Method for producing low-boiling point compound through hydrocracking of cracking heavy oil and catalyst used therefor

Abstract

Provided are: a method for producing a low-boiling point compound having a boiling point of 150°C or lower, the method being characterized by hydrocracking cracking heavy oil in the presence of a catalyst for hydrocracking cracking heavy oil, wherein the catalyst includes a zeolite supporting a metal sulfide obtained by sulfurizing a metal-supporting zeolite with sulfur or a sulfur compound; a catalyst for hydrocracking cracking heavy oil, used in said method; a method for producing a low-boiling point compound having a boiling point of 150°C or lower by hydrocracking cracking heavy oil by said production method; a catalyst used for hydrocracking; and a method for producing the catalyst.

Description

Method for producing light boiling point compounds by hydrocracking of cracked heavy oil and catalyst used therein

[0001] The present invention relates to a method for producing light-boiling compounds by hydrocracking cracked heavy oil and a catalyst used therein, and more specifically to a method for producing light-boiling compounds by hydrocracking cracked heavy oil using a catalyst for hydrocracking cracked heavy oil and a catalyst for hydrocracking cracked heavy oil used therein.

[0002] Cracked fuel oil is a heavy fraction produced during the naphtha cracking process. It is composed of polycyclic aromatic compounds and has low sulfur and nitrogen content. As such, it is used in part as a raw material in the field of carbon materials such as carbon black, but most of it is consumed as fuel equivalent to heavy oil C.

[0003] In recent years, carbon dioxide emissions have been restricted from the viewpoint of carbon neutrality, and therefore it has become necessary to switch over to using cracked heavy oil as fuel, which emits large amounts of carbon dioxide. For example, if monocyclic aromatic compounds (light boiling point compounds with a boiling point of 150°C or less) such as benzene, toluene, and xylene can be produced from cracked heavy oil, the CO2 emissions from fuel use can be reduced. ２ Since carbon dioxide emissions can be avoided and used as a raw material for other chemical products, carbon dioxide emissions can be reduced.

[0004] Technologies for effectively utilizing heavy oil composed of polycyclic aromatic compounds have been known (Patent Documents 1 to 4). For example, Patent Document 1 describes a technology for converting heavy oil composed of polycyclic aromatic compounds into BTX. However, the properties of the heavy oil are a boiling point of 230°C or less, which differs from the cracked heavy oil described in this patent (containing 40% or more of components with a boiling point of 230°C or higher). Patent Document 2 describes a heavy oil upgrading technology, but does not convert polycyclic aromatic compounds to monocyclic aromatic compounds; it only removes impurities containing heteroelements. Patent Document 3 describes a technology for upgrading heavy crude oil. Patent Document 4 describes a method for obtaining monocyclic aromatic compounds by upgrading thermally cracked oil, but the examples only describe cracking using model substances and do not mention application to bottom oil containing trace amounts of catalyst-poisoning substances such as sulfur and nitrogen. Patent Document 5 also uses a strong acid, a heteropolyacid, as a catalyst, which is thought to promote coking of heavy components, such as tricyclic aromatic compounds, contained in ethylene bottom oil, resulting in catalyst deactivation and reduced selectivity for light components.

[0005] Therefore, there was no prior art technology for producing light boiling compounds with boiling points of 150°C or less by hydrocracking cracked heavy oil.

[0006] Japanese Patent No. 7185625, Special Publication No. 2020-520338, Japanese Patent No. 6204471, Special Publication No. 2022-539121, Japanese Patent Application Laid-Open No. 2023-117818

[0007] Therefore, an object of the present invention is to provide a method for producing light-boiling compounds having a boiling point of 150° C. or less by hydrocracking cracked heavy oil, a catalyst to be used in hydrocracking, and a method for producing the same.

[0008] As a result of intensive research to solve the above problems, the present inventors have found that a catalyst that has undergone a specific treatment is excellent for hydrocracking of cracked heavy oil, that this catalyst can be obtained by a specific treatment, and that low-boiling compounds having a boiling point of 150°C or less can be produced from cracked heavy oil by hydrocracking using the catalyst, thereby completing the present invention.

