Method for producing hydrocarbon oil

Abstract

To provide a method for producing hydrocarbon oil that enables efficient production of hydrocarbon oil including a jet fuel base with the use of a raw material mainly composed of C4 hydrocarbon.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 C4 hydrocarbon in the presence of a liquid catalyst containing an acid, wherein the content of the C4 hydrocarbon in the total mass of the raw material is 90 mass% or more, the C4 hydrocarbon includes olefin and may include isobutane, and the volume ratio, in terms of liquid conversion, of isobutane to the olefin is 0 or more and 6 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] The jet fuel production method described in Patent Document 1 requires hydrocarbons with a carbon number of 5 or more, such as olefins with a carbon number of 5 or isopentane, in addition to hydrocarbons with a carbon number of 4. Furthermore, due to the decline in gasoline demand described above, there is a possibility that paraffins and olefins with a carbon number of 4 will become surplus, and there is a demand for effective utilization of paraffins and olefins with a carbon number of 4.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for producing a hydrocarbon oil, which can efficiently produce a hydrocarbon oil, including a jet fuel base stock, using a raw material mainly composed of a hydrocarbon having a carbon number of 4. [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 a hydrocarbon having a carbon number of 4 in the presence of a liquid catalyst containing an acid, wherein the content of the hydrocarbons having a carbon number of 4 relative to the total mass of the feedstock is 90 mass% or more, the hydrocarbons having a carbon number of 4 include C4 olefins and may also include isobutane, and the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the C4 olefins is 0 or more and 6 or less. [2] The method for producing a hydrocarbon oil according to [1], wherein the C4 olefins include isobutene, and the content of isobutene relative to the total mass of the C4 olefins is 15 mass% or more. [3] The method for producing a hydrocarbon oil according to [1] or [2], wherein the acidity function H0 of the liquid catalyst is −10.2 to −6.9. [4] The method for producing a hydrocarbon oil according to any one of [1] to [3], wherein the acid includes sulfuric acid. [5] The method for producing a hydrocarbon oil according to [4], wherein the content of sulfuric acid relative to the total mass of the liquid catalyst is 80 to 98 mass%. [6] The method for producing a hydrocarbon oil according to [4] or [5], wherein the content of sulfuric acid relative to the total mass of the liquid catalyst is 83 to 90 mass%, and the ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of the C4 olefin is 0 or more and 1 or less. [7] The method for producing a hydrocarbon oil according to any one of [1] to [6], wherein the raw material contains hydrocarbons derived from a fluid catalytic cracking unit. [8] The method for producing a hydrocarbon oil according to any one of [1] to [7], comprising fractionating the hydrocarbon oil to obtain hydrocarbons having a carbon number of 8 or less, dehydrogenating the obtained hydrocarbons to obtain olefins having a carbon number of 8 or less, and mixing the obtained olefins having a carbon number of 8 or less with the raw material. Effect of the Invention

[0009] According to the present invention, there is provided a method for producing a hydrocarbon oil, which can efficiently produce a hydrocarbon oil including a jet fuel base stock by using a raw material mainly composed of a hydrocarbon having four carbon atoms. 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 a hydrocarbon having 4 carbon atoms 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 content of the hydrocarbon having 4 carbon atoms relative to the total mass of the feedstock is 90 mass% or more. The hydrocarbon having 4 carbon atoms includes an olefin, and may also include isobutane. The ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the olefin is 0 or more and 6 or less.

[0012] <Liquid 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 −6.9, more preferably from −8.6 to −7.4, and further preferably from −8.6 to −7.7. When the acidity function H0 of the liquid catalyst is within the above range, the content of the jet fuel base stock in the hydrocarbon oil (hereinafter, also referred to as the "yield of the jet fuel base stock") is improved. The following mechanism is considered to be the factor of the improvement in the yield of the jet fuel base stock. When the acidity function H0 of the liquid catalyst is equal to or greater than the lower limit of the above range, it is considered that the rate of the carbocation generation reaction caused by the contact of the olefin with the acid, which is the initiation reaction of the alkylation, decreases. As a result, it is considered that the amount of olefins that do not become carbocations increases, promoting the growth reaction of the carbocation, suppressing the generation of light fractions that are not suitable for jet fuel base stocks, and improving the yield of fractions suitable for jet fuel base stocks. 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 proceeds, and the yield of the jet fuel base stock in the hydrocarbon oil is improved. In addition, the generation 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 the jet fuel base stock is improved.

