2-Stage Fixed-Bed Catalytic Process for Upgrading Pyrolysis Oil to BTX

Abstract

A system for upgrading pyrolysis oil comprises a first fixed-bed reactor having a first catalyst layer and a second catalyst layer. The first catalyst layer comprises a first treatment catalyst containing alumina, a binder, Mo, Ni, and P; a second treatment catalyst containing Al2O3, SiO2, ZrO2, NiO, and WO3; or both. The second catalyst layer comprises a mixed metal oxide catalyst. The first fixed-bed reactor contacts the pyrolysis oil with hydrogen in the presence of the treatment catalyst and the mixed metal oxide catalyst to produce an intermediate stream containing light aromatic compounds. The system comprises a downstream second fixed-bed reactor comprising a mesoporous support metal catalyst having nickel and tungsten on a mesoporous support. The second fixed-bed reactor contacts the intermediate stream with hydrogen in the presence of the mesoporous support metal catalyst to produce a second reactor effluent containing aromatic compounds having 6 to 8 carbon atoms.

Description

Technology Field

[0001] Cross-reference regarding related patents

[0002] This application claims priority to U.S. application 18 / 407,866 filed January 9, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention generally relates to a method and system for upgrading pyrolysis oil, and more specifically, to a method and system for upgrading pyrolysis oil to light aromatic compounds using a two-stage fixed-bed catalytic process. Background Technology

[0005] Crude oil can be converted into valuable chemical intermediates and products through one or more refining processes. Refining processes may include steam cracking, which cracks larger hydrocarbons in the crude oil to form smaller hydrocarbons. For example, a naphtha stream separated from a crude oil and gas condensate stream can be steam cracked to produce higher-value product intermediates. Additionally, light hydrocarbon gases can be steam cracked to produce higher-value product intermediates, such as olefins but not limited to them. The steam cracking unit generates a bottom stream, which is called pyrolysis oil. Pyrolysis oil may contain higher concentrations of aromatic compounds compared to the crude oil feedstock. In many crude oil processing facilities, this pyrolysis oil is burned as fuel. However, the aromatic compounds in the pyrolysis oil can be converted into higher-value chemical products and intermediates, which can be used as building blocks for chemical synthesis processes. For example, aromatic compounds from pyrolysis oil can be converted into xylene, which can serve as an initial building block for terephthalic acid production, which can then be used in polyester production. Aromatic compounds in pyrolysis oil can be upgraded into various higher-value aromatic products and intermediates. Market demand for these higher-value aromatic compounds is continuously growing.

[0006] Multi-ring aromatic compounds in pyrolysis oil can be converted into light aromatic compounds, which may include benzene, toluene, ethylbenzene, xylene (BTEX), other aromatic compounds, or combinations thereof, through various reactions including but not limited to hydrogenation, ring opening, disproportionation, dealkylation, transalkylation, cracking, or aromatic cracking. Generally, a combination of these reactions can convert a portion of the multi-ring aromatic compounds in pyrolysis oil into light aromatic compounds in a single process step. However, carrying out multiple reactions in a single process step can be complex, and unless harsh conditions are applied, the yield may be insufficient to meet the demand for BTEX, thereby increasing the investment and operating costs of the process. Additionally, current methods for achieving these reactions result in excessive coke production, which can cause reactor plugging.

[0007] Therefore, there is a continuing need for improved systems and methods for upgrading pyrolysis oil to produce light aromatic compounds for increased BTEX yield using mild processing conditions without excessive coke generation. An aspect of the present invention satisfies this need by providing a two-stage catalytic process capable of upgrading pyrolysis oil to BTEX in a single process by using two fixed-bed reactors in series. The first fixed-bed reactor may comprise at least a first catalyst layer and a second catalyst layer, wherein a processing catalyst is located in the first catalyst layer and a mixed metal oxide catalyst is located in the second catalyst layer. The first fixed-bed reactor may be operable to convert at least a portion of the polycyclic compounds in the pyrolysis oil into intermediate aromatic compounds, such as diaromatic compounds. The second fixed-bed reactor may comprise a mesoporous supported metal catalyst and may be operable to convert at least a portion of the intermediate aromatic compounds into BTEX. The above method and system can convert a portion of polycyclic aromatic compounds in pyrolysis oil into BTEX in a two-stage fixed-bed catalytic process without performing a subsequent chemical reaction step. The above method and system can produce a greater yield of BTEX by upgrading pyrolysis oil under milder conditions compared to upgrading pyrolysis oil according to conventional methods using harsher reaction conditions. The above method and system can produce BTEX by upgrading pyrolysis oil without coke formation and reactor clogging, which are problems that occur in more conventional systems.

[0008] According to one or more aspects of the present invention, a system for upgrading pyrolysis oil may comprise a first fixed-bed reactor comprising a first catalyst layer and a second catalyst layer disposed downstream of the first catalyst layer. The first catalyst layer may comprise (1) a first treatment catalyst comprising a plurality of first particles, wherein the plurality of first particles each comprise alumina, a binder, Mo, Ni, and P; (2) a second treatment catalyst comprising a plurality of second particles, wherein the plurality of second particles each comprise Al2O3, SiO2, ZrO2, NiO, and WO3; or (3) a treatment catalyst comprising both. The second catalyst layer may comprise a mixed metal oxide catalyst. The first fixed-bed reactor may be operable to contact a pyrolysis oil feed with hydrogen in the presence of the treatment catalyst and the mixed metal oxide catalyst to produce an intermediate stream comprising light aromatic compounds including mono-aromatic compounds, di-aromatic compounds, tri-aromatic compounds, or both. The system may further comprise a second fixed-bed reactor downstream of the first fixed-bed reactor and comprising a mesoporous supported metal catalyst. The second fixed-bed reactor may be operable to contact an intermediate stream 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 onto a mesoporous support comprising alumina and one or more zeolites.

[0009] According to another aspect of the present invention, a method for upgrading a pyrolysis oil feed may include the step of moving the pyrolysis oil feed to a system comprising a first fixed-bed reactor and a second fixed-bed reactor downstream of the first fixed-bed reactor. The first fixed-bed reactor may include a first catalyst layer and a second catalyst layer disposed downstream of the first catalyst layer. The first catalyst layer may include (1) a first treatment catalyst comprising a plurality of first particles, wherein the plurality of first particles each comprise alumina, a binder, Mo, Ni, and P; (2) a second treatment catalyst comprising a plurality of second particles, wherein the plurality of second particles each comprise Al2O3, SiO2, ZrO2, NiO, and WO3; or (3) a treatment catalyst comprising both. The second catalyst layer may include a mixed metal oxide catalyst. The second fixed-bed reactor may comprise a mesoporous supported metal catalyst comprising nickel and tungsten impregnated onto a mesoporous support comprising alumina and one or more zeolites. The method may further comprise the step of contacting a pyrolysis oil feed with hydrogen in the presence of a treatment catalyst and a mixed metal oxide catalyst in the first fixed-bed reactor to produce an intermediate stream comprising a di-aromatic compound, a tri-aromatic compound, or a combination thereof. The method may further comprise the step of contacting the intermediate stream with hydrogen in the presence of a mesoporous supported metal catalyst in the second fixed-bed reactor to produce a second reactor effluent comprising an aromatic compound having 6 to 8 carbon atoms.

[0010] Further features and advantages of the technology and technology of the present invention are set forth in the following detailed description, which will, in part, become readily apparent to those skilled in the art from these detailed descriptions or will be recognized by practicing the technology and technology as described in the present invention, including the detailed description, claims, and drawings below. Brief explanation of the drawing

[0011] The following detailed description of specific embodiments of the present invention is best understood when read together with the drawings, and similar structures are indicated by similar reference numbers: FIG. 1 schematically illustrates a generalized flowchart of a system for pyrolysis oil upgrading according to one or more embodiments illustrated and described herein; FIG. 2 schematically illustrates a generalized flowchart of a pyrolysis oil feed supply system according to one or more embodiments illustrated and described herein; FIG. 3 schematically illustrates a generalized flowchart of a pyrolysis oil feed supply system according to one or more embodiments illustrated and described herein; FIG. 4 schematically illustrates the components of heavy pyrolysis oil; FIG. 5 schematically illustrates a generalized flowchart of another system for pyrolysis oil upgrading according to one or more embodiments illustrated and described herein; FIG. 6 schematically illustrates a generalized flowchart of another system for pyrolysis oil upgrading according to one or more embodiments illustrated and described herein; FIG. 7 schematically illustrates a generalized flowchart of another system for pyrolysis oil upgrading according to one or more embodiments illustrated and described herein; FIG. 8 schematically illustrates a generalized flowchart of a system for pyrolysis oil upgrading according to one or more embodiments illustrated and described herein, and FIG. 9 graphs the change over time of liquid hourly space velocity (LHSV) in a reactor according to one or more embodiments illustrated and described herein; FIG. 10 graphs the change over time of liquid hourly space velocity (LHSV) in a reactor according to one or more embodiments illustrated and described herein. For the purpose of describing the simplified schematic examples and descriptions of FIGS. 1 through 3 and FIGS. 5 through 8, many valves, temperature sensors, electronic controllers, etc., which are used and well known to those skilled in the art of specific chemical processing operations are not included. Additionally, auxiliary components commonly included in chemical processes, such as air supplies, heat exchangers, surge tanks, catalyst hoppers, or other related systems, are not illustrated. These components should be understood to be included within the gist and scope of the embodiments of the present invention. However, operating components as described in the present invention may be added to the embodiments described in the present invention. It should also be noted that the arrows in the drawings refer to process streams. However, arrows may equally refer to transport lines to provide process stream transport between two or more system components. Additionally, arrows connecting system components define the inlet or outlet of each given system component. The direction of the arrows generally corresponds to the primary direction of movement of the material of the stream contained within the physical transport line indicated by the arrows. Furthermore, arrows that do not connect two or more system components indicate product streams exiting the depicted system or system inlet streams introduced into the depicted system. Product streams may be further processed in an accompanying chemical process system or commercialized as final products. System inlet streams may be streams transported from the accompanying chemical processing system or unprocessed feedstock streams. Some arrows may indicate recirculation streams, which are effluent streams of system components that are recirculated back into the system. However, it should be understood that in some embodiments, any depicted recirculation stream may be replaced by a system inflow stream of the same material, and that a portion of the recirculation stream may exit the system as a system product. Additionally, arrows in the drawing may schematically illustrate process steps for transporting a stream from one system component to another system component. For example, an arrow pointing from one system component to another system component may indicate "moving" system component effluent to the other system component, which may include "introducing" the contents of a process stream and the contents of a corresponding product stream that are "discharged" or "removed" from one system component into the other system component. In the schematic flowcharts of FIGS. 1 through 3 and FIGS. 5 through 8, it should be understood that two or more process streams are "mixed" or "combined" when two or more lines intersect. Mixing or combining may also include mixing the two streams by introducing them directly into a similar reactor, separation device, or other system component. For example, when two streams are described as being combined just before entering a separator or reactor, it should be understood that in some embodiments, said streams may be introduced equally into the separator or reactor and mixed in the reactor. Various aspects of the present invention will be described in more detail, some of which are illustrated in the accompanying drawings. Where possible, the same reference numerals have been used throughout the drawings to refer to identical or similar parts. Specific details for implementing the invention

[0012] An aspect of the present invention relates to a method and system for upgrading pyrolysis oil in a two-stage fixed-bed catalytic process. Referring now to FIG. 1, a system (100) for upgrading pyrolysis oil may include a first fixed-bed reactor (110) and a second fixed-bed reactor (120) downstream of the first fixed-bed reactor (110). The first fixed-bed reactor (110) may include at least a first catalyst layer (111) and a second catalyst layer (115). The first catalyst layer (111) may include a treatment catalyst (119). The treatment catalyst (119) may be a first treatment catalyst comprising alumina, a binder, Mo, Ni, and P; a second treatment catalyst comprising Al2O3, SiO2, ZrO2, NiO, and WO3, or both; or both. The second catalyst layer (115) of the first fixed-bed reactor (110) may include a mixed metal oxide (MMO) catalyst (112). The first fixed-bed reactor (110) may be operated to produce an intermediate stream (118) comprising di-aromatic compounds, tri-aromatic compounds, or a combination thereof by contacting a pyrolysis oil feed (102) with hydrogen (116) in the presence of a treatment catalyst (119) in the first catalyst layer (111) followed by contact with the MMO catalyst (112) in the second catalyst layer (115). The mixed metal oxide catalyst (112) may have a composition different from that of the treatment catalyst (119). For example, the mixed metal oxide catalyst (112) may include a plurality of catalyst particles, and the plurality of catalyst particles may each include iron oxide (Fe2O3), zirconium oxide (ZrO2), cerium oxide (CeO2), and alumina (Al2O3). A second fixed-bed reactor (120) downstream of the first fixed-bed reactor (110) may include a mesoporous supporting metal catalyst (122).The second fixed-bed reactor (120) may be operable to contact the intermediate stream (118) with hydrogen in the presence of a mesoporous supporting metal catalyst (122) to produce a second reactor effluent (130) comprising an aromatic compound having 6 to 8 carbon atoms. The mesoporous supporting metal catalyst (122) may comprise nickel and tungsten impregnated onto a mesoporous support comprising alumina and at least one zeolite.

[0013] Referring still to FIG. 1, a method for upgrading pyrolysis oil may include contacting a pyrolysis oil feed (102) in a first fixed-bed reactor (110) with hydrogen (116) in the presence of a treatment catalyst (119) in a first catalyst layer (111) and then in the presence of an MMO catalyst (112) in a second catalyst layer (115). The pyrolysis oil feed (102) may include a polycyclic aromatic compound containing 16 or more carbon atoms. The treatment catalyst (119) may include a first treatment catalyst comprising alumina, a binder, Mo, Ni, and P; a second treatment catalyst comprising Al2O3, SiO2, ZrO2, NiO, and WO3; or both; or both. The MMO catalyst may include a plurality of catalyst particles, and each of the plurality of catalyst particles may include Fe2O3, ZrO2, CeO2, and Al2O3. In a first fixed-bed reactor (110), a pyrolysis oil feed (102) is contacted with hydrogen (116) in the presence of a treatment catalyst (119) in a first catalyst layer (111) and then in the presence of an MMO catalyst in a second catalyst layer (115), at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102) may react to produce an intermediate stream comprising di-aromatic compounds, tri-aromatic compounds, or both. The method may further include contacting the intermediate stream (118) with hydrogen (124) in the presence of a mesoporous supporting metal catalyst (122) in a second fixed-bed reactor (120). The mesoporous supporting metal catalyst (122) may comprise nickel and tungsten impregnated onto a mesoporous support comprising alumina and at least one zeolite. Contacting the intermediate stream (118) with hydrogen (124) in the presence of a mesoporous supporting metal catalyst (122) can cause at least some of the di-aromatic compounds, tri-aromatic compounds, or combinations thereof in the intermediate stream (118) to react to produce a second reactor effluent (130) containing an aromatic compound having 6 to 8 carbon atoms.

[0014] The system and method of the present invention demonstrate improved performance in upgrading feedstock pyrolysis oil into a high-value aromatic stream in a fixed-bed catalytic process. While coke formation and system clogging are significantly reduced, the total yield of mono-aromatics can be considerably higher than in previous systems. Additionally, the process of the present invention can achieve these yields by using a feedstock heavy pyrolysis oil feedstream and a fixed-bed system. Furthermore, using a fixed-bed system eliminates the need to separate the solid catalyst from the reactor effluent in a separate step.

[0015] The term "catalyst" as used in the present invention refers to any substance that increases the rate of a specific chemical reaction. The catalysts and catalytic components described herein may be used to promote various reactions, such as but not limited to selective hydrogenation, ring opening, disproportionation, dealkylation, hydrodealkylation, transalkylation, cracking, aromatic cracking, other chemical reactions, or combinations thereof.

[0016] The term "cracking" as used in the present invention refers to a chemical reaction in which a molecule having carbon-carbon bonds is broken into one or more molecules by the breaking of one or more carbon-carbon bonds, for example, a chemical reaction in which a molecule containing a plurality of aromatic rings is broken into several molecules containing aromatic rings; a chemical reaction in which a molecule having one or more cyclic moieties, which are the same as but not limited to aromatic compounds, undergoes a reaction in which one or more of the cyclic moieties are opened; or a chemical reaction in which a molecule having carbon-carbon double bonds is reduced to carbon-carbon single bonds. Some catalysts may have various forms of catalytic activity, and just because a catalyst is designated by a specific function does not mean that it cannot be catalytically active for another function. The term "hydrocracking" as used in the present invention refers to cracking in the presence of added hydrogen.

[0017] The term "aromatic compound" as used in the present invention refers to a compound having one or more aromatic ring structures. The term "light aromatic compound" refers to a compound having an aromatic ring having 6 to 8 carbon atoms, regardless of substitution. The term "BTEX" refers to one or more combinations of benzene, toluene, ethylbenzene, para-xylene, meta-xylene, and ortho-xylene. The term "BTX" refers to one or more combinations of benzene, toluene, para-xylene, meta-xylene, and ortho-xylene.