[0009] That is, the present invention provides the following: 1) A method for producing light-boiling compounds having a boiling point of 150°C or less, which comprises hydrocracking cracked heavy oil in the presence of a catalyst for hydrocracking cracked heavy oil, the catalyst comprising a zeolite carrying a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound. 2) The sulfur compounds are represented by the following general formula (1): (In formula (1), R １ , R ２ each independently represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R １ , R ２may be bonded to each other to form a cyclic structure. n represents 2 to 10. 3) The method according to 1) or 2), wherein the metal is one or more metals selected from the group consisting of Groups 6, 9, and 10. 4) The method according to any one of 1) to 3), wherein the low-boiling point compound is a hydrocarbon having 1 to 8 carbon atoms and a monocyclic aromatic compound. 5) The method according to any one of 1) to 4), wherein the catalyst for hydrocracking of cracked heavy oil is prepared in the same system as that for hydrocracking of cracked heavy oil. 6) The method according to any one of 12) to 5), wherein the metal-supported zeolite is a zeolite in which a metal is supported on the zeolite in the presence of a chelating agent. 7) The method according to any one of 1) to 6), wherein the metal-supported zeolite includes a binder. 8) The method according to 7), wherein the binder is one or more binders selected from the group consisting of boehmite, alumina, silica, clay, titania, zirconia, and ceria. 9) A catalyst for hydrocracking of cracked heavy oil, comprising a zeolite supported with a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound. 10) The catalyst according to 9), wherein the sulfur compound is represented by the above general formula (1). 11) The catalyst according to 9) or 10), wherein the metal is one or more metals selected from the group consisting of Groups 6, 9, and 10. 12) The catalyst according to any one of 9) to 11), wherein the metal-supported zeolite is a zeolite supported with a metal in the presence of a chelating agent. 13) The catalyst according to any one of 9) to 12), wherein the metal-supported zeolite includes a binder. 14) The catalyst according to 13), wherein the binder is one or more binders selected from the group consisting of boehmite, alumina, silica, clay, titania, zirconia, and ceria. 15) A method for producing a catalyst for hydrocracking of cracked heavy oil, comprising a step of sulfurizing a metal-supported zeolite with sulfur or a sulfur compound to obtain a zeolite supported with a metal sulfide. 16) The method according to 15), wherein the sulfur compound is represented by the above general formula (1). 17) The method according to 15) or 16), wherein the metal is one or more metals selected from the group consisting of Groups 6, 9, and 10.18) The method according to any one of 15) to 17), which comprises a step of supporting a metal on a zeolite in the presence of a chelating agent to obtain a metal-supported zeolite. 19) The method according to any one of 15) to 18), in which the metal-supported zeolite contains a binder. 20) The method according to 19), in which the binder is one or more binders selected from the group consisting of boehmite, alumina, silica, clay, titania, zirconia, and ceria.

[0010] The method of the present invention for producing light-boiling compounds having a boiling point of 150° C. or less can produce light-boiling compounds having a boiling point of 150° C. or less from cracked heavy oil in one step.

[0011] Furthermore, the catalyst for hydrocracking of cracked heavy oil of the present invention is easy to produce and can be easily used to produce the above-mentioned light-boiling compounds.

[0012] 1 is a schematic diagram of a fixed-bed flow-type reactor used in the present invention. 2 is a diagram showing the XRD measurement results of the boehmite-mixed zeolite prepared in Reference Example 5 (from the bottom, the results for boehmite-free zeolite, Z5Al30, Z5Al50, and Z5Al70).

[0013] The method of the present invention for producing light-boiling compounds having a boiling point of 150°C or less (hereinafter referred to as the "production method of the present invention") involves hydrocracking cracked heavy oil in the presence of a catalyst for hydrocracking of cracked heavy oil, which comprises a zeolite supported on a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound.

[0014] The light-boiling compounds having a boiling point of 150°C or less obtained by the process of the present invention refer to compounds having a boiling point of 150°C or less, preferably -100 to 150°C, as measured by a boiling point meter or boiling point measuring device. Such light-boiling compounds are not particularly limited, but examples thereof include hydrocarbons and monocyclic aromatic compounds having 1 to 8 carbon atoms, and specific examples thereof include benzene (80.1°C), toluene (110°C), o-xylene (144°C), m-xylene (139°C), p-xylene (138°C), ethylbenzene (138°C), methane (-161°C), ethane (-89°C), propane (-42°C), butane (-0.5°C), isobutane, and pentane (36°C). , 2-methylbutane, cyclopentane, hexane (69°C), 2-methylpentane, 3-methylpentane, 2-ethylbutane, cyclohexane, methylcyclopentane, heptane (100°C), 2-methylhexane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 2,2,3-trimethylbutane, cycloheptane, methylcyclohexane, ethyl cyclopentane, 1,1-dimethylcyclohexane, 1,2-dimethylcyclohexane, 1,3-dimethylcyclohexane, octane (126°C), 2-methylheptane, 3-methylheptane, 4-methylheptane, 2,2-dimethylhexane, 2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane, 3,3-dimethylhexane, 3,4-dimethylhexane, 3-ethylhexane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane, 2,3,3-trimethylpentane, 2,3,4-trimethylpentane, 2-methyl-3-ethylpentane, 3-methyl-3-ethylpentane, 2,2,3,3-tetramethylbutane, ethylcyclohexane (129°C), 1,2-dimethylcyclohexane (130°C), 1,3-dimethylcyclohexane (124°C), 1,4-dimethylcyclohexane (120°C), and the like.

[0015] The cracked heavy oil used as a feedstock in the production method of the present invention is produced by a naphtha cracker, which cracks naphtha to produce ethylene, propylene, and other products. This cracked heavy oil is also known as heavy oil, ethylene bottoms, ethylene heavy ends, and the like. Cracked heavy oil contains various components, but its chemical composition is primarily composed of polycyclic aromatic compounds. For example, heavy oils produced by the applicant's naphtha cracking unit can be divided into CR-L, which is primarily composed of two- to three-ring aromatic compounds (65% by mass or more), Q-Oil, which is primarily composed of three- or more heavy aromatic compounds (55% by mass or more), and CR-H, which has a wide range of compositions from light to heavy (polycyclic aromatic compounds 90% by mass or more). While any cracked heavy oil can be used in the production method of the present invention, CR-L, Q-Oil, and CR-H are preferred, with CR-L, which has a low heteroatom content of less than 0.2 wt% and a two-ring aromatic compound content of 50% or more, being more preferred.

