Method for producing hydrocracked oil and liquefied petroleum gas, and method for producing fuel

Abstract

[Problem] To provide a method for efficiently producing high-quality hydrocracked oil and liquefied petroleum gas while reducing production cost. [Solution] A method for producing a hydrocracked oil and a liquefied petroleum gas according to the present invention is characterized by comprising: a step for preparing a raw material oil obtained by mixing a petroleum-based hydrocarbon with an oil to be treated containing an oil and fat derived from an animal or vegetable oil and a fatty acid component; a step for obtaining a hydrogenated refined oil by introducing hydrogen into the raw material oil and by performing hydrogenation refining under reaction conditions including the presence of a sulfide hydrogenation catalyst, a reaction temperature of 280 to 400°C, a hydrogen pressure of 2 to 20 MPa, a liquid space velocity (LHSV) of 0.1 h−1 to 5.0 h−1, and a hydrogen / oil ratio of 100 to 2000 NL / L; and a step for obtaining a hydrocracked oil and a liquefied petroleum gas by introducing hydrogen into the hydrogenated refined oil and by performing hydrocracking under reaction conditions including the presence of a sulfide hydrocracking catalyst, a reaction temperature of 350 to 430°C, a hydrogen pressure of 10 to 20 MPa, a liquid space velocity (LHSV) of 0.1 h−1 to 3.0 h−1, and a hydrogen / oil ratio of 500 to 2000 NL / L, wherein the reaction temperature in the hydrocracking step is higher than the reaction temperature in the hydrogenation refining step, the hydrogen / oil ratio in the hydrocracking step is higher than the hydrogen / oil ratio in the hydrogenation refining step, the liquefied petroleum gas contains methane, and the conversion rate of oxygen and carbon-containing compounds to methane in the hydrocracking step is 35% or greater.

Description

Method for producing hydrocracked oil and liquefied petroleum gas, and method for producing fuel

[0001] The present invention relates to a method for producing hydrocracked oil and liquefied petroleum gas, and also to a method for producing fuel using the hydrocracked oil as a raw material.

[0002] In recent years, sustainable aviation fuel (SAF) has been attracting attention as an alternative to fossil fuels. SAF is an aviation fuel made from renewable raw materials containing a base material produced by fermenting, oil extraction, pyrolysis, or the like using organic resources (biomass) derived from living organisms as raw materials.

[0003] One biomass-derived fuel that is currently attracting particular attention is "HEFA (Hydroprocessed Esters and Fatty Acids)." HEFA is a technology that produces sustainable aviation fuel (SAF) equivalent to jet fuel by hydrotreating fatty acid esters of fats and oils (such as waste cooking oil, animal tallow, and inedible vegetable oil).

[0004] For example, Patent Document 1 describes a method for producing environmentally friendly fuel, which includes a step of preparing a feedstock containing fat and oil components derived from animal and vegetable oils, including a fraction with a boiling point of 230° C. or higher, and a hydrocracking step of hydrocracking the feedstock, or a feedstock that has been subjected to a predetermined pretreatment step as necessary, in the presence of a hydrocracking catalyst containing at least one metal selected from the group consisting of metals belonging to Groups 6A and 8 of the periodic table and an inorganic oxide having acidic properties. In such a fuel production method including a hydrocracking step, liquefied petroleum gases such as methane are also by-produced by the hydrogenation reaction of carbon dioxide, etc.

[0005] Japanese Patent Application Laid-Open No. 2007-153928

[0006] However, the hydrocracking process described in Patent Document 1 has low efficiency in synthesizing methane (methanation) through a carbon dioxide hydrogenation reaction, making it unsuitable for industrializing methanation. Meanwhile, the industrialization of methanation poses challenges, such as procuring carbon dioxide as a raw material and constructing large-scale processing facilities. Therefore, there is a need to utilize existing facilities to reduce production costs and produce not only high-quality hydrocracked oil but also liquefied petroleum gases such as methane.

[0007] Therefore, the present inventors have conducted extensive research to solve the above problems and have surprisingly discovered that by improving the hydrorefining process and hydrocracking process of a feedstock oil in which petroleum hydrocarbons and an oil to be treated are mixed, it is possible to efficiently produce high-quality hydrocracked oil and liquefied petroleum gas while reducing production costs. Based on this discovery, the present inventors have completed the present invention. Based on this discovery, the present inventors have completed the present invention.

[0008] According to one aspect of the present invention, the following invention is provided: [1] A process for preparing a feedstock oil by mixing petroleum hydrocarbons with an oil to be treated containing fats and oils derived from animal and vegetable oils and fatty acid components, and introducing hydrogen into the feedstock oil to perform a hydrogenation process in the presence of a sulfide hydrogenation catalyst at a reaction temperature of 280°C to 400°C, a hydrogen pressure of 2 MPa to 20 MPa, and a liquid hourly space velocity (LHSV) of 0.1 h -１ Over 5.0 hours -１ and a hydrogen / oil ratio of 100 NL / L or more and 2000 NL / L or less to obtain a hydrorefined oil; and introducing hydrogen into the hydrorefined oil and subjecting the hydrorefined oil to a reaction at a temperature of 350°C or more and 430°C or less, a hydrogen pressure of 10 MPa or more and 20 MPa or less, and a liquid hourly space velocity (LHSV) of 0.1 h in the presence of a sulfide hydrocracking catalyst. -１ Over 3.0 hours -１and a step of hydrocracking under reaction conditions of a hydrogen / oil ratio of 500 NL / L or more and a hydrogen / oil ratio of 500 NL / L or more and 2000 NL / L or less to obtain hydrocracked oil and liquefied petroleum gas, wherein the reaction temperature in the hydrocracking step is higher than the reaction temperature in the hydrotreating step, the hydrogen / oil ratio in the hydrocracking step is higher than the hydrogen / oil ratio in the hydrotreating step, the liquefied petroleum gas contains methane, and a conversion rate of oxygen- and carbon-containing compounds to methane in the hydrocracking step is 35% or more. [2] A method for producing hydrocracked oil and liquefied petroleum gas as described in [1], wherein the petroleum hydrocarbons include a fraction with a boiling point of 150°C or more, and have a sulfur content of 0.01% by mass or more and a nitrogen content of 0.001% by mass or more and 0.5% by mass or less. [3] The method for producing hydrocracked oil and liquefied petroleum gas according to [1] or [2], wherein the oil to be treated contains a fraction with a boiling point of 230°C or higher and an oxygen content of 0.3% by mass to 13.0% by mass. [4] The method for producing hydrocracked oil and liquefied petroleum gas according to any of [1] to [3], wherein the mixing ratio of the petroleum hydrocarbon to the oil to be treated is 1:99 to 99:1 by volume. [5] The method for producing hydrocracked oil and liquefied petroleum gas according to any of [1] to [4], wherein the hydrogenation catalyst contains at least one metal selected from the group consisting of metals belonging to Groups 6, 9, and 10 of the Periodic Table. [6] The method for producing hydrocracked oil and liquefied petroleum gas according to any of [1] to [5], wherein the feedstock oil contains 0.1% by mass to 35% by mass of oxygen atoms derived from carboxylic acids or ester bonds. [7] The method for producing hydrocracked oil and liquefied petroleum gas according to any one of [1] to [6], wherein the petroleum hydrocarbons have been subjected to hydrodesulfurization treatment. [8] The method for producing hydrocracked oil and liquefied petroleum gas according to any one of [1] to [7], wherein the hydrorefined oil contains aliphatic hydrocarbons having from 12 to 22 carbon atoms. [9] The method for producing hydrocracked oil and liquefied petroleum gas according to any one of [1] to [8], wherein the reaction temperature in the hydrocracking step is 5°C or more higher than the reaction temperature in the hydrorefining step.

