Method for producing hydrocarbon oil

Abstract

To provide a novel method for producing hydrocarbon oil that enables efficient production of hydrocarbon oil containing a fraction having a boiling point range equivalent to that of a jet fuel base material with the use of an alkylation unit.SOLUTION: There is provided a method for producing hydrocarbon oil containing a jet fuel base material, the method comprising causing a reaction of a raw material including a C8 olefin and isobutane in the presence of a liquid catalyst containing an acid, wherein the volume ratio, in terms of liquid conversion, of isobutane to the C8 olefin is 4 or more and 9 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a hydrocarbon oil. [Background technology]

[0002] There are concerns that demand for gasoline will decline due to the planned ban on the sale of new gasoline-powered vehicles in line with the declaration of carbon neutrality by 2050, the spread of electric vehicles, etc. However, since it is difficult to switch to electricity or hydrogen as a power source for aircraft, and the global economy is expected to grow, it is expected that demand for fuel used in aviation jet engines (hereinafter referred to as "jet fuel") will continue to be strong in the future.

[0003] One method for producing gasoline base stocks is known to be the use of an alkylation unit, which reacts paraffins and olefins with a carbon number of 4 derived from a fluid catalytic cracking unit with paraffin with a carbon number of 4 (isobutane) derived from a crude oil atmospheric distillation unit in the presence of a liquid catalyst containing an acid to produce a gasoline base stock mainly composed of paraffins with a carbon number of 8.

[0004] Patent Document 1 describes a method for producing jet fuel using an alkylation unit. Specifically, the method describes a production method in which an olefin having a carbon number of 5 isobutane, an olefin having a carbon number of 4 isopentane, or an olefin having a carbon number of 5 isopentane is reacted to produce hydrocarbons having a carbon number of 9 or 10 (corresponding to jet fuel). On the other hand, it also describes that when an olefin having a carbon number of 4 isobutane is reacted with isobutane, hydrocarbons having a carbon number of 8 (corresponding to gasoline) are produced as the main component, and hydrocarbons having a carbon number of 9 or 10 are hardly produced. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2022-532940 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the expected increase in demand for jet fuel, it is necessary to establish a new method for producing jet fuel. In addition, due to the decline in gasoline demand mentioned above, the operating rate of alkylation units may decrease, so there is a need to make effective use of alkylation units.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a novel method for producing a hydrocarbon oil, which is capable of efficiently producing a hydrocarbon oil including a jet fuel base stock using an alkylation unit. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention has the following aspects. [1] A method for producing a hydrocarbon oil, including a jet fuel base stock, by reacting a feedstock containing an olefin having a carbon number of 8 and isobutane in the presence of a liquid catalyst containing an acid, wherein the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the olefin having a carbon number of 8 is 4 or more and 9 or less. [2] The method for producing a hydrocarbon oil according to [1], wherein the acidity function H0 of the liquid catalyst is −10.2 to −7.3. [3] The method for producing a hydrocarbon oil according to [1] or [2], wherein the acid includes sulfuric acid. [4] The method for producing a hydrocarbon oil according to [3], wherein the content of sulfuric acid relative to the total mass of the liquid catalyst is 80 to 98 mass%. [5] The method for producing a hydrocarbon oil according to any one of [1] to [4], wherein the olefin having 8 carbon atoms is obtained by reacting a raw material containing an olefin having 4 carbon atoms and isobutane in the presence of a liquid catalyst containing an acid to obtain a fraction containing hydrocarbons having 8 carbon atoms, and dehydrogenating paraffins having 8 carbon atoms in the fraction. Effect of the Invention

[0009] According to the present invention, it is possible to provide a novel method for producing a hydrocarbon oil, which is capable of efficiently producing a hydrocarbon oil including a jet fuel base stock using an alkylation unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The following describes in detail the embodiments of the present invention. However, the following description is an example of an embodiment of the present invention, and the present invention is not limited to these contents and can be modified and implemented within the scope of its gist.

[0011] <Method for producing hydrocarbon oil> The method for producing a hydrocarbon oil according to the present embodiment is a method for producing a hydrocarbon oil containing a jet fuel base stock by reacting a feedstock containing an olefin having 8 carbon atoms and isobutane in the presence of a liquid catalyst containing an acid. Hereinafter, the hydrocarbon oil containing a jet fuel base stock produced by the method for producing a hydrocarbon oil according to the present embodiment is also referred to as "hydrocarbon oil". The ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the olefin having 8 carbon atoms is 4 or more and 9 or less.

