by mass, 15% to 40% by mass, 15% to 35% by mass, 15% to 30% by mass, 15% to 25% by mass, 20% to 50% by mass, 20% to 49.9% by mass, 20% to 40% by mass, 20% to 35% by mass, 20% to 30% by mass, 20% to 25% by mass, or 24% to 25% by mass, based on the total mass of the dry solid mixture. In the embodiment, the solid mixture may contain 0.01% to 2% by mass of methylcellulose, for example, 0.01% to 1% by mass, 0.1% to 2% by mass, or 0.1% to 1% by mass, or about 0.1% by mass of methylcellulose, based on the total mass of the dry solid mixture. In the embodiment, the dry solid mixture may contain about 75% by mass of MMO particles, about 24.9% by mass of a binder, and about 0.1% by mass of methylcellulose, based on the total mass of the dry solid mixture.

[0065] The dry solid mixture can be thoroughly mixed to produce a homogeneous solid mixture by mixing with a mortar and pestle, or by using an automatic mixing device such as a V-type blender, Shugi mixer, or other powder mixing device, but not limited to the following. After mixing, water can be added to the dry solid mixture to form an extrudeable paste. In this embodiment, approximately 1.5 mL of water per gram of dry material can be added to the dry solid mixture to form an extrudeable paste.

[0066] The extrudeable paste comprises MMO particles, a binder, methylcellulose, and water, which can then be extruded in an extruder. In some embodiments, the extrudeable paste can be placed in a syringe of a syringe pump. Alternatively, the paste can be pressurized using other pressurizing devices such as a peristaltic pump, a screw extruder, or a twin-screw extruder. The pressurized paste can be pushed through an extrusion die to form an extruder composed of extruded strands. The extrusion die and the resulting extruder may have a circular cross-section, or any other cross-sectional shape, such as star-shaped, square, hexagonal, trefoil-shaped, daisy-shaped, notched cylindrical, 7-hole, or donut-shaped. The extrusion die and the resulting extruder may have diameters ranging from 1 mm to 3 mm, for example, 1.5 mm to 3 mm, 2.0 mm to 3 mm, 1 mm to 2.5 mm, 1.5 mm to 2.5 mm, 1.75 mm to 2.25 mm, or any subset thereof.

[0067] After extrusion, the extruded material can be dried and calcined. The extruded strands can be cut to predetermined lengths to form pellets before drying, after drying but before calcination, or after calcination. Generally, it is desirable to dry the extruded strands or pellets before calcination, as excess moisture in the catalyst particles can cause vapor pressure buildup, potentially leading to weakening or damage of the catalyst during or after calcination.

[0068] The extruded strand or pellet can be dried at a high temperature. In the embodiment, the extruded strand or pellet can be dried at a temperature of at least 40°C, for example, at least 50°C, 40°C to 100°C, 40°C to 90°C, 40°C to 80°C, 50°C to 70°C, or any subset thereof. The extruded strand or pellet can be dried at the high temperature for at least 6 hours, for example, at least 12 hours, at least 18 hours, 6 hours to 48 hours, 12 hours to 48 hours, or any subset thereof.

[0069] After drying, the dried strands or pellets of the extruded material can be subsequently calcined. In the embodiment, the dried strands or pellets of the extruded material can be calcined at temperatures of at least 400°C, for example, at least 500°C, at least 600°C, 400°C to 800°C, 500°C to 700°C, 600°C to 700°C, 625°C to 675°C, or any subset thereof. The dried strands or pellets can be calcined for at least 1 hour, for example, at least 1.5 hours, 1 hour to 5 hours, 1 hour to 3 hours, 1.5 hours to 2.5 hours, or any subset thereof. The calcination atmosphere may include an oxygen-containing gas such as air. The calcined strands can be crushed and sieved, if not done before calcination, to produce the mixed metal oxide catalyst 112 in the form of pellets.

[0070] The mixed metal oxide catalyst pellets may contain MMO particles and a binder. The mixed metal oxide catalyst pellets may also contain any calcination residue derived from methylcellulose. Each of the MMO particles contains Fe2O3, ZrO2, CeO2, and Al2O3. In the embodiments, the mixed metal oxide catalyst pellets may contain 65% to 85% by mass, 65% to 80% by mass, 70% to 85% by mass, 70% to 80% by mass, 75% to 85% by mass, 75% to 80% by mass, 75% to 80% by mass, 80% to 85% by mass, or about 75% by mass of MMO particles, based on the total mass of the mixed metal oxide catalyst, with the remainder being the binder and any calcination residue derived from methylcellulose. In the embodiment, the mixed metal oxide catalyst may contain 15% to 35% by mass, 15% to 30% by mass, 15% to 25% by mass, 20% to 35% by mass, 20% to 30% by mass, 20% to 25% by mass, 25% to 35% by mass, 25% to 30% by mass, or about 25% by mass of binder, based on the total mass of the mixed metal oxide catalyst. The concentration of methylcellulose residue in the mixed metal oxide catalyst may be less than 0.1% by mass, less than 0.05% by mass, and even less than or equal to 0.01% by mass, based on the total mass of the mixed metal oxide catalyst. In the embodiment, the pellet of the mixed metal oxide catalyst may contain at least 80% by mass, at least 90% by mass, at least 95% by mass, at least 99% by mass, and even 99.9% by mass of Fe2O3, ZrO2, CeO2, and Al2O3, as well as binder. In this embodiment, the mixed metal oxide catalyst may contain 75% by mass of MMO particles and 25% by mass of a binder.

[0071] The pellets of the mixed metal oxide catalyst 112 can have a diameter of 1 mm to 3 mm, for example, 1.5 mm to 3 mm, 1 mm to 2.5 mm, 1.5 mm to 2.5 mm, or any subset thereof. In the embodiment, the pellets of the mixed metal oxide catalyst 112 may be cylindrical in shape, having a pellet diameter and a pellet length. The pellet length may be about 2 mm to about 4 mm.

[0072] Referring again to Figure 1, when the pyrolysis oil raw material 102 is brought into contact with hydrogen 116 in the first fixed-bed reactor 110 under the reaction conditions in the presence of the mixed metal oxide catalyst 112, at least a portion of the polycyclic aromatic compounds in the pyrolysis oil raw material 102 can be converted to bicyclic aromatic compounds, tricyclic aromatic compounds, or both in a single step without subsequent chemical reaction steps. Converting at least a portion of the polycyclic aromatic compounds to lighter aromatic compounds containing bicyclic aromatic compounds, tricyclic aromatic compounds, or both is a complex reaction system involving multiple synchronous selective reactions, which may include reactions that selectively hydrogenate only one of the multiple aromatic rings in the compound, reactions that subsequently cleave the ring of the hydrogenated and saturated tetracyclic aromatic compound, hydrogenation-dealkylation reactions, transalkylation reactions, and disproportionation reactions. While not intended to be bound by any particular theory, the process of modifying the pyrolysis oil feedstock 102 may include selectively hydrogenating at least one aromatic ring structure or polycyclic aromatic compound to produce molecules having one or more aromatic rings and at least one saturated ring. The saturated ring portion can then undergo ring-opening to produce a substituted aromatic compound. The substituted aromatic compound can then undergo one or more hydrogen-alkylation, trans-alkylation, or disproportionation to produce monocyclic aromatic compounds, bicyclic aromatic compounds, and / or tricyclic aromatic compounds. It will be understood that multiple variations and combinations of these reactions, as well as other chemical reactions, may occur during the modification process. This complex sequence of synchronous reactions for modifying the pyrolysis oil feedstock 102 can be catalyzed using a mixed metal oxide catalyst 112.

[0073] The first fixed-bed reactor 110 can contact the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of a mixed metal oxide catalyst 112 under mild operating conditions sufficient to modify at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock 102 to produce an intermediate flow 118, where the intermediate flow 118 contains bicyclic aromatic compounds, tricyclic aromatic compounds, or both. The first fixed-bed reactor 110 can be operated at operating temperatures in the range of 300°C to 500°C, for example, 350°C to 500°C, 400°C to 500°C, 300°C to 450°C, 350°C to 450°C, or 400°C to 450°C. The first fixed-bed reactor 110 operates from 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar), for example, from 3 MPa (30 bar) to 20 MPa (200 bar), from 5 MPa (50 bar) to 20 MPa (200 bar), from 7 MPa (70 bar) to 20 MPa (200 bar), from 10 MPa (100 bar) to 20 MPa (200 bar), and from 12 MPa (120 bar) to 18 MPa (180 bar). The reactor can be operated at operating pressures of 14 MPa (140 bar) to 16 MPa (160 bar), 1 MPa (10 bar) to 15 MPa (150 bar), 3 MPa (30 bar) to 15 MPa (150 bar), 5 MPa (50 bar) to 15 MPa (150 bar), 7 MPa (70 bar) to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The first fixed-bed reactor 110 can be operated at volume ratios of hydrogen 116 to pyrolysis oil feedstock 102 of 500 to 1500, 500 to 1400, 500 to 1300, 500 to 1200, 800 to 1500, 800 to 1400, 800 to 1300, or 800 to 1200. The first fixed-bed reactor 110 lasts 0.1 hours. -1 From 1.2 hours -1 , 0.1h -1 1 hour from -1 , 0.1h -1 0.8h -1 , 0.1h -1 0.6h -1 , 0.2h -1 0.4h -1It can be operated at the liquid space velocity (LHSV) of any subset thereof. The first fixed-bed reactor 110 is operated for 200 h -1 from 1500h -1 For example, 200h -1 from 1200h -1 , 400h -1 from 1200h -1 , 600h -1 from 1000h -1 , 700h -1 from 900h -1 It can be operated at the gas space velocity (GHSV) of any subset thereof, or at any subset thereof.

