Two-stage catalytic process for upgrading mixed pyrolysis oil to BTEX

Abstract

According to one or more embodiments of the present disclosure, a multi-stage process for upgrading mixed pyrolysis oil containing polycyclic aromatic compounds to benzene, toluene, ethylbenzene, and xylenes (BTEX) includes blending a light pyrolysis oil with a heavy pyrolysis oil to form a mixed pyrolysis oil; upgrading the mixed pyrolysis oil in a slurry-phase reaction zone to produce an intermediate product, the slurry-phase reaction zone comprising a mixed metal oxide catalyst; and hydrocracking the intermediate product in a fixed-bed reaction zone to produce BTEX, the fixed-bed reaction zone comprising a mesoporous zeolite-supported metal catalyst.

Description

Description of Related Applications

[0001] This application claims the benefit of priority to U.S. Patent Application No. 18 / 046,034, filed October 12, 2022, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to petroleum products, and more particularly to a process for upgrading mixed pyrolysis oils. [Background technology]

[0003] In a typical hydrocarbon cracking process, a stream called pyrolysis oil is discharged as the bottom layer from the steam cracker. Pyrolysis oil can range from heavy liquid to light liquid based on the different steam cracker feeds. Two major sources of pyrolysis oil are heavy pyrolysis oil from the naphtha steam cracker and light pyrolysis oil from the gas steam cracker.

[0004] Both heavy and light pyrolysis oils are low in sulfur but rich in aromatics. These properties make pyrolysis oils desirable feedstocks for subsequent chemical conversion, but conventional upgrading processes for pyrolysis oils are complex and inefficient. Summary of the Invention [Problem to be solved by the invention]

[0005] Both heavy and light pyrolysis oils are typically burned as fuel and are not considered high-value. However, the high content of aromatic compounds makes relatively inexpensive pyrolysis oil an ideal feedstock for the production of valuable intermediate petrochemicals such as benzene, toluene, ethylbenzene, and xylenes (BTEX). BTEX can then be processed to maximize para-xylene, a key building block for producing purified terephthalic acid (PTA) and ultimately polyester. Therefore, there remains a need for novel, simplified, and more efficient pyrolysis oil upgrading processes. Embodiments of the present disclosure relate to such processes. [Means for solving the problem]

[0006] According to one embodiment, a multi-stage process for upgrading mixed pyrolysis oil containing polycyclic aromatic compounds to benzene, toluene, ethylbenzene, and xylenes (BTEX) is provided, comprising: combining a light pyrolysis oil with a heavy pyrolysis oil to form a mixed pyrolysis oil; upgrading the mixed pyrolysis oil to produce an intermediate product in a slurry-phase reaction zone, the slurry-phase reaction zone containing a mixed metal oxide catalyst; and hydrocracking the intermediate product to produce BTEX in a fixed-bed reaction zone, the fixed-bed reaction zone containing a mesoporous zeolite-supported metal catalyst.

[0007] Additional features and advantages of the embodiments described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description, or may be learned by practice of the described embodiments, including the detailed description and claims provided below. [Brief explanation of the drawings]

[0008] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings. [Figure 1]1 is a schematic diagram of a system for producing BTEX from a mixed pyrolysis oil feed according to embodiments disclosed herein. [Figure 2] Illustrative of the reaction sequence that may occur within a slurry-phase reaction zone according to embodiments described herein. [Figure 3] 1 is a diagram of the reaction sequence that may occur within a fixed bed reaction zone according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0009] As used herein, the term "light pyrolysis oil" refers to a stream having a composition similar to the stream exiting the bottom layer of a gas steam cracker. In some embodiments, all or a portion of the stream exiting the bottom layer of a gas steam cracker can be further processed. In some embodiments, the stream exiting the bottom layer of a gas steam cracker can be further processed in a hydrogenation unit and separated to produce one or more processed streams. In some embodiments, the light pyrolysis oil has an initial boiling point of 30°C to 150°C, 40°C to 120°C, 40°C to 100°C, 40°C to 90°C, 50°C to 90°C, 60°C to 90°C, 70°C to 90°C, 75°C to 85°C, or 75°C to 80°C. According to one or more embodiments, the light pyrolysis oil has a final boiling point of 120° C. to 450° C., 150° C. to 450° C., 200° C. to 450° C., 250° C. to 450° C., 200° C. to 450° C., 250° C. to 450° C., 300° C. to 400° C., or 325° C. to 375° C. According to one or more embodiments, the light pyrolysis oil comprises paraffins, BTEX, single ring aromatics, naphthalene, indene, single ring naphthenes, and dicyclopentadiene (DCPD). In some embodiments, the light pyrolysis oil does not comprise polyaromatic compounds, as defined herein. According to one or more embodiments, the light pyrolysis oil comprises paraffins at a concentration of 1% to 30%, 1% to 20%, 2% to 20%, 2% to 15%, 3% to 15%, 5% to 15%, or 5% to 10% by weight. In some embodiments, the light pyrolysis oil comprises BTEX at a concentration of 1% to 20%, 1% to 15%, 2% to 15%, 1% to 10%, 2% to 10%, 2% to 8%, 2% to 6%, or 2% to 5% by weight.According to embodiments, the light pyrolysis oil comprises single ring aromatic compounds at a concentration of 10% to 90%, 15% to 90%, 20% to 90%, 20% to 85%, 25% to 85%, 30% to 85%, 35% to 85%, 40% to 85%, 40% to 80%, 45% to 75%, 50% to 70%, or 55% to 65% by weight. In some embodiments, the light pyrolysis oil comprises naphthalene at a concentration of 1% to 15%, 2% to 15%, 1% to 10%, 2% to 10%, 1% to 8%, 1% to 6%, 2% to 6%, or 2% to 5% by weight. According to one or more embodiments, the light pyrolysis oil comprises indene at a concentration of 1% to 30%, 1% to 20%, 2% to 20%, 2% to 15%, 5% to 15%, or 8% to 12% by weight. In some embodiments, the light pyrolysis oil comprises mono-ring naphthenes at a concentration of 1% to 15%, 2% to 15%, 1% to 10%, 2% to 10%, 1% to 8%, 1% to 6%, 2% to 6%, or 2% to 5% by weight. According to one or more embodiments, the light pyrolysis oil comprises DCPD at a concentration of 1% to 60%, 1% to 50%, 1% to 40%, 1% to 30%, 1% to 20%, 2% to 20%, 2% to 15%, 5% to 15%, or 8% to 12% by weight. In some embodiments, the light pyrolysis oil comprises 3% to 15% by weight paraffins, 2% to 8% by weight BTEX, 40% to 80% by weight single-ring aromatics, 1% to 6% by weight naphthalene, 5% to 15% by weight indene, 1% to 6% by weight single-ring naphthenes, and 5% to 15% by weight DCPD.

