Method for producing hydrorefined oil and method for producing fuel

Abstract

[Problem] To provide a method for efficiently producing a high-quality hydrorefined oil while reducing the cost of maintenance management or the like by stably suppressing acid corrosion of a production apparatus. [Solution] A method for producing a hydrorefined oil according to the present invention is characterized by comprising: a step for preparing a starting material oil that is obtained by mixing a petroleum hydrocarbon and an oil to be processed containing an oil or fat derived from an animal / plant oil and a fatty acid component; and a step for introducing hydrogen into the starting material oil, and performing hydrorefining in the presence of a hydrogenation catalyst under the reaction conditions of a reaction temperature of 250°C to 430°C inclusive, a hydrogen pressure of 5 MPa to 20 MPa inclusive, a liquid hourly space velocity (LHSV) of more than 1.5 h-1 but not more than 5.0 h-1, and a hydrogen / oil ratio of 100 NL / L to 2,000 NL / L inclusive so as to obtain a hydrorefined oil. This method for producing a hydrorefined oil is also characterized in that, in the hydrorefining step, the pH of by-product water is set to 7.0 or more by having an organic acid and / or an inorganic acid, which is mixed and / or generated in the hydrorefining step, neutralized with a hydrogenated compound of a compound that is contained in the starting material oil and comprises at least one of an oxygen atom, a sulfur atom, and a nitrogen atom.

Description

Hydrorefined oil production method and fuel production method

[0001] The present invention relates to a method for producing hydrorefined oil. The present invention also relates to a method for producing fuel using the hydrorefined oil as a feedstock.

[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] However, it has been pointed out that when fatty acid esters are used as diesel fuel or aviation fuel, the high oxygen content of the fatty acid esters can adversely affect engine materials and cause phenomena such as corrosion. Therefore, as a method for obtaining a fuel with a sufficiently low oxygen content and suitable as a base material for heavy oil, light oil, kerosene, etc., in high yield, Patent Document 1 describes a method for producing environmentally friendly fuels, which includes the steps 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 hydrocracking the feedstock, or a feedstock that has undergone 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 particular, the hydrocracking step is carried out under a hydrogen pressure of 6 to 20 MPa and a liquid hourly space velocity (LHSV) of 0.2 to 1.5 h －１ and a hydrogen / oil ratio of 200 to 2000 NL / L.

[0005] Furthermore, in the manufacturing equipment for hydrogenating fatty acid esters, the water and acidic substances produced during the hydrogenation reaction of fats and oils create an acidic environment, causing severe acid corrosion of the manufacturing equipment. To address this acid corrosion, extensive material adaptation work and careful maintenance management are required, which results in high costs.

[0006] Japanese Patent Application Laid-Open No. 2007-153928

[0007] In the invention described in Patent Document 1, the hydrocracking step causes the hydrorefined oil to be cracked (lightened) and the naphtha and kerosene contents increase, leaving room for improvement in quality. Furthermore, in the hydrorefining step of the feedstock oil, it was necessary to stably suppress acid corrosion.

[0008] Therefore, the present inventors conducted extensive research to solve the above-mentioned problems and surprisingly discovered that by improving the hydrorefining process of a feedstock oil obtained by mixing petroleum hydrocarbons and an oil to be treated, it is possible to stably suppress acid corrosion of the production equipment, reduce maintenance costs, and efficiently produce a high-quality hydrorefined oil. Based on this discovery, the present inventors have completed the present invention. Based on this discovery, the present inventors have completed the present invention.

[0009] 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 and subjecting it to a hydrogenation process in the presence of a hydrogenation catalyst at a reaction temperature of 250°C to 430°C, a hydrogen pressure of 5 MPa to 20 MPa, and a liquid hourly space velocity (LHSV) of 1.5 h -１ Super 5.0h -１and a step of hydrotreating the feedstock oil under reaction conditions of a hydrogen / oil ratio of 100 NL / L or more and 2000 NL / L or less to obtain a hydrorefined oil, wherein in the hydrorefining step, a hydrogenated compound of a compound containing at least one of oxygen, sulfur, and nitrogen atoms contained in the feedstock oil neutralizes organic acids and / or inorganic acids mixed in and / or generated in the hydrorefining step, thereby raising the pH of by-product water to 7.0 or higher. [2] A method for producing a hydrorefined oil according to [1], wherein the petroleum hydrocarbons include a petroleum hydrocarbon-based fraction having a boiling point of 150°C or higher and 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 a hydrorefined oil according to [1] or [2], wherein the oil to be treated includes a fraction having a boiling point of 230°C or higher and an oxygen content of 0.3% by mass or more and 13.0% by mass or less. [4] The method for producing a hydrorefined oil according to any one of [1] to [3], wherein the mixing ratio of the petroleum hydrocarbon to the oil to be treated is 40:60 to 99:1 on a volume basis. [5] The method for producing a hydrorefined oil according to any one 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 a hydrorefined oil according to any one of [1] to [5], wherein the organic acid produced in the hydrorefining step is a water-soluble carboxylic acid having 6 or less carbon atoms produced by hydrogenation and polymerization of carbon dioxide. [7] The method for producing a hydrorefined oil according to any one of [1] to [6], wherein the petroleum hydrocarbon has been subjected to hydrodesulfurization treatment. [8] The method for producing a hydrorefined oil according to any one of [1] to [7], wherein the hydrorefined oil contains aliphatic hydrocarbons having from 12 to 22 carbon atoms. [9] A method for producing a hydrorefined oil according to any one of [1] to [8], wherein the hydrorefined oil has a naphtha content of 1.0 mass% or less.