[0013] Examples of the acid include sulfuric acid, hydrogen fluoride, and ionic liquid. Among them, sulfuric acid is preferable from the viewpoint of increasing the yield of the jet fuel base material and suppressing 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 83 to 90 mass%, and further preferably from 85 to 90 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 raw material contains hydrocarbons having a carbon number of 4. The hydrocarbons having a carbon number of 4 (hereinafter also referred to as "C4 hydrocarbons") contain olefins (hereinafter also referred to as "C4 olefins") and may contain isobutane.

[0016] The content of C4 hydrocarbons relative to the total mass of the raw material is 90 mass% or more, preferably 92 mass% or more, more preferably 96 mass% or more, and even more preferably 98 mass% or more. The upper limit of the 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 content of C4 hydrocarbons relative to the total mass of the raw material is equal to or greater than the above lower limit, the C4 hydrocarbons can be effectively utilized.

[0017] The raw material may contain other hydrocarbons besides 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 7 carbon atoms, and hydrocarbons having 5 to 6 carbon atoms are preferred. The content of other hydrocarbons relative to the total mass of the raw material is 10 mass% or less, preferably 7 mass% or less, more preferably 5 mass% or less, and even more preferably 3 mass% or less.

[0018] 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 isobutene is more preferred. The C4 olefins may be used alone or in combination of two or more.

[0019] 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 at least the lower limit, the yield of the jet fuel base stock is improved.

[0020] The content of isobutene relative to the total mass of C4 olefins is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. The upper limit of the content of isobutene relative to the total mass of C4 olefins is not particularly limited, and may be 100% by mass. When the content of isobutene is equal to or more than the lower limit, the yield of the jet fuel base stock is improved.

[0021] The content of C4 olefins relative to the total mass of the raw materials is preferably 14.3 to 100 mass%, more preferably 20 to 91 mass%, further preferably 33 to 83 mass%, and particularly preferably 50 to 80 mass%. When the C4 olefin content is equal to or greater than the lower limit of the above range, the production of fractions lighter than the jet fuel base stock can be suppressed, thereby improving the yield of the jet fuel base stock.

[0022] The content of isobutane relative to the total mass of the raw materials is preferably 0 to 85.7 mass%, more preferably 9 to 80 mass%, further preferably 17 to 67 mass%, and particularly preferably 20 to 50 mass%. When the isobutane content is equal to or less than the upper limit of the above range, the production of fractions lighter than the jet fuel base stock can be suppressed, thereby improving the yield of the jet fuel base stock.

[0023] The ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of C4 olefin is from 0 to 6, preferably from 0.1 to 4, more preferably from 0.2 to 2, and even more preferably from 0.25 to 1. In one embodiment of the present invention, the ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of C4 olefin is preferably from 0 to 1. 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 C4 olefins is equal to or less than the upper limit of the above range, the production of fractions lighter than the jet fuel base stock can be suppressed, thereby improving the yield of the jet fuel base stock.

[0024] The molar ratio of isobutane to C4 olefin (isobutane / C4 olefin) is preferably 0-1, more preferably 0.2-1, and further preferably 0.25 or more and less than 1. When the molar ratio of isobutane to C4 olefins is within the above range, the production of fractions lighter than the jet fuel base stock can be suppressed, thereby improving the yield of the jet fuel base stock.

[0025] The raw material preferably contains hydrocarbons derived from a fluid catalytic cracking unit. It is preferable that the raw material contains C4 hydrocarbons produced in the fluid catalytic cracking reaction, and more preferably contains C4 olefins produced in the 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.

[0026] The feedstock may include hydrocarbons derived from a crude oil atmospheric distillation unit, preferably including paraffins having a carbon number of 4 fractionated by atmospheric distillation of crude oil, and more preferably including isobutane fractionated by atmospheric distillation of crude oil.

[0027] <Reaction conditions> A feedstock containing a hydrocarbon having a carbon number of 4 is subjected to an alkylation reaction in the presence of a liquid catalyst containing an acid. 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.

[0028] The content of the liquid catalyst relative to the total volume of the liquid catalyst and the liquid-based raw material is preferably 25 to 75 volume%, more preferably 45 to 60 volume%, even more preferably 45 to 55 volume%, and particularly preferably 47 to 53 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.

[0029] The reaction temperature is preferably 7.0 to 12.0°C, more preferably 7.0 to 10.0°C, and further preferably 7.0 to 8.0°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, 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 pressure is preferably from 0.40 to 0.80 MPa, more preferably from 0.40 to 0.60 MPa, and further preferably from 0.45 to 0.55 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.