[0018] The term "xylene" as used in the present invention refers to one or more of meta-xylene, ortho-xylene, para-xylene, and mixtures of these xylene isomers when used without the designation of isomers such as the prefixes para, meta, or ortho.

[0019] The terms "boiling point temperature" or "boiling temperature" as used throughout this invention refer to the boiling point temperature at atmospheric pressure unless otherwise specified.

[0020] As used in the present invention, the term “initial boiling point” or “IBP” of a composition refers to the temperature at which a component of the composition having the lowest boiling point temperature begins to transition from the liquid phase to the vapor phase.

[0021] As used in the present invention, the term “final boiling point” or “FBP” of a composition refers to the temperature at which the highest boiling point component of the composition transitions from the liquid phase to the vapor phase.

[0022] The term "external surface" as used in the present invention refers to a surface at the outer periphery of a catalyst or catalyst support, such as a mesoporous support.

[0023] The term "pore surface" as used in the present invention refers to the inner surface of the pores of a catalyst or catalyst support, and said pores include at least pores that are fluidly connected to the outer surface of the catalyst or catalyst support and are accessible to reactants.

[0024] As used in the present invention, the term "average pore size" of a catalyst or catalyst support refers to the average pore size determined by Barrett-Joiner-Halenda (BJH) analysis. BJH analysis measures the amount of gas (argon) separated from a material, such as a mesoporous support, over various pressure ranges starting from 87 Kelvin. 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.

[0025] The term "fixed-bed reactor" as used in the present invention refers to a reactor in which a catalyst is contained within the reactor and maintained at a fixed position within the reactor.

[0026] The term “separation unit” as used in the present invention refers to any separation device that separates one or more chemical substances in a mixture at least partially from one another. For example, a separation unit may selectively separate different chemical species to form one or more chemical fractions. Examples of separation units include, without limitation, distillation columns, fractionators, flash drums, knock-out drums, knock-out ports, centrifuges, filtration devices, traps, scrubbers, expansion devices, membranes, solvent extraction devices, high-pressure separators, low-pressure separators, etc. It should be understood that the separation method described in the present invention may not completely separate all of a consistent chemical composition from all other chemical components. It should be understood that the separation method described in the present invention separates different chemical components “at least partially” from one another, and that separation may include only partial separation, even if not explicitly stated. One or more chemical components used in the present invention may be “separated” from a process stream to form a new process stream. Generally, the process stream may be introduced into a separation unit and may be split or separated into two or more process streams of the desired composition.

[0027] The terms "upstream" and "downstream" as used in the present invention refer to the relative positions of unit operations with respect to the flow direction of a process stream. A first unit operation of the system may be considered the "upstream" of a second unit operation if the process stream flowing through the system encounters the first unit operation before encountering the second unit operation. Likewise, a second unit operation may be considered the "downstream" of a first unit operation if the process stream flowing through the system encounters the first unit operation before encountering the second unit operation.

[0028] As used in the present invention, "directly" moving a stream or effluent from one unit to another unit refers to moving a stream or effluent from a first unit to a second unit without moving the stream or effluent through an intervening reaction system or separation system that substantially changes the composition of the stream or effluent. 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 as intervening systems that change the composition of the stream or effluent. Furthermore, combining two streams or effluents with the upstream of a process unit is not considered to involve an intervening system that changes the composition of one or both of the streams or effluents being combined. Simply splitting a stream into two streams having the same composition is also not considered to involve an intermediate system that changes the composition of the stream.

[0029] The term "effluent" as used in this invention refers to a stream discharged from a reactor, reaction zone, or separator after a specific reaction or separation process. Generally, the effluent has a different composition from the stream introduced into the separation unit, reactor, or reaction zone. It should be understood that when the effluent is transferred to another system unit, only a portion of the corresponding system stream may be transferred. For example, a slip stream (having the same composition) may carry a portion of the effluent away, meaning that only a portion of the effluent may be introduced into the downstream system unit. The term "reaction effluent" is used more specifically to refer to a stream discharged from a reactor or reaction zone.

[0030] Additionally, it is further understood that a stream may be named with respect to a component of the stream, and that the component named with the stream may be a major component of said stream (e.g., 50 wt.% of the stream content, 70 wt.%, 90 wt.%, 95 wt.%, 99 wt.%, 99.5 wt.%, or even from 99.9 wt.% to 100 wt.% of said stream content, excluding any inert gas or diluent added to said stream). Also, when a stream containing a component is described as moving from one system component to another component, the component of the stream is understood to be moving from one system component to another component. For example, a "hydrogen stream" described as moving to a first system component or from a first system component to a second system component should be understood as equivalently describing "hydrogen" moving to the first system component or moving from a first system component to a second system component.

[0031] Referring again to FIG. 1, a system (100) for upgrading a pyrolysis oil feed (102) is schematically illustrated. The system (100) for upgrading a pyrolysis oil feed (102) may include a first fixed-bed reactor (110) and a second fixed-bed reactor (120) downstream of the first fixed-bed reactor (110). The first fixed-bed reactor (110) may include one or more fixed-bed reactors and may be operable to produce an intermediate stream (118) by contacting the pyrolysis oil feed (102) with hydrogen (116) in the presence of a treatment catalyst (119) of a first catalyst layer (111) and subsequently a mixed metal oxide catalyst (112) of a second catalyst layer (115). The intermediate stream (118) may include a di-aromatic compound, a tri-aromatic compound, or both. The second fixed-bed reactor (120) may be operated to contact the intermediate stream (118) with hydrogen (124) in the presence of a mesoporous supporting metal catalyst (122) to produce a second reactor effluent (130) containing an aromatic compound having 6 to 8 carbon atoms.

[0032] The above system and method demonstrate enhanced performance in upgrading raw pyrolysis oil into a high-value aromatic stream (containing a relatively high concentration of mono-aromatics) in a single process. Using a fixed-bed reactor eliminates the catalyst / product separation and catalyst recirculation steps. The fixed-bed reactor used herein may include multiple material inlets but has a single effluent outlet. Using the first catalyst layer (111) upstream of the second catalyst layer (115) in the first fixed-bed reactor (110) prevents coke formation and clogging of the system (100).

[0033] The pyrolysis oil feed (102) may include heavy pyrolysis oil (250). In an embodiment, the pyrolysis oil feed (102) may include a diluent (104) such as, but not limited to, light pyrolysis oil, toluene, other light aromatic compounds, or a combination thereof. Referring now to FIGS. 2 and FIGS. 3, the heavy pyrolysis oil (250) may be a stream from a hydrocarbon processing facility rich in aromatic compounds, such as polycyclic aromatic compounds. In an embodiment, the heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may be a top bottom stream from a liquid steam cracking process, such as the naphtha steam cracking system (200) of FIG. 2. As used in the present invention, "top bottom stream" may refer to a residue or fraction of a stream (e.g., feed for a steam cracking process) introduced into a separation system containing the least volatile component that is not separately captured as condensed steam.

[0034] The heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may include mono-aromatic compounds and polycyclic aromatic compounds. The polycyclic aromatic compounds may include aromatic compounds having two, three, four, five, six, seven, eight, or more aromatic ring structures. The polycyclic aromatic compounds may include aromatic compounds having 16 or more carbon atoms. The heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may include other components such as saturated hydrocarbons, but not limited thereto. Now, referring to FIG. 4, one exemplary embodiment of the composition of a conventional heavy pyrolysis oil (250) that can be used in the pyrolysis oil feed (102) is schematically illustrated. The heavy pyrolysis oil (250) provided in FIG. 4 is a pyrolysis oil produced from steam cracking naphtha. As illustrated in FIG. 4, the heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may contain aromatic compounds having one-aromatic, two-aromatic, three-aromatic, four-aromatic, five-aromatic, and six or more aromatic rings (six or more aromatics in FIG. 4). The heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may contain, as shown in FIG. 4, a high concentration of two-aromatic compounds and aromatic compounds having six or more aromatic rings. In an embodiment, the heavy pyrolysis oil (250) of the polycyclic aromatic compound-rich pyrolysis oil feed (102) may contain at least 50 wt.% of polycyclic aromatic compounds based on the unit weight of the heavy pyrolysis oil (250) of the pyrolysis oil feed (102), for example, at least 60 wt.%, at least 65 wt.%, at least 70 wt.%, at least 75 wt.%, or even at least 80 wt.% of polycyclic aromatic compounds.

[0035] A substantial portion of the heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may be a polycyclic aromatic compound having more than 16 carbon atoms or more than 4 aromatic rings. The heavy pyrolysis oil (250) may contain more than 30 wt.% of a polycyclic aromatic compound having more than 16 carbon atoms, for example more than 35 wt.%, more than 40 wt.%, or even more than 45 wt.% of a polycyclic aromatic compound having more than 16 carbon atoms, where the weight percentage (wt.%) is based on the unit weight of the heavy pyrolysis oil (250) of the pyrolysis oil feed (102). The heavy pyrolysis oil (250) may contain at least 30 wt.% of polycyclic aromatic compounds having a boiling point temperature of 750 degrees Fahrenheit (℉) (399°C), for example, at least 35 wt.%, at least 40 wt.%, or even at least 45 wt.% of polycyclic aromatic compounds having a boiling point temperature of 399°C or higher, where the weight percentage is based on the unit weight of the heavy pyrolysis oil (250) of the pyrolysis oil feed (102).

[0036] In an embodiment, heavy pyrolysis oil (250) may have a density of 1.00 g (g / cm³) or more per cubic centimeter at 15°C, for example 1.01 g / cm³ or more, 1.02 g / cm³ or more, 1.00 g / cm³ to 1.20 g / cm³, 1.01 g / cm³ to 1.10 g / cm³, or 1.02 g / cm³ to 1.10 g / cm³, as measured according to the test method of ASTM D5002. In an embodiment, the heavy pyrolysis oil (250) may have a dynamic viscosity of 10 millipascals (mPa*s) or more at 60°C, for example, 10 mPa*s to 20 mPa*s, or 12 mPa*s to 15 mPa*s, and the dynamic viscosity is measured according to the test method of ASTM D7042. In an embodiment, the heavy pyrolysis oil (250) may have a kinematic viscosity of 10 square millimeters (mm² / s) or more per second at 60°C, for example 12 mm² / s or more, 10 mm² / s to 20 mm² / s, 10 mm² / s to 15 mm² / s, 12 mm² / s to 20 mm² / s, or 12 mm² / s to 15 mm² / s, as measured according to the test method of ASTM D7042.

[0037] In an 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 measured according to the test method of ASTM D2887. In an embodiment, the heavy pyrolysis oil (250) may have a final boiling point temperature (FBP) of 500°C or higher, e.g. 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 measured according to the test method of ASTM D2887 and the ISO test method EN 15199-1-3. In an embodiment, the heavy pyrolysis oil (250) may have a 50% boiling point 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 measured according to the test method of ASTM D2887.

[0038] The heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may also have low concentrations of sulfur and sulfur compounds. The heavy pyrolysis oil (250) of the pyrolysis oil feed (102) may have a concentration of sulfur and sulfur-containing compounds of less than 1000 parts per million (ppmw) by weight, for example, less than 500 ppmw, less than 400 ppmw, or even less than 300 ppmw, as measured according to the test method of ASTM D2622. In an embodiment, the heavy pyrolysis oil (250) may have a concentration of sulfur and sulfur-containing compounds greater than 0 ppmw to 1000 ppmw, for example, from 300 ppmw to 1000 ppmw, or from 300 ppmw to 500 ppmw. In an embodiment, the heavy pyrolysis oil (250) may have a concentration of iron, nickel, or both of 100 ppmw or less, 50 ppmw or less, or 20 ppmw or less, as measured according to the test method of ASTM D2622. Characteristics for an exemplary embodiment of the heavy pyrolysis oil (250) obtained from the steam cracking of naphtha are provided in Table 1.

[0039]

[0040] As previously discussed, in an embodiment, the pyrolysis oil feed (102) may contain a diluent (104) (e.g., a light aromatic stream). Due to the high viscosity of the heavy pyrolysis oil (250) (dynamic viscosity > 10 mPa*s, or kinetic viscosity > 10 mm² / s), the diluent (104) may be added to increase the fluidity of the pyrolysis oil feed (102). When the diluent (104) is included in the pyrolysis oil feed (102), the contact of the pyrolysis oil feed (102) with the surface of the treatment catalyst (119) and the mixed metal oxide catalyst (112) in the first fixed-bed reactor (110) may be increased. The diluent (104) may include, but is not limited to, light pyrolysis oil, benzene, mixed xylene, toluene, ethylbenzene, or a combination thereof. As illustrated in FIG. 3, in an embodiment, the diluent (104) may include light pyrolysis oil (350) derived from the bottom stream of a hydrocarbon gas steam cracker.

[0041] The characteristics of a diluent (104) containing light pyrolysis oil (350) from a hydrocarbon gas steam cracking system are provided in Table 1. In an embodiment, the light pyrolysis oil (350) may have a density of less than 0.98 g / cm³, for example 0.97 g / cm³ or less, 0.96 g / cm³ or less, 0.92 g / cm³ to 0.978 g / cm³, or 0.92 g / cm³ to 0.97 g / cm³ at 15°C, which is measured from the test method of ASTM D5002. In an embodiment, the light pyrolysis oil (350) may have a dynamic viscosity of 5 millipascal seconds (mPa*s) or less at 60°C, for example 4 mPa*s or less, 0.5 mPa*s to 5 mPa*s, 1 mPa*s to 4 mPa*s, or 1 mPa*s to 2 mPa*s, and the dynamic viscosity is measured according to the test method of ASTM D7042. In an embodiment, the light pyrolysis oil (350) may have a kinematic viscosity of 5 square millimeters (mm² / s) or less per second at 60°C, for example, 4 mm² / s or less, 2 mm² / s or less, 0.5 mm² / s to 5 mm² / s, 0.5 mm² / s to 4 mm² / s, 1 mm² / s to 5 mm² / s, or 1 mm² / s to 2 mm² / s, as measured according to the test method of ASTM D7042.

[0042] In an embodiment, the light pyrolysis oil (350) may have an initial boiling point temperature (IBP) of 120°C or less, for example, less than 100°C, 40°C to 120°C, or 50°C to 100°C, as measured according to the test method of ASTM D2887. In an embodiment, the light pyrolysis oil (350) may have a final boiling point temperature (FBP) of less than 500°C, for example, less than 450°C, 400°C or less, 250°C to less than 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 measured according to the test method of ASTM D2887. In an embodiment, the light pyrolysis oil (350) may have a 50% boiling point temperature of less than 230°C, 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, as measured according to the test method of ASTM D2887.

[0043] The light pyrolysis oil (350) of the pyrolysis oil feed (102) may have low concentrations of sulfur and sulfur compounds. The light pyrolysis oil (350) may have a concentration of sulfur and sulfur-containing compounds of 500 parts per million (ppmw) or less by weight, for example, 400 ppmw or less, or even 300 ppmw or less, as measured according to the test method of ASTM D2622. In an embodiment, the light pyrolysis oil (350) may have a concentration of sulfur and sulfur-containing compounds of greater than 0 ppmw to 500 ppmw, for example, 1 ppmw to 500 ppmw, 1 ppmw to 400 ppmw, or 1 to 300 ppmw. In an embodiment, the light pyrolysis oil (350) may have a concentration of iron, nickel, or both of 100 ppmw or less, 50 ppmw or less, 20 ppmw or less, or even 10 ppmw or less, for example, 0 ppmw or more to 100 ppmw or less, as measured according to the test method of ASTM D2622. Characteristics for an exemplary embodiment of the light pyrolysis oil (350) obtained from steam cracking of a light hydrocarbon gas stream are provided in Table 1.

[0044] The pyrolysis oil feed (102) may contain 10 wt.% to 90 wt.% of a diluent (104) based on the total weight of the pyrolysis oil feed (102). The diluent (104) may contain an aromatic compound having 6 to 8 carbon atoms in an amount of at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or even at least 99 wt.% based on the total hydrocarbon weight of the diluent (104). In an embodiment, the diluent (104) essentially consists of an aromatic compound having 6 to 8 carbon atoms, such as benzene, toluene, xylene, and combinations thereof. The pyrolysis oil feed (102) may include a diluent (104) in an amount of 10 wt.% to 80 wt.%, 10 wt.% to 70 wt.%, 10 wt.% to 60 wt.%, 10 wt.% to 40 wt.%, 10 wt.% to 30 wt.%, 10 wt.% to 20 wt.%, 15 wt.% to 90 wt.%, 15 wt.% to 75 wt.%, 15 wt.% to 60 wt.%, 15 wt.% to 45 wt.%, 15 wt.% to 30 wt.%, 15 wt.% to 25 wt.%, or a subset thereof, based on the total weight of the pyrolysis oil feed (102). In an embodiment, heavy pyrolysis oil (250) may be mixed with a diluent (104) (e.g., light pyrolysis oil (350)) upstream of a mixing unit (not shown) of a first fixed-bed reactor (110) to produce a pyrolysis oil feed (102), which may then be transferred to the first fixed-bed reactor (110). In an embodiment, the pyrolysis oil feed (102) may not contain the diluent added upstream of the heavy pyrolysis oil (250) of the first fixed-bed reactor (110). However, in this embodiment, the pyrolysis oil feed (102) may still contain toluene, xylene, or benzene that may be included from the process of producing the heavy pyrolysis oil (250).