[10] A method for producing a hydrorefined oil according to any one of [1] to [9], wherein the hydrorefined oil has a total content of kerosene, light oil, and heavy oil of 95.0 mass% or more.

[11] A method for producing a fuel using the hydrorefined oil obtained by the method according to any one of [1] to

[10] as a feedstock.

[0010] According to the present invention, there is provided a method for efficiently producing high-quality hydrorefined oil while reducing costs for maintenance, etc., by improving the hydrorefining process of feedstock oil and stably suppressing acid corrosion of the production equipment. The present invention also provides a method for producing fuel using the hydrorefined oil as a feedstock.

[0011] Preferred embodiments of the present invention will be described in detail below.

[0012] (Method for Producing Hydrogenated Refined Oil) The method for producing hydrorefined oil of this embodiment includes the steps of: preparing a feedstock oil by mixing petroleum hydrocarbons with an oil to be treated that contains fats and oils derived from animal and vegetable oils and fatty acid components; and introducing hydrogen into the feedstock oil and subjecting the oil to a hydrogenation reaction in the presence of a hydrogenation catalyst at a reaction temperature of 250°C to 430°C, a hydrogen pressure of 5 MPa to 20 MPa, and a liquid hourly space velocity (LHSV) of 1.5 h. -１ Super 5.0h -１ and a step of hydrotreating the feedstock oil under reaction conditions of 100 NL / L or more and a hydrogen / oil ratio of 100 NL / L or more and 2000 NL / L or less to obtain a hydrorefined oil, wherein in the hydrorefining step, a hydrogenated compound of a compound containing at least one of oxygen, sulfur, and nitrogen atoms contained in the feedstock oil neutralizes organic acids and / or inorganic acids that are mixed in and / or generated in the hydrorefining step, thereby raising the pH of the by-product water to 7.0 or more.

[0013] Each step in the method for producing hydrorefined oil will be described in detail below.

[0014] (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.

[0015] (Feedstock Oil) The feedstock oil is a mixture of petroleum hydrocarbons and oil to be treated. The mixture ratio of petroleum hydrocarbons to oil to be treated is preferably 40:60 to 99:1, more preferably 45:55 to 95:5, and even more preferably 50:50 to 90:10, on a volume basis. If the mixture ratio of petroleum hydrocarbons to oil to be treated is within the above range, it is preferable because the target fuel can be produced stably while suppressing equipment corrosion under operating conditions that can avoid excessive cracking of the feedstock oil and even runaway exothermic reactions. Petroleum hydrocarbons and 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 mass% or more and 0.5 mass% or less, more preferably 0.003 mass% or more and 0.1 mass% or less, and even more preferably 0.005 mass% or more and 0.05 mass% or less. The oxygen content of the petroleum hydrocarbons is preferably 0.5 mass% or less, more preferably 0.1 mass% or less, even more preferably 0.05 mass% or less, and may even be 0 mass%. If the sulfur, nitrogen, and oxygen contents of the petroleum hydrocarbons are within the above numerical ranges, the components produced in the hydrogenation reaction of the petroleum hydrocarbons are in appropriate amounts for the neutralization reaction, which is preferable because it suppresses catalyst degradation while suppressing corrosion in the process under conditions that satisfy the product properties after distillation of the resulting oil. 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 fats and 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 fats and 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, 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, this is preferable because the product properties of the aviation fuel produced by the cracking reaction are improved.