[0010] As used herein, the term "heavy pyrolysis oil" refers to a stream having a composition similar to the stream exiting the bottom layer of a naphtha steam cracker. In some embodiments, all or a portion of the stream exiting the bottom layer of a naphtha steam cracker can be further processed. In some embodiments, the stream exiting the bottom layer of a naphtha steam cracker can be further processed in a hydrogenation unit and separated to produce one or more processed streams. In some embodiments, the heavy pyrolysis oil has an initial boiling point of 90°C to 250°C, 100°C to 200°C, 110°C to 190°C, 120°C to 180°C, 130°C to 170°C, or 140°C to 160°C. According to one or more embodiments, the heavy pyrolysis oil has a final boiling point of 500° C. to 950° C., 500° C. to 900° C., 550° C. to 850° C., 600° C. to 800° C., 650° C. to 750° C., or 700° C. to 750° C. In some embodiments, the heavy pyrolysis oil comprises single-ring aromatics, two-ring aromatics, three-ring aromatics, four-ring aromatics, five-ring aromatics, six-ring aromatics, and seven or more ring aromatics. According to one or more embodiments, the heavy pyrolysis oil comprises single-ring aromatics at a concentration of 1% to 50%, 1% to 40%, 2% to 40%, 5% to 40%, 5% to 35%, 5% to 30%, 10% to 30%, 10% to 25%, 15% to 25%, or 15% to 20% by weight. In some embodiments, the heavy pyrolysis oil comprises two-ring aromatic compounds at a concentration of 2% to 50%, 5% to 50%, 5% to 45%, 10% to 40%, 15% to 45%, 20% to 40%, 20% to 35%, 25% to 35%, or 25% to 30% by weight. According to one or more embodiments, the heavy pyrolysis oil comprises three-ring aromatic compounds at a concentration of 1% to 20%, 1% to 15%, 2% to 15%, 1% to 10%, 2% to 10%, 2% to 8%, 3% to 7%, or 4% to 6% by weight.In some embodiments, the heavy pyrolysis oil contains tetra-ring aromatic compounds at a concentration of 1% to 20%, 1% to 15%, 2% to 15%, 1% to 10%, 2% to 10%, 2% to 8%, 3% to 7%, or 4% to 6% by weight. According to one or more embodiments, the heavy pyrolysis oil contains pentanoic compounds at a concentration of 1% to 30%, 1% to 20%, 2% to 20%, 2% to 15%, 5% to 15%, 8% to 12%, or 8% to 10% by weight. In some embodiments, the heavy pyrolysis oil comprises 6-ring aromatic compounds at a concentration of 1% to 30%, 1% to 20%, 2% to 20%, 2% to 15%, 5% to 15%, or 8% to 12% by weight. According to one or more embodiments, the heavy pyrolysis oil comprises 2% to 50%, 5% to 50%, 5% to 45%, 10% to 40%, 15% to 45%, 15% to 40%, 15% to 35%, 15% to 30%, 20% to 30%, or 20% to 25% by weight of 7- or higher ring aromatic compounds. In some embodiments, the heavy pyrolysis oil comprises 10% to 30% by weight of single-ring aromatic compounds, 15% to 45% by weight of two-ring aromatic compounds, 2% to 10% by weight of three-ring aromatic compounds, 2% to 10% by weight of four-ring aromatic compounds, 5% to 15% by weight of five-ring aromatic compounds, 5% to 15% by weight of six-ring aromatic compounds, and 10% to 40% by weight of seven-ring or higher aromatic compounds.

[0011] As used herein, the terms "hydrocarbon oil" or "hydrocarbon feedstock" refer to an oily liquid consisting mostly of a mixture of hydrocarbon compounds. Hydrocarbon oils may include crude oil, synthetic crude oil, bitumen, oil sands, shale oil, or refined oils obtained from petroleum. The term "refined oil" includes, but is not limited to, vacuum gas oil (VGO), depolyaromatized oil (DAO) or demetallized oil (DMO) obtained from a depolyaromatization process, light and / or heavy coker gas oil obtained from a coking process, cycle oil obtained from an FCC process, and gas oil obtained from a visbreaking process.

[0012] As used herein, the term "hydrocarbon" refers to a compound consisting entirely of carbon and hydrogen atoms. x -C y Phrases such as "hydrocarbon" refer to hydrocarbons having x to y carbon atoms. For example, C1-C5 hydrocarbons include methane, ethane, propane, butane, and pentane.

[0013] As used herein, the term "polycyclic aromatic compound" refers to a compound consisting of three or more aromatic rings.

[0014] As used herein, the term "naphtheno / reophino-benzos" refers to compounds having a naphthalene-like structure with one or more branches of olefins, cyclo-paraffins, or combinations thereof.

[0015] As used herein, the term "seven or more ring aromatic compounds" refers to polycyclic aromatic compounds having seven or more aromatic rings.

[0016] As used herein, the terms "hydrogen / oil ratio" or "hydrogen to oil ratio" or "hydrogen to hydrocarbon ratio" refer to a standard measure of the volumetric ratio of hydrogen circulating through a reactor to the volume of feed. The hydrogen / oil ratio can be determined by comparing the flow rate of the hydrogen gas stream to the flow rate of the hydrocarbon feed.

[0017] As used herein, the term "liquid hourly space velocity" or "LHSV" refers to the ratio of the liquid flow rate of the hydrocarbon feed to the volume of the catalyst.

[0018] As used herein, the term "conduit" includes casings, liners, pipes, tubes, coiled tubing, and mechanical structures having internal cavities.

[0019] As used herein, the term "depleted content" of a substance means that the concentration of the substance is greater before passing through a stage in the process of interest than after passing through that stage. As used herein, the term "enhanced content" means that the concentration of the substance is greater after passing through a stage in the process of interest than before passing through that stage.

[0020] As used throughout this disclosure, "zeolite" can refer to a micropore-containing inorganic material with ordered intracrystalline cavities and molecular-sized passageways. Zeolites generally comprise a crystalline structure, as opposed to an amorphous structure, such as that observed in some porous materials, such as amorphous silica. Zeolites generally comprise a microporous framework, which can be identified by framework type. The micropore structure of zeolites (e.g., pore diameters of 0.3 nm to 2 nm) can provide high surface area and desirable size / shape selectivity, which can be beneficial for catalysis. Zeolites described herein may include aluminosilicates, titanosilicates, or pure silicates. In embodiments, the zeolites described herein may comprise micropores (present in the zeolite microstructure) and, in addition, may comprise mesopores. As used throughout this disclosure, micropores refer to pores in a structure having a diameter of 0.1 nm or more and 2 nm or less, and mesopores refer to pores in a structure having a diameter of more than 2 nm and 50 nm or less. Unless otherwise specified, the "pore size" of a material refers to the average pore size, although the material may additionally contain micropores and / or mesopores having specific sizes that are not identical to the average pore size.