[10] A method for producing hydrocracked oil and liquefied petroleum gas according to any one of [1] to [9], wherein the hydrogen / oil ratio in the hydrocracking step is at least 100 NL / L higher than the hydrogen / oil ratio in the hydrorefining step.

[11] A method for producing hydrocracked oil and liquefied petroleum gas according to any one of [1] to

[10] , wherein the oxygen- and carbon-containing compound is at least one selected from the group consisting of carbon monoxide, carbon dioxide, methanol, and formic acid.

[12] A method for producing fuel, using the hydrocracked oil obtained by the method according to any one of [1] to

[11] as a raw material.

[0009] According to the present invention, by improving the hydrorefining process and hydrocracking process of feedstock oil, a method for efficiently producing high-quality hydrocracked oil and liquefied petroleum gas while reducing production costs is provided. The present invention also provides a method for producing fuel using the hydrorefined oil as a feedstock.

[0010] Preferred embodiments of the present invention will now be described in detail.

[0011] (Method for Producing Hydrocracked Oil and Liquefied Petroleum Gas) The method for producing hydrocracked oil and liquefied petroleum gas of this embodiment includes the steps of: preparing a feedstock oil in which petroleum hydrocarbons and an oil to be treated containing fats and oils derived from animal and vegetable oils and fatty acid components are mixed; and introducing hydrogen into the feedstock oil and subjecting it to a hydrogenation reaction in the presence of a sulfide hydrogenation catalyst at a reaction temperature of 280°C to 400°C, a hydrogen pressure of 2 MPa to 20 MPa, and a liquid hourly space velocity (LHSV) of 0.1 h. -１ Over 5.0 hours -１ and a hydrogen / oil ratio of 100 NL / L or more and 2000 NL / L or less to obtain a hydrorefined oil; and introducing hydrogen into the hydrorefined oil and subjecting the hydrorefined oil to a reaction at a temperature of 350°C or more and 430°C or less, a hydrogen pressure of 10 MPa or more and 20 MPa or less, and a liquid hourly space velocity (LHSV) of 0.1 h in the presence of a sulfide hydrocracking catalyst. -１ Over 3.0 hours -１and a step of hydrocracking under reaction conditions of a hydrogen / oil ratio of 500 NL / L or more and 2000 NL / L or less to obtain hydrocracked oil and liquefied petroleum gas, wherein the reaction temperature in the hydrocracking step is higher than the reaction temperature in the hydrotreating step, the hydrogen / oil ratio in the hydrocracking step is higher than the hydrogen / oil ratio in the hydrotreating step, the liquefied petroleum gas contains methane, and the conversion rate of oxygen- and carbon-containing compounds to methane in the hydrocracking step is 35% or more.

[0012] Each step in the process for producing hydrocracked oil and liquefied petroleum gas will be described in detail below.

[0013] (Stock Oil Preparation Step) The stock oil preparation step is a step of preparing a stock oil by mixing the following petroleum hydrocarbons and the following oil to be treated.

[0014] (Feedstock) The feedstock is a mixture of petroleum hydrocarbons and oil to be treated. The mixing ratio of petroleum hydrocarbons to oil to be treated is preferably 1:99 to 99:1, more preferably 25:75 to 95:5, and even more preferably 50:50 to 90:10, on a volume basis. A mixing ratio of petroleum hydrocarbons to oil to be treated within the above range is preferable because it allows for an improved conversion rate of oxygen- and carbon-containing compounds (particularly carbon monoxide, carbon dioxide, methanol, and formic acid) to methane through a hydrogen-donating reaction from the petroleum hydrocarbons under operating conditions that can avoid excessive cracking of the feedstock and even runaway exothermic reactions.

[0015] The content of oxygen atoms derived from carboxylic acids or ester bonds in the feedstock is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, still more preferably 2% by mass or more, and preferably 35% by mass or less, more preferably 20% by mass or less, even more preferably 12% by mass or less, and still more preferably 8% by mass or less. In a preferred embodiment of the present invention, the content of oxygen atoms derived from carboxylic acids or ester bonds in the feedstock is preferably 0.1% by mass or more and 35% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, even more preferably 1% by mass or more and 12% by mass or less, and still more preferably 2% by mass or more and 8% by mass or less. It is preferable that the content of oxygen atoms derived from carboxylic acids or ester bonds in the feedstock is within the above-mentioned range, because it is possible to achieve a balance between the conversion rate of oxygen- and carbon-containing compounds (particularly carbon monoxide, carbon dioxide, methanol, and formic acid) to methane and the methane yield under operating conditions that can avoid excessive cracking of the feedstock and runaway exothermic reactions. Petroleum hydrocarbons and the oil to be treated are described in detail below.

[0016] (Petroleum-based hydrocarbons) The petroleum-based hydrocarbons may be petroleum-based hydrocarbon fractions obtained in a typical petroleum refining process. For example, fractions corresponding to a predetermined boiling point range obtained from an atmospheric distillation unit or a vacuum distillation unit, or fractions corresponding to a predetermined boiling point range obtained from a hydrodesulfurization unit, hydrocracking unit, residual oil direct desulfurization unit, fluid catalytic cracking unit, or the like, may be used. The petroleum-based hydrocarbons may be a single petroleum-based hydrocarbon fraction obtained from any of the above units, or a mixture of petroleum-based hydrocarbon fractions obtained from multiple units. In a preferred embodiment of the present invention, the petroleum-based hydrocarbons are preferably those that have been subjected to hydrodesulfurization treatment.

[0017] The petroleum hydrocarbons preferably contain a petroleum hydrocarbon fraction having a boiling point of 150°C or higher, and the content of the petroleum hydrocarbon fraction having a boiling point of 150°C or higher in the petroleum hydrocarbons is preferably 50% by mass or higher, more preferably 70% by mass or higher, and even more preferably 90% by mass or higher, and may be 100% by mass. In this specification, the boiling point is a value measured in accordance with the "Distillation Test Method" of JIS-K2254 or the method specified in ASTM-D86.

[0018] The sulfur content of the petroleum hydrocarbons is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, even more preferably 0.05% by mass or more, and preferably 5.0% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.3% by mass or less. In a preferred embodiment of the present invention, the sulfur content of the petroleum hydrocarbons is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.03% by mass or more and 1.0% by mass or less, and even more preferably 0.05% by mass or more and 0.3% by mass or less. In particular, it is preferable to use a petroleum hydrocarbon fraction whose sulfur content has been reduced by 50% by mass or more by hydrodesulfurization treatment. The nitrogen content of the petroleum hydrocarbons is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, even more preferably 0.005% by mass or more, and preferably 0.5% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less. In a preferred embodiment of the present invention, the nitrogen content of the petroleum hydrocarbons is preferably 0.001% by mass or more and 0.5% by mass or less, more preferably 0.003% by mass or more and 0.1% by mass or less, and even more preferably 0.005% by mass or more and 0.05% by mass or less. The oxygen content of the petroleum hydrocarbons is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, and may even be 0% by mass. If the sulfur content, nitrogen content, and oxygen content of the petroleum hydrocarbons are within the above numerical ranges, this is preferable because it is possible to suppress excessive cracking of the feedstock oil while increasing the conversion rate to methane under conditions in which the hydrotreating product oil satisfies the product properties after fractionation. Note that, in this specification, the sulfur content, nitrogen content, and oxygen content can be measured using a general elemental analyzer.