[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 10.0% by mass or more and 12.0% by mass or less. It is preferable that the sulfur, nitrogen, and oxygen contents of the oil to be treated are within the above-mentioned numerical ranges, since fatty acids with a small number of carbon atoms can be removed while the purity of the oil or fatty acid is high, thereby increasing the yield of aviation fuel.

[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 present inventors have discovered that in the hydrorefining process, carbon dioxide is produced by the hydrodecarboxylation reaction of fatty acid components in the feedstock oil, and organic acids (particularly water-soluble carboxylic acids having 6 or fewer carbon atoms, such as formic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid) are produced by hydrogenation and polymerization of the carbon dioxide. Furthermore, during the hydrorefining process, there is a risk of sulfonic acid-based inorganic acids being produced or inorganic acids such as hydrogen chloride from the feedstock being contaminated. Therefore, the by-product water obtained during the hydrorefining process contains these organic and inorganic acids, making the by-product water acidic and, if left untreated, causing acid corrosion of the production equipment. Therefore, the present inventors have discovered that neutralizing the organic and inorganic acids in the by-product water with hydrogenated compounds (e.g., ammonium hydrogen sulfide and ammonium thiosulfate) of compounds containing at least one of oxygen, sulfur, and nitrogen atoms contained in the feedstock oil can adjust the pH of the by-product water to 7.0 or higher and form a basic buffer solution, thereby stably suppressing acid corrosion of the production equipment. The pH of the by-product water is preferably 7.5 or higher, more preferably 8.0 or higher, even more preferably 8.5 or higher, and preferably 10 or lower, more preferably 9.8 or lower, even more preferably 9.6 or lower, and even more preferably 9.4 or lower. In a preferred embodiment of the present invention, the pH of the by-product water is preferably 7.0 or higher and 10 or lower, more preferably 7.5 or higher and 9.8 or lower, even more preferably 8.0 or higher and 9.6 or lower, and even more preferably 8.5 or higher and 9.4 or lower.

[0024] 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.

[0025] In the hydrorefining step, the hydrodeoxygenation reaction conditions are as follows: The reaction temperature is 250°C or higher, preferably 300°C or higher, more preferably 350°C or higher, even more preferably 370°C or higher, and 430°C or lower, preferably 420°C or lower, more preferably 410°C or lower, and even more preferably 405°C or lower. In a preferred embodiment of the present invention, the reaction temperature is 250°C or higher and 430°C or lower, preferably 300°C or higher and 420°C or lower, more preferably 350°C or higher and 410°C or lower, and even more preferably 370°C or higher and 405°C or lower. The hydrogen pressure is 5 MPa or higher, preferably 6 MPa or higher, more preferably 7 MPa or higher, even more preferably 8 MPa or higher, and 20 MPa or lower, preferably 16 MPa or lower, more preferably 14 MPa or lower, and even more preferably 12 MPa or lower. In a preferred embodiment of the present invention, the pressure is 5 MPa or more and 20 MPa or less, preferably 6 MPa or more and 16 MPa or less, more preferably 7 MPa or more and 14 MPa or less, and even more preferably 8 MPa or more and 12 MPa or less. -１ More than 1.6 h, preferably -１ More preferably, 1.7 h -１ More preferably, 1.8 h -１ That's all, and 5.0h -１ Preferably, the time is 4.5 hours or less. -１ More preferably, 4.3 hours or less. -１ More preferably, it is 4.0 h or less. -１ In a preferred embodiment of the present invention, -１ Super 5.0h -１ Preferably, it is 1.6 h or less. -１ 4.5 hours or more -１ More preferably, it is 1.7 h or less. -１ More than 4.3 hours -１ More preferably, it is 1.8 h or less. -１ Over 4.0 hours -１The hydrogen / oil ratio is 100 NL / L or more, preferably 500 NL / L or more, more preferably 750 NL / L or more, even more preferably 1000 NL / L or more, and 2000 NL / L or less, preferably 1800 NL / L or less, more preferably 1600 NL / L or less, and even more preferably 1400 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 500 NL / L or more and 1800 NL / L or less, more preferably 750 NL / L or more and 1600 NL / L or less, and even more preferably 1000 NL / L or more and 1400 NL / L or less. When the conditions for the hydrodeoxygenation reaction are within the above numerical ranges, a high-quality hydrorefined oil can be efficiently produced.

[0026] (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, and are preferably converted into sulfides for use.

[0027] 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 (B２ O ３ The carrier may further contain a phosphate.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] (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.

[0034] 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 less than 151°C) 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. The increase in naphtha (a fraction with a boiling point range of more than 36°C and less than 151°C) 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. If the total content of kerosene, light oil, and heavy oil in the hydrorefined oil is within the above-mentioned range, cracking (lightening) of the hydrorefined oil is suppressed, making it suitable as a fuel, which is preferable.