[0021] According to one embodiment, a multi-stage process for upgrading mixed pyrolysis oil containing polycyclic aromatic compounds to benzene, toluene, ethylbenzene, and xylenes (BTEX) is provided. The process includes blending a light pyrolysis oil with a heavy pyrolysis oil to form a mixed pyrolysis oil. While not intending to be bound by any particular theory, it is believed that blending the heavy pyrolysis oil with the light pyrolysis oil provides a mixed pyrolysis oil with increased fluidity compared to the heavy pyrolysis oil alone, such that the mixed pyrolysis oil can better contact the mixed metal oxide catalyst than the heavy pyrolysis oil alone. Furthermore, components of both the light pyrolysis oil and the heavy pyrolysis oil can be productively converted to BTEX in this process. Therefore, the light pyrolysis oil can beneficially serve the function of a diluent for the heavy pyrolysis oil, and components of the light pyrolysis oil, in addition to the heavy pyrolysis oil, can be upgraded to BTEX in the multi-stage process. In some embodiments, the mixed pyrolysis oil comprises light pyrolysis oil in a concentration of 5% to 50%, 5% to 45%, 5% to 40%, 10% to 40%, 10% to 35%, 10% to 30%, or 15% to 25% by weight. According to one or more embodiments, the mixed pyrolysis oil comprises heavy pyrolysis oil in a concentration of 50% to 95%, 55% to 95%, 60% to 95%, 65% to 95%, 65% to 90%, 70% to 90%, or 75% to 90% by weight. In some embodiments, the mixed pyrolysis oil comprises 5% to 40% by weight of light pyrolysis oil and 60% to 95% by weight of heavy pyrolysis oil.

[0022] The process may further include upgrading the mixed pyrolysis oil in a slurry phase reaction zone to produce an intermediate product, and hydrocracking the intermediate product in a fixed bed reaction zone to produce BTEX. Although the presently described process is not limited to any particular apparatus, Figure 1 provides a schematic diagram of a system suitable for carrying out embodiments of the process described herein.

[0023] Referring to Figure 1, the upgrading system 10 includes a first reactor 12 and a second reactor 14. In an embodiment, the first reactor 12 can be a slurry reactor (e.g., a fluidized bed slurry reactor) and the second reactor 14 can be a fixed bed reactor. In an embodiment, the catalyst regeneration unit can be a heated liquid-solid separator.

[0024] During operation, heavy pyrolysis oil 15 and light pyrolysis oil 16 can be combined to produce a mixed pyrolysis oil feed 17. The heavy pyrolysis oil 15 can be a bottoms fraction discharged from a naphtha steam cracker (not shown). The light pyrolysis oil 16 can be a bottoms fraction discharged from a gas steam cracker (not shown). The mixed pyrolysis oil feed 17 can be added to a first reactor 12. The first reactor 12 can include a mixed metal oxide catalyst, which is described in more detail below. The mixed pyrolysis oil can be contacted with the mixed metal oxide catalyst while hydrogen gas is being added to the first reactor 12. In an embodiment, the mixed metal oxide catalyst can be added simultaneously with the mixed pyrolysis oil feed 17 so that the liquid and solid phases can mix to produce a slurry in a slurry reactor. After the reaction, the entire slurry can be transferred to a separator 18, which is used to separate the gas product, liquid product, and spent catalyst (solids) via conduit 19. The gas product can be collected via outlet 20, the liquid product can be sent to the second reactor 14 via conduit 22, and the solids can be sent to a catalyst regeneration unit 24 via conduit 25. In the catalyst regeneration unit 24, the catalyst is separated from the remaining polycyclic aromatic compounds and other heavy residues. The catalyst can be collected via conduit 26, and the residue can be recycled back into the mixed pyrolysis oil feed 17 via conduit 27. The collected catalyst can be restored and recycled back into the first reactor 12.

[0025] As previously mentioned, second reactor 14 may be a fixed-bed reactor and may contain a mesoporous zeolite-supported metal catalyst, which is described in more detail below. The liquid product from first reactor 12 may be contacted with the mesoporous zeolite-supported metal catalyst while hydrogen gas is being added to second reactor 14. Optionally, the liquid product from separator 18 may be passed through heat exchanger 28 via conduit 30 to second reactor 14, as shown in FIG. 1, before contacting the mesoporous zeolite-supported metal catalyst. The resulting gaseous products are reacted and separated from the liquid products in separator 32, then discharged via conduit 34 or analyzed, for example, by gas chromatograph 36. The liquid products may be collected in a collector. In embodiments, the liquid products may be cooled by passing through a heat exchanger (not shown) before being collected in collector 38. Various means for controlling flow rates, such as valves and pumps 40, may be used throughout the system if desired.

[0026] Having described an embodiment of a system for carrying out a multi-stage process for upgrading mixed pyrolysis oil, an embodiment of the process will now be described.

[0027] In embodiments, the mixed pyrolysis oil, hydrogen, and mixed metal oxide catalyst are added to a slurry phase reactor. These components can be added simultaneously in some embodiments and at different times in other embodiments. The reactor can be agitated. In embodiments, agitation can include stirring. In other embodiments, agitation can include shaking. In embodiments, the reactor can be agitated by stirring and shaking.

[0028] Contacting the mixed pyrolysis oil with a mixed metal oxide catalyst in a slurry-phase reaction zone decomposes polycyclic aromatic compounds by sequential selective hydrogenation, selective saturated ring opening, hydrodealkylation, transalkylation, and disproportionation, thereby producing two-ring aromatic intermediates, as described in more detail below. An example of such a reaction sequence, beginning with pyrene and ending with methylated naphthalene, is shown in Figure 2. The formation of methylated naphthalene from pyrene is, of course, only one example of a reaction sequence, and other starting materials and products are possible.

[0029] In embodiments, the mixed pyrolysis oil may include one or more polycyclic aromatic compounds. The polycyclic aromatic compounds may be C 16 ~C 110 Polycyclic aromatic compounds, etc., with 16 or more aromatic carbon atoms (C 16 For example, polycyclic aromatic compounds may contain C 16 ~C 100 , C 16 ~C 90 , C 16 ~C 80 , C 16 ~C 70 , C 16 ~C 60 , C 16 ~C 50 , C 16 ~C 40 , C 16 ~C 30 , C 16 ~C 20 , C 20 ~C 110 , C 30 ~C 110 , C 40 ~C 110 , C 50 ~C 110 , C 60 ~C 110 , C 70 ~C 110 , C 80 ~C 110 , C 90 ~C 110 , and even C 100 ~C 110In embodiments, the polycyclic aromatic compound may include multiple fused aromatic rings, such as 3, 4, 5, 6, 7, 8, 9, or 10 fused benzene rings.

[0030] According to one or more embodiments, the mixed pyrolysis oil comprises dicyclopentadiene (DCPD). In some embodiments, the mixed pyrolysis oil comprises DCPD at a concentration of 0.1% to 50%, 0.1% to 20%, 0.2% to 10%, 0.2% to 5%, 0.5% to 5%, 0.5% to 4%, or 1% to 3% by weight. In some embodiments, DCPD consumption can be monitored to assess catalytic activity.

[0031] Reactor conditions, such as the flow rate into the reactor, the temperature within the reactor, and the pressure within the reactor, can be varied to control the reaction in the first reactor. In embodiments, the hydrogen gas flow rate can be between 15 ml / min and 35 ml / min, e.g., between 20 ml / min and 35 ml / min, between 25 ml / min and 35 ml / min, between 30 ml / min and 35 ml / min, between 15 ml / min and 30 ml / min, between 15 ml / min and 25 ml / min, or even between 15 ml / min and 20 ml / min. It is contemplated that the hydrogen flow rate can range from any of the lower limits disclosed herein to any of the upper limits disclosed herein. While not intending to be bound by any particular theory, it is believed that a hydrogen flow rate into the reactor below 15 ml / min may not deliver sufficient levels of hydrogen to the reactor. However, a hydrogen flow rate above 35 ml / min may result in too much hydrogen circulating within the system, resulting in unacceptable hydrogen consumption.