[0074] Referring here to Figure 2, the intermediate flow 118 may contain bicyclic aromatic compounds. The intermediate flow 118 may contain a higher proportion of bicyclic aromatic compounds having 10 to 18 carbon atoms compared to the pyrolysis oil feedstock 102. Based on the total mass of the intermediate flow 118, the intermediate flow 118 may contain at least 35% by mass, at least 40% by mass, at least 45% by mass, at least 50% by mass, and even at least 55% by mass of bicyclic aromatic compounds having 10 to 18 carbon atoms (C10 to C18 aromatic compounds), which include any C10 to C18 aromatic compounds in the diluent 104 that has been added to the pyrolysis oil feedstock 102 and passed through the first fixed-bed reactor 110. The intermediate flow 118 may also contain other components, in addition to bicyclic aromatic compounds, including but not limited to unreacted hydrogen, unreacted pyrolysis oil components, light hydrocarbon gases, light aromatic compounds having 6 to 8 carbon atoms, tricyclic aromatic compounds, and combinations thereof. The bicyclic aromatic compounds in the intermediate flow 118 can be sent to a second fixed-bed reactor 120, where they can be hydrocracked to produce BTEX. The second fixed-bed reactor 120 can increase the yield of BTEX and reduce the recirculation of unreacted pyrolysis oil that is recycled back into the process.

[0075] Referring now to Figure 5, in this embodiment, the first fixed-bed reactor 110 may include a mixed metal oxide catalyst 112 and an auxiliary catalyst 114. The mixed metal oxide catalyst 112 may be in a separate bed from the auxiliary catalyst 114 in the first fixed-bed reactor 110. The mixed metal oxide catalyst 112 may be located upstream of the auxiliary catalyst 114. As the pyrolysis oil raw material 102 passes through the first fixed-bed reactor 110, it may encounter the mixed metal oxide catalyst 112 in the first bed before encountering the auxiliary catalyst 114 in the second bed.

[0076] The co-catalyst 114 may contain metal atoms including aluminum atoms, silicon atoms, zirconium atoms, nickel atoms, tungsten atoms, or combinations thereof. In embodiments, the metal atoms may be in oxide form (Al2O3, SiO2, ZrO2, NiO, and WO3). In embodiments, the co-catalyst 114 may contain 18.5% to 21.5% by mass of Al2O3. In embodiments, the co-catalyst 114 may contain 36.5% to 39.5% by mass of SiO2. In embodiments, the co-catalyst 114 may contain 9.2% to 10.2% by mass of ZrO2. In embodiments, the co-catalyst 114 may contain 10.5% to 11.5% by mass of NiO. In embodiments, the co-catalyst 114 may contain 18.5% to 21.5% by mass of WO3. In the embodiment, the co-catalyst 114 may contain 18.5% to 21.5% by mass of Al2O3, 36.5% to 39.5% by mass of SiO2, 9.2% to 10.2% by mass of ZrO2, 10.5% to 11.5% by mass of NiO, and 18.5% to 21.5% by mass of WO3. The mass percentages of the components of the co-catalyst are calculated relative to the total mass of the co-catalyst.

[0077] The pyrolysis oil feedstock 102 can enter the first fixed-bed reactor 110. Inside the first fixed-bed reactor 110, the pyrolysis oil feedstock 102 can come into contact with the mixed metal oxide catalyst 112 in the presence of hydrogen 116, thereby converting at least a portion of the pyrolysis oil feedstock 102. The resulting reaction products and the unconverted pyrolysis oil feedstock can subsequently come into contact with the auxiliary catalyst 114 inside the first fixed-bed reactor 110 in the presence of hydrogen 116. In the embodiment, the conditions under which the pyrolysis oil feedstock 102 comes into contact with the mixed metal oxide catalyst 112 and the auxiliary catalyst 114 are substantially the same.

[0078] The first fixed-bed reactor 110 can contact the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of a mixed metal oxide catalyst 112, and then in the presence of an auxiliary catalyst 114 downstream of the mixed metal oxide catalyst 112, under operating conditions mild enough to reform at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock 102 to produce an intermediate flow 118, where the intermediate flow 118 contains bicyclic aromatic compounds and / or tricyclic aromatic compounds. The first fixed-bed reactor 110 can be operated at operating temperatures ranging from 300°C to 500°C, for example, 350°C to 500°C, 400°C to 500°C, 300°C to 450°C, 350°C to 450°C, or 400°C to 450°C. The first fixed-bed reactor 110 operates from 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar), for example, from 3 MPa (30 bar) to 20 MPa (200 bar), from 5 MPa (50 bar) to 20 MPa (200 bar), from 7 MPa (70 bar) to 20 MPa (200 bar), from 10 MPa (100 bar) to 20 MPa (200 bar), and from 12 MPa (120 bar) to 18 MPa (180 bar). The reactor can be operated at operating pressures of 14 MPa (140 bar) to 16 MPa (160 bar), 1 MPa (10 bar) to 15 MPa (150 bar), 3 MPa (30 bar) to 15 MPa (150 bar), 5 MPa (50 bar) to 15 MPa (150 bar), 7 MPa (70 bar) to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The first fixed-bed reactor 110 can be operated at volume ratios of hydrogen to pyrolysis oil feedstock 102 of 500 to 1500, 500 to 1400, 500 to 1300, 500 to 1200, 800 to 1500, 800 to 1400, 800 to 1300, or 800 to 1200. The first fixed-bed reactor 110 lasts 0.1 hours. -1 From 1.2 hours -1 , 0.1h -1 1 hour from -1 , 0.1h -1 0.8h -1 , 0.1h -1 0.6h -1 , 0.2h -1 0.4h-1 It can be operated at the liquid space velocity (LHSV) of any subset thereof. The first fixed-bed reactor 110 is operated for 200 h -1 from 1500h -1 For example, 200h -1 from 1200h -1 , 400h -1 from 1200h -1 , 600h -1 from 1000h -1 It can be operated at the gas space velocity (GHSV) of any subset thereof, or at any subset thereof.

[0079] Referring here to Figure 6, the first fixed-bed reactor 110 can contact the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of an auxiliary catalyst 114, and then in the presence of a mixed metal oxide catalyst 112 downstream of the auxiliary catalyst 114, under operating conditions mild enough to reform at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock 102 to produce an intermediate flow 118, where the intermediate flow 118 contains bicyclic aromatic compounds and / or tricyclic aromatic compounds. The first fixed-bed reactor 110 can be operated at operating temperatures ranging from 300°C to 500°C, for example, 350°C to 500°C, 400°C to 500°C, 300°C to 450°C, 350°C to 450°C, or 400°C to 450°C. The first fixed-bed reactor 110 operates from 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar), for example, from 3 MPa (30 bar) to 20 MPa (200 bar), from 5 MPa (50 bar) to 20 MPa (200 bar), from 7 MPa (70 bar) to 20 MPa (200 bar), from 10 MPa (100 bar) to 20 MPa (200 bar), and from 12 MPa (120 bar) to 18 MPa (180 bar). The reactor can be operated at operating pressures of 14 MPa (140 bar) to 16 MPa (160 bar), 1 MPa (10 bar) to 15 MPa (150 bar), 3 MPa (30 bar) to 15 MPa (150 bar), 5 MPa (50 bar) to 15 MPa (150 bar), 7 MPa (70 bar) to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The first fixed-bed reactor 110 can be operated at volume ratios of hydrogen to pyrolysis oil feedstock 102 of 500 to 1500, 500 to 1400, 500 to 1300, 500 to 1200, 800 to 1500, 800 to 1400, 800 to 1300, or 800 to 1200. The first fixed-bed reactor 110 lasts 0.1 hours. -1 1 hour from -1 , 0.1h -1 0.8h -1 , 0.1h -1 0.6h -1 , 0.2h -1 0.4h -1It can be operated at the liquid space velocity (LHSV) of any subset thereof. The first fixed-bed reactor 110 is operated for 200 h -1 from 1500h -1 For example, 200h -1 from 1200h -1 , 400h -1 from 1200h -1 , 600h -1 from 1000h -1 It can be operated at the gas space velocity (GHSV) of any subset thereof, or at any subset thereof.

[0080] Referring again to Figure 1, the intermediate flow 118 can be sent from the first fixed-bed reactor 110 to the second fixed-bed reactor 120 downstream. In this embodiment, the intermediate flow 118 can be sent directly from the first fixed-bed reactor 110 to the second fixed-bed reactor 120 without passing through any intermediate unit operations that cause chemical reactions or remove one or more components of the intermediate flow 118. The second fixed-bed reactor 120 may be configured to contact the intermediate flow 118 with hydrogen 124 in the presence of a mesoporous supported metal catalyst 122 to produce a second reactor effluent 130. When the intermediate flow 118 is contacted with hydrogen 124 in the presence of the mesoporous supported metal catalyst 122, at least a portion of the bicyclic aromatic compounds and / or tricyclic aromatic compounds in the intermediate flow 118 can react to form aromatic compounds having 6 to 8 carbon atoms. Unreacted hydrogen can be delivered from the first fixed-bed reactor 110 to the second fixed-bed reactor 120 as part of the intermediate flow 118. Additional hydrogen 124 may be added to the second fixed-bed reactor 120. The hydrogen 124 may include recirculated hydrogen flow or makeup hydrogen from external hydrogen sources inside or outside the refinery's equipment boundary. The hydrogen 124 may be delivered directly to the second fixed-bed reactor 120 or mixed with the intermediate flow 118 upstream of the second fixed-bed reactor 120. The hydrogen 124 can be used to pressurize the second fixed-bed reactor 120 to operating pressure.