[0012] <Catalyst> The liquid catalyst of the present embodiment contains an acid. The acidity function H0 of the liquid catalyst is preferably from −10.2 to −7.3, more preferably from −10.2 to −8.9, and further preferably from −10.2 to −9.2. When the acidity function H0 of the liquid catalyst is within the above range, the content of jet fuel base stock in the hydrocarbon oil (hereinafter also referred to as "yield of jet fuel base stock") is improved. When the acidity function H0 of the liquid catalyst is equal to or greater than the lower limit of the above range, the production of light fractions unsuitable for jet fuel base stocks can be suppressed, and the yield of fractions suitable for jet fuel base stocks is improved. When the acidity function H0 of the liquid catalyst is equal to or less than the upper limit of the above range, the alkylation reaction is more likely to proceed, and the yield of jet fuel base stocks from the hydrocarbon oil is improved. In addition, the production of acid esters (e.g., sulfate esters) as by-products is suppressed. As a result, the liquid catalyst is used effectively, and the yield of jet fuel base stock is improved.

[0013] Examples of the acid include sulfuric acid, hydrogen fluoride, and ionic liquid. Among them, sulfuric acid is preferred from the viewpoint of increasing the yield of the jet fuel base material and inhibiting corrosion of the equipment. The acid may be used alone or in combination of two or more kinds. The liquid catalyst may contain other components besides the acid. The other components are preferably water, and the acid is preferably dissolved in water. The acidity function H0 of the liquid catalyst can be adjusted by adjusting the type and content of the acid.

[0014] The content of the acid relative to the total mass of the liquid catalyst is preferably from 80 to 98 mass%, more preferably from 90 to 98 mass%, and further preferably from 93 to 98 mass%. When the acid content is equal to or greater than the lower limit of the range, the alkylation reaction proceeds more easily, improving the yield of the jet fuel base stock. In addition, the production of by-product acid esters (e.g., sulfate esters) is suppressed. As a result, the liquid catalyst is used effectively, improving the yield of the jet fuel base stock. When the acid content is equal to or less than the upper limit of the range, the production of light fractions unsuitable for jet fuel base stocks can be suppressed, improving the yield of the jet fuel base stock.

[0015] <Raw materials> The feedstock includes 8 carbon olefins and isobutane. The total content of olefins having 8 carbon atoms (hereinafter also referred to as "C8 olefins") and isobutane relative to the total mass of the raw material is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 97% by mass or more. The upper limit of the total content of C8 olefins and isobutane relative to the total mass of the raw material is not particularly limited, and may be 100% by mass. When the combined content of C8 olefins and isobutane relative to the total mass of the raw material is equal to or greater than the lower limit, the yield of the jet fuel base stock is improved.

[0016] The raw material may contain other hydrocarbons other than an olefin having 8 carbon atoms and isobutane. The hydrocarbon may be an olefin or paraffin, but is preferably an olefin. Examples of other hydrocarbons include hydrocarbons having 1 to 7 carbon atoms, and preferably hydrocarbons having 5 to 7 carbon atoms. The content of other hydrocarbons relative to the total mass of the raw material is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0017] Examples of C8 olefins include linear C8 olefins having one double bond such as 1-octene, 2-octene, 3-octene, and 4-octene, branched C8 olefins having one double bond such as diisobutylene, 2,2-methyl-3-hexene, 3-methyl-1-heptene, and 2-ethyl-1-hexene, and C8 olefins having two or more double bonds such as octadiene. Among them, C8 olefins having one double bond are preferred, branched C8 olefins having one double bond are more preferred, and diisobutylene is even more preferred. The C8 olefins may be used alone or in combination of two or more.

[0018] The total content of C8 olefins having one double bond relative to the total mass of C8 olefins is preferably 95% by mass or more, more preferably 97% by mass or more, and even more preferably 98% by mass or more. The upper limit of the total content of C8 olefins having one double bond relative to the total mass of C8 olefins is not particularly limited, and may be 100% by mass. When the total content of C8 olefins having one double bond is equal to or more than the above lower limit, the yield of the jet fuel base stock is improved.