[0032] In embodiments, the pyrolysis oil, diluent, hydrogen, and mixed metal oxide catalyst may reside in the slurry phase reactor for a period of from 1.5 hours to 7.5 hours. For example, the components can reside in the slurry phase reactor for 1.5 to 7 hours, 1.5 to 6.5 hours, 1.5 to 6 hours, 1.5 to 5.5 hours, 1.5 to 5 hours, 1.5 to 4.5 hours, 1.5 to 4 hours, 1.5 to 3.5 hours, 1.5 to 3 hours, 1.5 to 2.5 hours, 1.5 to 2 hours, 2 to 7.5 hours, 2.5 to 7.5 hours, 3 to 7.5 hours, 3.5 to 7.5 hours, 4 to 7.5 hours, 4.5 to 7.5 hours, 5 to 7.5 hours, 5.5 to 7.5 hours, 6 to 7.5 hours, 6.5 to 7.5 hours, or even 7 to 7.5 hours. It is expected that the flow rates of the pyrolysis oil and diluent can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein. Without intending to be bound by any particular theory, it is believed that if the components are allowed to reside in the slurry-phase reactor for less than 1.5 hours, there will not be enough time for one or more of the following processes to proceed to completion: sequential selective hydrogenation, selective ring-opening of saturated rings, hydrodealkylation, transalkylation, and disproportionation. However, if this time is extended beyond 7.5 hours, undesirable by-products will be produced.

[0033] In embodiments, the first reactor of the slurry-phase reaction zone may be operated at a temperature of from 350°C to 450°C, e.g., from 360°C to 450°C, from 370°C to 450°C, from 380°C to 450°C, from 390°C to 450°C, from 400°C to 450°C, from 410°C to 450°C, from 420°C to 450°C, from 430°C to 450°C, from 440°C to 450°C, from 350°C to 440°C, from 350°C to 430°C, from 350°C to 420°C, from 350°C to 410°C, from 350°C to 400°C, from 350°C to 390°C, from 350°C to 380°C, from 350°C to 370°C, or even from 350°C to 360°C. It is expected that the temperature can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein. Without intending to be bound by any particular theory, it is believed that reactor temperatures below 350°C will cause one or more of the sequential selective hydrogenation, selective saturated ring opening, hydrodealkylation, transalkylation, and disproportionation reactions to proceed too slowly to be commercially viable, while reactor temperatures above 450°C will cause one or more of these reactions to proceed too rapidly, resulting in a runaway reaction or premature catalyst deactivation.

[0034] In an embodiment, the first reactor in the slurry phase reaction zone is operated at a pressure of 3 MPa to 18 MPa, 3 MPa to 18 MPa, 3.5 MPa to 18 MPa, 4 MPa to 18 MPa, 4.5 MPa to 18 MPa, 5 MPa to 18 MPa, 5.5 MPa to 18 MPa, 6 MPa to 18 MPa, 6.5 MPa to 18 MPa, 7 MPa to 18 MPa, 7.5 MPa to 18 MPa, 8 MPa to 18 MPa, 8.5 MPa to 18 MPa, 9 MPa to 18 MPa, 9.5 MPa to 18 MPa, 10 MPa to 18 MPa, 10.5 MPa to 18 MPa, 11 MPa to 18 MPa, 11.5 MPa to 18 MPa, 12 MPa to 18 MPa, 12.5 MPa to 18 MPa, 13 MPa to 18 MPa, 13.5 MPa to 18 MPaMPa, 14MPa to 18 MPaMPa, 14.5MPa to 18 MPaMPa, 15MPa to 18 MPaMPa, 15.5MPa to 18 MPaMPa, 16MPa to 18 MPaMPa, 3MPa to 17.5 MPaMPa, 3MPa to 17 MPaMPa, 3MPa to 16.5 MPaMPa, 3MPa to 16 MPaMPa, 3MPa to 15.5 MPaMPa, 3MPa to 15 MPaMPa, 3MPa to 14.5 MPaMPa, 3MPa to 14 MPaMPa, 3MPa to 13.5 MPaMPa, 3MPa to 13 MPaMPa, 3MPa to 12.5 MPaMPa, 3MPa to 12 MPaMPa, 3MPa to 11.5 MPaMPa, 3MPa to 11 MPaMPa, 3MPa to 10.5 MPaMPa, 3MPa to 10 MPaMPa, 3MPa to 9.5 MPaMPa, 3MPa to 9 MPaMPa, 3MPa to 8.5 It may operate at pressures of 3 MPa to 8 MPa, 3 MPa to 7.5 MPa, 3 MPa to 7 MPa, 3 MPa to 6.5 MPa, 3 MPa to 6 MPa, 3 MPa to 5.5 MPa, or even 3 MPa to 5 MPa.It is expected that the pressure can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein. Without intending to be bound by any particular theory, it is believed that a pressure lower than 3 MPa would be insufficient to allow one or more of the following to occur: sequential selective hydrogenation, selective ring-opening of saturated rings, hydrodealkylation, transalkylation, and disproportionation. However, a pressure higher than 18 MPa would require dedicated high-pressure equipment, which would increase the cost of carrying out the reaction.

[0035] The slurry-phase reactor includes a mixed metal oxide catalyst. In embodiments, the mixed metal oxide catalyst includes two or more of Fe2O3, ZrO2, CeO2, Al2O3, TiO2, MoO3, Co2O3, and NiO. In embodiments, the mixed metal oxide catalyst may include 50% to 98%, 55% to 95%, 60% to 95%, 65% to 95%, 65% to 90%, 70% to 90%, 75% to 90%, or 80% to 85% Fe2O3 by weight. In some embodiments, the mixed metal oxide catalyst may include 1% to 60%, 2% to 60%, 2% to 50%, 2% to 40%, 2% to 30%, 2% to 20%, 2% to 15%, 3% to 15%, 3% to 10%, 5% to 10%, or 7% to 8% by weight of ZrO. According to one or more embodiments, the mixed metal oxide catalyst may include 0.5% to 10%, 0.5% to 7%, 0.5% to 5%, 1% to 5%, 1% to 4%, 2% to 4%, or 2% to 3% by weight of CeO. In some embodiments, the mixed metal oxide catalyst may comprise 1% to 50%, 1% to 40%, 1% to 30%, 1% to 20%, 2% to 20%, 2% to 15%, 3% to 15%, 3% to 12%, 5% to 10%, or 6% to 8% by weight of Al2O3, where the weight percentages are calculated based on the total amount of oxides.

[0036] After contacting the pyrolysis oil with the mixed metal oxide catalyst, gas, liquid, and solid phases are produced, which can be separated from one another. The gas phase can be discharged or collected. It is convenient to analyze the gas phase before collection or discharge so that the balance of materials before and after the reaction can be calculated. The solid phase includes the spent mixed metal oxide catalyst, which can be recycled to the slurry-phase reactor. The liquid phase includes the intermediate product, which is sent to the fixed-bed reaction zone for further processing. In embodiments, the intermediate product may include two-ring aromatic compounds and one-ring aromatic compounds. Examples of two-ring aromatic compounds include, but are not limited to, naphthalene and tetralin, both of which may be unsubstituted or substituted with linear or branched hydrocarbon substituents. Examples of one-ring aromatic compounds include, but are not limited to, benzene, which may be unsubstituted or substituted with linear or branched hydrocarbon substituents.