[0019] (Oil to be treated) The oil to be treated contains fats and oils derived from animal and vegetable oils and fatty acid components. In the present invention, fats and oils derived from animal and vegetable oils refer to fats and oils and fatty acid components that are naturally or artificially produced or manufactured using animal and vegetable oils as raw materials. The type of animal and vegetable oil is not particularly limited, and examples include vegetable oils such as rapeseed oil, soybean oil, coconut oil, palm kernel oil, palm oil, cottonseed oil, corn oil, sunflower oil, safflower oil, sesame oil, olive oil, linseed oil, rice bran oil, camellia oil, perilla oil, grapeseed oil, peanut oil, almond oil, and avocado oil, and animal oils such as fish oil, beef tallow, lard, and chicken fat. Among these, rapeseed oil, soybean oil, coconut oil, and palm kernel oil are more preferred in terms of the carbon number and reactivity of the fatty acid components. The oil to be treated may be a mixture of fats and oils derived from animal and vegetable oils and fatty acid components, or may be waste oil after using these.

[0020] The oil to be treated preferably contains a fraction having a boiling point of 230°C or higher, and the content of the fraction having a boiling point of 230°C or higher in the oil to be treated is preferably 90% by mass or higher, more preferably 95% by mass or higher, and even more preferably 99% by mass or higher, and may even be 100% by mass. If the content of the fraction having a boiling point of 230°C or higher in the oil to be treated is within the above numerical range, the yield of the product produced by the cracking reaction will be in a range that is favorable from the viewpoint of profitability.

[0021] The sulfur content of the oil to be treated is preferably 0.1% by mass or less, more preferably 0.01% by mass or less, and even more preferably 0.001% by mass or less. The nitrogen content of the oil to be treated is preferably 0.01% by mass or less, and more preferably 0.005% by mass or less. The oxygen content of the oil to be treated is preferably 0.3% by mass or more, more preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, still more preferably 10.0% by mass or more, and also preferably 13.0% by mass or less, more preferably 12.5% ​​by mass or less, and even more preferably 12.0% by mass or less. In a preferred embodiment of the present invention, the oxygen content of the oil to be treated is preferably 0.3% by mass or more and 13.0% by mass or less, more preferably 3.0% by mass or more and 12.5% ​​by mass or less, and even more preferably 5.0% by mass or more and 12.0% by mass or less. If the sulfur, nitrogen, and oxygen contents of the oil to be treated are within the above-mentioned numerical ranges, the conversion rate of carbon monoxide, carbon dioxide, methanol, and formic acid to methane can be improved by a hydrogen-donating reaction from petroleum hydrocarbons under operating conditions that can avoid excessive cracking of the feedstock oil and even runaway exothermic reactions, while the hydrogenation reaction product oil satisfies the product properties after fractionation, and fatty acids with a small carbon number can be eliminated under conditions where the purity of the fats and oils or fatty acids is high, thereby increasing profitability, which is preferable.

[0022] (Hydrorefining step) The hydrorefining step is a step in which hydrogen is introduced into a feedstock oil and hydrorefining is performed under specific reaction conditions in the presence of a hydrogenation catalyst to obtain a hydrorefined oil. In the hydrorefining step, a hydrodeoxygenation reaction of fatty acid components in the feedstock oil proceeds, and the oxygen content in the feedstock oil is reduced. In a preferred embodiment of the present invention, the oxygen content in the feedstock oil is reduced by preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0023] The reactor used in the hydrotreating step is not particularly limited, and for example, a fixed bed reactor type can be selected. The hydrogen introduced can be either countercurrent or cocurrent with respect to the feedstock. The reactor may also be composed of multiple reaction towers, with a combination of countercurrent and cocurrent flow. A common type is downflow, and a gas-liquid bi-cocurrent type can be used. A single reactor or a combination of multiple reactors can be used, and a single reactor may be divided into multiple catalyst beds.

[0024] In the hydrorefining step, the hydrodeoxygenation reaction conditions are as follows. The reaction temperature is 280°C or higher, preferably 300°C or higher, more preferably 320°C or higher, even more preferably 340°C or higher, and 400°C or lower, preferably 390°C or lower, more preferably 380°C or lower, and even more preferably 370°C or lower. In a preferred embodiment of the present invention, the reaction temperature is 280°C or higher and 400°C or lower, preferably 300°C or higher and 390°C or lower, more preferably 320°C or higher and 380°C or lower, and even more preferably 340°C or higher and 370°C or lower. The hydrogen pressure is 2 MPa or higher, preferably 2.5 MPa or higher, more preferably 3 MPa or higher, and even more preferably 3.5 MPa or higher. The hydrogen pressure is 20 MPa or lower, preferably 15 MPa or lower, more preferably 12 MPa or lower, and even more preferably 10 MPa or lower. In a preferred embodiment of the present invention, the pressure is 2 MPa or more and 20 MPa or less, preferably 2.5 MPa or more and 15 MPa or less, more preferably 3 MPa or more and 12 MPa or less, and even more preferably 3.5 MPa or more and 10 MPa or less. -１ or more, preferably 0.2 h -１ More preferably, 0.3 h -１ More preferably, 0.5 h -１ That's all, and 5.0h -１ Preferably, the time is 4.5 hours or less. -１ More preferably, it is 4.0 h or less. -１More preferably, it is 3.0 h or less. -１ In a preferred embodiment of the present invention, -１ Over 5.0 hours -１ less than 0.2 h, preferably -１ 4.5 hours or more -１ More preferably, it is 0.3 h or less. -１ Over 4.0 hours -１ More preferably, it is 0.5 h or less. -１ Over 3.0 hours -１ The hydrogen / oil ratio is 100 NL / L or more, preferably 120 NL / L or more, more preferably 140 NL / L or more, even more preferably 160 NL / L or more, and 2000 NL / L or less, preferably 1500 NL / L or less, more preferably 1000 NL / L or less, and even more preferably 750 NL / L or less. In a preferred embodiment of the present invention, the hydrogen / oil ratio is 100 NL / L or more and 2000 NL / L or less, preferably 120 NL / L or more and 1500 NL / L or less, more preferably 140 NL / L or more and 1000 NL / L or less, and even more preferably 160 NL / L or more and 750 NL / L or less. When the conditions for the hydrodeoxygenation reaction are within the above numerical ranges, hydrorefined oil and a feedstock for methane production can be produced efficiently.

[0025] (Hydrogenation Catalyst) The hydrogenation catalyst used in the hydrorefining step contains, as an active metal, at least one metal selected from the group consisting of metals belonging to Groups 6, 9, and 10 of the periodic table, and preferably contains two or more metals. Metals belonging to Group 6 of the periodic table include chromium, molybdenum, and tungsten. Metals belonging to Group 9 of the periodic table include cobalt, rhodium, and iridium. Metals belonging to Group 10 of the periodic table include nickel, palladium, and platinum. In a preferred embodiment of the present invention, the hydrogenation catalyst preferably contains at least one of molybdenum, nickel, and tungsten, and more preferably contains two or more of these. Furthermore, these active metals may exist in the form of oxides in the hydrogenation catalyst, but are converted to sulfides before use.