[0081] The second fixed-bed reactor 120 is a fixed-bed reactor. The fixed-bed reactor may contain a mesoporous supported metal catalyst 122 in a packed bed. Hydrogen can flow in parallel with the intermediate flow 118. In some embodiments, hydrogen can rise through the reaction bed as osmosis or as bubbles. In some embodiments, the second fixed-bed reactor 120 may include one or more fixed-bed reactors. If the second fixed-bed reactor 120 includes multiple fixed-bed reactors, these multiple fixed-bed reactors can be operated in series, in parallel, or in a combination thereof.

[0082] The mesoporous supported metal catalyst 122 can be configured to react at least a portion of the bicyclic aromatic compounds and / or tricyclic aromatic compounds in the intermediate flow 118 to form polycyclic aromatic compounds (BTEX) having 6 to 8 carbon atoms. The mesoporous supported metal catalyst 122 may include a first metal catalyst, a second metal catalyst, and a mesoporous support. The mesoporous support may include a zeolite support component.

[0083] The zeolite carrier component can consist of ultrastable Y-type (USY) zeolite, beta-zeolite, or both. The beta-zeolite may be nano-sized beta-zeolite. The zeolite carrier component can have a USY zeolite:beta-zeolite ratio of 1:1 to 2:1. In embodiments, the zeolite carrier component can have a USY zeolite:beta-zeolite ratio of 1.25:1 to 2:1, 1.4:1 to 2:1, 1.45:1 to 2:1, 1:1 to 1.75:1, 1:1 to 1.6:1, 1:1 to 1.55:1, 1.25:1 to 1.75:1, 1.45:1 to 1.55:1, or any subset thereof. In embodiments, the zeolite carrier component can have a USY zeolite:beta-zeolite ratio of about 3:2.

[0084] The zeolite support component may have an average pore diameter sufficient for polycyclic aromatic compounds to access reaction sites within the pores of the zeolite support component. The zeolite support component may have an average pore diameter of 2 nanometers (nm) or more, 3 nm or more, or 4 nm or more, as determined by the Barrett-Joiner-Hallenda (BJH) method. The zeolite support component may have an average pore diameter of 40 nm or less, 30 nm or less, or even 25 nm or less, as determined by the BJH method. In the embodiment, the zeolite support component may have an average pore diameter of 2 nm to 40 nm, 2 nm to 30 nm, 2 nm to 25 nm, 5 nm to 40 nm, 5 nm to 30 nm, 5 nm to 25 nm, 8 nm to 40 nm, 8 nm to 30 nm, 8 nm to 25 nm, 3 nm to 6 nm, or any subset thereof, and this average pore diameter is determined by the BJH method. In this embodiment, the zeolite support component can have an average pore size of 3 nm to 6 nm. The aforementioned pore size of the zeolite support component can be applied to USY zeolite, beta zeolite, or both.

[0085] The zeolite support component may have a silica (SiO2) to alumina (Al2O3) molar ratio of 10 or more, for example, 20 or more, 30 or more, 40 or more, 50 or more, or 60 or more. The zeolite support component may have a SiO2 to Al2O3 molar ratio of 70 or less, for example, 60 or less, 50 or less, 40 or less, 30 or less, and even 20 or less. The zeolite support component may have a SiO2 to Al2O3 molar ratio of 10 to 70. In the embodiment, the zeolite support component may have a SiO2 to Al2O3 molar ratio of 10 to 60, 10 to 50, 10 to 40, 20 to 70, 20 to 60, 20 to 50, 20 to 40, 30 to 70, 30 to 60, 30 to 50, 40 to 70, 40 to 60, 50 to 70, or 10 to 30. The aforementioned molar ratio of silica to alumina in the zeolite support component can be applied to USY zeolite, beta zeolite, or both.

[0086] The zeolite support component may contain particles, which, when measured at their longest dimension, may have an average diameter of 2000 nm to 5000 nm. In the embodiment, the particles of the zeolite support component may have an average diameter of 2000 nm to 4500 nm, 2000 nm to 4000 nm, 2000 nm to 3500 nm, 2000 nm to 3000 nm, 2000 nm to 2500 nm, 2500 nm to 5000 nm, 3000 nm to 5000 nm, 3500 nm to 5000 nm, 4000 nm to 5000 nm, 4500 nm to 5000 nm, 2500 nm to 4500 nm, 3000 nm to 4000 nm, or any subset thereof, when measured at their maximum dimension. In the embodiment, the zeolite support component exists as a single crystal structure. The particle size of the zeolite support component described above can be applied to USY zeolite, beta zeolite, or both.

[0087] The zeolite support component is at least 400m 2 It can have an average surface area of ​​ / g. In the embodiment, the zeolite carrier component has at least 425m 2 / g, 400m 2 / g to 450m 2 / g, 400m 2 / g to 440m 2 / g, 400m 2 / g to 430m 2 / g, 400m 2 / g to 420m 2 / g, 410m 2 / g to 450m 2 / g, 420m 2 / g to 450m 2 / g, 430m 2 / g to 450m 2 / g, 410m 2 / g to 440m 2 / g, 420m 2 / g to 430m 2It may have a surface area of ​​ / g or the average surface area of ​​any subset thereof. The surface area can be measured according to the Brunauer-Emmett-Teller (BET) method. The above-mentioned surface area of ​​the zeolite support component can be applied to USY zeolite, beta zeolite, or both.

[0088] The zeolite carrier component can have an average pore volume of 0.3 ml / g to 0.6 ml / g, determined using the BJH method. In the embodiment, the zeolite carrier component can have an average pore volume of 0.3 ml / g to 0.5 ml / g, 0.3 ml / g to 0.4 ml / g, 0.4 ml / g to 0.6 ml / g, 0.5 ml / g to 0.6 ml / g, 0.4 ml / g to 0.5 ml / g, or any subset thereof. The above-mentioned pore volumes of the zeolite carrier component can be applied to USY zeolite, beta zeolite, or both.

[0089] The mesoporous carrier may further contain a binder and large-pore alumina in addition to the zeolite carrier component.

[0090] The binder may include alumina such as acid-peptized alumina; clay; or amorphous silica-alumina. In some embodiments, the binder may include acid-peptized alumina. Acid-peptized alumina suitable for use as a binder is commercially available from Sasol Inc. under the trade name CATAPAL B.

[0091] Large-pore alumina measured by BET, at least 100m 2 It can have an average surface area of ​​ / g. In the embodiment, the large-pore alumina has at least 125m 2 / g, at least 150m 2 / g, 100m 2 / g to 300m 2 / g, 125m 2 / g to 300m 2 / g, 150m 2The average surface area can range from / g or any subset thereof. The large-pore alumina can have an average BJH pore radius of at least 5 nm. In the embodiment, the large-pore alumina can have an average BJH pore radius of at least 8 nm, at least 10 nm, at least 11 nm, 5 nm to 20 nm, 8 nm to 20 nm, 10 nm to 20 nm, 11 nm to 20 nm, or any subset thereof. The large-pore alumina can have an average BJH pore volume of 0.8 ml / g to 1.1 ml / g, for example, 0.9 ml / g to 1.1 ml / g, 1.0 ml / g to 1.1 ml / g, 0.8 ml / g to 1.0 ml / g, 0.8 ml / g to 0.9 ml / g, or 0.9 ml / g to 1.0 ml / g.

[0092] The mesoporous support can be extruded into pellets. Next, the pellets can be impregnated with a first metal catalyst and a second metal catalyst to produce a mesoporous supported metal catalyst 122.

[0093] Pellets can be formed by first preparing a binder paste. Next, the binder paste can be mixed with dry catalyst components (zeolite and large-pore alumina) to form a carrier paste. The carrier paste can be extruded to form a carrier extruder. The carrier extruder can be dried, calcined, and impregnated with a first metal catalyst (Ni) and a second metal catalyst (W).

[0094] A binder paste can be formed by mixing an acid (such as nitric acid) with alumina binder particles. The binder paste can be homogeneous and free of visible large particles. Next, the binder paste can be mixed with large-pore alumina, USY zeolite, and nanobeta zeolite to form a carrier paste. Next, the carrier paste can be extruded to form a carrier extruder with a diameter of about 1 mm to 2 mm. Next, the carrier extruder can be dried, for example, at about 110°C for at least 12 hours. Next, the dried carrier extruder can be calcined in air at about 550°C for at least 4 hours at a heating rate of about 2°C / min. The carrier extruder can be cut or crushed into pellets with a length of about 2 mm to 4 mm either before or after calcination. The carrier extruder can have a circular cross-section, or any other cross-sectional shape such as star-shaped, square-shaped, hexagonal, trefoil-shaped, daisy-shaped, notched cylindrical, 7-hole-shaped, or donut-shaped.