[0019] The total content of the branched C8 olefins having one double bond relative to the total mass of the C8 olefins is preferably 90% by mass or more, more preferably 93% by mass or more, and even more preferably 95% by mass or more. The upper limit of the total content of the branched C8 olefins having one double bond relative to the total mass of the C8 olefins is not particularly limited, and may be 100% by mass. When the content of the branched C8 olefin having one double bond is at least the lower limit, the yield of the jet fuel base stock is improved.

[0020] The content of C8 olefins relative to the total mass of the raw material is preferably 10 to 20 mass%, more preferably 11 to 17 mass%, further preferably 11 to 14 mass%, and particularly preferably 12 to 13 mass%. When the content of C8 olefins is equal to or greater than the lower limit of the above range, the yield of the jet fuel base stock is improved. When the content of C8 olefins is equal to or less than the upper limit of the above range, the production of fractions heavier than the jet fuel base stock can be suppressed. As a result, the yield of the jet fuel base stock is improved.

[0021] The content of isobutane relative to the total mass of the raw materials is preferably 80 to 90 mass%, more preferably 83 to 89 mass%, further preferably 86 to 89 mass%, and particularly preferably 87 to 88 mass%. When the isobutane content is equal to or greater than the lower limit of the range, the production of fractions heavier than the jet fuel base stock can be suppressed, and as a result, the yield of the jet fuel base stock is improved. When the isobutane content is equal to or less than the upper limit of the range, the yield of the jet fuel base stock is improved.

[0022] The ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of C8 olefin is 4 to 9, preferably 5 to 8, more preferably 6 to 8, and even more preferably 6.5 to 7.5. In this specification, the liquid-equivalent volume means the volume of the liquid at -20°C. When the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of C8 olefins is equal to or greater than the lower limit of the range, the production of fractions heavier than the jet fuel base stock can be suppressed. As a result, the yield of the jet fuel base stock is improved. When the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of C8 olefins is equal to or less than the upper limit of the range, the yield of the jet fuel base stock is improved.

[0023] Although the C8 olefin is not particularly limited, it is preferable to use a C8 olefin produced from a raw material containing an olefin having a carbon number of 4 and isobutane, which will be described later. By using such a C8 olefin, it becomes possible to produce a jet fuel base stock from a raw material containing substantially a hydrocarbon having a carbon number of 4 as a main component. As described above, due to the decline in gasoline demand, there is a possibility that paraffins and olefins having a carbon number of 4 will become surplus, and there is a demand for effective use of paraffins and olefins having a carbon number of 4. By using a C8 olefin produced from a raw material containing an olefin having a carbon number of 4 and isobutane, it is possible to effectively use paraffins and olefins having a carbon number of 4.

[0024] The content of the C8 olefin produced from an olefin having a carbon number of 4 and isobutane relative to the total mass of the raw material C8 olefins is preferably 50 to 100 mass%, more preferably 70 to 100 mass%, and even more preferably 90 to 100 mass%.

[0025] Although there is no particular limitation on the isobutane, it is preferable to use isobutane derived from an atmospheric distillation unit for crude oil.

[0026] <Reaction conditions> In the presence of a liquid catalyst containing an acid, a raw material containing an olefin having a carbon number of 8 and isobutane is subjected to an alkylation reaction. The reaction may be carried out in a continuous manner or a batch manner. In the case of a continuous manner, the reaction can be carried out by continuously supplying the liquid catalyst and the raw material to a reactor. The reactor may be a horizontal reactor or a vertical reactor. In addition, the number of reactors may be multiple. When the reaction is carried out continuously in an apparatus equipped with a plurality of reactors, the raw material may be supplied to the reactors in series or in parallel. The liquid catalyst may also be supplied to the reactors in series or in parallel. Supplying the raw material or liquid catalyst in series means, for example, supplying the raw material or liquid catalyst after the reaction discharged from the first reactor to the second reactor (hereinafter, the same applies to the third reactor and onward). Supplying the raw material or liquid catalyst in parallel means supplying fresh raw material or liquid catalyst to each reactor.