[0026] The hydrogenation catalyst may be one in which the above metal is supported on a carrier. The carrier may be a porous inorganic oxide. Examples of porous inorganic oxides include alumina (Al ２ O ３ Examples of the carrier constituent components other than alumina include porous inorganic oxides containing silica (SiO ２ ), titania (TiO ２ ), zirconia (ZrO ２ ) and Boria (B ２ O ３ The carrier may further contain a phosphate.

[0027] As the support for the hydrogenation catalyst, a composite oxide containing alumina and at least one selected from the above-mentioned components other than alumina is preferably used. The use of such a composite oxide can improve the deoxidation efficiency of the feedstock oil in the hydrorefining process. The reason for this effect is thought to be that in the composite oxide, the support components other than alumina form a composite oxide state with aluminum, which increases the support surface area and interacts with the active metal, thereby favorably affecting activity. The total content of components other than alumina in the support is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 15% by mass. When the total content of components other than alumina in the support is within the above-mentioned range, sufficient catalyst surface area can be ensured, and activity tends to be high. Furthermore, the content of phosphorus oxide in the support is preferably 0.1% by mass to 5% by mass, more preferably 1% by mass to 4% by mass.

[0028] The raw materials serving as precursors of silica, titania, zirconia, or boria used in producing the above composite oxides are not particularly limited, and common solutions containing silicon, titanium, zirconium, or boron can be used. For example, silicic acid, water glass, silica sol, etc. can be used for silicon; titanium sulfate, titanium tetrachloride, or various alkoxide salts can be used for titanium; zirconium sulfate or various alkoxide salts can be used for zirconium; and boric acid can be used for boron. For phosphorus, phosphoric acid or an alkali metal salt of phosphoric acid can be used.

[0029] These raw materials for the support components other than alumina are preferably added in any step prior to the calcination of the support. For example, they may be added in advance to an aluminum aqueous solution to form an aluminum hydroxide gel containing these components, or they may be added to a prepared aluminum hydroxide gel, or they may be added in a step of adding water or an acidic aqueous solution to a commercially available alumina intermediate or boehmite powder and kneading them, but a method in which they are made to coexist at the stage of preparing an aluminum hydroxide gel is more preferred.

[0030] The content of the active metal in the hydrogenation catalyst can be appropriately adjusted depending on the type of active metal. For example, when molybdenum and / or tungsten are contained as the active metal, the total amount of them supported is preferably 12% by mass or more and 35% by mass or less, more preferably 15% by mass or more and 30% by mass or less, based on the catalyst weight in terms of oxides. When the total amount of molybdenum and tungsten supported is within the above numerical range, these metals are effectively dispersed, and sufficient catalytic activity is easily obtained. Furthermore, when nickel and / or cobalt are contained as the active metal, the total amount of them supported is preferably 1.5% by mass or more and 18% by mass or less, more preferably 2% by mass or more and 15% by mass or less, based on the catalyst weight in terms of oxides. When the total amount of nickel and cobalt supported is within the above numerical range, these metals are effectively dispersed, and sufficient catalytic activity is easily obtained.

[0031] In the case of a hydrogenation catalyst, the method for incorporating an active metal into a support is not particularly limited, and known methods that are applied in the production of ordinary desulfurization catalysts can be used. Usually, a method of impregnating a support with a solution containing an active metal salt is preferably used. Also preferably used are the equilibrium adsorption method, the pore-filling method, the incipient wetness method, and the like. For example, the pore-filling method is a method in which the pore volume of the support is measured in advance and the support is impregnated with a metal salt solution of the same volume. However, the impregnation method is not particularly limited, and impregnation can be carried out by an appropriate method depending on the amount of metal supported and the physical properties of the catalyst support.

[0032] (Hydrorefined Oil) The hydrorefined oil obtained by the method for producing hydrorefined oil according to the present embodiment contains aliphatic hydrocarbons having a carbon number of 12 to 22. The aliphatic hydrocarbons may be either saturated aliphatic hydrocarbons or unsaturated aliphatic hydrocarbons.

[0033] The hydrorefined oil obtained by the method for producing a hydrorefined oil of this embodiment preferably has the following properties. The content of gas (a fraction with a boiling point range of 36°C or less) in the hydrorefined oil is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, and even more preferably 2.0% by mass or less. The content of naphtha (a fraction with a boiling point range of more than 36°C and 151°C or less) in the hydrorefined oil is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, even more preferably 0.5% by mass or less, and may even be 0% by mass. Furthermore, the increase in naphtha in the hydrorefined oil relative to the feed oil is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, even more preferably 0.6% by mass or less, even more preferably 0.4% by mass or less, and may even be 0% by mass. The total content of kerosene, light oil, and heavy oil in the hydrorefined oil is preferably 95.0% by mass or more, more preferably 96.0% by mass or more, even more preferably 97.0% by mass or more, and even more preferably 98.0% by mass or more. If the total content of kerosene, light oil, and heavy oil in the hydrorefined oil is within the above range, excessive cracking into gas fractions in the subsequent hydrocracking step is suppressed, which is preferable.

[0034] (Hydrocracking Process) The hydrocracking process is a process in which hydrogen is introduced into the hydrorefined oil obtained in the hydrorefining process described above, and hydrocracking is carried out under specific reaction conditions in the presence of a hydrocracking catalyst to obtain hydrocracked oil and liquefied petroleum gas. In the hydrocracking process, the hydrocracking reaction of the hydrorefined oil progresses, causing the hydrorefined oil to be lighter, resulting in hydrocracked oil in which heavy oil is converted into naphtha, kerosene, etc., and liquefied petroleum gas containing methane, etc.

[0035] In the hydrocracking step, hydrogen is donated from petroleum hydrocarbon fractions (particularly compounds having a cyclic saturated hydrocarbon skeleton) to oxygen- and carbon-containing compounds (particularly oxygen-containing compounds containing one or two carbon atoms), thereby accelerating the hydrogenation reaction and improving the conversion rate to methane. Examples of the cyclic saturated hydrocarbon skeleton in the petroleum hydrocarbon fraction include structures such as cyclohexane, tetrahydronaphthalene, and decahydronaphthalene. Examples of the oxygen- and carbon-containing compounds (particularly oxygen-containing compounds containing one or two carbon atoms) include carbon monoxide, carbon dioxide, methanol, formaldehyde, formic acid, ethanol, acetaldehyde, acetic acid, and oxalic acid. Among these, oxygen-containing compounds containing one carbon atom, such as carbon monoxide, carbon dioxide, methanol, and formic acid, are preferred. The conversion rate of oxygen- and carbon-containing compounds to methane is 35% or higher, preferably 37% or higher, and more preferably 40% or higher.

[0036] The reactor used in the hydrocracking step is not particularly limited, and the same reactor as that used in the hydrotreating step described above can be used. The reactors may be used alone or in combination, and a structure in which the interior of one reactor is divided into multiple catalyst beds may be adopted.