[0095] The mesoporous supported metal catalyst 122 can be prepared from a mesoporous support by wetting and impregnating the outer surface, pore surface, or both of the mesoporous support with at least a first metal catalyst precursor and a second metal catalyst precursor. The wetting and impregnation of the mesoporous support with the first and second metal catalysts may include the step of preparing an aqueous metal solution containing the first and second metal catalysts. The first and second metal catalysts may be prepared in a hydrated form (e.g., ammonium metatungstate (NH4)). 10 (H2W 12 O 42)·xH2O and nickel nitrate hexahydrate Ni(NO3)2) can be introduced into water. Dried and calcined zeolite pellets can be immersed in a metal solution for a sufficient time to impregnate them with metal, such as at least 3 hours. The impregnated zeolite particles can be dried again at 110°C for 12 hours. The dried impregnated zeolite particles can be calcined again at approximately 500°C (at a heating rate of approximately 2°C / min) for approximately 4 hours. The dried impregnated zeolite particles can be calcined in air. The calcined impregnated zeolite particles can thereby form a mesoporous supported metal catalyst 122 suitable for use in a fixed-bed reactor.

[0096] The mesoporous supported metal catalyst 122 may contain 40% to 60% by mass of zeolite support components. In embodiments, the mesoporous supported metal catalyst may contain total zeolites, including nanobeta zeolite and Y-type zeolite, in amounts of 40% to 55% by mass, 40% to 50% by mass, 45% to 60% by mass, 50% to 60% by mass, 45% to 55% by mass, or any subset thereof, based on the total mass of the mesoporous supported metal catalyst 122.

[0097] The mesoporous supported metal catalyst 122 may contain a binder in amounts of 10% to 20% by mass, 12.5% ​​to 20% by mass, 15% to 20% by mass, 17.5% to 20% by mass, 10% to 17.5% by mass, 10% to 15% by mass, 10% to 12.5% ​​by mass, 12.5% ​​to 17.5% by mass, or any subset thereof, based on the total mass of the mesoporous supported metal catalyst 122.

[0098] The mesoporous supported metal catalyst 122 may contain 2% to 10% by mass of large-pore alumina. In the embodiment, the mesoporous supported metal catalyst 122 may contain large-pore alumina in amounts of 2% to 8% by mass, 2% to 6% by mass, 2% to 4% by mass, 4% to 10% by mass, 6% to 10% by mass, 8% to 10% by mass, 4% to 8% by mass, or any subset thereof. As previously described, the mesoporous supported metal catalyst 122 may include a first metal catalyst and a second metal catalyst supported on a mesoporous carrier. The first metal catalyst may be a nickel catalyst. The nickel catalyst may exist as nickel oxide (NiO). In the embodiment, the mesoporous supported metal catalyst 122 may contain the first metal catalyst in amounts of 4% to 8% by mass, 6% to 8% by mass, 4% to 6% by mass, 5% to 7% by mass, or any subset thereof, based on the total mass of the mesoporous supported metal catalyst 122.

[0099] The second metal catalyst may be a tungsten catalyst. The tungsten catalyst can exist as tungsten oxide (WO3). The mesoporous supported metal catalyst 122 may contain the second metal catalyst in amounts of 20% to 30% by mass, 22% to 30% by mass, 24% to 30% by mass, 26% to 30% by mass, 28% to 30% by mass, 20% to 28% by mass, 20% to 26% by mass, 20% to 24% by mass, 20% to 22% by mass, 22% to 28% by mass, 24% to 26% by mass, or any subset thereof, based on the total mass of the mesoporous supported metal catalyst 122.

[0100] The mesoporous supported metal catalyst 122 was measured by BET at 200m 2 / g to 400m 2 It can have a surface area of ​​ / g. In the embodiment, the mesoporous supported metal catalyst 122 was measured by BET and had a surface area of ​​200m 2 / g to 350m 2 / g, 200m 2 / g to 300m 2 / g, 200m 2 / g to 250m2 / g, 250m 2 / g to 400m 2 / g, 300m 2 / g to 400m 2 / g, 350m 2 / g to 400m 2 / g, 250m 2 / g to 350m 2 The mesoporous supported metal catalyst 122 can have a surface area of ​​0.4 ml / g to 0.7 ml / g. In the embodiment, the mesoporous supported metal catalyst 122 can have a pore volume of 0.4 ml / g to 0.6 ml / g, 0.4 ml / g to 0.5 ml / g, 0.5 ml / g to 0.7 ml / g, 0.6 ml / g to 0.7 ml / g, and 0.5 ml / g to 0.6 ml / g. The mesoporous supported metal catalyst 122 can have an average pore diameter of 6 nm to 10 nm. In the embodiment, the mesoporous supported metal catalyst 122 can have an average pore diameter of 6 nm to 9 nm, 6 nm to 8 nm, 6 nm to 7 nm, 7 nm to 10 nm, 8 nm to 10 nm, 9 nm to 10 nm, 7 nm to 9 nm, or an average pore diameter of 7 nm to 9 nm or an average pore diameter of 6 nm to 9 nm, 6 nm to 8 nm, 6 nm to 7 nm, 7 nm to 10 nm, 8 nm to 10 nm, 9 nm to 10 nm, and an average pore diameter of 7 nm to 9 nm or an average pore diameter of 6 nm to 9 nm.

[0101] Referring again to Figure 1, under the reaction conditions described above, contacting the intermediate flow 118 with hydrogen 124 in the presence of the mesoporous supported metal catalyst 122 allows for the reaction of at least a portion of the bicyclic aromatic compounds, tricyclic aromatic compounds, or both in the intermediate flow 118 in a single step, without any subsequent chemical reaction steps, to form light aromatic compounds having 6 to 8 carbon atoms. Converting at least a portion of the bicyclic aromatic compounds and / or tricyclic aromatic compounds in the intermediate flow to aromatic compounds having 6 to 8 carbon atoms is also a complex reaction system involving multiple synchronous selective reactions, which may include reactions that selectively hydrogenate only a portion of the aromatic rings in the compound, reactions that subsequently open the hydrogenated and saturated naphthene rings, hydrogenation-dealkylation reactions, transalkylation reactions, and disproportionation reactions. While not intended to be bound by any particular theory, the process of reforming intermediate flow 118 may include selectively hydrogenating at least one aromatic ring structure of a polycyclic aromatic compound, such as a bicyclic aromatic compound, in intermediate flow 118 to produce a molecule having one aromatic ring and at least one saturated ring. The saturated ring can then be opened to produce a substituted aromatic compound. The substituted aromatic compound can then undergo one or more of hydrogenoalkylation, transalkylation, or disproportionation to produce an aromatic compound having 6 to 8 carbon atoms, such as BTEX. It will be understood that multiple variations and combinations of these reactions, as well as other chemical reactions, will similarly occur during the reforming process in the second fixed-bed reactor 120. This complex sequence of synchronous reactions for reforming intermediate flow 118 can be catalyzed using a mesoporous supported metal catalyst 122.

[0102] The second fixed-bed reactor 120 can contact the intermediate flow 118 with hydrogen 124 in the presence of a mesoporous supported metal catalyst 122 under operating conditions mild enough to react at least a portion of the bicyclic and / or tricyclic aromatic compounds in the intermediate flow 118 to form aromatic compounds having 6 to 8 carbon atoms. The second fixed-bed reactor 120 can be operated at operating temperatures in the range of 300°C to 500°C, for example, 350°C to 500°C, 400°C to 500°C, 300°C to 450°C, 350°C to 450°C, or 400°C to 450°C. The second fixed-bed reactor 120 can be operated at operating pressures ranging from 1 MPa (10 bar) to 20 MPa (200 bar), for example, 3 MPa (30 bar) to 20 MPa (200 bar), 5 MPa (50 bar) to 20 MPa (200 bar), 7 MPa (70 bar) to 20 MPa (200 bar), 10 MPa (100 bar) to 20 MPa (200 bar), 1 MPa (10 bar) to 15 MPa (150 bar), 3 MPa (30 bar) to 15 MPa (150 bar), 5 MPa (50 bar) to 15 MPa (150 bar), 7 MPa (70 bar) to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The second fixed-bed reactor 120 operates at 0.3h -1 1.5 hours from -1 For example, 0.5h -1 1.5 hours from -1 , 0.9h -1 1.4h -1 , 0.9h -1 1.3h -1 , 0.9h -1 From 1.2 hours -1 , 1.0h -1 1.5 hours from -1 , 1.1h -1 1.5 hours from -1 , 1.2h -1 1.5 hours from -1 , 1.0h -1 1.4h -1 , 1.1h -1 1.3h -1 Or it can be operated with LHSV of any subset thereof. The second fixed-bed reactor 120 is operated for 200 hours.-1 from 1500h -1 For example, 200h -1 from 1200h -1 , 400h -1 from 1200h -1 , 600h -1 from 1000h -1 , 700h -1 from 900h -1 Approximately 800 hours -1 It can be operated with GHSV, or any subset thereof.

[0103] The second fixed-bed reactor 120 can produce a second reactor effluent 130. The second reactor effluent 130 may contain aromatic compounds having 6 to 8 carbon atoms. These aromatic compounds may include benzene, toluene, ethylbenzene, xylene, or a combination thereof. The second reactor effluent 130 may also contain any unreacted components of the pyrolysis oil feedstock 102, the intermediate flow 118, or both, such as unreacted heavy aromatic compounds. The second reactor effluent 130 may contain, based on the total mass of the second reactor effluent 130, at least 50% by mass, for example, at least 60% by mass, at least 70% by mass, at least 73% by mass, 50% to 80% by mass, 60% to 80% by mass, or 70% to 80% by mass of products that are liquid at room temperature. Aromatic compounds having 6 to 8 carbon atoms produced in the second fixed-bed reactor 120 may account for at least 20% of the second reactor effluent 130, based on the total mass of the second reactor effluent 130, for example, at least 30% by mass, at least 35% by mass, at least 40% by mass, at least 45% by mass, 20% to 60% by mass, 30% to 60% by mass, 40% to 60% by mass, or 45% to 60% by mass.