[0027] The content of the liquid catalyst relative to the total volume of the liquid catalyst and the liquid-based raw material is preferably 40 to 60% by volume, more preferably 45 to 60% by volume, and even more preferably 45 to 55% by volume. When the content of the liquid catalyst is equal to or more than the lower limit, the consumption of the acid can be suppressed, whereas when the content of the liquid catalyst is equal to or less than the upper limit, the outflow of the acid to the downstream process can be prevented.

[0028] The reaction temperature is preferably from 5 to 12°C, more preferably from 6 to 10°C, and further preferably from 7 to 8°C. When the reaction temperature is equal to or higher than the lower limit of the above range, for example, when an aqueous sulfuric acid solution is used as the acid, precipitation of sulfuric acid and freezing of water can be suppressed. When the reaction temperature is equal to or lower than the upper limit of the above range, the yield of the jet fuel base stock is improved.

[0029] The reaction pressure is preferably from 0.40 to 0.60 MPa, more preferably from 0.45 to 0.55 MPa, and further preferably from 0.47 to 0.53 MPa. When the reaction pressure is equal to or higher than the lower limit of the above range, the raw material hydrocarbon (including those that are gaseous at normal pressure) can be reacted with the acid in a liquid state. When the reaction pressure is equal to or lower than the upper limit of the above range, excessive propagation reaction of carbocations is suppressed, and the production of fractions heavier than the jet fuel base stock can be suppressed.

[0030] The reaction is preferably carried out with stirring. Stirring is preferably carried out with a rotary stirrer. The stirring speed is preferably 500 to 700 rpm, more preferably 550 to 650 rpm, and even more preferably 575 to 625 rpm. When the stirring speed is equal to or higher than the lower limit of the above range, a stable mixed state of the hydrocarbon and the acid can be maintained and oligomerization can be promoted, whereas when the stirring speed is equal to or lower than the upper limit of the above range, a rapid reaction between the olefin and the acid is suppressed and oligomerization is promoted, thereby improving the yield of the jet fuel base stock.

[0031] Agitation power: 2.9 to 12.4kW / m 3 is preferably 2.9 to 5.9 kW / m 3 More preferably, it is 3.6 to 5.1 kW / m 3 More preferably, it is 3.9 to 4.7 kW / m 3 It is particularly preferred that: When the stirring power is equal to or greater than the lower limit of the above range, a stable mixed state of the hydrocarbon and the acid can be maintained and oligomerization can be promoted, whereas when the stirring power is equal to or less than the upper limit of the above range, a rapid reaction between the olefin and the acid is suppressed and oligomerization is promoted, thereby improving the yield of the jet fuel base stock. The stirring power can be calculated using the Kamei-Hiraoka formula.

[0032] After the reaction is completed, the LPG, the hydrocarbon oil, and the liquid catalyst are separated. When the reaction is performed continuously, the mixture of the LPG, the hydrocarbon oil, and the liquid catalyst after the reaction may be transferred to a sulfuric acid separation layer, where the LPG, the hydrocarbon oil, and the liquid catalyst are separated. The separated liquid catalyst may be supplied to the reactor again. When the acid concentration in the liquid catalyst is decreased (i.e., when the acidity function H0 is increased), the separated liquid catalyst may be transferred to a liquid catalyst regenerator to increase the acid concentration, and then supplied to the reactor again.

[0033] <Production method of C8 olefin> The C8 olefin used as the raw material in the method for producing a hydrocarbon oil of this embodiment is preferably produced from a raw material containing an olefin having a carbon number of 4 and isobutane. The method for producing a C8 olefin will be described below.

[0034] The method for producing C8 olefins comprises reacting a raw material containing an olefin having a carbon number of 4 and isobutane in the presence of a liquid catalyst containing an acid to obtain a fraction containing hydrocarbons having a carbon number of 8 (hereinafter also referred to as "C8 hydrocarbons"), and dehydrogenating paraffins having a carbon number of 8 in the fraction.

[0035] <Liquid catalyst> As the liquid catalyst, the same liquid catalyst as that explained in the method for producing a hydrocarbon oil can be used.

[0036] <Raw materials> The raw material contains olefins having four carbon atoms (hereinafter also referred to as "C4 olefins") and isobutane.

[0037] The total content of C4 olefins and isobutane relative to the total mass of the raw material is preferably 92 mass% or more, more preferably 96 mass% or more, and even more preferably 98 mass% or more. The upper limit of the total content of hydrocarbons having a carbon number of 4 relative to the total mass of the raw material is not particularly limited, and may be 100 mass%. When the combined content of C4 olefins and isobutane relative to the total mass of the raw material is equal to or greater than the above lower limit, hydrocarbons having four carbon atoms can be effectively utilized.