[0016] Of the cracked heavy oils mentioned above, CR-L generally contains the following: Naphthalene 15-30% by mass Methylnaphthalene 7-16% by mass Ratio of monocyclic aromatic compounds 5% by mass or less Ratio of two- and three-ring aromatic compounds 60-80% by mass Ratio of four-ring aromatic compounds 15-30% by mass Elemental analysis Carbon content 87-93% by mass Sulfur content 0.5% by mass or less Nitrogen content 0.1% by mass or less

[0017] Q-Oil generally contains the following: Monocyclic aromatics: 5% by mass or less Bicyclic to tricyclic aromatics: 25-40% by mass Tetracyclic aromatics: 55-85% by mass Elemental analysis Carbon content: 90-95% by mass Sulfur content: 0.5% by mass or less Nitrogen content: 0.1% by mass or less

[0018] CR-H generally has the following characteristics: Ratio of monocyclic aromatic compounds: 5% by mass or less Ratio of two- to three-cyclic aromatic compounds: 45-55% by mass Ratio of four-cyclic aromatic compounds: 45-55% by mass Elemental analysis Carbon content: 87-95% by mass Sulfur content: 0.5% by mass or less Nitrogen content: 0.1% by mass or less

[0019] In the production method of the present invention, the method of hydrocracking in the presence of a catalyst for hydrocracking of cracked heavy oil comprising a zeolite supported with a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound is not particularly limited, and hydrocracking may be carried out in a conventional manner using the catalyst for hydrocracking of cracked heavy oil as a catalyst in a fixed-bed flow-type reactor or the like, and using cracked heavy oil as a feedstock. The conditions for hydrocracking are not particularly limited, but are, for example, in a hydrogen atmosphere (atmospheric pressure to 10 MPa) at 300 to 450°C.

[0020] In the process of the present invention, the catalyst for hydrocracking of cracked heavy oil, which is made of zeolite carrying a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound, may be prepared in advance, but it is preferable to prepare it in the same system as the hydrocracking of the cracked heavy oil before hydrocracking in terms of reducing the risk of catalyst poisoning and workability. Here, "preparing it in the same system as the hydrocracking of the cracked heavy oil" means, for example, placing a metal-supported zeolite in a fixed-bed flow-type reactor used for hydrocracking, sulfurizing it with sulfur or a sulfur compound, preparing a catalyst for hydrocracking of cracked heavy oil made of zeolite carrying a metal sulfide, and then performing hydrocracking in the same reactor.

[0021] After hydrocracking in the process of the present invention, further steps such as distillation and recycling may be carried out. In recycling, the hydrocracking product of the cracked heavy oil may be recovered and used again as a feedstock, or unreacted feedstock may be added. The residue from the distillation may also be used as a feedstock. Furthermore, a part or all of these may be combined and used as a feedstock.

[0022] Whether or not a low-boiling compound having a boiling point of 150° C. or less has been produced by the process of the present invention can be confirmed by a known measurement method, for example, GC-FID.

[0023] The catalyst for hydrocracking of cracked heavy oil used in the production process of the present invention (hereinafter also referred to as the catalyst of the present invention) comprises a zeolite carrying a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound.

[0024] The metal-supported zeolite used as the raw material for the catalyst of the present invention is prepared by supporting a metal on a zeolite in accordance with a conventional method.

[0025] The metal used in the metal-supported zeolite is not particularly limited, but may be, for example, one or more metals selected from the group consisting of Groups 6, 9, and 10, preferably one or more metals selected from the group consisting of Ni, Co, W, and Mo, more preferably a combination of Ni and Mo, or Ni and W.

[0026] The zeolite used for the metal-supported zeolite is not particularly limited as long as it can support metals, but for example, it should have a pore size of 5 Å or more. Examples of such zeolites include BETA and ZSM-5. The particle size of the zeolite itself is not particularly limited, but it should be recovered by sieving through a 10 to 100 mesh, preferably a 20 to 80 mesh, sieve.

[0027] Examples of methods for supporting a metal on a zeolite include ion exchange and impregnation, which can be used alone or in combination. The amount of metal supported is not particularly limited, but it is sufficient that the metal content is 1% by mass or more, preferably 1 to 25% by mass, based on the mass of the zeolite.

[0028] It is preferable to support a metal on a zeolite in the presence of a chelating agent, as this allows the metal to be supported on the zeolite with good dispersibility and also improves catalytic performance. The chelating agent used here is not particularly limited, but examples thereof include citric acid. The conditions for using the chelating agent are not particularly limited, but in the ion exchange method or impregnation method, the chelating agent may be contained in an amount of 1 mass % or more, preferably 5 to 25 mass %, per gram of zeolite. When multiple metals are supported on a zeolite, a chelating agent may be used to support all of the metals, or a chelating agent may be used for some of the metals.

[0029] Furthermore, if a chelating agent is present when metals are supported on zeolite, the chelating agent remains on the metal-supported zeolite, which carbonizes during sulfurization and covers the catalyst surface, causing the catalyst to lose its activity. However, sulfurization with sulfur or a sulfur compound removes the chelating agent from the catalyst surface while sulfurizing the metal, thereby simultaneously improving metal dispersion and preventing catalyst deterioration by preventing carbonization of the chelating agent. On the other hand, conventional sulfurization using hydrogen sulfide cannot solve the problem of carbonization of the chelating agent.

[0030] It is preferable that the metal-supported zeolite further contains a binder (catalyst molding aid) from the viewpoint of handling the molded product when handling the catalyst of the present invention on an industrial scale.