[0104] By modifying the pyrolysis oil feedstock 102 with the two-stage catalytic process of this disclosure, the yield of benzene, toluene, ethylbenzene, xylene, or combinations thereof can be increased compared to a conventional one-stage catalytic process. In embodiments, the system 100 of this disclosure can produce benzene, toluene, ethylbenzene, xylene, or combinations thereof in total yields of 30% by mass or more, 35% by mass or more, 40% by mass or more, and even 45% by mass or more, based on the total mass of pyrolysis oil from the pyrolysis oil feedstock 102 introduced into the two-stage catalytic process of this disclosure.

[0105] Referring again to Figure 1, the method for modifying the pyrolysis oil feedstock 102 may include the step of separating the second reactor effluent 130 into at least a BTEX product stream 144 and a residual bottom stream 146 in a separation unit 140. In an embodiment, the method may further include the step of separating a light gas stream 142 from the second reactor effluent 130.

[0106] The separation unit 140 may be any unit operation capable of separating the BTEX product flow 144 from the residual bottom flow 146. In this embodiment, the separation unit may be a separation unit capable of separating the light gas flow 142 from the second reactor effluent 130.

[0107] The light gas stream 142 may contain multiple gaseous components. In the embodiment, the light gas stream 142 may contain hydrogen and C1-C4 hydrocarbons such as methane, ethane, propane, and butane. In the embodiment, the light gas stream 142 may contain hydrogen and C1-C4 hydrocarbons in a total mass of at least 80% by mass, for example, at least 90% by mass, at least 95% by mass, and even more than 99% by mass.

[0108] The BTEX product stream 144 may contain light aromatic compounds such as benzene, toluene, ethylbenzene, and xylene. In embodiments, the BTEX product stream 144 may contain at least 80% by mass, for example, at least 90% by mass, at least 95% by mass, and even more than 99% by mass of light aromatic compounds.

[0109] The residual bottom flow 146 may contain polycyclic aromatic compounds, bicyclic aromatic compounds, and tricyclic aromatic compounds. In this embodiment, all or part of the residual bottom flow 146 may be supplied as a bottom recirculation flow 150 that is returned to the first fixed-bed reactor 110.

[0110] Referring further to Figure 1, a method for modifying the pyrolysis oil feedstock 102 may include contacting the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of a mixed metal oxide catalyst 112 under reaction conditions that produce an intermediate flow 118 containing bicyclic aromatic compounds and / or tricyclic aromatic compounds. As previously stated in this disclosure, contacting the pyrolysis oil feedstock 102 with hydrogen 116 in the presence of the mixed metal oxide catalyst 112 under these reaction conditions can convert at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feedstock 102 into bicyclic aromatic compounds and / or tricyclic aromatic compounds. These reaction conditions may include a temperature of 300°C to 500°C, a pressure of 1 MPa (10 bar) to 20 MPa (200 bar), a volume ratio of the mixed metal oxide catalyst 112 to the pyrolysis oil feedstock 102 in the first fixed-bed reactor 110 ranging from 500 to 1500, or a combination of these reaction conditions.

[0111] The first fixed-bed reactor 110 may have any of the features, catalysts, or operating conditions described earlier in this disclosure for the first fixed-bed reactor 110. The method may also include a step of contacting the pyrolysis oil feedstock 102 and hydrogen 116 with the auxiliary catalyst 111 in the first fixed-bed reactor 110. The pyrolysis oil feedstock 102 can be contacted with the auxiliary catalyst 111 under substantially the same conditions as the conditions under which the pyrolysis oil feedstock 102 contacts the mixed metal oxide catalyst 112.

[0112] The method may include the step of sending an intermediate flow 118 containing a bicyclic aromatic compound and / or a tricyclic aromatic compound to a second fixed-bed reactor 120 located downstream of a first fixed-bed reactor 110. This method may include the step of contacting the intermediate flow 118 with hydrogen 124 in the presence of a mesoporous supported metal catalyst 122 under reaction conditions that produce a second reactor effluent 130 containing an aromatic compound having 6 to 8 carbon atoms. As previously stated in this disclosure, contacting the intermediate flow 118 with hydrogen 124 in the presence of the mesoporous supported metal catalyst 122 under these reaction conditions allows at least a portion of the bicyclic aromatic compound and / or tricyclic aromatic compound in the intermediate flow 118 to react to form an aromatic compound having 6 to 8 carbon atoms. These reaction conditions may include a temperature of 300°C to 500°C, a pressure of 1 MPa (10 bar) to 20 MPa (200 bar), or a combination of these reaction conditions. The second fixed-bed reactor 120 may have any of the features, catalysts, or operating conditions described earlier in this disclosure for the second fixed-bed reactor 120.

[0113] According to the first embodiment, a method for reforming pyrolysis oil is a step of contacting pyrolysis oil raw materials with hydrogen in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor, wherein the pyrolysis oil raw materials include a polycyclic aromatic compound having 16 or more carbon atoms, and the mixed metal oxide catalyst may include a plurality of MMO particles, each of which includes Fe2O3, ZrO2, CeO2, and Al2O3, and when the pyrolysis oil raw materials are contacted with hydrogen in the presence of the mixed metal oxide catalyst in the first fixed-bed reactor, at least a portion of the polycyclic aromatic compound in the pyrolysis oil raw materials reacts to form a bicyclic aromatic compound, a tricyclic aromatic compound, or the same. The process may include: generating an intermediate flow containing a combination of the above; and contacting the intermediate flow with hydrogen in a second fixed-bed reactor in the presence of a mesoporous supported metal catalyst, wherein the mesoporous supported metal catalyst contains nickel and tungsten impregnated in a mesoporous support containing large-pore alumina, a binder, and at least one zeolite, and contacting the intermediate flow with hydrogen in the presence of the mesoporous supported metal catalyst causes at least a portion of the bicyclic aromatic compounds and / or tricyclic aromatic compounds in the intermediate flow to react to produce a second reactor effluent containing aromatic compounds having 6 to 8 carbon atoms.

[0114] According to a second embodiment used in conjunction with the first embodiment, the method may further include the steps of mixing heavy pyrolysis oil from a naphtha steam cracking unit with a stream of light aromatic compounds upstream of a first fixed-bed reactor to produce pyrolysis oil raw materials, and sending the pyrolysis oil raw materials to the first fixed-bed reactor.

[0115] According to a third embodiment used in conjunction with embodiment 2, the light aromatic compound stream can be light pyrolysis oil from a gas raw material vapor cracking unit.

[0116] According to a fourth embodiment used in combination with any of embodiments 2 to 3, the light aromatic compound stream can substantially consist of aromatic hydrocarbons having 6 to 8 carbon atoms.

[0117] According to a fifth embodiment used in combination with any one of embodiments 2 to 4, the light aromatic compound stream may include benzene, toluene, ethylbenzene, xylene, or a combination thereof.

[0118] According to a sixth embodiment used in combination with any one of embodiments 2 to 5, the pyrolysis oil raw material may include 75% to 85% by mass of heavy pyrolysis oil and 15% to 25% by mass of light aromatic compound flow.

[0119] According to a seventh embodiment used in combination with any one of embodiments 1 to 6, the aromatic compound having 6 to 8 carbon atoms may include benzene, toluene, ethylbenzene, xylene, or a combination thereof.

[0120] According to an eighth embodiment used in combination with any one of embodiments 1 to 7, the first fixed-bed reactor may include a first catalyst bed and a second catalyst bed downstream of the first catalyst bed, the first catalyst bed may include a mixed metal oxide catalyst, and the second catalyst bed may include an auxiliary catalyst, and the method may include the step of contacting a pyrolysis oil raw material and hydrogen with a mixed metal oxide catalyst in the first catalyst bed, and then contacting an auxiliary catalyst downstream of the mixed metal oxide catalyst in the second catalyst bed in the first fixed-bed reactor.

[0121] According to a ninth embodiment used in conjunction with embodiment 8, the auxiliary catalyst may include nickel oxide, tungsten oxide, and zirconium oxide on a carrier material.

[0122] According to a tenth embodiment used in combination with any of embodiments 8 to 9, the co-catalyst may contain, based on the total mass of the metal oxides of the co-catalyst, 18.5% to 21.5% by mass of Al2O3, 36.5% to 39.5% by mass of SiO2, 9.2% to 10.2% by mass of ZrO2, 10.5% to 11.5% by mass of NiO, and 18.5% to 21.5% by mass of WO3.

[0123] According to the eleventh embodiment, used in combination with any one of embodiments 1 to 10, each of the MMO particles may contain 60% to 95% by mass of iron oxide, 1% to 20% by mass of zirconium oxide, 0.1% to 10% by mass of cerium oxide, and 1% to 20% by mass of aluminum oxide, the mass percentages being based on the total mass of the MMO particles in the mixed metal oxide catalyst.

[0124] According to a twelfth embodiment used in combination with any one of embodiments 1 to 11, each of the MMO particles may contain about 83% by mass of iron oxide, about 7.5% by mass of zirconium oxide, about 2.5% by mass of cerium oxide, and about 7.0% by mass of aluminum oxide, the mass percentages being based on the total mass of the MMO particles in the mixed metal oxide catalyst.