[0031] The reaction is preferably carried out with stirring. Stirring is preferably carried out with a rotary stirrer. The stirring speed is preferably 500 to 1000 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.

[0032] 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.

[0033] 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.

[0034] <Recycling of light fractions> The hydrocarbon oil produced by the method for producing a hydrocarbon oil of this embodiment may contain a fraction lighter than the jet fuel base stock. The light fraction means, for example, a hydrocarbon having a boiling point of less than 140° C. at normal pressure or a hydrocarbon having 8 or less carbon atoms. The light fraction is preferably recycled as a raw material for the method for producing a hydrocarbon oil of this embodiment.

[0035] The recycling method includes a step of obtaining hydrocarbons having a carbon number of 8 or less by fractional distillation of the hydrocarbon oil, a step of obtaining hydrocarbons having a carbon number of 8 or less, a step of dehydrogenating the obtained hydrocarbons to obtain olefins having a carbon number of 8 or less, and a step of mixing the obtained olefins with the raw material for the production method of the hydrocarbon oil of this embodiment.

[0036] Fractional distillation of the hydrocarbon oil can be carried out using an atmospheric distillation unit. For example, the hydrocarbon oil can be distilled at atmospheric pressure using an atmospheric distillation unit to obtain a fraction having a boiling point of less than 140° C. The fraction having a boiling point of less than 140° C. contains hydrocarbons having a carbon number of 8 or less.

[0037] The dehydrogenation of the resulting hydrocarbon having 8 or less carbon atoms can be carried out using a dehydrogenation catalyst and reaction conditions known in the art. The resulting olefin having 8 or less carbon atoms may be an olefin having one double bond or an olefin having two or more double bonds, but is preferably an olefin having one double bond, and more preferably an olefin having one double bond and being a branched chain.

[0038] The mixing ratio of olefins having a carbon number of 8 or less to the total mass of the feedstock oil and olefins having a carbon number of 8 or less is preferably 20 to 90 mass %, more preferably 30 to 80 mass %, and even more preferably 50 to 80 mass %.

[0039] <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.

[0040] 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 3The 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).

[0041] <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 90% by volume, more preferably 40 to 90% by volume, and even more preferably 60 to 90% by volume. The proportion of the fraction having a boiling point range of 140 to 280°C at normal pressure to the total volume of the hydrocarbon oil is preferably 20 to 80 volume%, more preferably 30 to 75 volume%, even more preferably 40 to 75 volume%, and particularly preferably 50 to 75 volume%.

[0042] The proportion of hydrocarbons having 9 to 16 carbon atoms relative to the total mass of the hydrocarbon oil is preferably 30 to 75 mass %, more preferably 40 to 75 mass %, and even more preferably 50 to 75 mass %. The proportion of hydrocarbons having 12 to 16 carbon atoms relative to the total mass of the hydrocarbon oil is preferably 10 to 70 mass %, more preferably 30 to 70 mass %, and even more preferably 50 to 70 mass %.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] <Mechanism of action> In a conventional method for producing gasoline base stock using an alkylation unit, an olefin having a carbon number of 4 reacts with isobutane to produce a paraffin having a carbon number of 8. The reaction mechanism is believed to be that the olefin having a carbon number of 4 reacts with a liquid catalyst containing an acid to produce a carbocation having a carbon number of 4, and then the carbocation having a carbon number of 4 reacts with the olefin having a carbon number of 4 to produce a carbocation having a carbon number of 8. The carbocation having a carbon number of 8 then reacts with isobutane to produce a paraffin having a carbon number of 8 and a carbocation having a carbon number of 4.

[0047] On the other hand, in the method for producing a hydrocarbon oil of the present invention, the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of olefins having a carbon number of 4 is 0 to 6. This ratio is lower than that of the method for producing a gasoline base stock using a conventional alkylation apparatus. As a result, it is considered that the carbocation having a carbon number of 8 further reacts with an olefin having a carbon number of 4, and a polymerized carbocation having a carbon number of 12 or more is generated as an intermediate. It is considered that the carbocation having a carbon number of 12 or more reacts with isobutane to generate paraffins having a carbon number of 12 or more and carbocations having a carbon number of 4. Note that, as shown in the examples, the effect of the present invention is achieved even when the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of olefins having a carbon number of 4 is 0, that is, when isobutane is not included. This is considered to be due to a cracking reaction occurring as a side reaction, and the paraffins generated by cracking react with the carbocations having a carbon number of 8 or more. EXAMPLES

[0048] 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.

[0049] [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 4. 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 The reaction temperature was controlled by a bath (hereinafter the same). In the following examples and comparative examples, unless otherwise noted, the volumes of the liquid catalyst and the raw materials were each 140 mL.