[0035] (Fuel Production Method) The fuel production method of this embodiment uses the hydrorefined oil obtained by the above-mentioned hydrorefined oil production method as a feedstock. The hydrorefined oil obtained by the above-mentioned hydrorefined oil production method mainly contains heavy oil base stocks and light oil base stocks, and is mainly composed of saturated hydrocarbons, so it can be suitably used as a feedstock for sustainable aviation fuel (SAF), which is equivalent to jet fuel.

[0036] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0037] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0038] (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.

[0039] 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 they 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.

[0040]

[0041] [Example 1] (Catalyst Pre-sulfurization Step) A reaction tube with an inner diameter of 21 mm was packed with 7.3 ml of catalyst A and attached to a fixed-bed flow reactor. Subsequently, a gas oil (sulfur content: 1 mass%) containing dimethyl disulfide was used, and the catalyst was pre-sulfurized at an average catalyst layer temperature of 280°C, a hydrogen pressure of 12 MPa (hereinafter, pressure units are gauge pressure unless otherwise specified), and a liquid hourly space velocity (LHSV) of 1.0 h －１ The temperature was raised to 340° C. over 40 hours under the condition of a hydrogen / oil ratio of 100 NL / L, and pre-sulfurization of catalyst A was carried out.

[0042] (Catalyst stabilization step) After the pre-sulfurization of catalyst A 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 catalyst A was stabilized by reacting for 100 hours or more under the conditions of a hydrogen / oil ratio of 1250 NL / L.

[0043] (Stock Oil Production Process) Thereafter, a stock oil 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 mass%, nitrogen content 0.005 mass%, oxygen content 11.5 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.

[0044] (Hydrorefining step) The above feedstock oil was fed to a reactor under the conditions of an average catalyst layer temperature of 370°C, a hydrogen pressure of 12 MPa, and a liquid hourly space velocity (LHSV) of 2.8 h －１ The oil was passed through under conditions of a hydrogen / oil ratio of 1,250 NL / L to carry out a hydrodeoxygenation reaction, thereby producing a hydrorefined oil.

[0045] (Example 2) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 375°C, 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 above-mentioned procedure was changed to the above.

[0046] (Example 3) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 380°C, 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 above-mentioned procedure was changed to the above.

[0047] (Example 4) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 395°C, 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 above-mentioned procedure was changed to the above.

[0048] (Example 5) A feedstock was produced in the same manner as in Example 1, except that the oil to be treated and the pretreated petroleum hydrocarbon fraction were mixed in a volume ratio of 50:50 in the feedstock production process. Subsequently, the feedstock was used to carry out the hydrodeoxygenation reaction in the hydrotreating step under the conditions of an average catalyst layer temperature of 375°C, a hydrogen pressure of 10 MPa, and a liquid hourly space velocity (LHSV) of 1.8 h －１ A hydrorefined oil was produced in the same manner as in Example 1, except that the above-mentioned procedure was changed to the above.

[0049] (Example 6) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were an average catalyst layer temperature of 405°C, a liquid hourly space velocity (LHSV) of 4.0 h －１ A hydrorefined oil was produced in the same manner as in Example 5, except that the above procedure was changed to the following.

[0050] (Comparative Example 1) The oil to be treated used in Example 1 was used as a feedstock oil without being mixed with the pretreated petroleum hydrocarbon fraction. Using this feedstock oil, the conditions for the hydrodeoxygenation reaction in the hydrotreating step were set as follows: average catalyst layer temperature 320°C, liquid hourly space velocity (LHSV) 4.0 h －１ A hydrorefined oil was produced in the same manner as in Example 1, except that the above-mentioned procedure was changed to the above.

[0051] Comparative Example 2 A 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 layer temperature of 335°C.

[0052] Comparative Example 3 A 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 layer temperature of 350°C.

[0053] Comparative Example 4 A 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 layer temperature of 360°C.

[0054] Comparative Example 5 A 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 layer temperature of 370°C.

[0055] Comparative Example 6 A 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 layer temperature of 380°C.

[0056] Comparative Example 7 A 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 layer temperature of 390°C.

[0057] (Comparative Example 8) The conditions for the hydrodeoxygenation reaction in the hydrotreating step were as follows: average catalyst layer temperature 395°C, liquid hourly space velocity (LHSV) 0.5 h －１ A hydrorefined oil was produced in the same manner as in Example 1, except that the above-mentioned procedure was changed to the above.