[0038] The raw material may contain other hydrocarbons other than C4 hydrocarbons. The hydrocarbons may be olefins or paraffins, but olefins are preferred. Examples of other hydrocarbons include hydrocarbons having 1 to 3 or 5 to 8 carbon atoms, and hydrocarbons having 5 to 8 carbon atoms are preferred. The content of other hydrocarbons relative to the total mass of the raw material is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0039] Examples of C4 olefins include C4 olefins having one double bond such as 1-butene, 2-butene, and isobutene, and C4 olefins having two double bonds such as butadiene. Among them, C4 olefins having one double bond are preferred, and 1-butene is more preferred. The C4 olefins may be used alone or in combination of two or more.

[0040] The total content of 1-butene, 2-butene, and isobutene relative to the total mass of C4 olefins is preferably 99.0 mass% or more, more preferably 99.5 mass% or more, and even more preferably 99.8 mass% or more. The upper limit of the total content of 1-butene, 2-butene, and isobutene relative to the total mass of C4 olefins is not particularly limited, and may be 100 mass%. When the total content of 1-butene, 2-butene, and isobutene is equal to or more than the lower limit, the final yield of C8 hydrocarbons is improved.

[0041] The total content of 1-butene and 2-butene relative to the total mass of C4 olefins is preferably 95% by mass or more, more preferably 97% by mass or more, and even more preferably 98% by mass or more. The upper limit of the total content of 1-butene and 2-butene relative to the total mass of C4 olefins is not particularly limited, and may be 100% by mass. When the total content of 1-butene and 2-butene is equal to or more than the lower limit, the yield of C8 hydrocarbons is improved.

[0042] The content of C4 olefins relative to the total mass of the raw materials is preferably 8 to 18 mass%, more preferably 8 to 16 mass%, and further preferably 10 to 15 mass%. When the content of C4 olefins is equal to or higher than the lower limit of the above range, the alkylation reaction proceeds smoothly, and the yield of C8 hydrocarbons is improved. When the content of C4 olefins is equal to or lower than the upper limit of the above range, the production of hydrocarbons having 9 or more carbon atoms can be suppressed. As a result, the yield of C8 hydrocarbons is improved.

[0043] The content of isobutane relative to the total mass of the raw materials is preferably from 82 to 92 mass%, more preferably from 84 to 92 mass%, and further preferably from 85 to 90 mass%. When the isobutane content is equal to or greater than the lower limit of the range, the production of hydrocarbons having 9 or more carbon atoms can be suppressed, and as a result, the yield of C8 hydrocarbons is improved. When the isobutane content is equal to or less than the upper limit of the range, the alkylation reaction proceeds smoothly, and the yield of C8 hydrocarbons is improved.

[0044] The ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of C4 olefin is preferably 7-11, more preferably 7-10, and further preferably 7-8. When the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of C4 olefins is equal to or greater than the lower limit of the above range, the production of hydrocarbons having a carbon number of 9 or more can be suppressed. When the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of C4 olefins is equal to or less than the upper limit of the above range, the alkylation reaction proceeds well, and the yield of C8 hydrocarbons is improved.

[0045] The raw material for the C8 olefin production method preferably contains hydrocarbons derived from a fluid catalytic cracking unit. It is preferable that the raw material contains C4 hydrocarbons produced in a fluid catalytic cracking reaction, and more preferably contains C4 olefins produced in a fluid catalytic cracking reaction. A raffinate obtained by extracting 1,3-butadiene and / or isobutene from the C4 hydrocarbons produced in the fluid catalytic cracking reaction by solvent extraction may be used. Since the raffinate contains C4 olefins and isobutane, the method for producing a hydrocarbon oil of this embodiment can be carried out using the raffinate as a raw material.

[0046] The feedstock for the C8 olefin production process may include hydrocarbons derived from a crude oil atmospheric distillation unit. It is preferable that the feedstock includes paraffins having a carbon number of 4 obtained by fractionation by atmospheric distillation of crude oil, and more preferably, the feedstock includes isobutane obtained by fractionation by atmospheric distillation of crude oil.