[0125] According to a thirteenth embodiment used in combination with any one of embodiments 1 to 12, the mixed metal oxide catalyst may further contain a binder.

[0126] According to a 14th embodiment used in conjunction with embodiment 13, the binder may include bentonite, silica, or both.

[0127] According to a 15th embodiment used in combination with any of embodiments 13 to 14, the mixed metal oxide catalyst may contain 65% to 85% by mass of MMO particles, based on the total mass of the mixed metal oxide catalyst.

[0128] According to a 16th embodiment used in combination with any one of embodiments 1 to 15, the mixed metal oxide catalyst may be in the form of pellets.

[0129] According to the 17th embodiment used in conjunction with embodiment 16, the pellets of the mixed metal oxide catalyst can have a diameter of 1 mm to 3 mm.

[0130] According to the 18th embodiment, used in combination with any of embodiments 16 to 17, the pellets of the mixed metal oxide catalyst may be cylindrical in shape, having a diameter of 1 mm to 3 mm and a length of 2 mm to 4 mm.

[0131] According to a 19th embodiment used in combination with any one of embodiments 1 to 18, the alumina of the mesoporous supported metal catalyst may include large-pore alumina having an average pore diameter of at least 5 nm.

[0132] According to a 20th embodiment used in combination with any one of embodiments 1 to 19, the zeolite of the mesoporous supported metal catalyst may include both nanozeolite beta and USY zeolite.

[0133] According to a 21st embodiment used in combination with any one of embodiments 1 to 20, the mesoporous supported metal catalyst may contain, based on the total mass of the mesoporous supported metal catalyst, 2 to 10 mass% of large-pore alumina, 10 to 20 mass% of a binder, 40 to 60 mass% of zeolite, 4 to 8 mass% of nickel oxide, and 20 to 30 mass% of tungsten oxide, wherein the zeolite may include USY zeolite and nano-sized zeolite beta, and the mass ratio of USY to nano-sized zeolite beta may be 1.25 to 1.75.

[0134] According to the 22nd embodiment, used in combination with any one of embodiments 1 to 21, the mesoporous supported metal catalyst may contain USY zeolite and nano-sized zeolite beta, and the mass ratio of USY to nano-sized zeolite beta may be 1.25 to 1.75.

[0135] According to a 23rd embodiment used in combination with any one of embodiments 1 to 22, the mesoporous supported metal catalyst may contain, based on the total mass of the mesoporous supported metal catalyst, about 7.5 mass% by mass of large-pore alumina, about 17.5 mass% by mass of beta-zeolite, about 30 mass% by mass of USY-zeolite, about 6 mass% by mass of nickel oxide, about 24 mass% by mass of tungsten oxide, and about 18 mass% by mass of binder.

[0136] According to a 24th embodiment used in combination with any one of embodiments 1 to 23, the pyrolysis oil raw material may contain a polycyclic aromatic compound having 16 or more carbon atoms in an amount of 30 mass percent (mass%) or more, based on the total mass of pyrolysis oil in the pyrolysis oil raw material.

[0137] According to a 25th embodiment used in combination with any one of embodiments 1 to 24, the method may include the steps of: contacting a pyrolysis oil feedstock with hydrogen in a first fixed-bed reactor in the presence of a mixed metal oxide catalyst under one or more of the following reaction conditions: (a) a temperature of 300 degrees Celsius (°C) to 500 degrees Celsius; (b) a pressure of 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar); (c) a hydrogen-to-pyrolysis oil feedstock volume ratio of 500 to 1500; or a combination of these reaction conditions; and contacting an intermediate flow with hydrogen in a second fixed-bed reactor in the presence of a mesoporous supported metal catalyst under one or more of the following reaction conditions: (a) a temperature of 300 degrees Celsius to 500 degrees Celsius; (b) a pressure of 1 MPa (10 bar) to 20 MPa (200 bar); or a combination of these reaction conditions.

[0138] According to the 26th embodiment, which is used in combination with any one of embodiments 1 to 25, when the pyrolysis oil raw material is brought into contact with hydrogen in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor, a portion of the polycyclic aromatic compounds in the pyrolysis oil raw material is converted into an intermediate flow in a single step without subsequent chemical reaction steps.

[0139] According to a 27th embodiment used in combination with any one of embodiments 1 to 26, the method may include a step of contacting an intermediate flow with hydrogen in a second fixed-bed reactor in the presence of a mesoporous supported metal catalyst, under one or more of the following reaction conditions: (a) a temperature of 300°C to 500°C; (b) a pressure of 1 MPa (10 bar) to 20 MPa (200 bar); or a combination of these reaction conditions.

[0140] According to the 28th embodiment, used in combination with any one of embodiments 1 to 27, when the intermediate flow is brought into contact with hydrogen in the presence of a mesoporous supported metal catalyst in a second fixed-bed reactor, a portion of the intermediate flow can be converted into an aromatic compound having 6 to 8 carbon atoms in a single step without subsequent chemical reaction steps.

[0141] According to a 29th embodiment used in combination with any one of embodiments 1 to 28, when a pyrolysis oil raw material is brought into contact with hydrogen in the presence of a mixed metal oxide catalyst, and an intermediate flow is brought into contact with hydrogen in the presence of a mesoporous supported metal catalyst, a yield of aromatic compounds having 6 to 8 carbon atoms of 45% by mass or more can be obtained based on the total mass of pyrolysis oil in the pyrolysis oil raw material.

[0142] According to a 30th embodiment used in combination with any one of embodiments 1 to 29, the method may further include the steps of: vapor-decomposing a naphtha stream to produce one or more product streams and heavy pyrolysis oil; and sending the heavy pyrolysis oil to a first fixed-bed reactor as at least part of the pyrolysis oil feedstock.

[0143] According to a 31st embodiment used in conjunction with embodiment 30, the method may further include the steps of vapor-decomposing a hydrocarbon gas to produce at least one light olefin stream and a light pyrolysis oil; and sending the light pyrolysis oil to a first fixed-bed reactor as at least part of the pyrolysis oil feedstock.

[0144] According to the 32nd aspect, a system for reforming pyrolysis oil may comprise a first fixed-bed reactor comprising a mixed metal oxide catalyst, the first fixed-bed reactor being configured to contact pyrolysis oil feedstock with hydrogen in the presence of the mixed metal oxide catalyst to produce an intermediate flow comprising a bicyclic aromatic compound, a tricyclic aromatic compound, or both, the mixed metal oxide catalyst comprising a plurality of catalyst particles, each of which may comprise Fe2O3, ZrO2, CeO2, and Al2O3; a second fixed-bed reactor being located downstream of the first fixed-bed reactor and comprising a mesoporous supported metal catalyst, the second fixed-bed reactor being configured to contact the intermediate flow with hydrogen in the presence of the mesoporous supported metal catalyst to produce a second reactor effluent comprising an aromatic compound having 6 to 8 carbon atoms, the mesoporous supported metal catalyst may comprise nickel and tungsten impregnated in a mesoporous support comprising alumina and at least one zeolite.

[0145] According to a 33rd aspect used in conjunction with the 32nd aspect, each catalyst particle of the mixed metal oxide catalyst may contain 60% to 95% by mass of iron oxide, 1% to 20% by mass of zirconium oxide, 0.1% to 10% by mass of cerium oxide, and 1% to 20% by mass of aluminum oxide, the mass percentages being based on the total mass of the metal oxides in the catalyst particles in the mixed metal oxide catalyst.

[0146] According to a 34th embodiment used in combination with any of embodiments 32 to 33, the mixed metal oxide catalyst may further include a binder and a matrix material.

[0147] According to a 35th embodiment used in combination with any one of embodiments 32 to 34, the first fixed-bed reactor may include a first catalyst bed and a second catalyst bed located downstream of the first catalyst bed, the first catalyst bed may contain a mixed metal oxide catalyst, and the second catalyst bed may contain an auxiliary catalyst.

[0148] According to the 36th embodiment, used in combination with any one of embodiments 32 to 35, the auxiliary catalyst may contain, based on the total mass of the auxiliary catalyst, 18.5% to 21.5% by mass of Al2O3, 36.5% to 39.5% by mass of SiO2, 9.2% to 10.2% by mass of ZrO2, 10.5% to 11.5% by mass of NiO, and 18.5% to 21.5% by mass of WO3, on an oxide basis.

[0149] According to a 37th embodiment, used in combination with any one of embodiments 32 to 36, the second fixed-bed reactor can be directly fluid-coupled to the first fixed-bed reactor so that the intermediate flow passes directly from the first fixed-bed reactor to the second fixed-bed reactor without passing through any intermediate reactor or separation unit. [Examples]

[0150] Various embodiments of methods and systems for processing heavy fuel oil will be further clarified by the following examples. These examples are for illustrative purposes only and should not be understood as limiting the subject matter of this disclosure.

[0151] Example 1: Preparation of mixed metal oxide catalyst To prepare a mixed metal oxide catalyst containing iron oxide, zirconium oxide, cerium oxide, and aluminum oxide, solution A was prepared by dissolving 40 grams (g) of iron(III) nitrate notahydrate (Fe(NO3)3·9H2O) in 800 milliliters (mL) of distilled water. Next, the other metal oxide precursors were added to solution A. Specifically, solution B was formed by adding 4.906 g of aluminum nitrate notahydrate (Al(NO3)3·9H2O), 1.549 g of zirconium(VI) oxynitrate hydrate (ZrO(NO3)2:3H2O), and 0.601 g of cerium(III) nitrate hexahydrate (Ce(NO3)3·6H2O) to solution A. Next, solution B was stirred for 30 minutes.