[0058] The experimental conditions for each step in Examples 1 to 6 and Comparative Examples 1 to 8 are shown in Tables 2 and 3.

[0059]

[0060]

[0061] <Evaluation> (Analysis of Hydrorefined Oil) The yields (mass%) of 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 hydrorefined oil obtained in Examples 1 to 6 and Comparative Examples 1 to 8 were determined by simulated distillation using gas chromatography (apparatus: Agilent-7890B, measurement conditions: SIMDIS D2887), and the oxygen concentration (mass%) in the hydrorefined oil was measured using the method specified in the Japan Petroleum Institute Petroleum Testing Standard JPI-5S-68. The measurement results are shown in Tables 4 and 5.

[0062] (Analysis of By-Product Water) The hydrogen ion concentration (pH) of the by-product water in each hydrotreating step of Examples 1 to 6 and Comparative Examples 1 to 8, the total amount of organic acid ions (ions of water-soluble carboxylic acids: formic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid), and the total amount of inorganic acid ions (fluoride ions, chloride ions, sulfate ions, sulfite ions, nitrate ions, nitrite ions, phosphate ions, and phosphite ions) were measured by anion chromatography. The measurement results are shown in Tables 4 and 5. In Tables 4 and 5, "-" indicates that the data was not measured.

[0063] The results of Examples 1 to 6 and Comparative Examples 1 to 6 above confirmed that, according to the present invention, in the hydrorefining process, hydrogenated compounds (e.g., ammonium hydrogen sulfide) of compounds containing at least one of oxygen, sulfur, and nitrogen atoms contained in the feedstock neutralize organic and inorganic acids in the by-product water to adjust the pH to 7.0 or higher and form a basic buffer solution, thereby stably suppressing acid corrosion of the production equipment. This allows for efficient production of high-quality hydrorefined oil while reducing maintenance and management costs. In Comparative Example 7, although the by-product water had a pH of 7.0 or higher, the hydrorefined oil underwent further cracking (lightening) compared to Examples 1 to 6, resulting in a significant decrease in the heavy oil content and an increase in the gas and naphtha content, resulting in poor commercial value as a hydrorefined oil (fuel). In Comparative Example 8, the pH of the by-product water was 7.0 or higher, but the cracking (lightening) of the hydrorefined oil had progressed compared to Examples 1 to 6, resulting in a decrease in the total content of kerosene, diesel, and heavy oil, and an increase in the naphtha and kerosene contents, resulting in poor commercial value as a hydrorefined oil (fuel). Furthermore, the hydrorefined oil produced as described above can be used as a fuel feedstock.

[0064]

[0065]

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; and introducing hydrogen into the feedstock oil and subjecting it to a hydrogenation process in the presence of a hydrogenation catalyst at a reaction temperature of 250°C to 430°C, a hydrogen pressure of 5 MPa to 20 MPa, and a liquid hourly space velocity (LHSV) of 1.5 h. -１ Super 5.0h -１ and a hydrogen / oil ratio of 100 NL / L or more and 2000 NL / L or less to obtain a hydrorefined oil, wherein in the hydrorefining step, a hydrogenated compound of a compound containing at least one of oxygen, sulfur, and nitrogen atoms contained in the feed oil neutralizes organic acids and / or inorganic acids that are mixed in and / or generated in the hydrorefining step, thereby raising the pH of by-product water to 7.0 or more.

2. A method for producing hydrorefined oil according to claim 1, wherein the petroleum hydrocarbons contain a petroleum hydrocarbon 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 hydrorefined oil according to claim 1, wherein the oil to be treated contains a fraction having a boiling point of 230°C or higher and an oxygen content of 0.3% by mass or more and 13.0% by mass or less.

4. The method for producing hydrorefined oil according to claim 1, wherein the mixing ratio of the petroleum hydrocarbon to the oil to be treated is 40:60 to 99:1 on a volume basis.

5. The method for producing hydrorefined oil 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. The method for producing hydrorefined oil according to claim 1, wherein the organic acid produced in the hydrorefining step is a water-soluble carboxylic acid having 6 or less carbon atoms produced by hydrogenation and polymerization of carbon dioxide.

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

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

9. The method for producing hydrorefined oil according to claim 1, wherein the content of naphtha in the hydrorefined oil is 1.0 mass% or less.

10. The method for producing hydrorefined oil according to claim 1, wherein the total content of kerosene, light oil, and heavy oil in the hydrorefined oil is 95.0 mass% or more.

11. A method for producing fuel, which uses the hydrorefined oil obtained by the method according to any one of claims 1 to 10 as a raw material.

Images