[0050] [Example 2] The reaction was carried out in the same manner as in Example 1, except that the ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of 1-butene was 1 / 3.

[0051] [Example 3] The reaction was carried out in the same manner as in Example 1, except that only 1-butene was used as the raw material.

[0052] [Example 4] The reaction was carried out in the same manner as in Example 2, except that a 90% by mass aqueous sulfuric acid solution was used as the liquid catalyst instead of the 97% by mass aqueous sulfuric acid solution.

[0053] [Example 5] The reaction was carried out in the same manner as in Example 2, except that an 85% by mass aqueous sulfuric acid solution was used as the liquid catalyst instead of the 97% by mass aqueous sulfuric acid solution.

[0054] [Example 6] An autoclave equipped with an agitator was charged with 140 mL of a 90% by mass aqueous sulfuric acid solution as a liquid catalyst. Isobutane and isobutene were pressure-fed into the autoclave as raw materials. The total liquid volume of isobutane and isobutene was 140 mL. The ratio of the liquid volume of isobutane to the liquid volume of isobutene was 1 / 3. The reaction was carried out for 1 hour 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.

[0055] [Example 7] An autoclave equipped with an agitator was charged with 70 mL of a 97% by mass aqueous sulfuric acid solution as a liquid catalyst. Isobutane and 1-butene were pressed into the autoclave as raw materials. The total liquid equivalent volume of isobutane and 1-butene was 210 mL. The ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of 1-butene was 1 / 3. The reaction was started with a reaction temperature of 7.2°C, a reaction pressure of 0.5 MPa, and an agitation speed of 100 rpm. The agitation speed was changed stepwise to 300 rpm and 600 rpm after confirming that there was no change in the reaction temperature and pressure. The reaction was carried out for a total of 2 hours. The agitation power at a stirring speed of 100 rpm was 0.1 kW / m 3 The stirring power at a stirring speed of 300 rpm is 1.0 kW / m 3 The stirring power at a stirring speed of 600 rpm is 4.3 kW / m 3 It was.

[0056] [Example 8] 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 pressed 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 1 / 3. The reaction was started with a reaction temperature of 7.2°C, a reaction pressure of 0.5 MPa, and a stirring speed of 100 rpm. The stirring speed was changed in stages by 50 rpm up to 800 rpm after confirming that there was no change in the reaction temperature or pressure. The reaction was carried out for a total of 2 hours and 40 minutes. The stirring power at a stirring speed of 100 rpm was 0.1 kW / m 3 The stirring power at a stirring speed of 800 rpm is 7.8 kW / m 3 It was.

[0057] [Example 9] The reaction was carried out in the same manner as in Example 1, except that an 85% by mass aqueous sulfuric acid solution was used as the liquid catalyst instead of a 97% by mass aqueous sulfuric acid solution, and the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of 1-butene was set to 1.

[0058] [Example 10] The reaction was carried out in the same manner as in Example 1, except that an 85% by mass aqueous sulfuric acid solution was used as the liquid catalyst instead of the 97% by mass aqueous sulfuric acid solution, and the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of 1-butene was 1 / 7.

[0059] [Example 11] The reaction was carried out in the same manner as in Example 9, except that a 90% by mass aqueous sulfuric acid solution was used as the liquid catalyst instead of the 85% by mass aqueous sulfuric acid solution.

[0060] [Example 12] An autoclave equipped with an agitator was charged with 140 mL of a 90% by mass aqueous sulfuric acid solution as a liquid catalyst. Isobutane and 1-butene were pressed 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 1 / 3. The reaction was started with a reaction temperature of 7.2°C, a reaction pressure of 0.5 MPa, and a stirring speed of 100 rpm. The stirring speed was changed in stages by 50 rpm up to 1000 rpm after confirming that there was no change in the reaction temperature or pressure. The reaction was carried out for a total of 3 hours and 30 minutes. The stirring power at a stirring speed of 100 rpm was 0.1 kW / m 3 The stirring power at a stirring speed of 1000 rpm is 12.4 kW / m 3 It was.

[0061] [Example 13] An autoclave equipped with an agitator was charged with 140 mL of a 90% 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 volume of isobutane and 1-butene was 210 mL. The ratio of the liquid volume of isobutane to the liquid volume of 1-butene was 1 / 3. The reaction was carried out for a total of 35 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.