[0037] In the hydrocracking step, the hydrocracking reaction conditions are as follows: The reaction temperature is 350°C or higher, preferably 360°C or higher, more preferably 370°C or higher, even more preferably 380°C or higher, and 430°C or lower, preferably 425°C or lower, more preferably 420°C or lower, and even more preferably 415°C or lower. In a preferred embodiment of the present invention, the reaction temperature is 350°C or higher and 430°C or lower, preferably 360°C or higher and 425°C or lower, more preferably 370°C or higher and 420°C or lower, and even more preferably 380°C or higher and 415°C or lower. The reaction temperature in the hydrocracking step is preferably higher than the reaction temperature in the hydrorefining step, more preferably by 5°C or higher, even more preferably by 10°C or higher, even more preferably by 15°C or higher, and most preferably by 20°C or higher. The hydrogen pressure is 10 MPa or more, preferably 11 MPa or more, more preferably 12 MPa or more, even more preferably 13 MPa or more, and 20 MPa or less, preferably 18 MPa or less, more preferably 16 MPa or less, and even more preferably 15 MPa or less. In a preferred embodiment of the present invention, the hydrogen pressure is 10 MPa or more and 20 MPa or less, preferably 11 MPa or more and 18 MPa or less, more preferably 12 MPa or more and 16 MPa or less, and even more preferably 13 MPa or more and 15 MPa or less. The liquid hourly space velocity (LHSV) is 0.1 h -１ or more, preferably 0.2 h -１ More preferably, 0.4 h -１ More preferably, 0.8 h -１ That's all, and 3.0h -１ Preferably, it is 2.7 hours or less. -１ More preferably, 2.4 hours or less. -１ More preferably, it is 2.1 h or less. -１ In a preferred embodiment of the present invention, -１ Over 3.0 hours -１ less than 0.2 h, preferably -１ More than 2.7 hours -１ More preferably, 0.4 h-１ More than 2.4 hours -１ It is more preferably 0.8 h or less. -１ 2.1 hours -１ The hydrogen / oil ratio is 500 NL / L or more, preferably 750 NL / L or more, more preferably 1000 NL / L or more, even more preferably 1250 NL / L or more, and 2000 NL / L or less, preferably 1950 NL / L or less, more preferably 1900 NL / L or less, and even more preferably 1850 NL / L or less. In a preferred embodiment of the present invention, the hydrogen / oil ratio is 500 NL / L or more and 2000 NL / L or less, preferably 750 NL / L or more and 1950 NL / L or less, more preferably 1000 NL / L or more and 1900 NL / L or less, and even more preferably 1250 NL / L or more and 1850 NL / L or less. The hydrogen / oil ratio in the hydrocracking step is preferably higher than the hydrogen / oil ratio in the hydrorefining step, more preferably by at least 100 NL / L, even more preferably by at least 150 NL / L, even more preferably by at least 200 NL / L, and most preferably by at least 250 NL / L. If the conditions for the hydrodeoxygenation reaction are within the above numerical ranges, high-quality hydrocracked oil and liquefied petroleum gas can be efficiently produced.

[0038] (Hydrocracking Catalyst) The hydrocracking catalyst used in the hydrocracking step contains, as an active metal, at least one metal selected from the group consisting of metals belonging to Groups 6, 9, and 10 of the periodic table, and preferably contains two or more metals. Metals belonging to Group 6 of the periodic table include chromium, molybdenum, and tungsten. Metals belonging to Group 9 of the periodic table include cobalt, rhodium, and iridium. Metals belonging to Group 10 of the periodic table include nickel, palladium, and platinum. In a preferred embodiment of the present invention, the hydrocracking catalyst preferably contains at least one of molybdenum, nickel, and tungsten, and more preferably contains two or more of these. Furthermore, these active metals may exist in the form of oxides in the hydrocracking catalyst, but are converted to sulfides before use.

[0039] The hydrocracking catalyst may be one in which the above metals are supported on a carrier. The carrier may be the same inorganic oxide as the carrier for the hydrogenation catalyst. In a preferred embodiment of the present invention, a composite oxide containing two or more selected from the group consisting of silica, alumina, boria, zirconia, magnesia, and zeolite is preferably used, and more preferably contains at least zeolite.

[0040] The components that constitute the crystalline framework of the zeolite include silica (SiO ２ ), alumina (Al ２ O ３ ), titania (TiO ２ In a preferred embodiment of the present invention, the hydrocracking catalyst is preferably a zeolite containing silica and alumina, i.e., an aluminosilicate. Many types of zeolite crystal structures have been reported, including faujasite, beta, mordenite, and pentasil. In a preferred embodiment of the present invention, faujasite, beta, and pentasil types are more preferred in terms of exhibiting sufficient hydrocracking activity, with faujasite and beta being even more preferred. These zeolites may be those in which the alumina content is adjusted according to the stoichiometric ratio of the raw materials at the start of synthesis, or those that have been subjected to a predetermined hydrothermal treatment and / or acid treatment. Of these, it is most preferred to use ultra-stable Y-type zeolites that have been ultra-stabilized by hydrothermal treatment and / or acid treatment. This ultra-stable Y-type zeolite has, in addition to the inherent micropore structure of zeolites, called micropores of 20 Å or less, new pores in the range of 20 to 100 Å are formed, which are presumably providing a good reaction field for converting the oxygen content of fat and oil components. The volume of pores having a diameter of 20 to 100 Å is preferably 0.03 ml / g or more, more preferably 0.04 ml / g. The pore volume can be determined by mercury intrusion porosimetry.

[0041] Known conditions can be used as hydrothermal treatment conditions. Regarding the physical properties of the ultra-stable Y-type catalyst, the silica / alumina ratio (molar ratio) is preferably 5 to 120, more preferably 10 to 70, and even more preferably 15 to 50. When the silica / alumina ratio (molar ratio) is within the above-mentioned range, sufficient hydrocracking activity is likely to be exhibited. The zeolite content is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and even more preferably 30 to 60% by mass, based on the mass of the carrier. When the zeolite content is within the above-mentioned range, sufficient hydrocracking activity is likely to be exhibited.

[0042] The content of the active metal in the hydrocracking catalyst can be adjusted appropriately depending on the type of active metal. For example, when the active metal contains molybdenum and / or tungsten, the total supported amount thereof is preferably 12% by mass or more and 35% by mass or less, more preferably 15% by mass or more and 30% by mass or less, based on the catalyst weight in terms of oxides. When the total supported amount of molybdenum and tungsten is within the above numerical range, these metals are effectively dispersed, making it easier to obtain sufficient catalytic activity. When the active metal contains nickel and / or cobalt, the total supported amount thereof is preferably 1.5% by mass or more and 18% by mass or less, more preferably 2% by mass or more and 15% by mass or less, based on the catalyst weight in terms of oxides. When the total supported amount of nickel and cobalt is within the above numerical range, these metals are effectively dispersed, making it easier to obtain sufficient catalytic activity.

[0043] In the case of a hydrocracking catalyst, the method for incorporating an active metal into a support is not particularly limited, and known methods that are applied in the production of ordinary desulfurization catalysts can be used. Usually, a method of impregnating a support with a solution containing an active metal salt is preferably used. Also preferably used are the equilibrium adsorption method, the pore-filling method, the incipient wetness method, and the like. For example, the pore-filling method involves measuring the pore volume of the support in advance and impregnating the support with a metal salt solution of the same volume. However, the impregnation method is not particularly limited, and impregnation can be carried out by a method appropriate for the amount of metal supported and the physical properties of the catalyst support.