[0152] Solution C, an ammonia solution, was prepared by adding 40 mL of ammonium hydroxide (NH4OH) (28-30 percent (%) based on NH3) to 60 mL of distilled water. Solution D was prepared by slowly adding Solution C to Solution B. Solution C was added until the pH of Solution D reached approximately 7. Solution D was then stirred for a further 1 hour.

[0153] Solution D was prepared and stirred for another hour. The precipitate was then separated from Solution D and dried in an oven overnight (i.e., for approximately 12 hours). Next, the dried precipitate was calcined in air at 500 degrees Celsius (°C) for 2 hours. After calcination, the dried and calcined precipitate was pulverized to obtain MMO particles in the form of a fine powder. The MMO particles were nanoparticles with particle sizes ranging from 20 nm to 200 nm.

[0154] Next, powdered MMO particles were mixed with bentonite and methylcellulose in the following ratios: 75% by mass of powdered MMO particles, 24.9% by mass of bentonite, and 0.1% by mass of methylcellulose. The masses of the MMO particles and bentonite were based on the masses of these components after calcination using the ignition loss method. The ignition loss of each component was determined by accurately weighing 3 grams of each component into a crucible and recording the mass of each component added. The crucible was placed in a furnace and the components were calcined by raising the temperature to 650°C at a heating rate of 2°C / min and holding the components at 650°C for 2 hours. After calcination was complete, the crucible was removed from the furnace and cooled in a desiccator to prevent re-adsorption of water and other components from the atmosphere. Next, the calcined components were weighed again and their masses were recorded. The ignition loss of each component was calculated from the mass recorded after calcination and the mass recorded before calcination.

[0155] The dry components were thoroughly mixed. Next, approximately 1.5 mL of water and approximately 1 g of catalyst were mixed to form an extrudeable paste. This extrudeable paste was inserted into the syringe of a syringe pump and extruded into a 2.1 mm diameter cylinder at a rate of 3 ml / min.

[0156] The extruded sample was dried in an oven at 60°C for 24 hours. The dried sample was then calcined in air at 650°C for 2 hours at a heating rate of 2°C / min. Next, the calcined sample was cooled to room temperature and then pulverized into pellets. The pellets were then sieved to obtain small amounts of mixed metal oxide catalyst pellets with a maximum overall dimension of 1 mm to 2 mm. The mixed metal oxide catalyst pellets are characterized in Table 2.

[0157] [Table 2]

[0158] Example 2: Preparation of Mesoporous Supported Metal Catalyst In Example 2, a mesoporous supported metal catalyst was prepared by first preparing a binder composition. 29.25 g of alumina binder (CATAPAL B, commercially available from Sasol Germany GmbH) was mixed with 63.3 g of water and 3.45 mL of 67-69% HNO3 to form a homogeneous binder paste.

[0159] Next, a zeolite paste was prepared. 7.4 g of large-pore alumina (150 m 2 A zeolite mixture was prepared by mixing 49.2 g of USY zeolite (commercially available from Zeolyst International as CBV-720) with a Brunauer-Emmett Teller (BET) surface area of ​​1 / g, a pore volume of 0.8 mL / g to 1.1 mL / g, and a pore radius of 11 nm (commercially available from Sasol Inc. as CATAPAL B), 28.6 g of nanozeolite beta. Details of nanozeolite beta are given in Table 3. Next, the zeolite mixture was mixed with a homogeneous binder paste to form a carrier paste.

[0160] [Table 3]

[0161] The carrier paste was inserted into a syringe pump and extruded into a 2.1 mm diameter cylinder at a rate of 3 ml / min. The extruded sample was dried overnight in an oven at 110°C. The dried sample was then calcined in air at 550°C for 4 hours at a heating rate of 2°C / min. The cooled sample was then pulverized into pellets approximately 2 mm to 4 mm in length.

[0162] Next, the pellets were impregnated with metallic nickel (Ni) and tungsten (W). The Ni / W metal solution was then (NH4) 10 (H2W 12 O 42 The Ni / W metal solution was prepared by mixing ammonium tungstate (NO3)·xH2O, nickel nitrate (NO3)2·6H2O, and water. The pellets were mixed with the Ni / W metal solution at room temperature for 3 hours. The impregnated samples were dried overnight in an oven at 110°C. The dried samples were then calcined in air at 500°C for 4 hours at a heating rate of 2°C / min.

[0163] Example 3: Modification of pyrolysis oil by two-stage hydrocracking In Example 3, the performance of a process including the mixed metal oxide catalyst of Example 1 and the mesoporous supported metal catalyst of Example 2 for modifying pyrolysis oil was evaluated. In Example 3, 80% by mass of heavy pyrolysis oil from a liquid fluid cracking unit was mixed with 20% by mass of light pyrolysis oil from a gaseous raw material vapor cracking unit to produce pyrolysis oil feedstock. The simulated distillation of the pyrolysis oil feedstock is shown in Table 4. The ratios of naphtha fraction, light oil fraction, and C16+ fraction of the pyrolysis oil feedstock are shown in Table 4. Table 5 gives the percentages of each of the different classifications of aromatic compounds in the pyrolysis oil feedstock based on the total mass of the pyrolysis oil feedstock.

[0164] The pyrolysis oil feedstock and hydrogen gas were introduced together into the first fixed-bed reactor. Prior to introduction, the pyrolysis oil feedstock was preheated to the reactor operating temperature. The first reactor consisted of a first bed and a second bed located downstream of the first bed. The first bed contained 2.3 g of mixed metal oxide (MMO) catalyst produced according to Example 1. Downstream of the MMO catalyst bed, but still within the first reactor, the second catalyst bed contained 1.8 g of auxiliary catalyst containing 18 to 21.5 mass% alumina, 36.5 to 39.5 mass% silica, 9.2 to 10.2 mass% zirconia, 10.5 to 11.5 mass% nickel oxide, and 18.5 to 21.5 mass% tungsten oxide.

[0165] The pyrolysis oil raw material is processed at 0.3h -1 Liquid space velocity (LHSV), 800h -1 It was introduced into a first fixed-bed reactor having a gas space velocity (GHSV), a pressure of 150 bar (15 MPa), and a reactor temperature of 390°C.

[0166] Subsequently, the intermediate product generated in the first reactor was introduced into the second fixed-bed reactor. The second fixed-bed reactor contained a bed of mesoporous supported metal catalyst produced in Example 2. The second fixed-bed reactor was operated for 1.2 hours. -1 LHSV, 800h -1 The reactor was operated at GHSV, a pressure of 150 bar (15 MPa), and a reactor temperature of 380°C. The outlet flow of the second fixed-bed reactor was analyzed, including simulated distillation, gas product analysis, and liquid product analysis. The results of the simulated distillation are shown in Table 4, and the results of the aromatic compound analysis are shown in Table 5.

[0167] Gas product analysis: The contents of the gas product were analyzed by online gas chromatography using both an FID detector and a TCD detector.

[0168] Liquid product analysis: API degrees were analyzed using a DMA4100M densimeter from Anton Paar, in accordance with ASTM D4052 and D5002.

[0169] Sulfur and nitrogen content was analyzed using Mitsubishi, Antek, and Analytik Jena analyzers according to ASTM D4629. Gaseous carbohydrates are defined as C1 to C4 hydrocarbons. Naphtha is defined as hydrocarbons from C5 up to 173°C that boil. Light oil fractions are defined as hydrocarbons that boil from 173°C to 404°C. 16+ Hydrocarbons are defined as hydrocarbons that boil at temperatures above 404°C.

[0170] Simulated distillation was performed using an Agilent 7890 gas chromatograph in accordance with CSN EN 15199-2.

[0171] Viscosity was analyzed according to ASTM D7042.

[0172] [Table 4]

[0173] [Table 5]

[0174] As shown in Table 5, this process can convert a considerable amount of bicyclic and tricyclic aromatic compounds into monocyclic aromatic compounds, thereby facilitating the production of useful chemical substances.

[0175] Comparative Example A (CE-A): Modification of pyrolysis oil by two-stage hydrocracking In CE-A, the performance of the same raw materials used in Example 3 was evaluated using a single reactor and a single catalyst system. In CE-A, 80% by mass of heavy pyrolysis oil from a liquid fluid cracking unit was mixed with 20% by mass of light pyrolysis oil from a gas raw material vapor cracking unit to produce pyrolysis oil raw materials. The ratios of naphtha fraction, diesel fraction, and C16+ fraction of the pyrolysis oil raw materials are shown in Table 4.

[0176] The pyrolysis oil feedstock and hydrogen gas were introduced together into the first fixed-bed reactor. Before introduction, the pyrolysis oil feedstock was preheated to the reactor operating temperature. The first reactor contained only the auxiliary catalyst (3.6 g in total). The auxiliary catalyst contained 18 to 21.5% by mass of alumina, 36.5 to 39.5% by mass of silica, 9.2 to 10.2% by mass of zirconia, 10.5 to 11.5% by mass of nickel oxide, and 18.5 to 21.5% by mass of tungsten oxide.

[0177] The pyrolysis oil raw material is processed at 0.3h -1 Liquid space velocity (LHSV), 800h -1 It was introduced into a first fixed-bed reactor having a gas space velocity (GHSV), a pressure of 150 bar (15 MPa), and a reactor temperature of 390°C.