[0037] In embodiments, 90% to 100% of the pyrolysis oil may be converted to intermediate products. For example, 90% to 99%, 90% to 98%, 90% to 97%, 90% to 96%, 90% to 95%, 90% to 94%, 90% to 93%, 90% to 92%, 90% to 91%, 91% to 100%, 92% to 100%, 93% to 100%, 94% to 100%, 95% to 100%, 96% to 100%, 97% to 100%, 98% to 100%, or even 99% to 100% of the pyrolysis oil may be converted to intermediate products. It is expected that the yield of the intermediate products can range from any of the lower limits disclosed herein to any of the upper limits disclosed herein.

[0038] The vapor phase can be sent to a second reactor in the fixed bed reaction zone. In embodiments, an optional heat exchanger can be located between the slurry reaction zone and the fixed bed reaction zone so that the temperature of the liquid phase can be controlled before it is introduced into the fixed bed reactor. The optional heat exchanger can help control the temperature of the liquid intermediate product to a temperature sufficient to avoid condensation of the intermediate product between the slurry reactor and the fixed bed reactor.

[0039] As described in more detail below, the intermediate from the slurry-phase reaction zone is contacted with a mesoporous zeolite-supported metal catalyst in a fixed-bed reactor to produce BTEX by selective hydrogenation, selective ring-opening of saturated rings, and further hydrodealkylation, transalkylation, and disproportionation. This reaction sequence, starting with naphthalene and ending with BTEX, is shown in Figure 3. In the case of over-cracking, saturated hydrocarbons may also be produced. The formation of BTEX from naphthalene is, of course, only one example of a reaction sequence, and other starting materials are contemplated.

[0040] Reactor conditions, such as the flow rate into the fixed-bed reactor, the temperature within the reactor, and the pressure within the reactor, can be varied to control the reaction in the second reactor. In embodiments, the hydrogen gas flow rate can be from 15 ml / min to 35 ml / min, e.g., 20 ml / min to 35 ml / min, 25 ml / min to 35 ml / min, 30 ml / min to 35 ml / min, 15 ml / min to 30 ml / min, 15 ml / min to 25 ml / min, or even 15 ml / min to 20 ml / min. It is contemplated that the hydrogen flow rate can range from any of the lower limits disclosed herein to any of the upper limits disclosed herein. While not intending to be bound by any particular theory, it is believed that a hydrogen flow rate into the reactor below 15 ml / min does not deliver sufficient levels of hydrogen to the reactor. However, a hydrogen flow rate above 35 ml / min circulates too much hydrogen within the system, resulting in unacceptable hydrogen consumption.

[0041] In embodiments, the flow rate of the liquid product stream from the slurry-phase reaction zone can be from 0.2 g / min to 1 g / min, e.g., from 0.3 g / min to 1 g / min, from 0.4 g / min to 1 g / min, from 0.5 g / min to 1 g / min, from 0.6 g / min to 1 g / min, from 0.7 g / min to 1 g / min, from 0.8 g / min to 1 g / min, from 0.9 g / min to 1 g / min, from 0.2 g / min to 0.9 g / min, from 0.2 g / min to 0.8 g / min, from 0.2 g / min to 0.7 g / min, from 0.2 g / min to 0.6 g / min, from 0.2 g / min to 0.5 g / min, from 0.2 g / min to 0.4 g / min, or even from 0.2 g / min to 0.3 g / min. It is expected that the flow rate of the liquid product stream from the slurry-phase reaction zone can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein. Any convenient device for controlling the flow rate, such as a liquid pump, may be used. Without intending to be bound by any particular theory, it is believed that a flow rate of the liquid product stream from the slurry-phase reaction zone less than 0.2 g / min does not allow a sufficient level of liquid product stream to be delivered to the reactor. However, a flow rate greater than 1 g / min circulates too much liquid product stream within the system, leaving an unacceptable amount of liquid product stream unreacted upon exiting the reactor.

[0042] In embodiments, the second reactor of the fixed bed reaction zone can be operated at a temperature of from 350° C. to 450° C., e.g., from 360° C. to 450° C., from 370° C. to 450° C., from 380° C. to 450° C., from 390° C. to 450° C., from 400° C. to 450° C., from 410° C. to 450° C., from 420° C. to 450° C., from 430° C. to 450° C., from 440° C. to 450° C., from 350° C. to 440° C., from 350° C. to 430° C., from 350° C. to 420° C., from 350° C. to 410° C., from 350° C. to 400° C., from 350° C. to 390° C., from 350° C. to 380° C., from 350° C. to 370° C., or even from 350° C. to 360° C. It is contemplated that the temperature can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein. The temperature in the fixed bed reactor may, but need not be, the same as the temperature in the slurry phase reactor. Without intending to be bound by any particular theory, it is believed that if the reactor temperature is below 350°C, the selective hydrogenation, selective ring opening of saturated rings, and further one or more of the hydrodealkylation, transalkylation, and disproportionation reactions will proceed too slowly to be commercially viable, while if the reactor temperature is above 450°C, one or more of these reactions will proceed too rapidly, resulting in a runaway reaction or premature catalyst deactivation.

[0043] In embodiments, the second reactor in the fixed bed reaction zone is operated at a pressure of 3 MPa to 18 MPa, 3.5 MPa to 18 MPa, 4 MPa to 18 MPa, 4.5 MPa to 18 MPa, 5 MPa to 18 MPa, 5.5 MPa to 18 MPa, 6 MPa to 18 MPa, 6.5 MPa to 18 MPa, 7 MPa to 18 MPa, 7.5 MPa to 18 MPa, 8 MPa to 18 MPa, 8.5 MPa to 18 MPa, 9 MPa to 18 MPa, 9.5 MPa to 18 MPa, 10 MPa to 18 MPa, 10.5 MPa to 18 MPa, 11 MPa to 18 MPa, 11.5 MPa to 18 MPa, 12 MPa to 18 MPa, 12.5 MPa to 18 MPa, 13 MPa to 18 MPa, 13.5 MPa to 18 MPa, 14 MPa to 18 MPa, 14.5 MPa to 18 MPa, 15 MPa to 18 MPa, 15.5 MPa to 18 MPa, The present invention can be operated at pressures ranging from 1 to 18 MPa, 16 MPa to 18 MPa, 3 MPa to 17.5 MPa, 3 MPa to 17 MPa, 3 MPa to 16.5 MPa, 3 MPa to 16 MPa, 3 MPa to 15.5 MPa, 3 MPa to 15 MPa, 3 MPa to 14.5 MPa, 3 MPa to 14 MPa, 3 MPa to 13.5 MPa, 3 MPa to 13 MPa, 3 MPa to 12.5 MPa, 3 MPa to 12 MPa, 3 MPa to 11.5 MPa, 3 MPa to 11 MPa, 3 MPa to 10.5 MPa, 3 MPa to 10 MPa, 3 MPa to 9.5 MPa, 3 MPa to 9 MPa, 3 MPa to 8.5 MPa, 3 MPa to 8 MPa, 3 MPa to 7.5 MPa, 3 MPa to 7 MPa, 3 MPa to 6.5 MPa, 3 MPa to 6 MPa, 3 MPa to 5.5 MPa, or even 3 MPa to 5 MPa. It is anticipated that the pressure can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein. The pressure in the fixed-bed reaction zone may, but need not, be the same as the pressure in the slurry-phase reactor. Without intending to be bound by any particular theory, it is believed that pressures below 3 MPa would be insufficient for selective hydrogenation, selective ring-opening of saturated rings, and further one or more of hydrodealkylation, transalkylation, and disproportionation to occur. However, pressures above 18 MPa would require dedicated high-pressure equipment.This would increase the cost of carrying out the reaction.