[0044] (Hydrocracked Oil) The hydrocracked oil obtained in the hydrocracking step preferably has the following properties. The content of gas (boiling point range: fraction of 36°C or less) in the hydrocracked oil is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less. In a preferred embodiment of the present invention, the content of gas in the hydrocracked oil is preferably 1% by mass or more and 35% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and even more preferably 5% by mass or more and 25% by mass or less. The content of naphtha (boiling point range: fraction of more than 36°C and 151°C or less) in the hydrocracked oil is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 60% by mass or less, and may be 20% by mass or more, or may be 30% by mass or more. In a preferred embodiment of the present invention, the naphtha content of the hydrocracked oil is preferably 20% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, even more preferably 20% by mass or more and 70% by mass or less, and even more preferably 20% by mass or more and 60% by mass or less. The kerosene content (boiling point range: fraction greater than 151°C and less than 254°C) of the hydrocracked oil is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and may be 50% by mass or less, or may be 40% by mass or more or less. In a preferred embodiment of the present invention, the kerosene content of the hydrocracked oil is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 50% by mass or less, and even more preferably 15% by mass or more and 50% by mass or less. The content of diesel fuel (boiling point range: fraction exceeding 254°C and not exceeding 356°C) in the hydrocracked oil is preferably 1% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2% by mass or more, and may be 30% by mass or less, or 25% by mass or more.In a preferred embodiment of the present invention, the content of light oil in the hydrocracked oil is preferably 1% by mass or more and 30% by mass or less, more preferably 1.5% by mass or more and 30% by mass or less, and even more preferably 2% by mass or more and 30% by mass or less. The content of heavy oil (boiling point range: fraction above 356°C) in the hydrocracked oil is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and may even be 0% by mass. The oxygen content of the hydrocracked oil is preferably 0.1% by mass or less, and may also be 0% by mass. It is preferable that each content of the hydrocracked oil is within the above numerical range, because high-quality hydrocracked oil and liquefied petroleum gas can be efficiently produced.

[0045] (Liquefied Petroleum Gas) The liquefied petroleum gas obtained by the hydrocracking process contains at least methane and may further contain other gas components such as ethylene, ethane, propylene, propane, butane, and isobutane.

[0046] The amount of liquefied petroleum gas produced in the hydrocracking step is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, relative to the total amount of hydrocracked oil and liquefied petroleum gas produced. In a preferred embodiment of the present invention, the amount of liquefied petroleum gas produced is preferably 1% by mass or more and 35% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and even more preferably 5% by mass or more and 25% by mass or less, relative to the total amount of hydrocracked oil and liquefied petroleum gas produced. If the amount of liquefied petroleum gas produced is within the above numerical range, high-quality hydrocracked oil and liquefied petroleum gas can be efficiently produced, which is preferable.

[0047] The methane content in the liquefied petroleum gas is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, even more preferably 0.3 mass% or more, and preferably 10 mass% or less, more preferably 6 mass% or less, and even more preferably 3 mass% or less, relative to the total amount of the hydrocracked oil and liquefied petroleum gas. In a preferred embodiment of the present invention, the methane content of the liquefied petroleum gas is preferably 0.1 mass% or more and 10 mass% or less, more preferably 0.2 mass% or more and 6 mass% or less, and even more preferably 0.3 mass% or more and 3 mass% or less. If the methane content in the liquefied petroleum gas is within the above numerical range, liquefied petroleum gas derived from the treated feedstock oil can be efficiently produced, which is preferable.

[0048] (Fuel Production Method) The fuel production method of this embodiment uses, as a feedstock, the hydrocracked oil obtained by the above-mentioned method for producing hydrocracked oil and liquefied petroleum gas. The hydrocracked oil obtained by the above-mentioned method for producing hydrocracked oil and liquefied petroleum gas mainly contains a gas base stock, a naphtha base stock, and a kerosene base stock. Although the kerosene base stock is produced by an isomerization cracking reaction under more severe reaction conditions than normal hydrocracking, the present invention can efficiently produce the kerosene base stock. Therefore, the hydrocracked oil obtained by the above-mentioned production method can be suitably used as a feedstock for sustainable aviation fuel (SAF), which is equivalent to jet fuel.

[0049] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0050] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0051] (Production of Hydrogenation Catalyst A) 1 kg of a 5% by mass aqueous sodium aluminate solution was added to water glass No. 3 and placed in a container kept at 70°C. Meanwhile, 1 kg of a 2.5% aqueous aluminum sulfate solution was placed in a separate container kept at 70°C, and this was added dropwise to the aforementioned sodium aluminate solution over 15 minutes. The amount of water glass was adjusted to achieve a predetermined silica content. The end point was the point at which the pH of the mixed solution reached 6.9 to 7.5, and the resulting slurry product was filtered to obtain a cake-like slurry. Next, the cake-like slurry was transferred to a container equipped with a reflux condenser, and 300 ml of distilled water and 3 g of 27% aqueous ammonia were added. The mixture was heated and stirred at 70°C for 24 hours. The heated and stirred slurry was then placed in a kneading device, heated to 80°C or higher, and kneaded while removing moisture, to obtain a clay-like kneaded product. Next, the kneaded mixture obtained was extruded into a cylindrical shape with a diameter of 1.5 mm by an extrusion molding machine, dried at 110° C. for 1 hour, and then calcined at 550° C. to obtain a shaped support.

[0052] Next, molybdenum trioxide, nickel nitrate hexahydrate, and phosphoric acid (85% concentration) were added to 150 ml of distilled water, and malic acid was added until these were fully dissolved to prepare an impregnation solution. The amounts of molybdenum trioxide, nickel nitrate hexahydrate, and phosphoric acid used were adjusted to achieve the desired loadings. Next, 300 g of the formed support obtained above was impregnated with the impregnation solution by spraying. Subsequently, this support was dried at 110°C for 1 hour and then calcined at 550°C to obtain hydrogenation catalyst A. The composition of the produced catalyst A is shown in Table 1.

[0053] (Production of Hydrogenation Catalyst B) A Y-type zeolite having a silica / alumina ratio of 5 was stabilized by a known ultrastabilization treatment method, and then subjected to an acid treatment with a 1N aqueous nitric acid solution to obtain a proton-type ultrastable Y-type zeolite having a unit cell length of 24.33 Å, a silica / alumina ratio of 30, and a pore volume of 0.055 ml / g relative to the zeolite weight, with pore diameters of 30 to 100 Å as measured by mercury intrusion porosimetry. Next, the obtained ultrastable Y-type zeolite (550 g) was added to an aqueous ammonium nitrate solution (concentration 2 N, 3 liters) and stirred at room temperature to convert it to the ammonium type.

[0054] Next, the clay-like kneaded product obtained by the same method as in the production of hydrogenation catalyst A and the zeolite obtained above were mixed to obtain a mixed kneaded product. This mixed kneaded product was extruded into a cylindrical shape with a diameter of 1.5 mm using an extrusion molding machine, dried at 110°C for 1 hour, and then calcined at 550°C to obtain a formed carrier containing 55% by mass of zeolite.