[0045] In an embodiment, the pyrolysis oil feed (102) may comprise at least 50 wt.%, for example, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, at least 99 wt.%, 10 wt.% to 100 wt.%, 50 wt.% to 100 wt.%, 50 wt.% to 99 wt.%, 60 wt.% to 99 wt.%, 75 wt.% to 99 wt.%, 75 wt.% to 90 wt.%, 75 wt.% to 85 wt.%, or a subset thereof of heavy pyrolysis oil (250). In an embodiment, the pyrolysis oil feed (102) may comprise 75 wt.% to 85 wt.% of heavy pyrolysis oil (250) and 15 wt.% to 25 wt.% of a diluent (104) (e.g., light pyrolysis oil (350)). In an embodiment, the pyrolysis oil feed (102) may comprise 80 wt.% of heavy pyrolysis oil (250) and 20 wt.% of a diluent (104), and the diluent (104) comprises light pyrolysis oil (350), toluene, benzene, xylene, ethylbenzene, or a combination of these diluents. The pyrolysis oil feed (102) may contain a polycyclic aromatic compound having 16 or more carbon atoms in an amount of 30 wt.% or more, for example, 35 wt.% or more, 40 wt.% or more, 40 wt.% or more, 45 wt.% or more, or 50 wt.% or more, based on the total weight of the pyrolysis oil in the pyrolysis oil feed.

[0046] In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a density of 0.98 g / cm³ to 1.03 g / cm³, for example 0.98 g / cm³ to 1.02 g / cm³, 1.00 g / cm³ to 1.03 g / cm³, or 1.00 g / cm³ to 1.02 g / cm³ at 15°C, which is measured from the test method of ASTM D5002. In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a dynamic viscosity at 60°C of 5 mPa*s to 10 mPa*s, greater than 5.0 mPa*s to less than 10.0 mPa*s, 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, and the dynamic viscosity is ASTM It is measured according to the D7042 test method. In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a kinematic viscosity of 5.0 mm² / s to 10.0 mm² / s at 60°C, for example, 5.0 mm² / s to 9.5 mm² / s, 5.0 mm² / s to 9.0 mm² / s, 5.5 mm² / s to 10 mm² / s, 5.5 mm² / s to 9.5 mm² / s, 5.5 mm² / s to 9.0 mm² / s, 6.0 mm² / s to 10.0 mm² / s, 6.0 mm² / s to 9.5 mm² / s, or 6.0 mm² / s to 9.0 mm² / s, which is ASTM As measured according to the D7042 test method.

[0047] In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have an initial boiling point temperature (IBP) of 120°C to 150°C, e.g., 120°C to 145°C, 125°C to 150°C, or 125°C to 145°C, as measured according to the test method of ASTM D2887. In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a final boiling point temperature (FBP) of 500°C or higher, e.g. 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, which is ASTM As measured according to the test method of D2887. In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a 50% boiling point 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 measured according to the test method of ASTM D2887.

[0048] A pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have low concentrations of sulfur and sulfur compounds. A pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a concentration of sulfur and sulfur-containing compounds of 500 parts per million (ppmw) or less by weight, for example 400 ppmw or less, or even 300 ppmw or less, as measured according to the test method of ASTM D2622. In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a concentration of sulfur and sulfur-containing compounds greater than 0 ppmw to 500 ppmw, for example, 1 ppmw to 500 ppmw, 1 ppmw to 400 ppmw, or 1 to 300 ppmw. In an embodiment, a pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) may have a concentration of iron, nickel, or both of 100 ppmw or less, 50 ppmw or less, 20 ppmw or less, or even 10 ppmw or less, for example, greater than 0 ppmw to 100 ppmw or less, as measured according to the test method of ASTM D2622. In an embodiment, the pyrolysis oil feed (102) comprising a mixture of heavy pyrolysis oil (250) and light pyrolysis oil (350) as a diluent (104) has the characteristics and composition provided in Table 1. Referring again to FIG. 1, in an embodiment, the pyrolysis oil feed (102) may further comprise a bottom recirculation stream (150) from a separation unit (140) placed downstream of the second fixed-bed reactor (120).

[0049] Referring again to FIG. 2, a naphtha steam cracking system (200) for producing heavy pyrolysis oil may include a naphtha steam cracking unit (210) upstream of a first fixed-bed reactor (110) of the system (100). The naphtha steam cracking unit (210) may provide at least a portion of the pyrolysis oil feed (102). In an embodiment, a naphtha feed stream (204) may be transferred to the naphtha steam cracking unit (210). The naphtha feed stream (204) may include hydrocarbons having a boiling point temperature in the range of 30°C to 225°C in naphtha. The naphtha feed stream (204) may include hydrocarbons having 5 to 12 carbon atoms. FIG. 2 illustrates one embodiment of the naphtha steam cracking unit (210), but steam cracking units of other configurations are considered. The naphtha steam cracking unit (210) may include a convection zone (220) and a pyrolysis zone (222). A naphtha feed stream (204) may be moved to the convection zone (220) along with steam (206). In the convection zone (220), a mixture of naphtha and steam may be preheated to a desired temperature. The contents of the convection zone (220) may then be moved to the pyrolysis zone (222), where hydrocarbons from the naphtha feed stream (204) are steam cracked. The steam-cracking naphtha effluent stream (230) may exit the naphtha steam cracking unit (210) and pass through a separation unit (240). The steam-cracking naphtha effluent stream (230) may contain a mixture of cracked hydrocarbon materials, which may be separated into one or more petrochemical products included in one or more system product streams. The separation unit (240) may be any unit operation or multiple unit operations capable of separating heavy pyrolysis oil (250) from the gas stream (242).In an embodiment, the separation unit (240) may be further operable 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 feed (102).

[0050] Depending on the embodiment, the pyrolysis zone (222) may be operated at a temperature of 750°C to 1000°C or 800°C to 950°C. The pyrolysis zone (222) may 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.

[0051] Now, referring to FIG. 3, heavy pyrolysis oil (250) from the naphtha steam cracking system (200) can be combined with light pyrolysis oil (350) from the gas steam cracking system (300) upstream of the system (100). The naphtha steam cracking system (200) and the gas steam cracking system (300) can be operated in parallel and both can be positioned upstream of the first fixed-bed reactor (110) of the system (100). The naphtha steam cracking system (200) may have any of the features or characteristics previously discussed herein for the naphtha steam cracking system (200). The gas steam cracking system (300) may include a gas steam cracking unit (310). In an embodiment, a gas supply stream (304) may be transferred to the gas steam cracking unit (310). The gas supply stream (304) may contain hydrocarbons having a boiling point temperature of 50°C or less, or 30°C or less. The gas supply stream (304) may contain hydrocarbons having five or fewer carbon atoms, or four or fewer carbon atoms. The gas steam cracking unit (310) may include a convection zone (320) and a pyrolysis zone (322). The gas supply stream (304) may be moved to the convection zone (320) together with steam (306). In the convection zone (320), a mixture containing the gas supply stream (304) and steam (306) may be preheated to a desired temperature. Subsequently, the contents of the convection zone (320) may be moved to the pyrolysis zone (322), where they are steam cracked. The gas steam cracker outflow stream (330) may exit the gas steam cracking unit (310) and pass through the separation unit (340). The gas steam cracker outflow stream (330) may contain a mixture of cracked hydrocarbon materials, which may be separated into one or more petrochemical products included in one or more system product streams.The separation unit (340) may be any unit operation or a plurality of unit operations capable of separating the gas steam cracker effluent stream (330) into a light gas stream (342), at least one product stream (344), and light pyrolysis oil (350). In an embodiment, at least one product stream (344) may be an olefin product stream. The light pyrolysis oil (350) may be combined with heavy pyrolysis oil (250) to form a pyrolysis oil feedstock (102).

[0052] According to one or more embodiments, the pyrolysis zone (322) may be operated at a temperature of 750°C to 1000°C or 800°C to 950°C. The pyrolysis zone (322) may be operated with a residence time of 0.05 seconds to 2 seconds. The mass ratio of steam (306) to gas supply stream (304) may be about 0.3:1 to about 2:1. FIGS. 2 and FIGS. 3 illustrate one embodiment of a naphtha steam cracking system (200) and a gas steam cracking system (300), but steam cracking units of other configurations for producing heavy pyrolysis oil (250), light pyrolysis oil (350), or a combination thereof, which are similar but not limited to steam cracking systems for steam cracking crude oil, light hydrocarbon gas streams, gas condensates, atmospheric residue oil, vacuum distillation residue oil, vacuum gas oil, or other heavy oils, are considered.

[0053] Referring again to FIG. 1, the pyrolysis oil feed (102) can be transferred to a first fixed-bed reactor (110). The first fixed-bed reactor (110) can be operated to produce an intermediate stream (118) by contacting the pyrolysis oil feed (102) with hydrogen (116) in the presence of a treatment catalyst (119) in a first catalyst layer (111) followed by a mixed metal oxide catalyst (112) in a second catalyst layer (115). Contacting the pyrolysis oil feed (102) with hydrogen (116) in the presence of a treatment catalyst (119) followed by a mixed metal oxide catalyst (112) can convert at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102) into di-aromatic compounds, tri-aromatic compounds, or both. Hydrogen (116) may include a recirculated hydrogen stream or supplemental hydrogen from an external hydrogen source located inside or outside the battery limits of the refinery. Hydrogen (116) may be transferred directly to the first fixed-bed reactor (110) or combined with a pyrolysis oil feed (102) upstream of the first fixed-bed reactor (110). Hydrogen (116) may be used to pressurize the first fixed-bed reactor (110) to an operating pressure.

[0054] The first fixed-bed reactor (110) is a fixed-bed reactor comprising at least a first catalyst layer (111) and a second catalyst layer (115). The second catalyst layer (115) may comprise a packed layer of mixed metal oxide catalyst (112). Hydrogen may flow in parallel or countercurrently with the pyrolysis oil feed (102). In an embodiment, hydrogen may flow in parallel with the pyrolysis oil feed (102). For example, hydrogen may be introduced along with the flowing pyrolysis oil feed (102). In an embodiment, hydrogen may flow countercurrently, for example, by infiltrating or bubbling across the first fixed-bed reactor (110) as the pyrolysis oil feed (102) flows downward across the first fixed-bed reactor (110). The first fixed-bed reactor (110) may be a continuous reactor. In an embodiment, the first fixed-bed reactor (110) may include one or more fixed-bed reactors. If the first fixed-bed reactor (110) includes more than one fixed-bed reactor, the more fixed-bed reactors may be operated in series, in parallel, or in a combination thereof. In an embodiment, the first fixed-bed reactor (110) may include more than one fixed-bed reactor in parallel, and each of the first fixed-bed reactors (110) includes a first catalyst layer (111) and a second catalyst layer (115).

[0055] Referring to FIG. 1, the first catalyst layer (111) includes a treatment catalyst (119). The treatment catalyst (119) may be a first treatment catalyst (113), a second treatment catalyst (114), or a combination of these catalysts. The first catalyst layer (111) may include at least 50 wt.%, for example, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, at least 99 wt.%, or at least 99.9 wt.% of the treatment catalyst (119) based on the total weight of the catalyst of the first catalyst layer (111).

[0056] The first treatment catalyst (113) may include metal atoms comprising aluminum atoms, silicon atoms, molybdenum, nickel atoms, phosphorus atoms, or a combination thereof. In an embodiment, the metal atoms may be in the form of oxides (Al2O3, MoO, NiO, and P4O6). In an embodiment, the first treatment catalyst (113) may contain 52 wt.% to 74.5 wt.% of Al2O3. In an embodiment, the first treatment catalyst (113) may contain 10 wt.% to 15 wt.% of MoO. In an embodiment, the first treatment catalyst (113) may contain 3 wt.% to 5 wt.% of NiO. In an embodiment, the first treatment catalyst (113) may contain 0.5 wt.% to 3 wt.% of P4O6. In an embodiment, the first treatment catalyst (113) may comprise a binder, for example, 15 wt.% to 25 wt.% of the binder. The binder may comprise boehmite, clay, colloidal silica, or a combination thereof. In an embodiment, the first treatment catalyst (113) may comprise 52 wt.% to 74.5 wt.% of Al2O3, 15 wt.% to 25 wt.% of the binder, 10 wt.% to 15 wt.% of MoO, 3 wt.% to 5 wt.% of NiO, and 0.5 wt.% to 3 wt.% of P4O6, based on the total weight of the metal oxide of the first treatment catalyst. The weight percentage of the components of the first treatment catalyst (113) is calculated based on the total weight of the first treatment catalyst (113).

[0057] The second treatment catalyst (114) may include metal atoms comprising aluminum atoms, silicon atoms, zirconium atoms, nickel atoms, tungsten atoms, or a combination thereof. In an embodiment, the metal atoms may be in the form of oxides (Al2O3, SiO2, ZrO2, NiO, and WO3). In an embodiment, the second treatment catalyst (114) may include 18.5 wt.% to 21.5 wt.% of Al2O3. In an embodiment, the second treatment catalyst (114) may include 36.5 wt.% to 39.5 wt.% of SiO2. In an embodiment, the second treatment catalyst (114) may include 9.2 wt.% to 10.2 wt.% of ZrO2. In an embodiment, the second treatment catalyst (114) may comprise 10.5 wt.% to 11.5 wt.% of NiO. In an embodiment, the second treatment catalyst (114) may comprise 18.5 wt.% to 21.5 wt.% of WO3. In an embodiment, the second treatment catalyst (114) may comprise 18.5 wt.% to 21.5 wt.% of Al2O3, 36.5 wt.% to 39.5 wt.% of SiO2, 9.2 wt.% to 10.2 wt.% of ZrO2, 10.5 wt.% to 11.5 wt.% of NiO, and 18.5 wt.% to 21.5 wt.% of WO3. The weight percentage of the component of the second treatment catalyst is calculated based on the total weight of the second treatment catalyst (114).

[0058] The treatment catalyst (119) may include a first treatment catalyst (113), a second treatment catalyst (114), or a combination thereof. In an embodiment, the treatment catalyst (119) may include at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, or at least 95 wt.% of the first treatment catalyst (113) based on the total weight of the treatment catalyst (119). In an embodiment, the treatment catalyst (119) may include at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, or at least 95 wt.% of the second treatment catalyst (114) based on the total weight of the treatment catalyst (119). In an embodiment, the treatment catalyst (119) may comprise a combination of a first treatment catalyst (113) and a second treatment catalyst (114) in an amount of at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% based on the total weight of the treatment catalyst (119).

[0059] Generally, a first catalyst layer (111) upstream of a second catalyst layer (115) and containing a treatment catalyst (119) is believed to help protect the second catalyst layer (115) from excessive coke formation and clogging. Without being limited to theory, the first catalyst layer (111) upstream of a second catalyst layer (115) and containing a treatment catalyst (119) is believed to protect the second catalyst layer (115) from clogging by saturating the olefin under conditions less severe than those occurring in the second catalyst layer (115) (e.g., low temperature).

[0060] Subsequently, the reaction mixture may be transferred from a first catalyst layer (111) containing a treatment catalyst (119) to a second catalyst layer (115) containing a mixed metal oxide catalyst (112). The mixed metal oxide catalyst (112) may have catalytic activity for converting polycyclic aromatic compounds having 16 or more carbon atoms in the pyrolysis oil feed (102) into diaromatic compounds, triaromatic compounds, or a combination thereof. The mixed metal oxide catalyst (112) may comprise a plurality of mixed metal oxide (MMO) particles. Each of the plurality of MMO particles may comprise a plurality of different metal oxides. The plurality of metal oxides of the MMO particles may comprise oxides of metals belonging to groups 3 through 13 of the International Union of Pure and Applied Chemistry (IUPAC) periodic table. In an embodiment, the plurality of metal oxides of the MMO particles may comprise a combination of oxides of iron, zirconium, cerium, aluminum, tungsten, molybdenum, and titanium. In addition, MMO particles may include metalloid oxides such as silicon oxide. MMO particles may include metal or metalloid oxides 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 of these metal oxides.