[0044] The fixed bed reactor includes a mesoporous zeolite-supported metal catalyst. In embodiments, the metal of the mesoporous zeolite-supported metal catalyst includes molybdenum, tungsten, or a combination thereof. According to one or more embodiments, the metal of the mesoporous zeolite-supported metal catalyst includes molybdenum, tungsten, or a combination thereof, and further includes nickel, cobalt, or a combination thereof. In some embodiments, the mesoporous zeolite-supported metal catalyst includes 2% to 20%, 3% to 20%, 3% to 18%, 3% to 15%, 5% to 15%, 7% to 13%, 8% to 12%, or 9% to 11% by weight of molybdenum. According to one or more embodiments, the mesoporous zeolite-supported metal catalyst comprises 0.1 to 10 wt%, 0.1 to 5 wt%, 0.2 to 5 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, 1 to 3 wt%, or 1.5 to 2.5 wt% nickel, cobalt, or a combination thereof. In some embodiments, the mesoporous zeolite-supported metal catalyst comprises 2 to 20 wt% molybdenum and 0.1 to 5 wt% nickel, cobalt, or a combination thereof. According to one or more embodiments, the mesoporous zeolite-supported metal catalyst comprises 0.1 to 10 wt%, 0.1 to 5 wt%, 0.2 to 5 wt%, 0.5 to 5 wt%, 0.5 to 3 wt%, 1 to 3 wt%, or 1.5 to 2.5 wt% nickel. In some embodiments, the mesoporous zeolite supported metal catalyst comprises 5% to 15% by weight molybdenum and 0.5% to 3% by weight nickel.

[0045] Mesoporous zeolite-supported metal catalysts include zeolite supports. Generally, zeolites can be characterized by a framework type that defines their mesoporous structure. The presently described zeolites, in one or more embodiments, are not particularly limited by framework type. Framework types are described, for example, in "Atlas of Zeolite Framework Types," Ch. Baerlocher et al., 5th Rev. ed., 2001, incorporated herein by reference. In embodiments, the zeolite may be, among others, * They may have a microstructure (including micropores) characterized as a BEA framework-type zeolite (such as, but not limited to, Beta zeolite), an FAU framework-type zeolite (such as, but not limited to, Y zeolite), an MOR framework-type zeolite, or an MFI framework-type zeolite (such as, but not limited to, ZSM-5). * It should be understood that BEA, MFI, MOR, and FAU refer to zeolite framework types identified by their respective three-letter codes established by the International Zeolite Association (IZA). Other framework types are contemplated in the presently disclosed embodiments. In embodiments, the zeolite support of the mesoporous zeolite-supported metal catalyst comprises a zeolite selected from the group consisting of beta zeolite, ZSM-5, mordenite, Y zeolite, and combinations thereof. In some embodiments, the zeolite support comprises a zeolite selected from the group consisting of beta zeolite, Y zeolite, or combinations thereof. According to one or more embodiments, the zeolite support comprises beta zeolite.

[0046] In some embodiments, the zeolite support of the mesoporous zeolite-supported metal catalyst has a silica-to-alumina molar ratio (SiO2 / Al2O3) of from 10 to 50. According to one or more embodiments, the zeolite support has a silica-to-alumina molar ratio of from 5 to 50, 10 to 50, 15 to 50, 20 to 50, 20 to 45, 25 to 45, 30 to 45, 30 to 40, or 35 to 40.

[0047] After contacting the liquid-phase intermediate product with the mesoporous zeolite-supported metal catalyst in the fixed-bed reaction zone, a gas phase and a liquid phase are produced. The gas and liquid phases can be separated from each other using a liquid-gas separator. The gas phase can be discharged or collected. The gas phase is conveniently analyzed before collection or discharge so that the material balance before and after the reaction can be calculated. The liquid phase, including BTEX, can be cooled, for example, using a heat exchanger, and then collected.

[0048] In embodiments, 25% to 45% by weight of the mixed pyrolysis oil can be converted to BTEX (the "total yield"). For example, the total yield can be 10% to 50%, 15% to 50%, 20% to 50%, 20% to 45%, 25% to 45%, 30% to 45%, 35% to 45%, or 38% to 42%. It is expected that the total yield can be from any of the lower limits disclosed herein to any of the upper limits disclosed herein.

[0049] In some embodiments, the multi-stage process consumes 80% to 100% of the DCPD in the mixed pyrolysis oil. According to one or more embodiments, the multi-stage process consumes 40% to 100%, 50% to 100%, 60% to 100%, 65% to 100%, 70% to 100%, 80% to 100%, 85% to 100%, 90% to 100%, 95% to 100%, or 98% to 100% of the DCPD in the mixed pyrolysis oil.

[0050] The embodiments described herein can help limit the aromatic content in fuels, thereby helping to protect the environment. Furthermore, the embodiments enable the production of aromatic compounds that are valuable in industry as intermediates under relatively mild conditions. For example, pyrolysis oil can now be used as a feedstock to produce para-xylene, a well-known intermediate for PTA production.

[0051] Embodiments of the present disclosure include a first embodiment that includes a multi-stage process for upgrading mixed pyrolysis oil containing polycyclic aromatic compounds to benzene, toluene, ethylbenzene, and xylenes (BTEX), the process including combining a light pyrolysis oil with a heavy pyrolysis oil to form a mixed pyrolysis oil; upgrading the mixed pyrolysis oil in a slurry phase reaction zone to produce an intermediate product, the slurry phase reaction zone comprising a mixed metal oxide catalyst; and hydrocracking the intermediate product in a fixed bed reaction zone to produce BTEX, the fixed bed reaction zone comprising a mesoporous zeolite-supported metal catalyst.

[0052] A second embodiment includes the first embodiment, wherein the mixed metal oxide catalyst includes two or more of Fe2O3, ZrO2, CeO2, Al2O3, TiO2, MoO3, Co2O3, and NiO.

[0053] A third embodiment includes the first and second embodiments, wherein the mixed metal oxide catalyst comprises 70 to 90 wt.% Fe2O3, 5 to 60 wt.% ZrO2, 1 to 4 wt.% CeO2, and 5 to 10 wt.% Al2O3, where the wt.% are calculated based on the total weight of the oxides.

[0054] A fourth embodiment includes any of the first through third embodiments, wherein the metal of the mesoporous zeolite-supported metal catalyst comprises molybdenum.