[0055] Next, ammonium paratungstate and nickel nitrate hexahydrate were dissolved in 150 ml of distilled water to prepare an impregnation solution. The amounts of ammonium paratungstate and nickel nitrate hexahydrate used were adjusted to achieve the desired supported amounts. Next, 300 g of the formed support obtained above was impregnated with the impregnation solution while spraying it, to obtain hydrogenation catalyst B. The composition of the produced catalyst B is shown in Table 1.

[0056]

[0057] [Example 1] (Catalyst Pre-sulfurization Step) 7.3 ml of catalyst A was packed into a reaction tube A having an inner diameter of 21 mm, and 34.0 ml of catalyst B was packed into a reaction tube B having an inner diameter of 21 mm. The reaction tubes A and B were attached to separate fixed-bed flow reactors. Then, using a light oil (sulfur content: 1% by mass) to which dimethyl disulfide had been added, the catalyst was pre-sulfurized at an average catalyst layer temperature of 280°C, a hydrogen pressure of 12 MPa (hereinafter, unless otherwise specified, the pressure unit is gauge pressure), and a liquid hourly space velocity (LHSV) of 1.0 h －１ The temperature was raised to 340° C. over 40 hours under conditions of a hydrogen / oil ratio of 100 NL / L, and pre-sulfurization of catalysts A and B was carried out.

[0058] (Catalyst stabilization step) After the pre-sulfurization of catalyst A and catalyst B was completed, a reduced-pressure petroleum hydrocarbon fraction (density at 15°C: 0.8918 g / ml, sulfur content: 0.1 mass%, nitrogen content: 0.05 mass%, oxygen content: 0.0 mass%, 10% distillation point: 330°C, 90% distillation point: 527°C; hereinafter referred to as "pretreated petroleum hydrocarbon fraction") whose sulfur content had been reduced by 50 mass% or more by hydrodesulfurization treatment was subjected to a catalyst layer average temperature of 380°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 3.0 h －１ The catalysts A and B were reacted for 100 hours or more under the conditions of a hydrogen / oil ratio of 1250 NL / L to stabilize them.

[0059] (Stock Oil Production Process) Thereafter, a stock oil (2.3% by mass of oxygen atoms derived from carboxylic acids or ester bonds) was produced by mixing a treated oil containing fats and oils derived from animal and vegetable oils (waste cooking oil, density at 15°C 0.9250 g / m, sulfur content 0.001% by mass, nitrogen content 0.005% by mass, oxygen content 11.5% by mass, 10% distillation point 413°C, 90% distillation point 608°C, iodine value 113, saponification value 76; hereinafter referred to as "treated oil") and the pretreated petroleum hydrocarbon fraction in a volume ratio of 20:80.

[0060] (Hydrorefining step) The above feedstock oil was fed to the reaction tube A under the conditions of an average catalyst layer temperature of 320°C, a hydrogen pressure of 5 MPa, and a liquid hourly space velocity (LHSV) of 0.5 h －１ The oil was passed through under conditions of a hydrogen / oil ratio of 175 NL / L to carry out a hydrodeoxygenation reaction, thereby producing a hydrorefined oil.

[0061] (Hydrocracking Step) The hydrorefined oil was introduced into an oil-water separator, and water was removed from the hydrorefined oil. After introduction into the oil-water separator, a portion of the hydrorefined oil was cooled to 40°C with cooling water and recovered for analysis. Most of the hydrorefined oil was pressurized as it was and introduced into reactor B under the conditions of an average catalyst layer temperature of 400°C, a hydrogen pressure of 15 MPa, and an LHSV of 1.0 h. －１ The oil was passed through under conditions of a hydrogen / oil ratio of 1750 NL / L to carry out a hydrocracking reaction, producing hydrocracked oil and liquefied petroleum gas.

[0062] (Example 2) A stock oil was produced in the same manner as in Example 1, except that in the stock oil production process, the oil to be treated and the pretreated petroleum hydrocarbon fraction were mixed in a volume ratio of 40:60. Subsequently, a hydrorefining step and a hydrocracking step were carried out in the same manner as in Example 1, except that the stock oil was used, to produce a hydrocracked oil and a liquefied petroleum gas.

[0063] (Example 3) A feedstock oil was produced in the same manner as in Example 1, except that in the feedstock oil production process, the oil to be treated and the pretreated petroleum hydrocarbon fraction were mixed at a volume ratio of 99:1. Subsequently, using this feedstock oil, the reaction conditions in the hydrotreating process were changed to a liquid hourly space velocity (LHSV) of 0.4 h －１A hydrorefined oil was produced in the same manner as in Example 1, except that the reaction conditions in the hydrocracking step were changed to a liquid hourly space velocity (LHSV) of 0.85 h －１ Hydrocracked oil and liquefied petroleum gas were produced in the same manner as in Example 1, except that the above-mentioned procedure was changed to the above.

[0064] (Example 4) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 350°C, a hydrogen pressure of 10 MPa, and a liquid hourly space velocity (LHSV) of 1.4 h －１ A hydrorefined oil was produced in the same manner as in Example 1, except that the hydrogen / oil ratio was changed to 625 NL / L. Subsequently, the hydrorefined oil was used and the reaction conditions in the hydrocracking step were changed to an average catalyst layer temperature of 400°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 0.85 h －１ Hydrocracked oil and liquefied petroleum gas were produced in the same manner as in Example 1, except that the hydrogen / oil ratio was changed to 913 NL / L.

[0065] (Example 5) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 380°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 4.0 h －１ Hydrogenated refined oil was produced in the same manner as in Example 1, except that the hydrogen / oil ratio was changed to 625 NL / L. Subsequently, using the hydrorefined oil, the reaction conditions in the hydrocracking step were changed to an average catalyst layer temperature of 400°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 2.0 h －１ Hydrocracked oil and liquefied petroleum gas were produced in the same manner as in Example 1, except that the hydrogen / oil ratio was changed to 1,250 NL / L.

[0066] (Comparative Example 1) The oil to be treated used in Example 1 was used as a feedstock oil without being mixed with a petroleum hydrocarbon fraction. Using this feedstock oil, the conditions for the hydrodeoxygenation reaction in the hydrotreating step were as follows: average catalyst layer temperature 335°C, hydrogen pressure 12 MPa, liquid hourly space velocity (LHSV) 4.0 h －１A hydrorefined oil was produced in the same manner as in Example 1, except that the hydrogen / oil ratio was changed to 1,250 NL / L. Subsequently, the hydrorefined oil was used and the reaction conditions in the hydrocracking step were changed to an average catalyst layer temperature of 345°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 0.85 h －１ Hydrocracked oil and liquefied petroleum gas were produced in the same manner as in Example 1, except that the conditions were changed to a hydrogen / oil ratio of 923 NL / L.

[0067] (Comparative Example 2) Hydrorefined oil was produced in the same manner as in Comparative Example 1, except that the conditions for the hydrodeoxygenation reaction in the hydrorefining step were changed to an average catalyst bed temperature of 380° C. Subsequently, using this hydrorefined oil, hydrocracked oil and liquefied petroleum gas were produced in the same manner as in Comparative Example 1, except that the reaction conditions in the hydrocracking step were changed to an average catalyst bed temperature of 390° C. and a hydrogen / oil ratio of 769 NL / L.