[0061] The MMO particles of the mixed metal oxide catalyst (112) may include iron oxide as one of a plurality of metal oxides. In an embodiment, the MMO particles may include 60 wt.% to 95 wt.% iron oxide, for example, 70 wt.% to 90 wt.%, 75 wt.% to 85 wt.%, or 80 wt.% to 85 wt.% iron oxide. The MMO particles may include zirconium oxide as one of a plurality of metal oxides. In an embodiment, the MMO particles may include 1 wt.% to 20 wt.% zirconium oxide, for example, 1 wt.% to 15 wt.%, 2.5 wt.% to 12.5 wt.%, or 5 wt.% to 10 wt.% zirconium oxide. The MMO particles may include cerium oxide as one of a plurality of metal oxides. In an embodiment, the MMO particles may comprise 0.1 wt.% to 10 wt.% cerium oxide, for example, 0.5 wt.% to 7.5 wt.%, 0.5 wt.% to 5 wt.%, or 1 wt.% to 5 wt.% cerium oxide. The MMO particles may comprise aluminum oxide (alumina) as one of a plurality of metal oxides. In an embodiment, the MMO particles may comprise 1 wt.% to 20 wt.% aluminum oxide (alumina), for example, 2.5 wt.% to 15 wt.%, 3 wt.% to 12.5 wt.%, or 5 wt.% to 10 wt.% alumina. The weight percentage of the plurality of metal oxides of the MMO particles is based on the total weight of the MMO particles. The MMO particles may comprise, consist of, or essentially consist of 60 wt.% to 95 wt.% iron oxide, 1 wt.% to 20 wt.% zirconium oxide, 0.1 wt.% to 10 wt.% cerium oxide, and 1 wt.% to 20 wt.% aluminum oxide (alumina). In an embodiment, the MMO particles may comprise 83 wt.% iron oxide, 7.5 wt.% zirconium oxide, 2.5 wt.% cerium oxide, and 7.0 wt.% aluminum oxide (alumina).In an embodiment, the MMO particles do not contain silica. In an embodiment, the MMO particles may comprise a plurality of metal oxides mixed and fused or aggregated together to form MMO particles comprising a homogeneous solid mixture of metal oxides instead of one or more metal oxides deposited on the surface of a support material. The MMO particles may be prepared by a co-precipitation method to produce MMO particles comprising each of a plurality of different metal oxides distributed across the MMO particles. After co-precipitation, the MMO particles may be ground into a powder to form a powder.

[0062] MMO particles are 20 nm to 200 nm, e.g. 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 of a subset thereof. It may include nanoparticles that can have a diameter. In some embodiments, the MMO particles may be non-porous. Without being limited to theory, it is believed that hydrocarbons can interact only with the surface of the MMO particles. Therefore, the increased surface area provided by the nanoparticle characteristics of the mixed metal oxide catalyst can help achieve a sufficient reaction rate.

[0063] MMO particles in powder form can be combined with, extruded, and calcined with a binder material, an extrusion additive, or other materials, such as but not limited to, other materials, to form a mixed metal oxide catalyst (112) in the form of catalyst pellets. In an embodiment, MMO particles in powder form can be combined and mixed with a binder material and methylcellulose to produce a solid mixture.

[0064] The binder material may include silica, alumina, silica-alumina, clay, or any combination thereof. Alumina may include acid-peptided alumina. Silica-alumina may include amorphous silica-alumina. Clay may include, but is not limited to, kaolin, montmorillonite, halloysite, bentonite, or a combination thereof. In an embodiment, the binder material may include bentonite, silica, or a combination thereof. In an embodiment, the mixed metal oxide catalyst (112) may include bentonite as a binder. Methylcellulose may be added to the solid mixture to facilitate extrusion, but may be burned during the calcination process. Thus, the mixed metal oxide catalyst (112) pellet may include, be composed of, or essentially consist of MMO particles and a binder.

[0065] The dry components, MMO particles, binder, and methylcellulose, can be well mixed to produce a solid mixture. In an embodiment, the solid mixture may comprise 50 wt.% to 90 wt.% of MMO particles based on the total weight of the solid mixture, for example, 50 wt.% to 85 wt.%, 50 wt.% to 80 wt.%, 60 wt.% to 90 wt.%, 60 wt.% to 85 wt.%, 60 wt.% to 80 wt.%, 65 wt.% to 90 wt.%, 65 wt.% to 85 wt.%, 65 wt.% to 80 wt.%, 70 wt.% to 90 wt.%, 70 wt.% to 85 wt.%, 70 wt.% to 80 wt.%, or about 75 wt.% of MMO particles based on the total weight of the dry solid mixture. In an embodiment, the solid mixture comprises about 10 wt.% to 50 wt.% of a binder based on the total weight of the dry solid mixture, for example, 10 wt.% to 49.9 wt.%, 10 wt.% to 40 wt.%, 10 wt.% to 35 wt.%, 10 wt.% to 30 wt.%, 10 wt.% to 25 wt.%, 15 wt.% to 50 wt.%, 15 wt.% to 49.9 wt.%, 15 wt.% to 40 wt.%, 15 wt.% to 35 wt.%, 15 wt.% to 30 wt.%, 15 wt.% to 25 wt.%, 20 wt.% to 50 wt.% based on the total weight of the dry solid mixture. It may contain 20 wt.% to 49.9 wt.%, 20 wt.% to 40 wt.%, 20 wt.% to 35 wt.%, 20 wt.% to 30 wt.%, 20 wt.% to 25 wt.%, or 24 wt.% to 25 wt.% of a binder. In an embodiment, the solid mixture may contain 0.01 wt.% to 2 wt.% methylcellulose based on the total weight of the dry solid mixture, for example, 0.01 wt.% to 1 wt.%, 0.1 wt.% to 2 wt.%, 0.1 wt.% to 1 wt.%, or about 0.1 wt.% methylcellulose.In an embodiment, the dry mixture may comprise about 75 wt.% of MMO particles, about 24.9 wt.% of binder material, and about 0.1 wt.% of methyl cellulose based on the total weight of the dry solid mixture.

[0066] The dry solid mixture can be thoroughly mixed to produce a homogeneous solid mixture, for example, by mixing with a mortar and pestle, or by using automatic mixing equipment such as a V-blender, a Schugie mixer, or other powder mixing devices, but not limited thereto. After mixing, water can be added to the dry solid mixture to form an extrudable paste. In an embodiment, about 1.5 mL of water per gram of dry material can be added to the dry solid mixture to form an extrudable paste.

[0067] Subsequently, an extrudable paste comprising MMO particles, a binder, methylcellulose, and water can be extruded from an extruder. In an embodiment, the extrudable paste can be inserted into the syringe of a syringe pump. Alternatively, other pressurizing devices, such as peristaltic pumps, screw extruders, twin-screw extruders, etc., may be used to apply pressure to the paste. The pressurized paste can be pressurized through an extrusion die to form an extruder comprising extruded strands. The extrusion die and the resulting extruder may have a circular cross-section, or any other cross-sectional shape such as a star shape, square shape, hexagonal shape, trilobate shape, daisy shape, cylindrical shape, 7-hole shape, or donut shape. The extrusion die and the resulting extruder may have a diameter of 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 a subset thereof.

[0068] After extrusion, the extruded product can be dried and calcined. The extruded strand can be cut into a certain length to form pellets before drying, after drying and before or after calcination. Generally, since the presence of an excess amount of water in the catalyst particles increases vapor pressure during or after calcination and can weaken or damage the catalyst, it is desirable to dry the extruded strand or pellet before calcination.

[0069] The extruded strand or pellet may be dried at an elevated temperature. In an embodiment, the extruded strand or pellet may be dried at 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 a subset thereof. The extruded strand or pellet may be dried at an elevated 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 a subset thereof.

[0070] After drying, the dried strand or pellet of the extruder may be calcined. In an embodiment, the dried strand or pellet of the extruder may be calcined at a temperature of at least 400°C, e.g., 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 a subset thereof. The dried strand or pellet may be calcined for at least 1 hour, e.g., at least 1.5 hours, 1 hour to 5 hours, 1 hour to 3 hours, 1.5 hours to 2.5 hours, or a subset thereof. The calcination atmosphere may include an oxygen-containing gas such as air. If not performed before calcination, the calcined strand may be broken and sieved to produce a mixed metal oxide catalyst (112) in pellet form.

[0071] The pellet of the mixed metal oxide catalyst may comprise MMO particles and a binder. The pellet of the mixed metal oxide catalyst may also comprise any calcination residue from methylcellulose. The MMO particles each comprise Fe2O3, ZrO2, CeO2, and Al2O3. In an embodiment, the pellet of the mixed metal oxide catalyst may comprise 65 wt.% to 85 wt.%, 65 wt.% to 80 wt.%, 70 wt.% to 85 wt.%, 70 wt.% to 80 wt.%, 75 wt.% to 85 wt.%, 75 wt.% to 80 wt.%, 80 wt.% to 85 wt.%, or about 75 wt.% of MMO particles based on the total weight of the mixed metal oxide catalyst, and the remainder is binder material and calcination residue of methylcellulose. In an embodiment, the mixed metal oxide catalyst may comprise 15 wt.% to 35 wt.%, 15 wt.% to 30 wt.%, 15 wt.% to 25 wt.%, 20 wt.% to 35 wt.%, 20 wt.% to 30 wt.%, 20 wt.% to 25 wt.%, 25 wt.% to 35 wt.%, 25 wt.% to 30 wt.%, or about 25 wt.% of a binder material based on the total weight of the mixed metal oxide catalyst. The concentration of methylcellulose residue in the mixed metal oxide catalyst may be less than 0.1 wt.%, less than 0.05 wt.%, or even 0.01 wt.% or less based on the total weight of the mixed metal oxide catalyst. In an embodiment, the pellet of the mixed metal oxide catalyst may comprise at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, at least 99 wt.%, or even at least 99.9 wt.% of Fe2O3, ZrO2, CeO2, and Al2O3, and a binder material based on the total weight of the mixed metal oxide catalyst. In an embodiment, the mixed metal oxide catalyst may comprise 75 wt.% of MMO particles and 25 wt.% of a binder material.

[0072] The pellets of the mixed metal oxide catalyst (112) may have a pellet diameter of, for example, 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 a subset thereof. In an embodiment, the pellets of the mixed metal oxide catalyst (112) may be cylindrical having a pellet diameter and a pellet length. The pellet length may be about 2 mm to about 4 mm.

[0073] Referring again to FIG. 1, if a pyrolysis oil feed (102) in a first fixed-bed reactor (110) is contacted with hydrogen (116) under reaction conditions in the presence of a treatment catalyst (119) in a first catalyst layer (111) and then in the presence of a mixed metal oxide (112) in a second catalyst layer (115), at least a portion of the polycyclic aromatic compounds in the pyrolysis oil feed (102) can be converted into di-aromatic compounds, tri-aromatic compounds, or both in a single step without performing a subsequent chemical reaction step. Converting at least a portion of the polycyclic aromatic compounds into lighter aromatic compounds including di-aromatic compounds, tri-aromatic compounds, or both is a complex reaction system comprising a number of simultaneous and selective reactions that may include selective hydrogenation of only one aromatic ring of the compound, subsequent ring opening of a saturated tetra-aromatic compound, hydrodealkylation, transalkylation, and disproportionation reactions. Without being bound by any specific theory, the upgrading of the pyrolysis oil feedstock (102) is considered to involve the selective hydrogenation of at least one aromatic ring structure or polycyclic aromatic compound to produce a molecule having one or more aromatic rings and at least one saturated ring. Subsequently, the saturated ring portion may produce a substituted aromatic compound by a ring-opening reaction. Subsequently, the substituted aromatic compound may produce a mono-aromatic compound, a di-aromatic compound, and / or a tri-aromatic compound by one or more of hydroalkylation, transalkylation, or disproportionation reactions. It should be understood that various variations and combinations of these reactions as well as other chemical reactions may occur during the upgrading process. This complex series of simultaneous reactions for upgrading the pyrolysis oil feedstock (102) may be catalyzed using a mixed metal oxide catalyst (112).

[0074] The first fixed-bed reactor (110) can produce an intermediate stream (118) by contacting the pyrolysis oil feed (102) with hydrogen (116) under mild operating conditions sufficient to upgrade at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102) in the presence of a treatment catalyst (119) in the first catalyst layer (111) and a mixed metal oxide catalyst (112) in the second catalyst layer (115), wherein the intermediate stream (118) comprises di-aromatic compounds, tri-aromatic compounds, or both. The first fixed-bed reactor (110) can be operated at an operating temperature range of 200°C to 400°C, e.g., 250°C to 400°C, 250°C to 300°C, 300°C to 350°C, 350°C to 400°C, or any combination of one or more of these ranges. The first fixed-bed reactor (110) is 1 megapascal (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), 12 MPa (120 bar) to 18 MPa (180 bar), 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) It may be operated at an operating pressure of 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The first fixed-bed reactor (110) may be operated at a volume ratio of hydrogen (116) to pyrolysis oil feed (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) is 0.1 h. -1 to 1.2 h -1 , 0.1 h -1 to 1 h -1 , 0.1 h -1 to 0.8 h -1 , 0.1 h -1 to 0.6 h -1 , 0.2 h -1 to 0.4 h -1 , or a subset thereof, can be operated at a liquid hourly space velocity (LHSV). The first fixed-bed reactor (110) is 200 h -1 to 1500 h -1 , for example 200 h -1 to 1200 h -1 , 400 h -1 to 1200 h -1 , 600 h -1 to 1000 h -1 , 700 h -1 to 900 h -1 , or can be operated at a gas hourly space velocity (GHSV) of a subset thereof.

[0075] Now, referring to FIG. 1, the intermediate stream (118) may contain a diaromatic compound. The intermediate stream (118) may contain a diaromatic compound having 10 to 18 carbon atoms in a greater percentage than the pyrolysis oil feed (102). The intermediate stream (118) may contain a diaromatic compound having 10 to 18 carbon atoms (C10 to C18 aromatic compound), which includes any C10 to C18 aromatic compound in the diluent (104) added to the pyrolysis oil feed (102) and passed through the first fixed-bed reactor (110), in an amount of at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, or even at least 55 wt% based on the total weight of the intermediate stream (118). In addition to di-aromatic compounds, the intermediate stream (118) may also include unreacted hydrogen, unreacted pyrolysis oil components, light hydrocarbon gas, light aromatic compounds having 6 to 8 carbon atoms, tri-aromatic compounds, and combinations thereof, but not limited to other components. The di-aromatic compounds contained in the intermediate stream (118) may be moved to a second fixed-bed reactor (120) and hydrogenated 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 recirculated throughout the process.

[0076] Referring to FIG. 1, an intermediate stream (118) can be transferred from downstream of a first fixed-bed reactor (110) to a second fixed-bed reactor (120). In an embodiment, the intermediate stream (118) can be transferred directly from the first fixed-bed reactor (110) to the second fixed-bed reactor (120) without transferring intermediate unit operations that cause a chemical reaction or separate one or more components of the intermediate stream (118). The second fixed-bed reactor (120) can be operated to produce a second reactor effluent (130) by contacting the intermediate stream (118) with hydrogen (124) in the presence of a mesoporous supporting metal catalyst (122). When the intermediate stream (118) is brought into contact with hydrogen (124) in the presence of a mesoporous supporting metal catalyst (122), at least some of the di-aromatic compounds and / or tri-aromatic compounds in the intermediate stream (118) may react to form aromatic compounds having 6 to 8 carbon atoms. Unreacted hydrogen may be transferred from the first fixed-bed reactor (110) to the second fixed-bed reactor (120) as part of the intermediate stream (118). Additional hydrogen (124) may be added to the second fixed-bed reactor (120). The hydrogen (124) may include a recirculated hydrogen stream or supplementary hydrogen from an external hydrogen source located inside or outside the battery limit of the refinery. The hydrogen (124) may be transferred directly to the second fixed-bed reactor (120) or combined with the intermediate stream (118) upstream of the second fixed-bed reactor (120). Hydrogen (124) can be used to pressurize the second fixed-bed reactor (120) to an operating pressure.

[0077] The second fixed-bed reactor (120) is a fixed-bed reactor. The fixed-bed reactor may contain a mesoporous supporting metal catalyst (122) within the packed bed. Hydrogen may flow in parallel with the intermediate stream (118). In an embodiment, hydrogen may be permeated or bubbled across the packed bed. In an embodiment, the second fixed-bed reactor (120) may include one or more fixed-bed reactors. If the second fixed-bed reactor (120) includes more than one fixed-bed reactor, the more fixed-bed reactors may be operated in series, in parallel, or in a combination thereof.

[0078] The mesoporous supporting metal catalyst (122) may be operable to react at least a portion of the di-aromatic compounds and / or tri-aromatic compounds in the intermediate stream (118) to form an aromatic compound (BTEX) having 6 to 8 carbon atoms. The mesoporous supporting metal catalyst (122) may comprise a first metal catalyst, a second metal catalyst, and a mesoporous support. The mesoporous support may comprise a zeolite support component.

[0079] The zeolite support component may include ultra-stable Y-type (USY) zeolite, beta zeolite, or both. The beta zeolite may be nano-sized beta zeolite. The zeolite support component may have a ratio of USY zeolite to beta zeolite of 1:1 to 2:1. In an embodiment, the zeolite support component may have a ratio of USY zeolite to beta zeolite 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, 1.4:1 to 1.6:1, 1.45:1 to 1.55:1, or a subset thereof. In this embodiment, the ratio of USY zeolite to beta zeolite in the zeolite support component may be approximately 3:2.

[0080] The zeolite support component may have an average pore size sufficient to access reactive sites within the pores of the zeolite support component. The zeolite support component may have an average pore size of 2 nanometers (nm) or greater, 3 nm or greater, or 4 nm or greater as measured using the Barrett-Joiner-Halendar (BJH) method. The zeolite support component may have an average pore size of 40 nm or less, 30 nm or less, or even 25 nm or less as measured using the BJH method. In an embodiment, the zeolite support component may have an average pore size 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, or 8 nm to 25 nm, 3 nm to 6 nm, or a subset thereof, and the average pore size is measured using the BJH method. In an embodiment, the zeolite support component may have an average pore size of 3 nm to 6 nm. The specified pore size of the zeolite support component may apply to USY zeolite, beta zeolite, or both.