[0031] The binder is not particularly limited as long as it is typically used as a catalyst molding aid, and examples thereof include boehmite, alumina, silica, clay, titania, zirconia, ceria, etc. One or more of these binders may be used. Among these binders, alumina and boehmite are preferred, and boehmite is more preferred.

[0032] The content of the binder in the metal-supported zeolite is not particularly limited, but for example, the mass ratio of the binder to zeolite is 1:0.3 to 10, preferably 0.4 to 2.4.

[0033] The method for incorporating a binder into a metal-supported zeolite is not particularly limited, but for example, the zeolite before metal loading may be mixed with a binder, and if necessary, the mixture may be subjected to extrusion, pressure molding, pulverization, sieving, etc. The particle size of the metal-supported zeolite when a binder is incorporated therein is not particularly limited, but may be in the same range as that of the zeolite described above.

[0034] The method for sulfurizing the metal-supported zeolite with sulfur or a sulfur compound is not particularly limited, but examples thereof include a method in which the metal-supported zeolite is contacted with sulfur or a sulfur compound according to a conventional method (so-called on-site sulfurization). For this sulfurization, an on-site sulfurization solution prepared by dissolving or diluting the sulfur or sulfur compound appropriately using a solvent such as decalin may be used. The conditions for the on-site sulfurization are also not particularly limited, but for example, the on-site sulfurization may be carried out at 150 to 250°C for 3 to 6 hours, followed by heating to 300 to 400°C for 1 to 3 hours in an inert atmosphere such as a nitrogen atmosphere, where the sulfur or sulfur compound and the metal-supported zeolite are mixed, and the on-site sulfurization solution is then passed through the metal-supported zeolite.

[0035] The sulfur used in the sulfurization may be in the form of a solid, liquid, or gas, and may include allotropes or isotopes.

[0036] The sulfur compound used for the sulfurization is not particularly limited, but does not include hydrogen sulfide, which is generally used for sulfurization of catalysts. Examples of such sulfur compounds include those represented by the following general formula (1): (In formula (1), R １ , R ２ each independently represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R １ , R ２ may bond to each other to form a cyclic structure. n represents 2 to 10. ) The sulfur compound used for sulfurization may be solid, liquid, or gaseous, but is preferably liquid at room temperature because it is easy to perform on-site sulfurization. Furthermore, the sulfur compound may contain a sulfur isotope.

[0037] Among the sulfur or sulfur compounds used in the sulfurization, the sulfur compound (polysulfide compound) represented by formula (1) is preferred, and among the sulfur compounds, dimethyl trisulfide (R １ and R ２ is a methyl group, n=3), di(1,1,3,3-tetramethylbutyl) polysulfide (R １ and R ２ is a 1,1,3,3-tetramethylbutyl group, and n=4.8 (mixture) is more preferred.

[0038] The catalyst of the present invention may be subjected to processes such as extrusion, pressure molding, pulverization, and sieving to make the particle size uniform, as long as the effect of the catalyst is not impaired.

[0039] The catalyst of the present invention can be produced, for example, by a process including a step of sulfurizing a metal-supported zeolite with sulfur or a sulfur compound to obtain a zeolite supported with a metal sulfide. Prior to the above process, it is preferable to carry out a step of supporting a metal on a zeolite in the presence of a chelating agent to obtain a metal-supported zeolite.

[0040] The catalyst of the present invention thus obtained is excellent for hydrocracking of cracked heavy oil.

[0041] Preferred embodiments of the catalyst of the present invention and its production method include the following. (Cracking catalyst for hydrogenating cracked heavy oil) Metal: Ni and Mo (Ni sulfide is granular, and Mo sulfide is layered like graphite with an edge structure.) Zeolite: Zeolite with a pore size of 5 Å or more, such as ZSM-5 or BETA. Metal content relative to zeolite: Ni 0.5 to 10 mass %, Mo 1 to 25 mass % (Production method) The metal is supported on the zeolite in the presence of a chelating agent to obtain a metal-supported zeolite. Next, the metal-supported zeolite is sulfided on-site with a sulfur compound represented by general formula (1) to obtain the catalyst of the present invention, which consists of a zeolite supported with a metal sulfide.

[0042] Further, other preferred embodiments of the catalyst of the present invention and its production method include the following. (Cracking catalyst for hydrogenating cracked heavy oil) Metal: Ni and W (Ni sulfide is granular, and W sulfide is in the form of tungsten clusters dispersed on a support.) Zeolite: Zeolite with a pore size of 5 Å or more, such as ZSM-5 or BETA. Metal content relative to zeolite: Ni 0.5 to 10 mass %, W 1 to 25 mass % (Production method) The metal is supported on the zeolite in the presence of a chelating agent to obtain a metal-supported zeolite. Next, the metal-supported zeolite is sulfided on-site with a sulfur compound represented by general formula (1), to obtain the catalyst of the present invention consisting of a zeolite supported with a metal sulfide.

[0043] In another preferred embodiment of the catalyst and the method for producing the same of the present invention, in the above-mentioned cracking catalyst for hydrogenating cracked heavy oil and the method for producing the same, a mixture of zeolite and binder is used in place of zeolite, in which a binder is contained in zeolite. The mass ratio of zeolite to binder is 1 part zeolite to 0.4 to 2.4 parts binder.