[0047] <Reaction conditions> As the alkylation reaction conditions, the same reaction conditions as those described in the method for producing a hydrocarbon oil can be applied. The dehydrogenation of the hydrocarbons having 8 or less carbon atoms obtained by the alkylation reaction can be carried out using a dehydrogenation catalyst and reaction conditions known in the art.

[0048] <Jet fuel base stock> The jet fuel base stock means, for example, a fraction having a boiling point in the range of 140 to 300°C at normal pressure, and preferably a fraction having a boiling point in the range of 140 to 280°C.

[0049] The density of jet fuel base stock at 15°C is 0.78 to 0.84 g / cm 3 and preferably 0.79 to 0.83 g / cm 3 More preferably, the density is 0.80 to 0.82 g / cm 3 The density at 15°C refers to a value measured in accordance with JIS K 2249 "Determination of density of crude oil and petroleum products and density / mass / volume conversion table." The freezing point of the jet fuel base stock is preferably −60 to −48° C., more preferably −55 to −48° C., and further preferably −53 to −48° C. The freezing point refers to a value measured in accordance with JIS K 2276 “Freezing Point Test Method (Aviation Fuel Oil)”. The calorific value of the jet fuel base stock is preferably 42.8 to 45.0 MJ / kg, more preferably 43.0 to 45.0 MJ / kg, and even more preferably 43.0 to 44.0 MJ / kg. The calorific value means a value measured in accordance with JIS K2279 "Crude oil and petroleum products-Test method for calorific value and method for estimating calorific value by calculation." The sulfur content of the jet fuel base stock is preferably 0 to 3000 ppm by mass, more preferably 0 to 300 ppm by mass, and even more preferably 0 to 100 ppm by mass. The sulfur content refers to a value measured in accordance with JIS K 2541 "Crude oil and petroleum products-Determination method for sulfur content." The flash point of the jet fuel base stock is preferably 38 to 50° C., more preferably 40 to 50° C., and even more preferably 40 to 45° C. The flash point refers to a value measured in accordance with JIS K2265-1 “Crude oil and petroleum products-Flash point test method” (Tag closed cup flash point test method).

[0050] <Hydrocarbon oil> The proportion of the fraction boiling in the range of 140 to 300° C. at normal pressure to the total volume of the hydrocarbon oil is preferably 20 to 50% by volume, more preferably 25 to 50% by volume, and even more preferably 30 to 50% by volume. The proportion of the fraction boiling in the range of 140 to 280° C. at normal pressure to the total volume of the hydrocarbon oil is preferably 25 to 50% by volume, more preferably 25 to 40% by volume, and even more preferably 30 to 40% by volume.

[0051] The proportion of hydrocarbons having 9 to 16 carbon atoms relative to the total mass of the hydrocarbon oil is preferably 30 to 60 mass %, more preferably 35 to 50 mass %, and even more preferably 40 to 50 mass %.

[0052] The hydrocarbon oil is distilled at atmospheric pressure in an atmospheric distillation apparatus to obtain a fraction having a boiling point range of, for example, 140 to 300°C as a jet fuel base stock. The above boiling point range can be appropriately changed. The fraction having a boiling point of less than 140°C can be used for recycling the above-mentioned light fraction. The fraction having a boiling point of more than 300°C can be used as a light oil or heavy oil base stock.

[0053] The obtained jet fuel base stock may be mixed with other base stocks to produce a jet fuel product. Examples of other base stocks include naphtha fractions and kerosene fractions obtained by atmospheric distillation of crude oil in an atmospheric distillation unit, and desulfurized naphtha and desulfurized kerosene obtained by desulfurizing them. Examples also include dewaxed kerosene fractions obtained by dewaxing the kerosene fractions, fractions ranging from naphtha to kerosene obtained from hydrodesulfurization units, hydrocracking units, catalytic cracking units, thermal cracking units, and the like, and base stocks obtained by directly hydrotreating them. Examples also include SAF (Sustainable Aviation Fuel) such as Fischer-Tropsch synthetic oils, oils obtained by hydrotreating animal or vegetable fats and oils, and alcohol synthetic paraffins. The other base materials may be used alone or in combination of two or more.