[0081] The molar ratio of silica (SiO2) to alumina (Al2O3) in the zeolite support component may be 10 or more, for example, 20 or more, 30 or more, 40 or more, 50 or more, or 60 or more. The molar ratio of SiO2 to Al2O3 in the zeolite support component may be 70 or less, for example, 60 or less, 50 or less, 40 or less, 30 or less, or even 20 or less. The molar ratio of SiO2 to Al2O3 in the zeolite support component may be 10 to 70. In an embodiment, the molar ratio of SiO2 to Al2O3 in the zeolite support component may be 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 specified molar ratio of silica to alumina in the zeolite support component may be applied to USY zeolite, beta zeolite, or both.

[0082] The zeolite support component may include particles, and the particles may have an average diameter of 2000 nm to 5000 nm measured based on their longest dimension. In an 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 a subset thereof, measured based on their longest dimension. In an embodiment, the microporous zeolite particles exist in a single-crystal structure. The specified particle size of the zeolite support component can be applied to USY zeolite, beta zeolite, or both.

[0083] The zeolite support component may have an average surface area of ​​at least 400 m² / g. In an embodiment, the zeolite support component may have an average surface area of ​​at least 425 m² / g, 400 m² / g to 450 m² / g, 400 m² / g to 440 m² / g, 400 m² / g to 430 m² / g, 400 m² / g to 420 m² / g, 410 m² / g to 450 m² / g, 420 m² / g to 450 m² / g, 430 m² / g to 45 m² / g, 410 m² / g to 440 m² / g, 420 m² / g to 430 m² / g, or a subset thereof. The surface area may be measured according to the Brunauer-Emmett-Teller (BET) method. The specified surface area of ​​the zeolite support component may apply to USY zeolite, beta zeolite, or both.

[0084] The zeolite support component may have an average pore volume of 0.3 ml / g to 0.6 ml / g as measured using the BJH method. In an embodiment, the zeolite support component may 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 a subset thereof. The specified pore volume of the zeolite support component may apply to USY zeolite, beta zeolite, or both.

[0085] In addition to the zeolite support component, the mesoporous support may further comprise a binder and large-pore alumina. The binder may comprise alumina such as acid-peptided alumina; clay or amorphous silica-alumina. In an embodiment, the binder may comprise acid-peptided alumina. Acid-peptided alumina suitable for use as a binder is marketed by Sasol Inc. under the trade name CATAPAL B.

[0086] Large pore alumina may have an average surface area of ​​at least 100 m² / g as measured by BET. In an embodiment, large pore alumina may have an average surface area of ​​at least 125 m² / g, at least 150, 100 m² / g to 300 m² / g, 125 m² / g to 300 m² / g, 150 m² / g, or a subset thereof. Large pore alumina may have an average BJH pore radius of at least 5 nm. In an embodiment, large pore alumina may 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 a subset thereof. Large pore alumina may 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.

[0087] The mesoporous support can be extruded into pellets. Subsequently, the pellets can be impregnated with a first metal catalyst and a second metal catalyst to produce a mesoporous support metal catalyst (122). The pellets can be formed by first preparing a binder paste. Subsequently, the binder paste can be mixed with dry catalyst components (zeolite and large pore alumina) to form a support paste. The support paste can be extruded to form a support extrude. The support extrude can be dried and calcined and impregnated with a first metal catalyst (Ni) and a second metal catalyst (W).

[0088] A binder paste can be formed by mixing an acid (e.g., nitric acid) with alumina binder particles. The binder paste can be uniform without visible large particles. The binder paste can then be mixed with large-pore alumina, USY zeolite, and nano-beta zeolite to form a support paste. The support paste can then be extruded to form a support extrude with a diameter of about 1 mm to 2 mm. The support extrude can then be dried, for example, at about 110°C for at least 12 hours. The support extrude can then be calcined in air at about 550°C for at least 4 hours at a ramp rate of about 2°C / min. Before or after calcination, the support extrude can be cut or broken into pellets with a length of about 2 mm to 4 mm. The support extrusion may have a circular cross-section or any other cross-sectional shape such as a star shape, square shape, hexagonal shape, trilobate shape, daisy shape, cylindrical shape, 7-hole shape, or donut shape.

[0089] A mesoporous supported metal catalyst (122) may be prepared from a mesoporous support by wet impregnating at least a first metal catalyst precursor and a second metal catalyst precursor onto the outer surface, the pore surface, or both of the mesoporous support. Wet impregnation of the first metal catalyst and the second metal catalyst into the mesoporous support may include the preparation of an aqueous metal solution comprising the first metal catalyst and the second metal catalyst. The first metal catalyst and the second metal catalyst may be introduced into water in the form of their hydrates (e.g., ammonium metatungstate (NH4) 10 (H2W 12 O 42)·xH2O and nickel nitrate hexahydrate Ni(NO3)2). The dried and calcined zeolite pellets can be immersed in a metal solution for a sufficient amount of time, for example, at least 3 hours, to be impregnated with the metal. The impregnated zeolite particles can be dried again at 110°C for 12 hours. The dried impregnated zeolite particles can be calcined again at, for example, about 500°C for about 4 hours (at a ramp rate of about 2°C / min). The dried impregnated zeolite particles can be calcined in air. Accordingly, the calcined impregnated zeolite particles can form a mesoporous supported metal catalyst (122) suitable for use in a fixed-bed reactor.

[0090] The mesoporous supporting metal catalyst (122) may comprise 40 wt.% to 60 wt.% of a zeolite support component. In an embodiment, the mesoporous supporting metal catalyst (122) may comprise a total zeolite comprising nano-beta zeolite and Y-type zeolite, comprising 40 wt.% to 55 wt.%, 40 wt.% to 50 wt.%, 45 wt.% to 60 wt.%, 50 wt.% to 60 wt.%, 45 wt.% to 55 wt.%, or a subset thereof, based on the total weight of the mesoporous supporting metal catalyst (122).

[0091] The mesoporous supporting metal catalyst (122) may comprise a binder in an amount of 10 wt.% to 20 wt.%, 12.5 wt.% to 20 wt.%, 15 wt.% to 20 wt.%, 17.5 wt.% to 20 wt.%, 10 wt.% to 17.5 wt.%, 10 wt.% to 15 wt.%, 10 wt.% to 12.5 wt.%, 12.5 wt.% to 17.5 wt.%, or a subset thereof, based on the total weight of the mesoporous supporting metal catalyst (122).

[0092] The mesoporous supporting metal catalyst (122) may comprise 2 wt.% to 10 wt.% of large pore alumina. In an embodiment, the mesoporous supporting metal catalyst (122) may comprise 2 wt.% to 8 wt.%, 2 wt.% to 6 wt.%, 2 wt.% to 4 wt.%, 4 wt.% to 10 wt.%, 6 wt.% to 10 wt.%, 8 wt.% to 10 wt.%, 4 wt.% to 8 wt.%, or a subset thereof of large pore alumina. As previously described, the mesoporous supporting metal catalyst (122) may comprise a first metal catalyst and a second metal catalyst supported on the mesoporous surface. The first metal catalyst may be a nickel catalyst. The nickel catalyst may exist as nickel oxide (NiO). In an embodiment, the mesoporous supporting metal catalyst (122) may comprise a first metal catalyst in an amount of 4 wt.% to 8 wt.%, 6 wt.% to 8 wt.%, 4 wt.% to 6 wt.%, 5 wt.% to 7 wt.%, or a subset thereof, based on the total weight of the mesoporous supporting metal catalyst (122).

[0093] The second metal catalyst may be a tungsten catalyst. The tungsten catalyst may exist as tungsten oxide (WO3). The mesoporous supporting metal catalyst (122) may comprise a second metal catalyst in an amount of 20 wt.% to 30 wt.%, 22 wt.% to 30 wt.%, 24 wt.% to 30 wt.%, 26 wt.% to 30 wt.%, 28 wt.% to 30 wt.%, 20 wt.% to 28 wt.%, 20 wt.% to 26 wt.%, 20 wt.% to 24 wt.%, 20 wt.% to 22 wt.%, 22 wt.% to 28 wt.%, 24 wt.% to 26 wt.%, or a subset thereof, based on the total weight of the mesoporous supporting metal catalyst (122).

[0094] The mesoporous supporting metal catalyst (122) may have a surface area of ​​200 m² / g to 400 m² / g as measured by BET. In an embodiment, the mesoporous supporting metal catalyst (122) may have a surface area of ​​200 m² / g to 350 m² / g, 200 m² / g to 300 m² / g, 200 m² / g to 250 m² / g, 250 m² / g to 400 m² / g, 300 m² / g to 400 m² / g, 350 m² / g to 400 m² / g, 250 m² / g to 350 m² / g, or a subset thereof as measured by BET. The mesoporous supporting metal catalyst (122) may have a pore volume of 0.4 ml / g to 0.7 ml / g. In an embodiment, the mesoporous supporting metal catalyst (122) may 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, 0.5 ml / g to 0.6 ml / g, or a subset thereof. The mesoporous supporting metal catalyst (122) may have an average pore size of 6 nm to 10 nm. In an embodiment, the mesoporous supporting metal catalyst (122) may have an average pore size 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 a subset thereof.

[0095] Referring again to FIG. 1, if the intermediate stream (118) is brought into contact with hydrogen (124) under reaction conditions in the presence of a mesoporous supporting metal catalyst (122) in a second fixed-bed reactor (120), at least a portion of the di-aromatic compound, tri-aromatic compound, or both in the intermediate stream (118) can be reacted in a single step without performing a subsequent chemical reaction step to form a light aromatic compound having 6 to 8 carbon atoms. Converting at least a portion of the di-aromatic compound and / or tri-aromatic compound in the intermediate stream into an aromatic compound having 6 to 8 carbon atoms is also a complex reaction scheme comprising a number of simultaneous and selective reactions, which may include selective hydrogenation of one of the aromatic rings of the compound, subsequent ring opening of a saturated naphthenic ring, hydrodealkylation, transalkylation, and disproportionation reactions. Without being bound by any specific theory, the upgrade of the intermediate stream (118) is considered to involve the selective hydrogenation of at least one aromatic ring structure of a polycyclic aromatic compound, for example, a di-aromatic compound of the intermediate stream (118), to produce a molecule having one aromatic ring and at least one saturated ring. Subsequently, the saturated ring may undergo ring opening to produce a substituted aromatic compound. It should be understood that various variations and combinations of these reactions, as well as other chemical reactions, may occur during the upgrade process in the second fixed-bed reactor (120). This complex series of simultaneous reactions for the upgrade of the intermediate stream (118) may be catalyzed using a mesoporous supporting metal catalyst (122).

[0096] The second fixed-bed reactor (120) can bring the intermediate stream (118) into contact with hydrogen (124) under mild operating conditions sufficient for at least some of the di-aromatic compounds and / or tri-aromatic compounds in the intermediate stream (118) to react to form an aromatic compound having 6 to 8 carbon atoms in the presence of a mesoporous supporting metal catalyst (122). The second fixed-bed reactor (120) can be operated at an operating temperature in the range of 200°C to 400°C, for example 250°C to 400°C, 250°C to 300°C, 300°C to 400°C, or any combination of these ranges. The second fixed-bed reactor (120) can be operated at an operating pressure of 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) is 0.3 h -1 to 1.5 h -1 , for example, 0.5 h -1 to 1.5 h -1 , 0.9 h -1 to 1.4 h -1 , 0.9 h -1 to 1.3 h -1 , 0.9 h -1 to 1.2 h -1 , 1.0 h -1 to 1.5 h -1 , 1.1 h -1 to 1.5 h -1 , 1.2 h -1 to 1.5 h-1 , 1.0 h -1 to 1.4 h -1 , 1.1 h -1 to 1.3 h -1 , or can be operated at an LHSV of a subset thereof. The second fixed-bed reactor (120) is 200 h -1 to 1500 h -1 , for example 200 h -1 to 1200 h -1 , 400 h -1 to 1200 h -1 , 600 h -1 to 1000 h -1 , 700 h -1 to 900 h -1 , about 800 h -1 , or can be operated on a subset of these GHSVs.

[0097] The second fixed-bed reactor (120) may produce a second reactor effluent (130). The second reactor effluent (130) may contain an aromatic compound having 6 to 8 carbon atoms. The aromatic compound having 6 to 8 carbon atoms may include benzene, toluene, ethylbenzene, xylene, or a combination thereof. The second reactor effluent (130) may also contain unreacted components of the pyrolysis oil feed (102), the intermediate stream (118), or both, for example, unretreated heavy aromatic compounds. The second reactor effluent (130) may contain a product that is liquid at room temperature, at least 50 wt.%, for example, at least 60 wt.%, at least 70 wt.%, at least 73 wt.%, 50 wt.% to 80 wt.%, 60 wt.% to 80 wt.%, 70 wt.% to 80 wt.%, based on the total weight of the second reactor effluent (130). Based on the total weight of the second reactor effluent (130), at least 20 wt.%, for example, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, 20 wt.% to 70 wt.%, 30 wt.% to 70 wt.%, 70 wt.% to 70 wt.%, 45 wt.% to 70 wt.% may comprise an aromatic compound having 6 to 8 carbon atoms.

[0098] Referring again to FIG. 1, the system (100) may include a separation unit (140) positioned downstream of the second fixed-bed reactor (120). A method for upgrading the pyrolysis oil feed (102) may include separating the second reactor effluent (130) in the separation unit (140) into at least a BTEX product stream (144) and a residue oil bottom stream (146). In an embodiment, the method may further include separating a light gas stream (142) from the second reactor effluent (130). The separation unit (140) may be any unit operation capable of separating the BTEX product stream (144) from the residue oil bottom stream (146). In an embodiment, the separation unit (140) may be a separation unit capable of separating the light gas stream (142) from the second reactor effluent (130).

[0099] The light gas stream (142) may contain gas. In an embodiment, the light gas stream (142) may contain hydrogen and C1-C4 hydrocarbons such as but not limited to methane, ethane, ethylene, propane, propylene, butane, butene, or other light hydrocarbons. In an embodiment, the light gas stream (142) may contain at least 80 wt.%, e.g., at least 90 wt.%, at least 95 wt.%, or even at least 99 wt.% of the combined weight of hydrogen and C1-C4 hydrocarbons based on the total mass flow rate of the light gas stream (142).

[0100] The BTEX product stream (144) may contain light aromatic compounds such as benzene, toluene, ethylbenzene, and xylene. In an embodiment, the BTEX product stream (144) may contain at least 80 wt.%, e.g., at least 90 wt.%, at least 95 wt.%, or even at least 99 wt.% of light aromatic compounds based on the total mass flow rate of the BTEX product stream (144).

[0101] The residue oil bottom stream (146) may contain polycyclic aromatic compounds, di-aromatic compounds, and tri-aromatic compounds. In an embodiment, all or part of the residue oil bottom stream (146) may be fed back to the first fixed-bed reactor (110) as a bottom recirculation stream (150).

[0102] Now, referring to FIG. 5, in an embodiment, the first fixed-bed reactor (110) may include a first catalyst layer (111) containing a first treatment catalyst (113) and a second catalyst layer (115) containing a mixed metal oxide catalyst (112). The mixed metal oxide catalyst (112) may be in a separate layer from the first treatment catalyst (113) within the first fixed-bed reactor (110). The first catalyst layer (111) containing the first treatment catalyst (113) may be placed upstream of the second catalyst layer (115) containing the mixed metal oxide catalyst (112). When passing through the first fixed-bed reactor (110), the pyrolysis oil feed (102) may encounter the first catalyst layer (111) containing the first treatment catalyst (113) before encountering the mixed metal oxide catalyst (112) in the second catalyst layer (115). Generally, it is believed that if a first catalyst layer (111) containing a first treatment catalyst (113) is present upstream of a second catalyst layer (115) containing an MMO catalyst (112), it can help prevent the formation of an excess amount of coke and the subsequent clogging of the reactor.

[0103] A pyrolysis oil feed (102) can be introduced into a first fixed-bed reactor (110). In the first fixed-bed reactor (110), the pyrolysis oil feed (102) can be converted at least a portion of the pyrolysis oil feed (102) by contacting a first treatment catalyst (113) in the presence of hydrogen (116) in the first catalyst layer (111). Subsequently, the generated reaction product and the unconverted pyrolysis oil feed can be moved from the first catalyst layer (111) to a second catalyst layer (115) and contacted with hydrogen in the first fixed-bed reactor (110) in the presence of hydrogen (116) in the presence of a mixed metal oxide catalyst (112) in the second catalyst layer (115). The hydrogen in the second catalyst layer (115) may include unreacted hydrogen that moves through the first catalyst layer (111) to the second catalyst layer (115). In an embodiment, the conditions under which the pyrolysis oil feed (102) contacts the mixed metal oxide catalyst (112) and the first treatment catalyst (113), respectively, are substantially the same. In an embodiment, the pyrolysis oil feed (102) may contact the first treatment catalyst (113) at a peak temperature lower than the peak temperature of contact in the second catalyst layer (115) in the first catalyst layer (111). In an embodiment, the difference in peak temperature between the second catalyst layer (115) and the first catalyst layer (111) may be at least 30°C, for example, at least 40°C, at least 50°C, or at least 60°C. In an embodiment, the difference in peak temperature between the second catalyst layer (115) and the first catalyst layer (111) may be 30°C to 80°C, for example, 30°C to 60°C, 30°C to 40°C, 40°C to 50°C, 50°C to 60°C, 60°C to 80°C, or any combination of one or more of these ranges. Generally, it is believed that if the pyrolysis oil feed (102) is brought into contact with the first treatment catalyst (113) at a temperature lower than the temperature at which the pyrolysis oil feed (102) is brought into contact with the mixed metal oxide catalyst (112), coke formation and clogging of the first fixed-bed reactor (110) are reduced.