[0044] The present invention will be described below with reference to examples thereof, but the present invention is not limited to these examples in any way.

[0045] The raw materials used in the following examples are as follows: Zeolite: HSZ-822HOA (ZSM-5 SiO ) manufactured by Tosoh Corporation ２ / Al ２ O ３ = 24) Nickel nitrate monohydrate: Fujifilm Wako Pure Chemical Industries (product number 147-01101) Ammonium molybdate tetrahydrate: Fujifilm Wako Pure Chemical Industries (product number 010-06905) Citric acid monohydrate: Fujifilm Wako Pure Chemical Industries (product number 033-03491) 1-methylnaphthalene: Fujifilm Wako Pure Chemical Industries (product number 139-18995) Dibenzothiophene: Fujifilm Wako Pure Chemical Industries (product number 045-00912) Cracked heavy oil (CR-L): A sample collected at Maruzen Petrochemical's Chiba Plant was used. Polysulfide compound: DIC, product name GS-440L (di(1,1,3,3,-tetramethylbutyl) polysulfide (R １ and R ２ 1,1,3,3-tetramethylbutyl group, n = 4.8 (mixture)) Ammonium tungstate parapentahydrate: Fujifilm Wako Pure Chemical Industries (product number 019-03572)

[0046] Reference Example 1 Preparation of a metal-supported zeolite catalyst: 300 mL of ion-exchanged water was added to 0.3 mol of nickel nitrate monohydrate to dissolve it. 10 g of zeolite was added to 100 mL of this nickel nitrate aqueous solution and the mixture was shaken until no more bubbles were generated from the zeolite. The mixture was heated and stirred at 95°C for 3 hours, allowed to cool to room temperature, and then subjected to suction filtration. The filtered product was collected and poured into 100 mL of nickel nitrate aqueous solution. This process of heating and stirring at 95°C was repeated three times, and the filtered product was collected. 100 mL of ion-exchanged water was added to the filtered product, and the mixture was heated and stirred at 50°C for 15 minutes, after which the solid was collected by suction filtration. The collected solid was heated and dried at 120°C for 2 hours and sieved to collect particles with a particle size of 20-80 mesh. The sieved product was calcined at 450°C for 8 hours to obtain nickel-supported zeolite (Ni-Z5). The total amount of Ni-Z5 obtained was added to a solution of 2.12 g of ammonium molybdate tetrahydrate in 17.5 g of ion-exchanged water, and the mixture was ultrasonically stirred for 30 minutes. The mixture was heated at 100°C for 30 minutes and then dried by heating at 120°C for 2 hours. The dried mixture was calcined at 500°C for 8 hours to obtain 13.1 g of a zeolite catalyst (15Mo / Ni-Z5) supporting nickel and molybdenum.

[0047] Reference Example 2 Preparation of zeolite catalyst supporting metal sulfide: A fixed-bed flow-type reactor shown in Figure 1 was used. The reactor 1 is equipped with a supply inlet 2, an exhaust outlet 3, an electric furnace 4, a reaction vessel 5, quartz sand 6, a catalyst 7, a thermometer 8, and a temperature controller 9. Gases and liquids can be supplied from the supply inlet using valves and pumps. The exhaust outlet is equipped with a gas-liquid separator and is connected to an analyzer such as GC-FID if necessary, and unnecessary liquids are exhausted.

[0048] 1.0 g of 15Mo / Ni-Z5 prepared in Reference Example 1 was packed into the catalyst portion of the reactor shown in Figure 1, and the reactor was placed under a nitrogen atmosphere. Then, a gas containing 5% hydrogen sulfide and 95% hydrogen was introduced from the supply port at atmospheric pressure at 1.8 x 10 －３ m ３ 1 / h, the mixture was heated at 100°C for 1 hour, 200°C for 1 hour, 300°C for 1 hour, and 400°C for 3 hours to obtain a catalyst (15Mo / Ni-Z5-S).

[0049] Comparative Example 1 Hydrocracking reaction of model oil: As in Reference Example 2, a catalyst (15Mo / Ni-Z5-S) was prepared in the reactor shown in Figure 1, and then the feed port path was changed to hydrogen pressure 5.0 MPa, WHSV (weight hourly space velocity) 20, H ２ A model oil (a mixture of 99% 1-methylnaphthalene (1-MN) and 1% dibenzothiophene (DBT)) was passed through the reactor at an oil / oil flow ratio of 1000. Samples were analyzed by GC-FID after 5 hours of operation at heating temperatures of 380°C, 400°C, 420°C, or 440°C, and the conversion rates were shown in Table 1.

[0050] *Each value is the mass % of the recovered liquid component. The total value does not add up to 100 because unknown peaks that could not be identified, such as heavy components generated in the reaction, were excluded.

[0051] These results show that this catalyst system was active even with sulfur-containing feedstocks, but the conversion of 1-methylnaphthalene was low, and the production of monocyclic aromatics and BTX (benzene, toluene, and xylenes) was minimal. Here, monocyclic aromatics refer to benzene derivatives other than BTX, and bicyclic aromatics refer to naphthalene derivatives other than the feedstock 1-methylnaphthalene. Tetralins refer to partially hydrogenated naphthalene compounds, such as tetralin. Indanes include indan and methylindan, which are by-products obtained during the hydrocracking process. BTX and monocyclic aromatics are the target products of hydrogenation and decomposition, bicyclic aromatics are isomerized by-products where the target reaction (hydrogenation) did not proceed, tetralin is a reaction intermediate where hydrogenation proceeded but decomposition did not proceed, and indene is a by-product where decomposition did not proceed during the tetralin decomposition process.