[0178] The outlet flow from the first fixed-bed reactor was analyzed in the same manner as the product flow in Example 3. The results of this analysis are given in Table 6.

[0179] [Table 6]

[0180] It should be noted that any two quantitative values ​​assigned to a characteristic may constitute the range of that characteristic. Furthermore, all combinations of ranges formed from all explicitly stated quantitative values ​​of a given characteristic are envisioned in this disclosure.

[0181] Note that the term “where” is used as a transitional clause in one or more of the following claims. By definition in this Art, this term is introduced into the claims as an open transitional clause used to enumerate a set of characteristics of a structure and should be interpreted similarly to the more commonly used open preamble term “comprising.”

[0182] While the subject matter of this disclosure has been described in detail with reference to specific embodiments, it should be noted that the various details of these embodiments should not be interpreted as suggesting that these details are essential components of those embodiments. Rather, the attached claims should be interpreted as representing the sole scope of this disclosure and the corresponding scope of the various embodiments described herein. Furthermore, it is clear that modifications and alterations are possible without departing from the scope of the attached claims. [Explanation of Symbols]

[0183] 100 Systems for modifying pyrolysis oils 102 Pyrolysis oil raw material 110 First fixed-bed reactor 112 Mixed metal oxide catalysts 114 Auxiliary catalyst 116, 124 Hydrogen 118 Intermediate flow 120 Second fixed-bed reactor 122 Mesoporous supported metal catalyst 130 Second reactor effluent 140, 240, 340 Separation Units 142, 342 Light gas flow 144 BTEX production logistics 146 Residual bottom flow 150 Bottom recirculation flow 200 Naphtha vapor cracking system 204 Naphtha supply flow 206, 306 steam 210 Naphtha vapor decomposition unit 220, 320 Convection Zones 222, 322 Pyrolysis Zone 230 Naphtha runoff 242 Gas flow 244 Olefin product flow 250 Heavy pyrolysis oil 300 Gas-fired vapor cracking system 304 Gas raw material supply flow 310 Gas raw material vapor decomposition unit 330 Outflow from gas raw material vapor cracking plant 344 At least one type of product flow 350 Light pyrolysis oil

Claims

1. In a method for modifying pyrolysis oil, A step in which a pyrolysis oil raw material is brought into contact with hydrogen in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor, The pyrolysis oil raw material includes a polycyclic aromatic compound having 16 or more carbon atoms. The mixed metal oxide catalyst comprises a plurality of MMO particles, each of which is Fe ２ O ３ , ZrO ２ , CEO ２ , and Al ２ O ３ Includes, In the first fixed-bed reactor, the pyrolysis oil raw material is brought into contact with hydrogen in the presence of the mixed metal oxide catalyst, and at least a portion of the polycyclic aromatic compound in the pyrolysis oil raw material reacts to produce an intermediate flow containing a bicyclic aromatic compound, a tricyclic aromatic compound, or a combination thereof; A step in which the intermediate flow is brought into contact with hydrogen in the presence of a mesoporous supported metal catalyst in a second fixed-bed reactor, The mesoporous supported metal catalyst comprises nickel and tungsten impregnated in a mesoporous support containing large-pore alumina, a binder, and at least one type of zeolite. The process involves contacting the intermediate flow with hydrogen in the presence of the mesoporous supported metal catalyst, thereby causing at least a portion of the bicyclic aromatic compounds and / or tricyclic aromatic compounds in the intermediate flow to react and produce a second reactor effluent containing aromatic compounds having 6 to 8 carbon atoms. A method that includes this.

2. The method according to claim 1, further comprising the steps of mixing heavy pyrolysis oil from a naphtha vapor cracking unit with a stream of light aromatic compounds upstream of the first fixed-bed reactor to produce the pyrolysis oil raw material, and sending the pyrolysis oil raw material to the first fixed-bed reactor, wherein the pyrolysis oil raw material comprises 75% to 85% by mass of the heavy pyrolysis oil and 15% to 25% by mass of the stream of light aromatic compounds.

3. The first fixed-bed reactor includes a first catalyst bed and a second catalyst bed located downstream of the first catalyst bed. The first catalyst bed contains the mixed metal oxide catalyst, The second catalyst bed includes an auxiliary catalyst. The method according to claim 1 or 2, further comprising the steps of contacting the pyrolysis oil raw material and the hydrogen with the mixed metal oxide catalyst in the first catalyst bed in the first fixed-bed reactor, and then contacting the auxiliary catalyst located downstream of the mixed metal oxide catalyst in the second catalyst bed.

4. The auxiliary catalyst is determined based on the total mass of the metal oxides in the auxiliary catalyst. 18.5% to 21.5% by mass of Al ２ O ３ , 36.5 mass% to 39.5 mass% of SiO ２ , 9.2% to 10.2% by mass of ZrO ２ , 10.5% to 11.5% by mass of NiO, 18.5% to 21.5% by mass of WO ３ The method according to claim 3, including the method described in claim 3.

5. Each of the aforementioned MMO particles is 60% to 95% by mass of iron oxide, 1% to 20% by mass of zirconium oxide, 0.1% to 10% by mass of cerium oxide, 1% to 20% by mass of aluminum oxide Includes, The method according to any one of claims 1 to 4, wherein these mass percentages are based on the total mass of the MMO particles in the mixed metal oxide catalyst.

6. The method according to any one of claims 1 to 5, wherein the mixed metal oxide catalyst further comprises a binder.

7. The method according to any one of claims 1 to 6, wherein the mixed metal oxide catalyst is in the form of pellets.

8. The method according to any one of claims 1 to 7, wherein the alumina of the mesoporous supported metal catalyst includes large-pore alumina having an average pore diameter of at least 5 nm.

9. The method according to any one of claims 1 to 8, wherein the zeolite of the mesoporous supported metal catalyst includes both nanozeolite beta and USY zeolite.

10. The mesoporous supported metal catalyst comprises, based on the total mass of the mesoporous supported metal catalyst, 2% to 10% by mass of large-pore alumina, 10% to 20% by mass of a binder, 40% to 60% by mass of zeolite, 4% to 8% by mass of nickel oxide, and 20% to 30% by mass of tungsten oxide. The zeolite comprises USY zeolite and nano-sized zeolite beta. USY: The method according to any one of claims 1 to 9, wherein the mass ratio of nano-sized zeolite beta is 1.25 to 1.

75.

11. The pyrolysis oil raw material contains a polycyclic aromatic compound having 16 or more carbon atoms in an amount of 30 mass percent (mass%) or more, based on the total mass of pyrolysis oil in the pyrolysis oil raw material. The method according to any one of claims 1 to 10, wherein the pyrolysis oil raw material is brought into contact with hydrogen in the presence of the mixed metal oxide catalyst, and the intermediate flow is brought into contact with hydrogen in the presence of the mesoporous supported metal catalyst, thereby yielding an aromatic compound having 6 to 8 carbon atoms in an amount of 45% by mass or more based on the total mass of pyrolysis oil in the pyrolysis oil raw material.

12. A step of contacting the pyrolysis oil raw material with hydrogen in the presence of the mixed metal oxide catalyst in the first fixed-bed reactor under one or more of the following reaction conditions: (a) a temperature of 300 degrees Celsius (°C) to 500 degrees Celsius; (b) a pressure of 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar); (c) a volume ratio of hydrogen to the pyrolysis oil raw material of 500 to 1500; or a combination of these reaction conditions; and A step of contacting the intermediate flow with hydrogen in the presence of the mesoporous supported metal catalyst in the second fixed-bed reactor under one or more of the following reaction conditions: (a) a temperature of 300°C to 500°C; (b) a pressure of 1 MPa (10 bar) to 20 MPa (200 bar); or a combination of these reaction conditions; The method according to any one of claims 1 to 11, including

13. A process of vapor-decomposing a naphtha flow to produce one or more product flows and heavy pyrolysis oil, and A step of sending the heavy pyrolysis oil as at least a portion of the pyrolysis oil raw material to the first fixed-bed reactor, The method according to any one of claims 1 to 12, further comprising:

14. A process of vapor-decomposing a hydrocarbon gas to produce at least one light olefin fluid and a light pyrolysis oil, and A step of sending the light pyrolysis oil as at least a portion of the pyrolysis oil raw material to the first fixed-bed reactor, The method according to claim 13, further comprising:

15. In a system for reforming pyrolysis oil, A first fixed-bed reactor comprising a mixed metal oxide catalyst, The first fixed-bed reactor can be configured to contact a pyrolysis oil feedstock with hydrogen in the presence of the mixed metal oxide catalyst to produce an intermediate stream containing a light aromatic compound including a monocyclic aromatic compound, a bicyclic aromatic compound, a tricyclic aromatic compound, or both, wherein the mixed metal oxide catalyst comprises a plurality of catalyst particles, each of which is Fe ２ O ３ , ZrO ２ , CEO ２ , and Al ２ O ３ including, The first fixed-bed reactor, A second fixed-bed reactor located downstream of the first fixed-bed reactor, comprising a mesoporous supported metal catalyst, The second fixed-bed reactor can be configured to bring the intermediate flow into contact with hydrogen in the presence of the mesoporous supported metal catalyst to produce a second reactor effluent containing an aromatic compound having 6 to 8 carbon atoms. The mesoporous supported metal catalyst comprises nickel and tungsten impregnated in a mesoporous support containing alumina and at least one zeolite. A second fixed-bed reactor, A system equipped with this feature.

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