[0104] The first fixed-bed reactor (110) can produce an intermediate stream (118) by contacting the pyrolysis oil feed (102) with hydrogen (116) under mild operating conditions sufficient to upgrade at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102) in the presence of the first treatment catalyst (113) and subsequently the mixed metal oxide catalyst (112) downstream of the first treatment catalyst (113), and the intermediate stream (118) comprises di-aromatic and / or tri-aromatic compounds. The first fixed-bed reactor (110) can be operated at a Park temperature of 200°C to 400°C, for example, 250°C to 400°C, 250°C to 300°C, 300°C to 400°C, or any combination of these ranges. The first fixed-bed reactor (110) is 1 megapascal (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), 12 MPa (120 bar) to 18 MPa (180 bar), 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) It may be operated at an operating pressure of up to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The first fixed-bed reactor (110) may be operated at a volume ratio of hydrogen to the pyrolysis oil feed (102) at the inlet of the first fixed-bed reactor (110) 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) is 0.1 h -1to 1.2 h -1 , 0.1 h -1 to 1 h -1 , 0.1 h -1 to 0.8 h -1 , 0.1 h -1 to 0.6 h -1 , 0.2 h -1 to 0.4 h -1 , or a subset thereof, can be operated at a liquid hourly space velocity (LHSV). The first fixed-bed reactor (110) is 200 h -1 to 1500 h -1 , for example 200 h -1 to 1200 h -1 , 400 h -1 to 1200 h -1 , 600 h -1 to 1000 h -1 , or can be operated at a gas hourly space velocity (GHSV) of a subset thereof.

[0105] Now, referring to FIG. 6, in an embodiment, the first fixed-bed reactor (110) may include a first catalyst layer (111) containing a second treatment catalyst (114) and a second catalyst layer (115) containing a mixed metal oxide catalyst (112). The mixed metal oxide catalyst (112) may be in a separate layer from the second treatment catalyst (114) within the first fixed-bed reactor (110). The first catalyst layer (111) containing the second treatment catalyst (114) may be placed upstream of the second catalyst layer (115) containing the mixed metal oxide catalyst (112). When passing through the first fixed-bed reactor (110), the pyrolysis oil feed (102) may encounter the first catalyst layer (111) containing the second treatment catalyst before encountering the mixed metal oxide catalyst (112) in the second catalyst layer (115). Generally, it is believed that if a first catalyst layer (111) containing a second treatment catalyst (114) is present upstream of a second catalyst layer (115) containing an MMO catalyst (112), it can help prevent the formation of an excess amount of coke and the subsequent clogging of the reactor.

[0106] A pyrolysis oil feed (102) can be introduced into a first fixed-bed reactor (110). In the first fixed-bed reactor (110), the pyrolysis oil feed (102) can be contacted with a second treatment catalyst (114) in the presence of hydrogen (116) in a first catalyst layer (111) to convert at least a portion of the pyrolysis oil feed (102). The resulting reaction product and unconverted pyrolysis oil feed can then be moved from the first catalyst layer (111) to a second catalyst layer (115) to be contacted with hydrogen in the first fixed-bed reactor (110) in the presence of a mixed metal oxide catalyst (112) in the second catalyst layer (115). The hydrogen in the second catalyst layer (115) may include unreacted hydrogen that moves through the first catalyst layer (111) to the second catalyst layer (115). In an embodiment, the conditions under which the pyrolysis oil feed (102) contacts the mixed metal oxide catalyst (112) and the second treatment catalyst (114), respectively, are substantially the same. In an embodiment, the pyrolysis oil feed (102) may contact the second treatment catalyst (114) at a peak temperature lower than the peak temperature of contact in the second catalyst layer (115) from the first catalyst layer (111). In an embodiment, the difference in peak temperature between the second catalyst layer (115) and the first catalyst layer (111) may be at least 30°C, for example, at least 40°C, at least 50°C, or at least 60°C. In an embodiment, the difference in peak temperature between the second catalyst layer (115) and the first catalyst layer (111) may be 30°C to 80°C, for example, 30°C to 60°C, 30°C to 40°C, 40°C to 50°C, 50°C to 60°C, 60°C to 80°C, or any combination of one or more of these ranges. Generally, it is believed that if the pyrolysis oil feed (102) is brought into contact with the second treatment catalyst (114) at a temperature lower than the temperature at which the pyrolysis oil feed (102) is brought into contact with the mixed metal oxide catalyst (112), coke formation and clogging of the first fixed-bed reactor (110) are reduced.

[0107] The first fixed-bed reactor (110) can produce an intermediate stream (118) by contacting the pyrolysis oil feed (102) with hydrogen (116) under mild operating conditions sufficient to upgrade at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102) in the presence of a second treatment catalyst (114) and subsequently a mixed metal oxide catalyst (112) downstream of the second treatment catalyst (114), wherein the intermediate stream (118) comprises di-aromatic and / or tri-aromatic compounds. The first fixed-bed reactor (110) can be operated at a peak temperature in the range of 200°C to 400°C, for example, 250°C to 400°C, 250°C to 300°C, 300°C to 400°C, or any combination of these ranges. The first fixed-bed reactor (110) is 1 megapascal (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), 12 MPa (120 bar) to 18 MPa (180 bar), 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) It may be operated at an operating pressure of up to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar). The first fixed-bed reactor (110) may be operated at a volume ratio of hydrogen to the pyrolysis oil feed (102) at the inlet of the first fixed-bed reactor (110) 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) is 0.1 h-1 to 1.2 h -1 , 0.1 h -1 to 1 h -1 , 0.1 h -1 to 0.8 h -1 , 0.1 h -1 to 0.6 h -1 , 0.2 h -1 to 0.4 h -1 , or a subset thereof, can be operated at a liquid hourly space velocity (LHSV). The first fixed-bed reactor (110) is 200 h -1 to 1500 h -1 , for example 200 h -1 to 1200 h -1 , 400 h -1 to 1200 h -1 , 600 h -1 to 1000 h -1 , or can be operated at a gas hourly space velocity (GHSV) of a subset thereof.

[0108] Now, referring to FIG. 7, in an embodiment, the first fixed-bed reactor (110) may comprise a first catalyst layer (111) comprising a treatment catalyst (119), a second catalyst layer (115) comprising a mixed metal oxide catalyst (112), and a third catalyst layer (117). The mixed metal oxide catalyst (112) may be in a separate layer from the treatment catalyst (119) in the first catalyst layer (111) and in the third catalyst layer (117) within the first fixed-bed reactor (110). The first catalyst layer (111) comprising the treatment catalyst (119) may be disposed upstream of the second catalyst layer (115) comprising the mixed metal oxide catalyst (112). The third catalyst layer (117) may comprise the treatment catalyst (119). When passing through the first fixed-bed reactor (110), the pyrolysis oil feed (102) may encounter the first catalyst layer (111) containing the treatment catalyst (119) before encountering the mixed metal oxide catalyst (112) in the second catalyst layer (115) and before encountering the treatment catalyst (119) in the third catalyst layer (117).

[0109] In an embodiment, the first catalyst layer (111) and the third catalyst layer (117) may both include the first treatment catalyst. In an embodiment, the first catalyst layer (111) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the first treatment catalyst based on the total weight of the first catalyst layer (111). In an embodiment, the third catalyst layer (117) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the first treatment catalyst based on the total weight of the third catalyst layer (117).

[0110] In an embodiment, the first catalyst layer (111) and the third catalyst layer (117) may both include a second treatment catalyst. In an embodiment, the first catalyst layer (111) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the second treatment catalyst based on the total weight of the first catalyst layer (111). In an embodiment, the third catalyst layer (117) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the second treatment catalyst based on the total weight of the third catalyst layer (117).

[0111] In an embodiment, the first catalyst layer (111) and the third catalyst layer (117) may each contain different treatment catalysts (119). In an embodiment, the first catalyst layer (111) may contain at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the first treatment catalyst based on the total weight of the first catalyst layer (111), and the third catalyst layer (117) may contain at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the second treatment catalyst based on the total weight of the third catalyst layer (117). In an embodiment, the first catalyst layer (111) may comprise at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of a second treatment catalyst based on the total weight of the first catalyst layer (111), and the third catalyst layer (117) may comprise at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of a first treatment catalyst based on the total weight of the third catalyst layer (117).

[0112] A pyrolysis oil feed (102) can be introduced into a first fixed-bed reactor (110). Within the first fixed-bed reactor (110), the pyrolysis oil feed (102) can be converted at least a portion of the pyrolysis oil feed (102) by contacting hydrogen in the presence of a treatment catalyst (119) in a first hydrogen catalyst layer (111). The generated reaction products and unconverted pyrolysis oil feed can be moved to a second catalyst layer (115) and subsequently contacted with hydrogen in the presence of a mixed metal oxide catalyst (112) in the second catalyst layer (115) to convert at least a portion of the reaction products of the first catalyst layer (111). The generated reaction products and unconverted pyrolysis oil feed discharged from the second catalyst layer (115) can be moved to a third catalyst layer (117) and subsequently contacted with hydrogen in the presence of a treatment catalyst (119) in the third catalyst layer (117). In an embodiment, the conditions under which the pyrolysis oil feed (102) comes into contact with the mixed metal oxide catalyst (112) of the second catalyst layer (115) and the catalyst of the third catalyst layer (117), respectively, are substantially the same.

[0113] The first fixed-bed reactor (110) can produce an intermediate stream (118) by contacting the pyrolysis oil feed (102) with hydrogen (116) under mild operating conditions sufficient to upgrade at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102), in the presence of a treatment catalyst (119) in the first catalyst layer (111), a mixed metal oxide catalyst in the second catalyst layer (115) downstream of the first catalyst layer (111), and a catalyst in the third catalyst layer (117) downstream of the second catalyst layer (115), and the intermediate stream (118) may contain di-aromatic, tri-aromatic compounds, or both. The first fixed-bed reactor (110) can be operated at a peak operating temperature in the range of 200°C to 400°C, for example, 250°C to 400°C, 250°C to 300°C, 300°C to 400°C, or any combination of these ranges. The first fixed-bed reactor (110) is 1 megapascal (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), 12 MPa (120 bar) to 18 MPa (180 bar), 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) It can be operated at an operating pressure of up to 15 MPa (150 bar), or 10 MPa (100 bar) to 15 MPa (150 bar).The first fixed-bed reactor (110) may be operated at a volume ratio of hydrogen to the pyrolysis oil feed (102) at the inlet of the first fixed-bed reactor (110) 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) is operated at 0.1 h. -1 to 1.2 h -1 , for example 0.1 h -1 to 1 h -1 , 0.1 h -1 to 0.8 h -1 , 0.1 h -1 to 0.6 h -1 , 0.2 h -1 to 0.4 h -1 , or a subset thereof, can be operated at a liquid hourly space velocity (LHSV). The first fixed-bed reactor (110) is 200 h -1 to 1500 h -1 , for example 200 h -1 to 1200 h -1 , 400 h -1 to 1200 h -1 , 600 h -1 to 1000 h -1 , or can be operated at a gas hourly space velocity (GHSV) of a subset thereof.

[0114] Now, referring to FIG. 8, in an embodiment, the second fixed-bed reactor (120) may include a first catalyst layer (121) and a second catalyst layer (123) downstream of the first catalyst layer (121), and the second catalyst layer (115) includes a mesoporous supporting metal catalyst (122). In an embodiment, the second fixed-bed reactor (120) may include a second catalyst layer (123) including a mesoporous supporting metal catalyst (122) and a third catalyst layer (125) downstream of the second catalyst layer (123). In an embodiment, the second fixed-bed reactor (120) may include a first catalyst layer (121), a second catalyst layer (123) downstream of the first catalyst layer (121) including a mesoporous supporting metal catalyst (122), and a third catalyst layer (125) downstream of the second catalyst layer (123). The first catalyst layer (121) may include a treatment catalyst (119) having any of the composition, properties, or other characteristics described above for the treatment catalyst (119) (e.g., a first treatment catalyst, a second treatment catalyst, or a combination thereof). The third catalyst layer (125) may include a treatment catalyst (119) having any of the composition, properties, or other characteristics described above for the treatment catalyst (119) (e.g., a first treatment catalyst, a second treatment catalyst, or a combination thereof). The mesoporous supporting metal catalyst (122) may be in a separate layer from the first catalyst layer (121) and the third catalyst layer (125) in the second fixed-bed reactor (120). The first catalyst layer (121) containing the first treatment catalyst or the second treatment catalyst may be placed upstream of the second catalyst layer (115) containing the mesoporous supporting metal catalyst (122). When passing through the second fixed-bed reactor (120), the intermediate stream (118) may meet the first catalyst layer (121) before meeting the mesoporous supporting metal catalyst (122) in the second catalyst layer (123) and before meeting the treatment catalyst (119) in the third catalyst layer (125).

[0115] In an embodiment, the first catalyst layer (121) and the third catalyst layer (125) may both include a first treatment catalyst. In an embodiment, the first catalyst layer (121) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the first treatment catalyst based on the total weight of the first catalyst layer (121); and the third catalyst layer (125) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the first treatment catalyst based on the total weight of the third catalyst layer (125).

[0116] In an embodiment, the first catalyst layer (121) and the third catalyst layer (125) may both include a second treatment catalyst. In an embodiment, the first catalyst layer (121) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the second treatment catalyst based on the total weight of the first catalyst layer (121); and the third catalyst layer (125) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the second treatment catalyst based on the total weight of the third catalyst layer (125).

[0117] In an embodiment, the first catalyst layer (121) and the third catalyst layer (125) may include different catalysts. In an embodiment, the first catalyst layer (121) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of a second treatment catalyst based on the total weight of the first catalyst layer (121); and the third catalyst layer (125) may include at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of a first treatment catalyst based on the total weight of the third catalyst layer (125). In an embodiment, the first catalyst layer (121) may comprise at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of a first treatment catalyst based on the total weight of the first catalyst layer (121); and the third catalyst layer (125) may comprise at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of a second treatment catalyst based on the total weight of the third catalyst layer (125).

[0118] An intermediate stream (118) may be introduced into a second fixed-bed reactor (120). In the second fixed-bed reactor (120), the intermediate stream (118) may be in contact with a first catalyst layer (121) in the presence of hydrogen (124) to convert at least a portion of the intermediate stream (118). The generated reaction product and unconverted intermediate stream may then be in contact with a mesoporous supporting metal catalyst (122) in the second fixed-bed reactor (120) in the presence of hydrogen (124) in the second catalyst layer (123) to convert at least a portion of the reaction product of the first catalyst layer (121). The generated reaction product and unconverted pyrolysis oil feed discharged from the second catalyst layer (115) may then be in contact with a third catalyst layer (125) containing a first treatment catalyst or a second treatment catalyst. In an embodiment, the conditions under which the intermediate stream (118) contacts the mesoporous supporting metal catalyst (122) of the second catalyst layer (123) and the catalyst of the first catalyst layer (212) and the third catalyst layer (125), respectively, are substantially the same.

[0119] The second fixed-bed reactor (120) can produce a second reactor effluent (130) by contacting the intermediate stream (118) with hydrogen (124) in the presence of a first catalyst layer (121), a second catalyst layer (123) downstream of the first catalyst layer (121), and a third catalyst layer (125) downstream of the second catalyst layer (123), under mild operating conditions sufficient to upgrade at least a portion of the polycyclic aromatic compounds in the intermediate stream (118), and the second reactor effluent (130) comprises aromatic compounds having 6 to 8 carbon atoms. The second fixed-bed reactor (120) can be operated at an operating temperature range of 200°C to 400°C, for example 250°C to 400°C, 250°C to 300°C, 300°C to 400°C, or any combination of these ranges. The second fixed-bed reactor (120) can be operated at an operating pressure of 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) is 0.3 h -1 to 1.5 h -1 , for example, 0.5 h -1 to 1.5 h -1 , 0.9 h -1 to 1.4 h -1 , 0.9 h -1 to 1.3 h -1 , 0.9 h -1 to 1.2 h -1 , 1.0 h -1to 1.5 h -1 , 1.1 h -1 to 1.5 h -1 , 1.2 h -1 to 1.5 h -1 , 1.0 h -1 to 1.4 h -1 , 1.1 h -1 to 1.3 h -1 , or can be operated at an LHSV of a subset thereof. The second fixed-bed reactor (120) is 200 h -1 to 1500 h -1 , for example 200 h -1 to 1200 h -1 , 400 h -1 to 1200 h -1 , 600 h -1 to 1000 h -1 , 700 h -1 to 900 h -1 , about 800 h -1 , or can be operated on a subset of these GHSVs.