[0052] Comparative Example 2 Hydrocracking reaction of cracked heavy oil: A hydrocracking reaction was carried out in the same manner as in Comparative Example 1, except that the model oil was cracked heavy oil (CR-L) and the LHSV (liquid hourly space velocity) was changed from WHSV 20 to 2.0. The yields analyzed by GC-FID are shown in Table 2. Note that in this system, a temperature of 440°C was not possible due to clogging of the feed pipe.

[0053] *Since CR-L is a complex mixture of polycyclic aromatic compounds, the conversion rate cannot be calculated. The results were compared using the weight composition of the reaction liquid obtained by GC. *Unlike the model oil, it is a mixture that contains 1-methylnaphthalene among the two-ring aromatic compounds, but has the same definition as the model oil.

[0054] Compared to the composition before the reaction, there was a slight decrease in monocyclic and bicyclic aromatic compounds, a small amount of reaction intermediates (tetralins) was produced (hydrogenation was progressing due to the production of tetralins), and there was also an increase in indans (hydrogenation was progressing but they had become by-products in the cracking reaction). The target products, BTX and monocyclic aromatic compounds, were also confirmed, but their proportions were small.

[0055] From these results, it was found that when a catalyst without the addition of a chelating agent was used, only a small amount of monocyclic aromatic compounds and BTX was produced from the cracked heavy oil used as the feed.

[0056] Reference Example 3 Preparation of metal-supported zeolite catalyst: 12.15 g of Ni-Z5 obtained in the same manner as in Reference Example 1 was weighed into a porcelain container, and an aqueous solution prepared by dissolving 3.28 g of citric acid monohydrate and 2.79 g of ammonium molybdate tetrahydrate in 10 g of ion-exchanged water was added thereto, followed by ultrasonic stirring for 30 minutes. The mixture was heated at 100°C for 30 minutes and then dried by heating at 120°C for 2 hours. The dried product was calcined at 500°C for 8 hours to obtain 15.0 g of a zeolite catalyst (15Mo(CA) / Ni-Z5) supporting nickel and molybdenum.

[0057] Reference Example 4 Preparation of Metal-Supported Zeolite Catalyst: 8.74 g of zeolite was weighed into a porcelain container, and an aqueous solution prepared by dissolving 1.46 g of citric acid monohydrate and 1.24 g of ammonium molybdate tetrahydrate in 12.0 g of ion-exchanged water was added thereto, followed by 30 minutes of ultrasonic irradiation. This was heated at 100°C for 30 minutes and then dried by heating at 120°C for 2 hours, yielding 10.9 g of a solid. An aqueous solution prepared by dissolving 1.01 g of nickel nitrate monohydrate and 1.46 g of citric acid monohydrate in 12.0 g of ion-exchanged water was added thereto, followed by 30 minutes of ultrasonic irradiation. This was then dried by heating at 100°C for 30 minutes and then 120°C for 2 hours, yielding 13.2 g of a zeolite catalyst (4Ni(CA)15Mo(CA) / Z5) supporting molybdenum and nickel.

[0058] Example 1 Preparation of zeolite catalyst supporting metal sulfide: An on-site sulfurization solution was prepared by adding 3.0 g of a polysulfide compound (GS-440L) to 297 g of decalin. A reactor was charged with 1.37 g of 15Mo(CA) / Ni-Z5 prepared in Reference Example 2 or 4Ni(CA)15Mo(CA) / Z5 prepared in Reference Example 4, and the reactor was placed under a nitrogen atmosphere. Hydrogen was introduced into the reactor at a pressure of 3.0 MPa and a flow rate of 0.01 m / s. ３ The on-site sulfurization solution was passed through the catalyst at a rate of 0.55 mL / min while flowing at a rate of 0.5 mL / h. The treatment was carried out at 190°C for 5 hours and then at 350°C for 2 hours. Through this reaction, 15Mo(CA) / Ni-Z5 or 4Ni(CA)15Mo(CA) / Z5 was on-site sulfurized to obtain a zeolite catalyst (15Mo(CA) / Ni-Z5-S or 4Ni(CA)15Mo(CA) / Z5-S) supporting a metal sulfide.

[0059] Example 2 Hydrocracking reaction of model oil: Hydrocracking reaction was carried out in the same manner as in Comparative Example 1, except that the catalyst was changed from 15Mo / Ni-Z5-S to 15Mo(CA) / Ni-Z5-S or 4Ni(CA)15Mo(CA) / Z5-S. The results are shown in Tables 3 and 4.

[0060]

[0061] Compared to Comparative Example 1, the hydrocracking reaction of model oil using 15Mo / Ni-Z5-S resulted in significantly lower residual amounts of 1-methylnaphthalene in the feedstock, especially at higher temperatures (i.e., higher conversion), and fewer by-products (indanes and undetected components). It was also confirmed that the higher the temperature, the higher the yield of monocyclic aromatics and BTX. Additionally, because the proportion of tetralin was low, hydrocracking did not stop at the reaction intermediates but proceeded fully to monocyclic aromatics and BTX. Therefore, compared to the catalyst in Comparative Example 1, 15Mo(CA) / Ni-Z5-S was found to be a catalyst that promoted comprehensive hydrogenation reactions.