[0055] A fifth embodiment includes any of the first through fourth embodiments, wherein the metal of the mesoporous zeolite supported metal catalyst further comprises nickel, cobalt, or a combination thereof.

[0056] A sixth embodiment includes any of the first to fifth embodiments, wherein the mesoporous zeolite supported metal catalyst comprises 2% to 20% by weight of molybdenum.

[0057] A seventh embodiment includes any of the first through sixth embodiments, wherein the mesoporous zeolite supported metal catalyst further comprises 0.1% to 5% by weight of nickel, cobalt, or a combination thereof.

[0058] An eighth embodiment includes any of the first to seventh embodiments, wherein the mesoporous zeolite supported metal catalyst comprises 5% to 15% by weight molybdenum, and 0.5% to 3% by weight nickel.

[0059] A ninth embodiment includes any of the first through eighth embodiments, wherein the zeolite support comprises a zeolite selected from the group consisting of beta zeolite, ZSM-5, mordenite, Y zeolite, and combinations thereof.

[0060] A tenth embodiment includes any of the first through ninth embodiments, wherein the zeolite support comprises a zeolite selected from the group consisting of beta zeolite, Y zeolite, and combinations thereof.

[0061] An eleventh embodiment includes any of the first to tenth embodiments, wherein the zeolite support has a silica to alumina ratio of 10 to 50.

[0062] A twelfth embodiment includes any of the first through eleventh embodiments, wherein the zeolite support has a silica to alumina ratio of from 20 to 45.

[0063] A thirteenth embodiment includes any of the first through twelfth embodiments, wherein the zeolite support comprises beta zeolite.

[0064] A fourteenth embodiment includes any of the first through thirteenth embodiments, wherein the zeolite support has a silica to alumina ratio of from 20 to 45.

[0065] A fifteenth embodiment includes any of the first through fourteenth embodiments, wherein the zeolite support has a silica to alumina ratio of 35 to 40.

[0066] A sixteenth aspect includes any of the first through fifteenth aspects, wherein between 25% and 45% of the mixed pyrolysis oil is converted to BTEX.

[0067] A seventeenth embodiment includes any of the first to sixteenth embodiments, wherein the mixed pyrolysis oil comprises 5% to 40% by weight of light pyrolysis oil and 60% to 95% by weight of heavy pyrolysis oil.

[0068] An eighteenth embodiment includes any of the first to seventeenth embodiments, wherein the mixed pyrolysis oil includes dicyclopentadiene.

[0069] A nineteenth embodiment includes any of the first through eighteenth embodiments, wherein the multi-stage process consumes between 80% and 100% of the dicyclopentadiene in the mixed pyrolysis oil.

[0070] A twentieth aspect of the present disclosure includes any of the first through nineteenth aspects, wherein the multi-stage process consumes between 95% and 100% of the dicyclopentadiene in the mixed pyrolysis oil. [Example]

[0071] Using the previously described embodiments, an exemplary scheme for producing BTEX was carried out.

[0072] Synthesis of mixed metal oxide catalysts An exemplary mixed metal oxide catalyst was formulated to have a composition of 83 wt% Fe2O3, 7.5 wt% ZrO2, 2.5 wt% CeO2, and 7 wt% Al2O3. The concentrations were calculated on an oxide basis. Fe(NO3)3·9H2O (40 g) was dissolved in 800 ml of distilled water to form solution A. Al(NO3)3·9H2O (4.906 g), ZrO(NO3)2 (1.549 g), and Ce(NO3)3·6H2O (0.601 g) were added to solution A to form solution B, which was stirred for 30 minutes. Ammonium hydroxide solution (40 ml, 23%-30% NH3 basis) was mixed with 60 ml of distilled water to form solution C. Solution B was titrated to pH 7 by slowly adding solution C. The appropriately titrated solution was mixed for 1 hour, thereby forming a precipitate. The precipitate was isolated and dried in an oven overnight. The dried solid was then calcined in air at 500°C for 2 hours. The calcined product was crushed to obtain the final mixed metal oxide catalyst as a powder.

[0073] Synthesis of mesoporous zeolite-supported metal catalysts Six different mesoporous zeolite-supported metal (MZM) catalysts were prepared according to the following general procedure: Appropriate amounts of metal precursor and zeolite were added to 100 mL of water in a 250 mL round-bottom flask equipped with a magnetic stir bar. The mixture was stirred at 500 rpm for 1 hour, at which point it was homogeneous. Water was removed under vacuum at 50°C on a rotary evaporator. The solid was dried overnight at 100°C. The dried solid was calcined at 550°C for 5 hours to obtain the catalyst.

[0074] Each of the prepared catalysts is detailed in Table 1. The zeolites used in the study were purchased from Zeolyst International. Specifically, zeolite Beta (SiO2 / Al2O3 ratio: 38) corresponds to Zeolyst product CP814C; zeolite Beta (SiO2 / Al2O3 ratio: 25) corresponds to Zeolyst product CP814E; zeolite Y (SiO2 / Al2O3 ratio: 30) corresponds to Zeolyst product CBV720; and zeolite Y (SiO2 / Al2O3 ratio: 12) corresponds to Zeolyst product CBV712.

[0075] The metal precursors used to prepare the MZM catalysts were purchased from Aldrich. The Mo precursor was (NH4)6Mo7O 24 ·4H2O, the Ni precursor was Ni(NO3)2·6H2O, and the Co precursor was Co(NO3)2·6H2O.

[0076] [Table 1]

[0077] Each catalyst was pretreated before use in the process. To pretreat, the catalyst was added to a fixed-bed reactor, which was then heated to 400°C at a heating rate of 5°C / min under a hydrogen flow of 25 ml / min and atmospheric pressure. Once the reactor temperature reached 400°C, the reactor was pressurized to 3 MPa with hydrogen gas, and the hydrogen flow was then maintained at a rate of 25 ml / min.

[0078] Obtaining BTEX from mixed pyrolysis oils Heavy pyrolysis oil (16 g) was combined with light pyrolysis oil (4 g) to form a mixed pyrolysis oil feed. The composition of the heavy pyrolysis oil is detailed in Table 2, and the composition of the light pyrolysis oil is detailed in Table 3.

[0079] [Table 2]

[0080] [Table 3]

[0081] The mixed pyrolysis oil feed and mixed metal oxide catalyst (5 g), prepared as described above, were added to a slurry reactor. The reactor was purged with hydrogen gas three times before being pressurized with hydrogen gas to 14 MPa. The mixture was then heated to 400°C and continuously stirred for 4 hours. The reaction mixture was cooled to room temperature, and the gas mixture was vented and collected in a gas bag. The slurry was transferred to a centrifuge tube and centrifuged at 10,000 rpm for 20 minutes, after which two layers were present. The top layer was the first-stage liquid product, and the bottom layer was the solid spent metal oxide catalyst. The spent metal oxide catalyst was washed with toluene to remove any possible condensates and dried under vacuum at 20°C to 100°C.

[0082] The first-stage liquid product was analyzed by simulated distillation (SIMDIS) gas chromatography, gas chromatography with vacuum ultraviolet absorption (GC-VUV), and high-performance liquid chromatography (HPLC). Based on the analysis, the first-stage liquid product contained 14.46 wt% two-ring aromatic compounds, 73.13 wt% single-ring aromatic compounds, 8.75 wt% dicyclopentadiene (DCPD), and 3.66 wt% BTEX.