[0120] When the pyrolysis oil feed (102) is upgraded by the 2-stage catalytic process of the present invention, the yield of benzene, toluene, ethylbenzene, xylene, or a combination thereof may be higher than when the pyrolysis oil is upgraded by the conventional single-stage catalytic process. In an embodiment, the system (100) of the present invention may have a combined yield of benzene, toluene, ethylbenzene, xylene, or a combination thereof that is 30 wt.% or more, 35 wt.% or more, 40 wt.% or more, or even 45 wt.% or more, based on the total weight of the pyrolysis oil of the pyrolysis oil feed (102) introduced into the 2-stage catalytic process of the present invention.

[0121] Referring again to FIG. 1, a method for upgrading a pyrolysis oil feed (102) may be to contact the pyrolysis oil feed (102) with hydrogen (116) under reaction conditions in the presence of a first catalyst layer (111) containing a treatment catalyst (119) and a second catalyst layer (115) containing a mixed metal oxide catalyst (112) to produce an intermediate stream (118) containing di-aromatic compounds and / or tri-aromatic compounds. As previously described in the present disclosure, when the pyrolysis oil feed (102) is contacted with hydrogen (116) under reaction conditions in the presence of a first catalyst layer (111) containing a treatment catalyst (119) and a second catalyst layer (115) containing a mixed metal oxide catalyst (112), at least some of the polycyclic aromatic compounds in the pyrolysis oil feed (102) may be converted into di-aromatic compounds and / or tri-aromatic compounds. The reaction conditions may include a peak temperature of 200°C to 400°C, a pressure of 1 MPa (10 bar) to 20 MPa (200 bar), and a volume ratio of the mixed metal oxide catalyst (112) to the pyrolysis oil feed (102) in the first fixed-bed reactor (110), which may be in the range of 500 to 1500, or a combination of these reaction conditions.

[0122] The first fixed-bed reactor (110) may have any one of the characteristics, catalysts, or reaction conditions discussed above for the first fixed-bed reactor (110). Additionally, the method may include contacting a pyrolysis oil feed (102) and hydrogen (116) upstream of the first fixed-bed reactor (110) of the mixed metal oxide catalyst (112) with a treatment catalyst (119). Additionally, the method may include contacting the reaction product from the mixed metal oxide catalyst (112) downstream of another treatment catalyst (119) of the mixed metal oxide catalyst (112) in the first fixed-bed reactor (110). The method may include moving an intermediate stream (118) containing a di-aromatic compound and / or a tri-aromatic compound downstream of the second fixed-bed reactor (120) of the first fixed-bed reactor (110). The above method may include contacting an intermediate stream (118) with hydrogen (124) under reaction conditions in the presence of a mesoporous supporting metal catalyst (122) to produce a second reactor effluent (130) comprising an aromatic compound having 6 to 8 carbon atoms. As previously described in the present disclosure, contacting the intermediate stream (118) with hydrogen (124) under reaction conditions in the presence of a mesoporous supporting metal catalyst (122) may cause at least a portion of the di-aromatic compound and / or tri-aromatic compound in the intermediate stream (118) to react to form an aromatic compound having 6 to 8 carbon atoms. The reaction conditions may include a peak temperature of 200°C to 400°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 one of the characteristics, catalysts, or reaction conditions discussed above for the second fixed-bed reactor (120).

[0123] A first aspect of the present invention may relate to a system for upgrading pyrolysis oil, comprising a first fixed-bed reactor comprising a first catalyst layer and a second catalyst layer disposed downstream of the first catalyst layer. The first catalyst layer may comprise: (1) a first treatment catalyst comprising a plurality of first particles, wherein the plurality of first particles each comprise alumina, a binder, Mo, Ni, and P; (2) a second treatment catalyst comprising a plurality of second particles, wherein the plurality of second particles each comprise Al2O3, SiO2, ZrO2, NiO, and WO3; or (3) a treatment catalyst comprising both. The second catalyst layer may comprise a mixed metal oxide catalyst. . A first fixed-bed reactor may be operable to produce an intermediate stream comprising light aromatic compounds, including mono-aromatic compounds, di-aromatic compounds, tri-aromatic compounds, or both, by contacting a pyrolysis oil feed with hydrogen in the presence of a treatment catalyst and a mixed metal oxide catalyst. The system may further comprise a second fixed-bed reactor downstream of the first fixed-bed reactor and comprising a mesoporous supported metal catalyst. The second fixed-bed reactor may be operable to produce a second reactor effluent comprising aromatic compounds having 6 to 8 carbon atoms by contacting the intermediate stream with hydrogen in the presence of a mesoporous supported metal catalyst. The mesoporous supported metal catalyst may comprise nickel and tungsten impregnated onto a mesoporous support comprising alumina and one or more zeolites.

[0124] A second aspect of the present invention may include a first aspect in which a mixed metal oxide catalyst may comprise a plurality of MMO particles, and each of the plurality of MMO particles comprises Fe2O3, ZrO2, CeO2, and Al2O3.

[0125] A third aspect of the present invention may include a second aspect in which each MMO particle of the mixed metal oxide catalyst may comprise 60 wt.% to 95 wt.% iron oxide, 1 wt.% to 20 wt.% zirconium oxide, 0.1 wt.% to 10 wt.% cerium oxide, and 1 wt.% to 20 wt.% aluminum oxide, with the weight percentage based on the total weight of the metal oxides of the MMO particles in the mixed metal oxide catalyst.

[0126] A fourth aspect of the present invention may include any one of the first to third aspects, wherein the mixed metal oxide catalyst may be in the form of a pellet.

[0127] A fifth aspect of the present invention may include any one of the first to fourth aspects, wherein the zeolite of the mesoporous supporting metal catalyst may include both nano zeolite beta and USY zeolite.

[0128] A sixth aspect of the present invention may comprise any one of the first to fifth aspects, wherein the mesoporous supporting metal catalyst may comprise, based on the total weight of the mesoporous supporting metal catalyst, 2 wt.% to 10 wt.% large pore alumina, 10 wt.% to 20 wt.% binder material, 40 wt.% to 60 wt.% zeolite, 4 wt.% to 8 wt.% nickel oxide, and 20 wt.% to 30 wt.% tungsten oxide; the zeolite may comprise USY zeolite and nano-sized zeolite beta; and the weight ratio of USY to nano-sized zeolite beta may be 1.25 to 1.75.

[0129] A seventh aspect of the present invention may include any one of the first to sixth aspects, wherein the treatment catalyst in the first catalyst layer may include a first treatment catalyst, and the first treatment catalyst may include 52 wt.% to 74.5 wt.% of Al2O3, 15 wt.% to 25 wt.% of a binder, 10 wt.% to 15 wt.% of MoO, 3 wt.% to 5 wt.% of NiO, and 0.5 wt.% to 3 wt.% of P4O6, based on the total weight of the metal oxide of the first treatment catalyst.

[0130] The eighth aspect of the present invention may include any one of the first to seventh aspects, wherein the treatment catalyst in the first catalyst layer may include a second treatment catalyst, and the second treatment catalyst may include 18.5 wt.% to 21.5 wt.% of Al2O3, 36.5 wt.% to 39.5 wt.% of SiO2, 9.2 wt.% to 10.2 wt.% of ZrO2, 10.5 wt.% to 11.5 wt.% of NiO, and 18.5 wt.% to 21.5 wt.% of WO3, based on the total weight of the metal oxide of the second treatment catalyst.

[0131] A ninth aspect of the present invention may include any one of the first to eighth aspects, wherein a first fixed-bed reactor may include a third catalyst layer downstream from a second catalyst layer, and the third catalyst layer may include a first treatment catalyst, a second treatment catalyst, or both.

[0132] A tenth aspect of the present invention may include a ninth aspect in which a second fixed-bed reactor may comprise a first catalyst layer, a second catalyst layer downstream from the first catalyst layer, and a third catalyst layer downstream from the second catalyst layer; the first catalyst layer and the third catalyst layer of the second fixed-bed reactor may comprise a treatment catalyst; and the second catalyst layer of the second fixed-bed reactor may comprise a mesoporous supporting metal catalyst.

[0133] The 11th aspect of the present invention may include a 10th aspect in which the first catalyst layer and the third catalyst layer of the first fixed-bed reactor and the first catalyst layer and the third catalyst layer of the second fixed-bed reactor may each include a first treatment catalyst.

[0134] The 12th aspect of the present invention may include any one of the first to eleventh aspects and may relate to a method for upgrading pyrolysis oil, the method comprising: introducing the pyrolysis oil into a system of any one of the first to eleventh aspects; contacting the pyrolysis oil feed with hydrogen in the presence of a treatment catalyst and a mixed metal oxide catalyst of a first fixed-bed reactor to produce an intermediate stream comprising a di-aromatic compound, a tri-aromatic compound, or a combination thereof; and contacting the intermediate stream with hydrogen in the presence of a mesoporous support metal catalyst of a second fixed-bed reactor to produce a second reactor effluent comprising an aromatic compound having 6 to 8 carbon atoms.

[0135] A 13th aspect of the present invention may further include a 12th aspect comprising the steps of mixing heavy pyrolysis oil from a naphtha steam cracker with a light aromatic stream upstream of a first fixed-bed reactor to produce a pyrolysis oil feed, and transferring the pyrolysis oil feed to the first fixed-bed reactor.

[0136] A 14th aspect of the present invention may include a 13th aspect in which the pyrolysis oil feed may comprise 75 wt.% to 85 wt.% heavy pyrolysis oil and 15 wt.% to 25 wt.% light aromatic stream.

[0137] The 15th aspect of the present invention may include any one of the 12th to 14th aspects, wherein the pyrolysis oil feed may contain at least 30 weight percent (wt.%) of a polycyclic aromatic compound having 16 or more carbon atoms based on the total weight of the pyrolysis oil in the pyrolysis oil feed.

[0138] A 16th aspect of the present invention comprises the step of contacting a pyrolysis oil feed with hydrogen in the presence of a first treatment catalyst or a second treatment catalyst of a first fixed-bed reactor at (a) a peak temperature of 200°C to 400°C; (b) a pressure of 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar); (c) a volume ratio of hydrogen to pyrolysis oil feed of 500 to 1500, or one or more of these reaction conditions; and contacting the pyrolysis oil feed in the presence of a mixed metal oxide catalyst in a first fixed-bed reactor at (a) a peak temperature of 200°C to 400°C; (b) a pressure of 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar); (c) a step of contacting hydrogen in one or more reaction conditions of a volume ratio of hydrogen to a pyrolysis oil feed of 500 to 1500, or a combination of these reaction conditions; and a step of contacting the intermediate stream with hydrogen in a second fixed-bed reactor in the presence of a mesoporous supporting metal catalyst in one or more reaction conditions of (a) a temperature of 200°C to 400°C, (b) a pressure of 1 MPa (10 bar) to 20 MPa (200 bar), or a combination of these reaction conditions, any one of the 12th to 15th aspects may be included.

[0139] The 17th aspect of the present invention may include any one of the 12th to 16th aspects, wherein the peak temperature of the first catalyst layer of the first reactor may be 30°C to 80°C lower than the peak temperature of the second catalyst layer of the first reactor.

[0140] The 18th aspect of the present invention may include any one of the 13th to 17th aspects, wherein an aromatic compound having 6 to 8 carbons can be obtained in a yield of 45 wt.% or more based on the total weight of the pyrolysis oil in the pyrolysis oil feed by contacting the pyrolysis oil feed with hydrogen in the presence of a first treatment catalyst and a mixed metal oxide catalyst, and by contacting the intermediate stream with hydrogen in the presence of a mesoporous zeolite-supported metal catalyst.

[0141] The 19th aspect of the present invention may further include any one of the 12th to 18th aspects, comprising the step of steam cracking a naphtha stream to produce one or more product streams and heavy pyrolysis oil; and the step of transferring the heavy pyrolysis oil to a first fixed-bed reactor as at least a portion of the pyrolysis oil feed.

[0142] The 20th aspect of the present invention may further include any one of the 12th to 19th aspects, comprising the step of steam cracking a hydrocarbon gas to produce at least one light olefin stream and a light pyrolysis oil; and the step of transferring the light pyrolysis oil to a first fixed-bed reactor as at least a portion of the pyrolysis oil feed.

[0143] Examples

[0144] Various aspects of methods and systems for treating heavy oil will become clearer through the following examples. The examples are illustrative in nature and should not be understood as limiting the subject matter of the invention.

[0145] In some embodiments included herein, a second treatment catalyst was used. The second treatment catalyst comprises a plurality of second particles, each of which comprises Al2O3, SiO2, ZrO2, NiO, and WO3. The second treatment catalyst comprises 18.5 wt.% to 21.5 wt.% of Al2O3, 36.5 wt.% to 39.5 wt.% of SiO2, 9.2 wt.% to 10.2 wt.% of ZrO2, 10.5 wt.% to 11.5 wt.% of NiO, and 18.5 wt.% to 21.5 wt.% of WO3, based on the total weight of the metal oxide of the second treatment catalyst.

[0146] Example 1: Preparation of a Mixed Metal Oxide Catalyst

[0147] To prepare a mixed metal oxide catalyst containing iron oxide, zirconium oxide, cerium oxide, and aluminum oxide, 40 g of iron(III) hexahydrate (Fe(NO3)3·9H2O) was dissolved in 800 ml of distilled water to prepare Solution A. Subsequently, the remaining metal oxide precursors were added to Solution A. Specifically, 4.906 g of aluminum nitrate hexahydrate (Al(NO3)3·9H2O), 1.549 g of zirconium(IV) oxynitrate hydrate (ZrO(NO3)2:3H2O), and 0.601 g of cerium(III) nitrate hexahydrate (Ce(NO3)3·6H2O) were added to Solution A to form Solution B. Subsequently, Solution B was stirred for 30 minutes.

[0148] Solution C, an ammonia solution, was prepared by adding 40 mL of ammonium hydroxide (NH4OH) (28 to 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. Subsequently, Solution D was stirred for 1 hour.

[0149] Solution D was prepared and stirred for an additional hour, after which the precipitate was separated from Solution D and dried overnight in an oven (i.e., for about 12 hours). Subsequently, the dried precipitate was calcined in air at 500°C for 2 hours. After calcination, the dried and calcined precipitate was crushed to obtain MMO particles in the form of a fine powder. The MMO particles were nanoparticles with a size ranging from 20 nm to 200 nm.

[0150] Next, powdered MMO particles were mixed with bentonite and methylcellulose in a ratio of 75 wt.% powdered MMO catalyst, 24.9 wt.% bentonite, and 0.1 wt.% methylcellulose. The weights of the MMO particles and bentonite were determined based on the weight of these components after calcination using the loss-on-ignition (IIO). The IIO weight of the components was determined by accurately weighing 3 g of each component, placing it in a crucible, and recording the mass of each added component. The crucible was placed in a furnace, and the components were heated to 650°C at a temperature ramp rate of 2°C / min and maintained at 650°C for 2 hours to calcin each component. Once calcination was complete, the crucible was removed from the furnace and cooled in a desiccator to prevent the re-adsorption of water or other components from the atmosphere. Next, the calcined components were weighed again and recorded. The loss on ignition of each component was calculated from the mass recorded after calcination and the mass recorded before calcination.

[0151] The dry ingredients were thoroughly mixed. Then, about 1.5 mL of water / 1 g of catalyst was mixed to form an extrudable paste. The extrudable paste was placed into a syringe of a syringe pump and extruded into a cylindrical shape with a diameter of 2.1 mm at 3 mL / min.

[0152] The extruded sample was dried in a 60°C oven for 24 hours. Subsequently, the dried sample was calcined in air at 650°C for 2 hours at a ramp rate of 2°C / min. Subsequently, the calcined sample was cooled to room temperature and broken into pellets. The pellets were then sieved to obtain a fraction of mixed metal oxide catalyst pellets with an overall maximum size of 1 mm to 2 mm. The characteristics of the mixed metal oxide catalyst pellets are shown in Table 2.

[0153]

[0154] Example 2: Preparation of Treatment Catalyst

[0155] In Example 2, a first treatment catalyst was prepared. First, a paste was formed by mixing a binder comprising an alumina support and large-pore boehmite with water. The large-pore boehmite binder was CATAPAL B boehmite from Sasol, which had a pore volume of 0.5 ml / g. Subsequently, the paste was extruded to form cylindrical extrusions with a length ranging from 3 mm to 5 mm and a diameter ranging from 2 mm to 3 mm. The extrusions were then dried at 100°C to 120°C for 4 to 12 hours, and then calcined in air at a temperature of 550°C for 4 hours (ramp 2°C / min).

[0156] Next, the calcined extruder was immersed in a solution of water, ammonium heptamolybdate, nickel carbide, and H3PO4 to impregnate the extruder with metal. Subsequently, the impregnated extruder was dried at 100°C to 120°C for 4 to 12 hours, and then calcined in air at a temperature of 550°C for 4 hours (ramp 2°C / min) to form a second treatment catalyst comprising 52 wt.% to 71.5 wt.% alumina, 15 wt.% to 25 wt.% binder, 10 wt.% to 14 wt.% molybdenum oxide, 3 wt.% to 5 wt.% nickel oxide, and 0.5 wt.% to 3 wt.% phosphorus oxide.