[0062]

[0063] The hydrocracking reaction of model oil using 4Ni(CA)15Mo(CA) / Z5-S showed the same conversion rate of 1-methylnaphthalene at all temperature ranges compared to Comparative Example 1. Although the production rate of monocyclic aromatic compounds (products) was lower than that of Comparative Example 1, it was confirmed that by-products (indanes, undetected components) were overwhelmingly low, and that a large amount of the reaction intermediate (tetralin) was produced in the high temperature range. Therefore, it was found that 4Ni(CA)15Mo(CA) / Z5-S is a catalytic system that exhibits the effect of reducing side reactions in the hydrogenation of hydrocracking reactions (especially the hydrogenation reaction of 1-methylnaphthalene to tetralins).

[0064] Example 3 Hydrocracking of cracked heavy oil: Hydrocracking was carried out in the same manner as in Comparative Example 2, except that the catalyst was changed from 15Mo / Ni-Z5-S to 15Mo(CA) / Ni-Z5-S. Selectivity was analyzed by GC-FID in the same manner as conversion. The results are shown in Table 5.

[0065]

[0066] These results demonstrate that the use of this catalyst makes it possible to obtain larger amounts of BTX and monocyclic aromatic hydrocarbons than in Comparative Example 2. Furthermore, the amount of indanes, which are cracking by-products, was small, confirming high selectivity for monocyclic aromatic hydrocarbons and BTX in the cracking reaction.

[0067] The above examples demonstrate that catalysts prepared by on-site sulfiding of metal-supported zeolites can be used in the hydrocracking of cracked heavy oil. Furthermore, the conversion of the catalyst was improved by on-site sulfiding of the catalyst precursor supported with the metal in the presence of a chelating agent.

[0068] Test Example 1 Fluorescent X-ray analysis of catalysts: Ni-Z5 and 15Mo / Ni-Z5 prepared in Reference Example 1 and 4Ni(CA)15Mo(CA) / Z5 prepared in Reference Example 4 were subjected to fluorescent X-ray analysis according to a conventional method to determine NiO and MoO. ３The content of was calculated, and the results are shown in Table 6. Note that, for the catalysts obtained by sulfurizing the metal-supported zeolite of Reference Example 1 and the metal-supported zeolite of Reference Example 4, the amount of metal itself did not change before and after sulfurization, so fluorescent X-ray measurement was performed on the metal-supported zeolite at the stage before sulfurization.

[0069]

[0070] These results confirmed that the same amount of metal was supported on the zeolite catalyst regardless of the presence of a chelating agent when preparing the metal-supported catalyst. Therefore, it was revealed that the improvement in the hydrogenation reaction was due to the effects of sulfurization with the polysulfide compound and the chelating agent (not the effect of the amount of metal, since the amount of supported metal was the same).

[0071] Reference Example 5: Preparation of boehmite-mixed zeolites: Zeolite and boehmite were mixed in the desired mass ratios (7.0 g / 3.0 g, 5.0 g / 5.0 g, 3.0 g / 7.0 g). The mixture was molded into pellets using an extruder and dried in an oven at 120°C for 2 hours at normal pressure. The pellets were sieved to a particle size of 20-80 mesh. The pellets were then calcined in an electric furnace at 600°C for 12 hours to obtain boehmite-mixed zeolites (referred to as Z5Al30, Z5Al50, and Z5Al70, respectively).

[0072] The XRD measurement results of each boehmite-mixed zeolite are shown in Figure 2. From these results, it was found that these were uniform mixtures of zeolite and boehmite.

[0073] Reference Example 6: Preparation of a metal-supported boehmite-mixed zeolite catalyst: 0.79 g of ammonium tungstate parapentahydrate, 0.54 g of citric acid, and 45 mL of ion-exchanged water were added and heated to 40°C for dissolution. The aqueous solution and 5.5 g of the boehmite-mixed zeolite (Z5-Al30) prepared in Reference Example 5 were added to a recovery flask and stirred at 40°C for 4 hours. The recovery flask containing this mixture was connected to a rotary evaporator, and water was removed by distillation at a vacuum of 70 torr and 50°C. The mixture was then dried at atmospheric pressure for 2 hours at 120°C and allowed to cool to room temperature. Next, 0.608 g of nickel nitrate hexahydrate, 0.87 g of citric acid, and 10 mL of ion-exchanged water were added to the dried product, and the mixture was subjected to ultrasonic irradiation for 30 minutes. The mixture was then heated at 100°C for 30 minutes and then dried at 120°C for 2 hours. The dried product was calcined at 500° C. for 8 hours to obtain 6.5 g of a boehmite mixed zeolite catalyst (10W / Ni(CA)-Z5Al30) supporting nickel and tungsten.

[0074] Example 4 Preparation of a boehmite-mixed zeolite catalyst supporting metal sulfides: The metal-supported boehmite-mixed zeolite (10W / Ni(CA)-Z5Al30) prepared in Reference Example 6 was treated under the conditions of Reference Example 2 to prepare a metal sulfide-supported boehmite-mixed zeolite catalyst (10W / Ni(CA)-Z5Al30-S).

[0075] Example 5 Hydrocracking reaction of model oil: Using the boehmite mixed zeolite catalyst (10W / Ni(CA)-Z5Al30-S) supporting metal sulfide prepared in Example 4, a test was carried out under the conditions of Comparative Example 1. The results are shown in Table 7.