[0062] [Example 14] In an autoclave equipped with an agitator, 140 mL of 90% by mass aqueous sulfuric acid was charged as a liquid catalyst. C4 raffinate was pressed into the autoclave as a raw material. The liquid equivalent volume of the C4 raffinate was 140 mL. The C4 raffinate is a fraction remaining after solvent extraction of 1,3-butadiene and isobutene from a fraction mainly composed of hydrocarbons with a carbon number of 4 derived from a fluid catalytic cracking unit. The composition of the C4 raffinate is shown in Table 1. The ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of olefins with a carbon number of 4 is 0.812. The reaction was carried out for 30 minutes at a reaction temperature of 7.2°C, a reaction pressure of 0.5 MPa, and a stirring speed of 600 rpm.

[0063] [Comparative Example 1] The reaction was carried out in the same manner as in Example 1, except that the ratio of the liquid-equivalent volume of isobutane to the liquid-equivalent volume of 1-butene was set to 7.

[0064] In Examples 1 to 14 and Comparative Example 1, after the reaction was completed, the mixture was allowed to stand and separated into LPG, a hydrocarbon oil layer, and an aqueous sulfuric acid 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 content (mass %) of a hydrocarbon having a carbon number of 12 to 16 was also determined by gas chromatography mass spectrometry (GC / MS). The results are shown in Table 2. In Table 2, "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 4. The reaction temperature means the set temperature of the bath. "C12-C16" means the content (mass %) of a hydrocarbon having a carbon number of 12 to 16 relative to the total mass of the hydrocarbon oil. "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 fractions with boiling points 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.

[0065] [Table 1]

[0066] [Table 2]

[0067] In Examples 1 to 14, in which the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the carbon number 4 olefin was 0 or more and 6 or less, the content of jet fuel base stock in the hydrocarbon oil was higher than that in Comparative Example 1, in which the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the carbon number 4 olefin was 7.

[0068] Furthermore, compared with Examples 1 to 3 and Comparative Example 1, in which a 97 mass% aqueous sulfuric acid solution was used and the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the carbon number 4 olefin was changed, it was found that the content of jet fuel base stock in the hydrocarbon oil increased as the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of the carbon number 4 olefin decreased.

[0069] In addition, when compared with Examples 2, 4, and 5 in which the ratio of the liquid equivalent volume of isobutane to the liquid equivalent volume of olefin was set to 1 / 3 and the sulfuric acid concentration was changed, it was found that the content of jet fuel base stocks in the hydrocarbon oil increased as the sulfuric acid concentration decreased.

[0070] Furthermore, in Example 14, in which C4 raffinate was used as the raw material, the content of jet fuel base stock in the hydrocarbon oil was high, and it was found that a jet fuel base stock can be produced even by using C4 raffinate as it is as a raw material. [Industrial Applicability]

[0071] 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 a raw material containing as a main component a hydrocarbon having four carbon atoms.

Claims

1. A method for producing a hydrocarbon oil including a jet fuel base stock by reacting a feedstock containing a hydrocarbon having a carbon number of 4 in the presence of a liquid catalyst containing an acid, the method comprising: the content of hydrocarbons having a carbon number of 4 relative to the total mass of the raw material is 90 mass% or more, The hydrocarbon having 4 carbon atoms includes a C4 olefin and may include isobutane; A method for producing a hydrocarbon oil, wherein a ratio of a liquid-equivalent volume of isobutane to a liquid-equivalent volume of the C4 olefin is 0 or more and 6 or less.

2. The method for producing a hydrocarbon oil according to claim 1, wherein the C4 olefins include isobutene, and a content of isobutene relative to a total mass of the C4 olefins is 15 mass% or more.

3. The acidity function H of the liquid catalyst ０ The method for producing a hydrocarbon oil according to claim 1 or 2, wherein the β-amino acid content is -10.2 to -6.

9.

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

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

6. The content of sulfuric acid relative to the total mass of the liquid catalyst is 83 to 90 mass%, The method for producing a hydrocarbon oil according to claim 4, wherein a ratio of a liquid-equivalent volume of isobutane to a liquid-equivalent volume of the C4 olefin is 0 or more and 1 or less.

7. The method for producing a hydrocarbon oil according to claim 1 or 2, wherein the feedstock contains hydrocarbons derived from a fluid catalytic cracking unit.

8. The method for producing a hydrocarbon oil according to claim 1 or 2, comprising the steps of: fractionating the hydrocarbon oil to obtain hydrocarbons having a carbon number of 8 or less; dehydrogenating the obtained hydrocarbons to obtain olefins having a carbon number of 8 or less; and mixing the obtained olefins having a carbon number of 8 or less with the raw material.

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