[0054] Furthermore, the jet fuel product may contain additives, such as antioxidants, conductivity modifiers, metal deactivators, and anti-icing agents. The amount of these additives added may be any amount, but the total amount added is preferably 0.5% by volume or less, and more preferably 0.2% by volume or less, based on the total volume of the jet fuel product. EXAMPLES

[0055] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0056] [Example 1] An autoclave equipped with an agitator was charged with 140 mL of a 97% by mass aqueous sulfuric acid solution as a liquid catalyst. Isobutane and diisobutylene were pressed into the autoclave as raw materials. The total liquid equivalent volume of isobutane and diisobutylene was 140 mL. The ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of diisobutylene was 7. The reaction was carried out for 50 minutes at a reaction temperature of 7.2°C, a reaction pressure of 0.5 MPa, and an agitation speed of 600 rpm. The agitation power was 4.3 kW / m 3 The reaction temperature was controlled by a bath.

[0057] [Comparative Example 1] An autoclave equipped with an agitator was charged with 140 mL of a 97% by mass aqueous sulfuric acid solution as a liquid catalyst. Isobutane and 1-butene were pressure-fed into the autoclave as raw materials. The total liquid equivalent volume of isobutane and 1-butene was 140 mL. The ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of 1-butene was 7. The reaction was carried out for 40 minutes at a reaction temperature of 7.2°C, a reaction pressure of 0.5 MPa, and an agitation speed of 600 rpm. The agitation power was 4.3 kW / m 3 It was.

[0058] In Example 1 and Comparative Example 1, after the reaction was completed, the mixture was allowed to stand and separated into LPG, a hydrocarbon oil layer, and a sulfuric acid aqueous solution layer. The obtained hydrocarbon oil was washed with caustic soda and then distilled at normal pressure to determine the content (volume %) of a fraction having a boiling point of 140 to 300°C and the content (volume %) of a fraction having a boiling point of 140 to 280°C. The results are shown in Table 1. In Table 1, "I / O" means the ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of an olefin having a carbon number of 8. The reaction temperature means the set temperature of the bath. "140 to 280°C" means the content (volume %) of a fraction having a boiling point of 140 to 280°C relative to the total mass of the hydrocarbon oil. "140 to 300°C" means the content (volume %) of a fraction having a boiling point of 140 to 280°C relative to the total mass of the hydrocarbon oil. In addition, the acidity function H0 means the acidity function H0 of the liquid catalyst.

[0059] [Table 1]

[0060] In Example 1, where a feedstock containing an olefin having a carbon number of 8 and isobutane was used and the ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of the olefin having a carbon number of 8 was 4 to 9, the content of jet fuel base stock in the hydrocarbon oil was high. On the other hand, in Comparative Example 1, where a feedstock containing an olefin having a carbon number of 4 and isobutane was used, as described in Patent Document 1, the content of jet fuel base stock in the hydrocarbon oil was low. [Industrial Applicability]

[0061] INDUSTRIAL APPLICABILITY The method for producing a hydrocarbon oil of the present invention is useful because it enables efficient production of a hydrocarbon oil including a jet fuel base stock using an alkylation unit.

Claims

1. A method for producing a hydrocarbon oil including a jet fuel base stock, comprising reacting a feedstock including an olefin having a carbon number of 8 and isobutane in the presence of a liquid catalyst including an acid, the method comprising: A method for producing a hydrocarbon oil, wherein a ratio of a liquid-equivalent volume of isobutane to a liquid-equivalent volume of the olefin having 8 carbon atoms is 4 or more and 9 or less.

2. The acidity function H of the liquid catalyst ０ The method for producing a hydrocarbon oil according to claim 1, wherein the β-amino acid content is -10.2 to -7.

3.

3. The method for producing a hydrocarbon oil according to claim 1 or 2, wherein the acid includes sulfuric acid.

4. The method for producing a hydrocarbon oil according to claim 3, wherein a content of sulfuric acid relative to a total mass of the liquid catalyst is 80 to 98 mass%.

5. 3. The method for producing a hydrocarbon oil according to claim 1 or 2, wherein the olefin having 8 carbon atoms is obtained by reacting a raw material containing an olefin having 4 carbon atoms and isobutane in the presence of a liquid catalyst containing an acid to obtain a fraction containing hydrocarbons having 8 carbon atoms, and dehydrogenating paraffins having 8 carbon atoms in the fraction.

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