[0076]

[0077] It was confirmed that the catalyst supporting nickel and tungsten had performance equivalent to that of the catalyst supporting nickel and molybdenum.

[0078] Reference Example 7 Preparation of metal-supported boehmite-mixed zeolite catalyst: A boehmite-mixed zeolite catalyst supporting nickel and molybdenum was prepared in the same manner as in Reference Example 1, except that the three types of boehmite-mixed zeolites (Z5Al30, Z5Al50, and Z5Al70) prepared in Reference Example 5 were used.

[0079] Example 6 Preparation of boehmite-mixed zeolite catalysts supporting metal sulfides: The metal-supported boehmite-containing zeolites prepared in Reference Example 7 were treated under the conditions of Reference Example 2 to prepare boehmite-mixed zeolite catalysts supporting metal sulfides (15Mo(CA) / Ni-Z5Al30-S, 15Mo(CA) / Ni-Z5Al50-S, 15Mo(CA) / Ni-Z5Al70-S).

[0080] Example 7 Hydrocracking reaction of model oil: Using the boehmite mixed zeolite catalysts (15Mo(CA) / Ni-Z5Al30-S, 15Mo(CA) / Ni-Z5Al50-S, 15Mo(CA) / Ni-Z5Al70-S) supported with metal sulfides prepared in Example 6, tests were carried out under the conditions of Example 2. The results are shown in Tables 8 to 10.

[0081]

[0082]

[0083]

[0084] It was confirmed that the boehmite-mixed zeolite catalyst supporting metal sulfide generally had a high yield of the hydrogenation reaction product (tetralins), which is the first half of the two-step reaction (= reaction conversion rate = consumption rate of 1-methylnaphthalene), and also had a high yield of BTX and monocyclic aromatics in the high temperature range.

[0085] The present invention can be used to produce light boiling compounds having a boiling point of 150° C. or less by hydrocracking cracked heavy oil.

[0086] REFERENCE SIGNS LIST 1 Reactor 2 Supply port 3 Exhaust port 4 Electric furnace 5 Reaction vessel 6 Quartz sand 7 Catalyst 8 Thermometer 9 Temperature controller

Claims

1. A method for producing light-boiling compounds having a boiling point of 150°C or less, characterized by hydrocracking cracked heavy oil in the presence of a catalyst for hydrocracking cracked heavy oil, which catalyst comprises a zeolite supported with a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound.

2. The sulfur compound is represented by the following general formula (1): (In formula (1), R １ , R ２ each independently represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R １ , R ２ may be bonded to each other to form a cyclic structure, and n is 2 to 10.

3. The method according to claim 1 or 2, wherein said metal is one or more metals selected from the group consisting of Groups 6, 9 and 10.

4. The method according to claim 1 or 2, wherein the low-boiling compounds are hydrocarbons having 1 to 8 carbon atoms and monocyclic aromatic compounds.

5. The method according to claim 1 or 2, wherein the catalyst for hydrocracking of cracked heavy oil is prepared in the same system as that for hydrocracking of cracked heavy oil.

6. The method according to claim 1 or 2, wherein the metal-supported zeolite is a zeolite in which a metal is supported in the presence of a chelating agent.

7. The method according to claim 1 or 2, wherein the metal-supported zeolite contains a binder.

8. The method according to claim 7, wherein said binder is one or more binders selected from the group consisting of boehmite, alumina, silica, clay, titania, zirconia and ceria.

9. A catalyst for hydrocracking of cracked heavy oil, comprising a zeolite carrying a metal sulfide obtained by sulfurizing a metal-supported zeolite with sulfur or a sulfur compound.

10. The sulfur compound is represented by the following general formula (1): (In formula (1), R １ , R ２ each independently represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R １ , R ２ may be bonded to each other to form a cyclic structure, and n is 2 to 10.

11. The catalyst according to claim 9 or 10, wherein the metal is one or more metals selected from the group consisting of Groups 6, 9 and 10.

12. The catalyst according to claim 9 or 10, wherein the metal-supported zeolite is a zeolite in which the metal is supported in the presence of a chelating agent.

13. The catalyst according to claim 9 or 10, wherein the metal-supported zeolite contains a binder.

14. The catalyst according to claim 13, wherein the binder is one or more binders selected from the group consisting of boehmite, alumina, silica, clay, titania, zirconia and ceria.

15. A method for producing a catalyst for hydrocracking of cracked heavy oil, comprising the step of sulfiding a metal-supported zeolite with sulfur or a sulfur compound to obtain a zeolite supported with a metal sulfide.

16. The sulfur compound is represented by the following general formula (1): (In formula (1), R １ , R ２ each independently represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R １ , R ２ may be bonded to each other to form a cyclic structure, and n is 2 to 10.

17. The method according to claim 15 or 16, wherein the metal is one or more metals selected from the group consisting of Groups 6, 9 and 10.

18. The method according to claim 15 or 16, further comprising the step of supporting a metal on a zeolite in the presence of a chelating agent to obtain a metal-supported zeolite.

19. The method according to claim 15 or 16, wherein the metal-supported zeolite contains a binder.

20. The method of claim 19, wherein the binder is one or more binders selected from the group consisting of boehmite, alumina, silica, clay, titania, zirconia, and ceria.

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