[0157] Example 3: Preparation of a Mesoporous Supported Metal Catalyst

[0158] In Example 3, a mesoporous supported metal catalyst was prepared by first preparing a binder composition. 29.25 g of alumina binder (CATAPAL B, available from Sasol Germany GmbH) was combined with 63.3 g of water and 3.45 mL of 67% to 69% HNO3 to form a uniform binder paste.

[0159] Next, a zeolite paste was prepared. A zeolite mixture was prepared by combining 7.4 g of large-pore alumina (Brunauer-Emmett-Teller (BET) surface area 150 m² / g, pore volume 0.8 mL / g to 1.1 mL / g, and pore radius 11 nm; available as CATAPAL B from Sasol Inc.), 49.2 g of USY zeolite (available as CBV-720 from Zeolist International), and 28.6 g of nano zeolite beta. Details regarding nano zeolite beta are presented in Table 3. Subsequently, the zeolite mixture was mixed with a homogeneous binder paste to form a support paste.

[0160]

[0161] The support paste was inserted into the syringe of a syringe pump and extruded into a cylindrical body with a diameter of 2.1 mm at 3 mL / min. The extruded sample was dried overnight in an oven at 110°C. The dried sample was calcined in air at 550°C for 4 hours at a ramp rate of 2°C / min. The cooled sample was broken into pellets with a length of approximately 2 mm to approximately 4 mm.

[0162] Next, the pellets were impregnated with metallic nickel (Ni) and tungsten (W). (NH4) 10 (H2W 12 O 42A Ni / W metal solution was prepared by combining )·xH2O (ammonium metatungsten); Ni(NO3)2.6H2O (nickel nitrate hexahydrate); and water. Pellet was mixed with the Ni / W metal solution at room temperature for 3 hours. The impregnated sample was dried overnight in a 110°C oven. Subsequently, the dried sample was calcined in air at 500°C for 4 hours at a ramp rate of 2°C / min.

[0163] Pyrolysis oil upgrade by 2-stage hydrogenation cracking

[0164] In the following Examples EX-4, EX-5, EX-6, EX-7, and EX-8, the performance of a process for pyrolysis oil upgrading was evaluated, comprising mutually discussed configurations of the mixed metal oxide catalyst of Example 1, the second treatment catalyst, the first treatment catalyst of Example 2, and the mesoporous supported metal catalyst of Example 3. In Examples 4 through 8, 80 wt.% heavy pyrolysis oil from a liquid stream cracker was mixed with 20 wt.% light pyrolysis oil from a gas steam cracker to produce a pyrolysis oil feed. The simulated distillation of the pyrolysis oil feed is shown in Table 4. The proportions of the naphtha fraction, diesel fraction, and C16+ fraction of the pyrolysis oil feed are shown in Table 4. Table 5 provides the percentages of each class of aromatic compounds in the pyrolysis oil feed based on the total weight of the pyrolysis oil feed.

[0165] Pyrolysis oil feed and hydrogen gas were introduced together into a first fixed-bed reactor. Before introduction, the pyrolysis oil feed was preheated to the reactor operating temperature. The first reactor included a first layer and a second layer downstream of the first layer.

[0166] In Example EX-4, the first reactor contained a single fixed bed. The single fixed bed contained 4.7 g of mixed metal oxide (MMO) catalyst prepared according to Example 1. The second fixed bed reactor contained a single layer containing 0.9 g of mesoporous supported metal catalyst prepared in Example 3.

[0167] In Example EX-5, the first reactor included a first fixed bed and a second fixed bed downstream of the first fixed bed. The first fixed bed included 2.3 g of a mixed metal oxide (MMO) catalyst prepared according to Example 1. The second fixed bed included 1.8 g of a second treatment catalyst. The second fixed bed reactor included a single layer of 0.9 g of a mesoporous supported metal catalyst prepared in Example 3.

[0168] In Example EX-6, the first reactor included a first fixed catalyst layer, a second fixed layer downstream of the first fixed layer, and a third fixed layer downstream of the second fixed layer. The first fixed layer and the third fixed layer each contained 4.0 g of the second treatment catalyst. The second fixed layer contained 3.1 g of the mixed metal oxide (MMO) catalyst prepared according to Example 1. In Example EX-6, the second fixed-layer reactor included a first fixed layer, a second fixed layer downstream of the first fixed layer, and a third fixed layer downstream of the second fixed layer. The first fixed layer and the third fixed layer of the second reactor each contained 4.0 g of the second treatment catalyst. The second fixed layer of the second reactor contained 3.0 g of the mesoporous supported metal catalyst prepared in Example 3.

[0169] In Example EX-7, the first reactor included a first fixed bed and a second fixed bed downstream of the first fixed bed. The first fixed bed contained 3.4 g of the second treatment catalyst. The second fixed bed contained 3.1 g of the mixed metal oxide (MMO) catalyst prepared according to Example 1. In Example EX-7, the second fixed bed reactor contained a single layer of 3.0 g of the mesoporous supported metal catalyst prepared in Example 3.

[0170] In Example EX-8, the first reactor included a first fixed bed and a second fixed bed downstream of the first fixed bed. The first fixed bed contained 2.5 g of the first treatment catalyst prepared according to Example 2. The second fixed bed contained 3.1 g of the mixed metal oxide (MMO) catalyst prepared according to Example 1. In Example EX-8, the second fixed bed reactor contained a single layer of 3.0 g of the mesoporous supported metal catalyst prepared in Example 3.

[0171] Pyrolysis oil feed, liquid hourly space velocity (LHSV) 0.3 h -1 , gas hourly space velocity (GHSV) 800h -1 It was introduced into a first fixed-bed reactor having a pressure of 150 bar and a reactor temperature of 280°C to 300°C. Subsequently, the intermediate stream generated in the first reactor was introduced into a second fixed-bed reactor. The second fixed-bed reactor has an LHSV of 1.2 h -1 , GHSV 800h -1 It was operated at a pressure of 150 bar and a reactor temperature of 260°C to 300°C. At the outlet of the second fixed-bed reactor, analyses including simulated distillation, gas product analysis, and liquid product analysis were performed. The results of the simulated distillation are shown in Table 1, and the results of the aromatic analysis are shown in Table 5.

[0172] Gas product analysis: Gas product content was analyzed by online gas chromatography using FID and TCD detectors. Liquid product analysis: API specific gravity was analyzed according to ASTM D4052 and D5002 using an Anton Paar DMA 4100 M densimeter. Sulfur and nitrogen content was analyzed according to ASTM D4629 using Mitsubishi, Antek, and Analytik Jena analyzers. Gas hydrocarbons are defined as C1 to C4 hydrocarbons. Naphtha is defined as C5 hydrocarbons to hydrocarbons that boil at 173°C. Diesel is defined as hydrocarbons that boil at 173°C to 404°C. C 16+ Hydrocarbons are defined as hydrocarbons that boil at temperatures above 404°C. Simulated distillation was performed on an Agilent 7890 gas chromatograph according to CSN EN 15199-2. Viscosity was analyzed according to ASTM D7042.

[0173]

[0174]

[0175] As shown in Table 5, the process of the present invention converts a significant amount of di-aromatic and tri-aromatic compounds into mono-aromatic compounds, thereby facilitating the production of useful chemicals.

[0176] Extended operation test

[0177] During the operation of Examples EX-4, EX-5, EX-6, and EX-7, the change in liquid hourly space velocity (LHSV) at a constant pump pressure was evaluated to confirm blockage due to coke formation. As shown in FIG. 9, Example EX-4 became blocked within 2 days of operation. As shown in FIG. 10, Example EX-5 became blocked within 4 days of operation.

[0178] Although not shown in the drawings, Example EX-6 did not exhibit clogging even after 13 days of operation. Table 6 shows the coke present in the reaction layer of Example EX-6 after 13 days of operation. As shown in Table 6, the catalyst in the first catalyst layer of the first reactor prevented clogging of the entire reactor. Without being limited to theory, this protection is believed to be because the first layer, which operates at a temperature about 50°C lower than the second layer zone of the first reactor, prevented the MMO catalyst in the second layer from generating an excess amount of coke.

[0179]

[0180] Example EX-8 did not show clogging or a decrease in LHSV after 70 days of operation. Without being limited to theory, this performance improvement is believed to be due to the first layer, which was operated at a temperature about 50°C lower than the second layer zone of the first reactor, preventing the MMO catalyst in the second layer from producing an excess amount of coke.

[0181] Any two quantitative values ​​assigned to a characteristic may constitute a category of the characteristic, and all combinations of the range formed from all described quantitative values ​​of a given characteristic are considered in the present invention.

[0182] It should be noted that one or more of the claims use the term “here” as a transitional phrase. For the purpose of defining the scientific and technical aspects of the invention, it should be noted that the term is introduced into the claims as an open transitional phrase used to introduce a reference to a series of features of the structure, and should be interpreted in the same way as the more commonly used open preposition “comprising”.

[0183] Since the subject matter of the present invention has been described in detail with reference to specific aspects, the various details of these aspects should not be construed as implying that such details are essential components of these aspects. Rather, the claims appended herein should be considered the sole representation of the scope of the invention and the corresponding scopes of the various aspects described in the invention. Furthermore, it will be apparent that modifications and variations are possible without departing from the scope of the appended claims.

Claims

Claim 1 A system for upgrading pyrolysis oil, wherein the system comprises: a first fixed-bed reactor comprising a first catalyst layer and a second catalyst layer disposed downstream of the first catalyst layer, wherein the first catalyst layer comprises a first treatment catalyst comprising a plurality of first particles, wherein the plurality of first particles each comprise alumina, a binder, Mo, Ni, and P; a second treatment catalyst comprising a plurality of second particles, wherein the plurality of second particles each comprise Al2O3, SiO2, ZrO2, NiO, and WO3; or a treatment catalyst comprising both; wherein the second catalyst layer comprises a mixed metal oxide catalyst; and wherein the first fixed-bed reactor is operable to produce an intermediate stream comprising light aromatic compounds comprising mono-aromatic compounds, di-aromatic compounds, tri-aromatic compounds, or both, by contacting a pyrolysis oil feed with hydrogen in the presence of the treatment catalyst and the mixed metal oxide catalyst. A system comprising: a second fixed-bed reactor downstream of the first fixed-bed reactor and comprising a mesoporous supporting metal catalyst, wherein the second fixed-bed reactor is operable to contact the intermediate stream with hydrogen in the presence of the mesoporous supporting metal catalyst to produce a second reactor effluent comprising an aromatic compound having 6 to 8 carbon atoms; and a second fixed-bed reactor comprising nickel and tungsten, wherein the mesoporous supporting metal catalyst is impregnated onto a mesoporous support comprising alumina and one or more zeolites. Claim 2 A system according to claim 1, wherein the mixed metal oxide catalyst comprises a plurality of MMO particles, and the plurality of MMO particles each comprise Fe2O3, ZrO2, CeO2, and Al2O3. Claim 3 A system according to claim 1 or 2, wherein the MMO particles of the mixed metal oxide catalyst each comprise 60 wt.% to 95 wt.% iron oxide; 1 wt.% to 20 wt.% zirconium oxide; 0.1 wt.% to 10 wt.% cerium oxide; and 1 wt.% to 20 wt.% aluminum oxide, wherein the weight percentages are based on the total weight of the metal oxides of the MMO particles in the mixed metal oxide catalyst. Claim 4 A system according to any one of claims 1 to 3, wherein the zeolite of the mesoporous supporting metal catalyst comprises both nano zeolite beta and USY zeolite. Claim 5 A system according to any one of claims 1 to 4, wherein the mesoporous supporting metal catalyst comprises, based on the total weight of the mesoporous supporting metal catalyst, 2 wt.% to 10 wt.% of the large pore alumina, 10 wt.% to 20 wt.% of the binder material, 40 wt.% to 60 wt.% of the zeolite, 4 wt.% to 8 wt.% of the nickel oxide, and 20 wt.% to 30 wt.% of the tungsten oxide; wherein the zeolite comprises USY zeolite and nano-sized zeolite beta; and wherein the weight ratio of USY to nano-sized zeolite beta is 1.25 to 1.

75. Claim 6 A system according to any one of claims 1 to 5, wherein the treatment catalyst in the first catalyst layer comprises the first treatment catalyst, and the first treatment catalyst comprises, based on the total weight of the metal oxide of the first treatment catalyst, 52 wt.% to 74.5 wt.% Al2O3, 15 wt.% to 25 wt.% binder, 10 wt.% to 15 wt.% MoO, 3 wt.% to 5 wt.% NiO, and 0.5 wt.% to 3 wt.% P4O6. Claim 7 A system according to any one of claims 1 to 6, wherein the treatment catalyst in the first catalyst layer comprises the second treatment catalyst, and the second treatment catalyst comprises, based on the total weight of the metal oxide of the second treatment catalyst, 18.5 wt.% to 21.5 wt.% of Al2O3, 36.5 wt.% to 39.5 wt.% of SiO2, 9.2 wt.% to 10.2 wt.% of ZrO2, 10.5 wt.% to 11.5 wt.% of NiO, and 18.5 wt.% to 21.5 wt.% of WO3. Claim 8 A system according to any one of claims 1 to 7, wherein the first fixed-bed reactor comprises a third catalyst layer downstream from the second catalyst layer, and the third catalyst layer comprises the first treatment catalyst, the second treatment catalyst, or both. Claim 9 A system according to claim 8, wherein the second fixed-bed reactor comprises a first catalyst layer, a second catalyst layer downstream from the first catalyst layer, and a third catalyst layer downstream from the second catalyst layer; wherein the first catalyst layer and the third catalyst layer of the second fixed-bed reactor comprise the treatment catalyst; and wherein the second catalyst layer of the second fixed-bed reactor comprises the mesoporous supporting metal catalyst. Claim 10 A system according to claim 9, wherein the first catalyst layer and the third catalyst layer of the first fixed-bed reactor and the first catalyst layer and the third catalyst layer of the second fixed-bed reactor each comprise the first treatment catalyst. Claim 11 A method for upgrading pyrolysis oil, the method comprising: introducing a pyrolysis oil feed into a system according to any one of claims 1 to 10; contacting the pyrolysis oil feed with hydrogen in the presence of the treatment catalyst and the mixed metal oxide catalyst of the first fixed-bed reactor to produce an intermediate stream comprising a di-aromatic compound, a tri-aromatic compound, or a combination thereof; and contacting the intermediate stream with hydrogen in the presence of the mesoporous support metal catalyst of the second fixed-bed reactor to produce a second reactor effluent comprising an aromatic compound having 6 to 8 carbon atoms. Claim 12 A method according to claim 11, further comprising the steps of mixing heavy pyrolysis oil from a naphtha steam cracker with a light aromatic stream upstream of the first fixed-bed reactor to produce the pyrolysis oil feed, and transferring the pyrolysis oil feed to the first fixed-bed reactor. Claim 13 A method according to claim 11 or 12, wherein the pyrolysis oil feed comprises 75 wt.% to 85 wt.% of the heavy pyrolysis oil and 15 wt.% to 25 wt.% of the light aromatic stream; or wherein the pyrolysis oil feed comprises 30 wt.% or more of a polycyclic aromatic compound having 16 or more carbon atoms based on the total weight of the pyrolysis oil in the pyrolysis oil feed. Claim 14 In any one of claims 11 to 13, the step of contacting the pyrolysis oil feed with hydrogen in the presence of the first treatment catalyst or the second treatment catalyst of the first fixed-bed reactor under one or more reaction conditions of: (a) a peak temperature of 200°C to 400°C; (b) a pressure of 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar); (c) a volume ratio of hydrogen to the pyrolysis oil feed of 500 to 1500, or a combination of these reaction conditions; the step of contacting the pyrolysis oil feed with hydrogen in the presence of the mixed metal oxide catalyst in the first fixed-bed reactor under: (a) a peak temperature of 200°C to 400°C; (b) a pressure of 1 megapascal (MPa) (10 bar) to 20 MPa (200 bar); (c) a step of contacting the intermediate stream with hydrogen in one or more reaction conditions of a volume ratio of hydrogen to the pyrolysis oil feed of 500 to 1500, or a combination of these reaction conditions; and a step of contacting the intermediate stream with hydrogen in the presence of the mesoporous supporting metal catalyst in the second fixed-bed reactor in one or more reaction conditions of (a) a temperature of 200°C to 400°C, (b) a pressure of 1 MPa (10 bar) to 20 MPa (200 bar), or a combination of these reaction conditions. Claim 15 A method according to any one of claims 11 to 14, further comprising the steps of steam cracking a naphtha stream to produce one or more product streams and heavy pyrolysis oil, and transferring said heavy pyrolysis oil to the first fixed-bed reactor as at least a portion of said pyrolysis oil feed; or steam cracking a hydrocarbon gas to produce at least one light olefin stream and light pyrolysis oil, and transferring said light pyrolysis oil to the first fixed-bed reactor as at least a portion of said pyrolysis oil feed.

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