[0083] This first-stage liquid product was fed at a rate of 0.6 g / hr to a fixed-bed reactor containing 0.5 g of pretreated catalyst. The fixed-bed reactor stage was repeated for each MZM catalyst. A fixed-bed reactor stage was also performed with a silicon carbide (SiC) catalyst for blank comparison. In each experiment, the reactor temperature was maintained at 400°C at 3 MPa. The hydrogen flow was maintained at a rate of 25 ml / min, and the reaction was allowed to proceed for 24 hours. After each reaction, the product mixture was separated into gaseous and liquid components and analyzed. The product mixture for each example is summarized in Table 4.

[0084] [Table 4]

[0085] Based on the product mixture, the overall BTEX yield and DCPD consumption were calculated. The use of silicon carbide as a catalyst did not substantially change the composition of the first-stage liquid product (see Comparative Example 1). Each of the MXM catalysts increased the amount of BTEX and decreased the amount of DCPD from the first-stage liquid product. The overall BTEX yield from the mixed pyrolysis oil, as well as DCPD consumption, are shown in Table 5.

[0086] [Table 5]

[0087] Using silicon carbide as the catalyst, the BTEX yield was negligible (3.93%) and only 6.77% DCPD was consumed. All of the MZM catalysts consumed at least 30% of the DCPD and gave BTEX yields of at least 8%. None of Examples 1-3, all of which featured catalysts with only Mo as the metal and Y-type zeolite supports, gave BTEX yields greater than 10.5%. By far the best results were obtained with MXM4 (40.44% BTEX yield and 97.46% DCPD consumption) and MXM5 (33.62% BTEX yield and 95.46% DCPD consumption). MXM4, which contains Mo and Ni, performed slightly better than MXM5, which contains Mo and Co. Both MXM4 and MXM5 contain beta zeolite with a silica-to-alumina ratio of 38 (see Table 1). In particular, as can be seen by comparing Example 4 with Example 6, changing the silica to alumina ratio from 38 to 25 significantly reduced the catalytic performance.

[0088] It should be noted that references in this disclosure to components of the disclosure being "operable" or "sufficient" in a particular way to embody certain properties or to function in a particular manner are structural references, as opposed to references to intended use. More specifically, references in this disclosure to aspects in which a component is "operable" or "sufficient" refer to the existing physical state of the component and are therefore considered express references to the structural characteristics of the component.

[0089] Nouns include plural referents unless otherwise specified.

[0090] Throughout this disclosure, ranges are given. Each individual value encompassed within those ranges is also contemplated. In addition, ranges that can be formed at each individual value encompassed within an expressly disclosed range are equally contemplated.

[0091] As used in this disclosure and the appended claims, the words "comprise," "has," and "include," as well as grammatical variations thereof, are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

[0092] As used in this disclosure, terms such as "first" and "second" are assigned arbitrarily and are intended only to distinguish between two or more instances or components. It should be understood that the words "first" and "second" serve no other purpose, are not part of the name or description of the component, and do not necessarily define the relative location, position, or order of the components. Furthermore, it should be understood that the mere use of the terms "first" and "second" does not require that there be an optional "third" component, the possibility of which is contemplated within the scope of this disclosure.

[0093] Although the subject matter of the present disclosure has been described in detail and with reference to specific embodiments, it should be noted that various details disclosed in this disclosure should not be construed to imply that these details relate to elements that are essential constituents of the various embodiments described in this disclosure. Moreover, it will be apparent that modifications and variations are possible without departing from the scope of the present disclosure, including but not limited to the embodiments defined in the appended claims. [Explanation of symbols]

[0094] 10 Upgrade System 12 First Reactor 14 Second Reactor 15 Heavy pyrolysis oil 16 Light pyrolysis oil 17 Mixed Pyrolysis Oil Feed 18, 32 Separation device 19, 22, 25, 27, 30, 34 conduit 20 Outlet 24 Catalyst Regeneration Unit 28 Heat exchanger 36 Gas chromatograph 40 Pump

Claims

1. In a multi-stage process for upgrading mixed pyrolysis oil containing polycyclic aromatic compounds to benzene, toluene, ethylbenzene, and xylenes (BTEX), blending the light pyrolysis oil with the heavy pyrolysis oil to form a blended pyrolysis oil; upgrading the mixed pyrolysis oil in a slurry phase reaction zone to produce an intermediate product, the slurry phase reaction zone containing a mixed metal oxide catalyst; and hydrocracking the intermediate product in a fixed bed reaction zone to produce the BTEX, the fixed bed reaction zone comprising a metal catalyst supported on a mesoporous zeolite; A multi-step process involving:

2. The mixed metal oxide catalyst comprises Fe ２ O ３ , ZrO ２ , CeO ２ , Al ２ O ３ , TiO ２ , MoO ３ , Co ２ O ３ 10. The multi-step process of claim 1, comprising two or more of:

3. the mixed metal oxide catalyst 70% to 90% by weight of Fe ２ O ３ , 5% to 60% by weight of ZrO ２ , 1% to 4% by weight of CeO ２ , and 5% to 10% by weight of Al ２ O ３ , Including, 3. The multi-stage process of claim 1, wherein the weight percentages are calculated based on the total weight of the oxides.

4. 4. The multi-step process of claim 1, wherein the metal of the mesoporous zeolite supported metal catalyst comprises molybdenum.

5. 5. The multi-step process of claim 1, wherein the metal of the mesoporous zeolite supported metal catalyst further comprises nickel, cobalt, or a combination thereof.

6. 6. The multi-stage process of claim 1, wherein the mesoporous zeolite supported metal catalyst comprises from 2% to 20% by weight of molybdenum.

7. 7. The multi-stage process of claim 1, wherein the mesoporous zeolite-supported metal catalyst further comprises 0.1% to 5% by weight of nickel, cobalt, or a combination thereof.

8. The mesoporous zeolite-supported metal catalyst is 5% to 15% by weight of molybdenum, and 0.5% to 3% by weight of nickel, 8. The multi-step process of claim 1, comprising:

9. 9. The multi-stage process of any one of claims 1 to 8, wherein the zeolite support comprises a zeolite selected from the group consisting of beta zeolite, ZSM-5, mordenite, Y zeolite, and combinations thereof.

10. 10. The multi-stage process of any one of claims 1 to 9, wherein the zeolite support has a silica to alumina ratio of from 10 to 50.

11. 11. The multi-stage process of claim 1, wherein the zeolite support comprises zeolite beta.

12. 12. The multi-stage process of any one of claims 1 to 11, wherein 25% to 45% of the mixed pyrolysis oil is converted to BTEX.

13. The mixed pyrolysis oil is 5% to 40% by weight of light pyrolysis oil, and 60% to 95% by weight of heavy pyrolysis oil; 13. The multi-step process of any one of claims 1 to 12, comprising:

14. 14. The multi-stage process of any one of claims 1 to 13, wherein the mixed pyrolysis oil comprises dicyclopentadiene.

15. 15. The multi-stage process of claim 14, wherein the multi-stage process consumes 95% to 100% of the dicyclopentadiene in the mixed pyrolysis oil.

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