[0068] (Comparative Example 3) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 375°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 4.0 h －１ A hydrorefined oil was produced in the same manner as in Example 1, except that the hydrogen / oil ratio was changed to 1,250 NL / L. Subsequently, the hydrorefined oil was used and the reaction conditions in the hydrocracking step were changed to an average catalyst layer temperature of 385°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 0.85 h －１ Hydrocracked oil and liquefied petroleum gas were produced in the same manner as in Example 1, except that the conditions were changed to a hydrogen / oil ratio of 769 NL / L.

[0069] (Comparative Example 4) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were a liquid hourly space velocity (LHSV) of 2.8 h －１ A hydrorefined oil was produced in the same manner as in Comparative Example 3, except that the hydrorefined oil was changed to:

[0045] Subsequently, a hydrocracked oil and a liquefied petroleum gas were produced in the same manner as in Comparative Example 3, except that the hydrorefined oil was used.

[0070] The experimental conditions for each step in Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Tables 2 and 3.

[0071]

[0072]

[0073] <Evaluation> (Analysis of Hydrocracked Oil) The yields (mass%) of the gas (boiling point range: fraction of 36 ° C or less), naphtha (boiling point range: fraction of more than 36 ° C or less), kerosene (boiling point range: fraction of more than 151 ° C or less), diesel (boiling point range: fraction of more than 254 ° C or less), and heavy oil (boiling point range: fraction of more than 356 ° C) obtained from each hydrocracked oil obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were determined by simulated distillation using gas chromatography (apparatus: Agilent-7890B, measurement conditions: SIMDIS D2887), and the oxygen concentration (mass%) in the hydrocracked oil was measured using the method specified in the Japan Petroleum Institute Petroleum Testing Standard JPI-5S-68. The amount of methane produced in the gas was also measured. The measurement results are shown in Tables 4 and 5. The content of each component (gas, methane, naphtha, kerosene, light oil, heavy oil, oxygen) in the table is the percentage relative to the total of liquefied petroleum gas and hydrocracked oil, which is 100% by mass.

[0074] Furthermore, the amount of methane produced was experimentally confirmed when a hydrocarbon feedstock with the same PIONA (P: normal paraffin, I: isoparaffin, O: olefin, N: naphthene, A: aroma) content was similar, assuming that the triglycerides and fatty acids in the feedstock oil were replaced with normal paraffins, and the amount of methane produced was confirmed to be 0.12 mass%. Therefore, calculations confirmed that methane produced from oxygen and carbon-containing compounds (at least one of carbon monoxide, carbon dioxide, methanol, and formic acid) in the hydrocracking step accounted for 0.23 mass%. Meanwhile, the amount of carbon dioxide produced from waste cooking oil was independently calculated by defining it as the progress ratio of the hydrodehydration reaction and the decarboxylation / decarbonylation reaction in the hydrorefining step from the ratio of C18 normal paraffins to C17 normal paraffins before and after the reaction. Adding to this the amounts of formic acid, acetic acid, propionic acid, butyric acid, and carbonic acid lost as a result of partial reduction of carbon dioxide and extraction into water, and assuming a 100% conversion rate of oxygen- and carbon-containing compounds to methane, the maximum theoretical yield of methane derived from oxygen- and carbon-containing compounds under the conditions of Example 1 was determined to be 0.34 mass%. Therefore, it was confirmed by calculation that the conversion rate of oxygen- and carbon-containing compounds to methane in Example 1 was 0.23 / 0.34=68%. Similarly, the conversion rates of oxygen- and carbon-containing compounds to methane in the hydrotreating steps of Examples 2 to 5 and Comparative Examples 1 to 4 were calculated and are shown in Tables 4 and 5.

[0075] The results of the above examples and comparative examples show that the present invention can efficiently produce high-quality hydrocracked oil and liquefied petroleum gas. Furthermore, the hydrocracked oil produced as described above can be used as a fuel raw material.

[0076]

[0077]

Claims

1. A process for preparing a feedstock oil by mixing petroleum hydrocarbons with an oil to be treated containing fats and oils derived from animal and vegetable oils and fatty acid components; 2. A process for introducing hydrogen into the feedstock oil and subjecting the oil to treatment to a hydrogenation reaction in the presence of a sulfide hydrogenation catalyst at a reaction temperature of 280°C to 400°C, a hydrogen pressure of 2 MPa to 20 MPa, and a liquid hourly space velocity (LHSV) of 0.1 h -１ Over 5.0 hours -１ and a hydrogen / oil ratio of 100 NL / L or more and 2000 NL / L or less to obtain a hydrorefined oil; and introducing hydrogen into the hydrorefined oil and subjecting the hydrorefined oil to a reaction at a temperature of 350°C or more and 430°C or less, a hydrogen pressure of 10 MPa or more and 20 MPa or less, and a liquid hourly space velocity (LHSV) of 0.1 h in the presence of a sulfide hydrocracking catalyst. -１ Over 3.0 hours -１ and performing hydrocracking under reaction conditions of a hydrogen / oil ratio of 500 NL / L or more and 2000 NL / L or less to obtain hydrocracked oil and liquefied petroleum gas, wherein the reaction temperature in the hydrocracking step is higher than the reaction temperature in the hydrotreating step, the hydrogen / oil ratio in the hydrocracking step is higher than the hydrogen / oil ratio in the hydrotreating step, the liquefied petroleum gas contains methane, and the conversion rate of oxygen- and carbon-containing compounds to methane in the hydrocracking step is 35% or more.

2. A method for producing hydrocracked oil and liquefied petroleum gas as described in claim 1, wherein the petroleum hydrocarbons contain a fraction having a boiling point of 150°C or higher, and contain a sulfur content of 0.01% by mass or more and 5.0% by mass or less, and a nitrogen content of 0.001% by mass or more and 0.5% by mass or less.

3. A method for producing hydrocracked oil and liquefied petroleum gas as described in claim 1, wherein the treated oil contains a fraction with a boiling point of 230°C or higher and an oxygen content of 0.3 mass% or more and 13.0 mass% or less.

4. A method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the mixing ratio of the petroleum hydrocarbon to the oil to be treated is 1:99 to 99:1 on a volume basis.

5. The method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the hydrogenation catalyst contains at least one metal selected from the group consisting of metals belonging to Groups 6, 9 and 10 of the periodic table.

6. A method for producing hydrocracked oil and liquefied petroleum gas as described in claim 1, wherein the raw oil contains 0.1 mass % or more and 35 mass % or less of oxygen atoms derived from carboxylic acid or ester bonds.

7. The method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the petroleum hydrocarbons have been subjected to hydrodesulfurization treatment.

8. The method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the hydrorefined oil contains aliphatic hydrocarbons having 12 to 22 carbon atoms.

9. The method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the reaction temperature in the hydrocracking step is at least 5°C higher than the reaction temperature in the hydrorefining step.

10. The method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the hydrogen / oil ratio in the hydrocracking step is at least 100 NL / L higher than the hydrogen / oil ratio in the hydrorefining step.

11. The method for producing hydrocracked oil and liquefied petroleum gas according to claim 1, wherein the oxygen- and carbon-containing compound is at least one selected from the group consisting of carbon monoxide, carbon dioxide, methanol, and formic acid.

12. A method for producing fuel, which uses hydrocracked oil obtained by the method according to any one of claims 1 to 11 as a raw material.

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