JP5334754B2 - Fuel composition for external combustion and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel composition, which reduces its emissions of soot and nitrogen oxides, for external combustion. <P>SOLUTION: In the fuel composition for external combustion, a density (15&deg;C) is 0.860-0.900 g/cm<SP>3</SP>, a 90% distilling temperature is 340-370&deg;C, a kinematic viscosity (30&deg;C) is 5-10 mm<SP>2</SP>/s, a kinematic viscosity (50&deg;C) is 3-5.5 mm<SP>2</SP>/s, a total sulfur content is 0.6 mass% or less, a total nitrogen content is 300 mass ppm or less, a total aromatic content is 36-45 vol.%, an aniline point is 55-65&deg;C, a bicyclic aromatic content is 8-10 vol.%, a tricyclic aromatic content is 3-5 vol.%, a water content is 120 mass ppm or less, and a cetane index (JIS-2280) is 47-65. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a fuel composition for external combustion and a method for producing the same, and more particularly to a fuel composition for external combustion that emits less soot and nitrogen oxides.

  In an external combustion engine such as a heating boiler and a heating boiler in a factory, soot is easily generated when the external combustion fuel used in the external combustion engine is burned, and nitrogen oxides are also generated. There are concerns about the impact on health and the surrounding environment.

  On the other hand, as a fuel for external combustion, natural gas is used as a raw material, and so-called GTL (prepared by distillation properties equivalent to petroleum-based kerosene, which does not contain sulfur or aromatics produced by Fischer-Tropsch synthesis, is prepared. Gas to liquid) may be used, but in order to produce GTL fuel, energy consumption is large and production equipment costs and operation costs are both high, so the supply amount is limited for the time being. Expected. For this reason, it is desired to improve the quality of petroleum-based fuels that are relatively inexpensive and produced and supplied in large quantities.

  On the other hand, in order to reduce soot emissions, it is known to use heavy fuel oil A blended with fatty acid alkyl esters obtained by esterifying fats and oils such as animal oils and vegetable oils as fuel for internal combustion engines such as diesel engines (described below). Patent Document 1). However, these fatty acid alkyl esters have a high raw material procurement cost, and the supply amount is limited for the time being.

JP 2007-231119 A

  Then, this invention makes it a subject to provide the fuel composition for external combustion with little discharge | emission amount of soot and nitrogen oxide, and its manufacturing method.

  As a result of intensive research aimed at solving the above-mentioned problems, the present inventors focused on a medium-sized light oil fraction of a specific petroleum-based fuel, and mixed this fraction with a commercially available A heavy oil base material, or dewaxing weight. It is found that the amount of soot and nitrogen oxides discharged can be suppressed by mixing with a diesel fuel base together with a commercial diesel fuel oil base and making the physical and chemical properties of the fuel composition for external combustion within a specific range. The present invention has been completed based on such findings.

That is, the fuel composition for external combustion of the present invention has a density (15 ° C.) of 0.860 to 0.900 g / cm ³ , a 90% distillation temperature of 340 to 370 ° C., and a kinematic viscosity (30 ° C.) of 5. 9 to 10 mm ² / s, kinematic viscosity (50 ° C.) is 3.6 to 5.5 mm ² / s, total sulfur content is 0.6 mass% or less, total nitrogen content is 300 mass ppm or less, total aromatic content is 36-45 vol%, aniline point is 55-65 ° C, bicyclic aromatic content is 8-10 vol%, tricyclic aromatic content is 3-5 vol%, moisture is 120 mass ppm or less, cetane index (JIS- 2280) is 47 to 65.

Moreover, the method for producing the fuel composition for external combustion according to the present invention has a density (15 ° C.) of 0.860 g / cm ³ or more and less than 0.880 g / cm ³ and a total sulfur content of 0.5 mass% or less. 70 to 95% by volume of heavy oil base material having an aromatic content of 5 to 9% by volume, density (15 ° C.) of 0.880 g / cm ^{3 to} 0.920 g / cm ³ and 90% distillation temperature of 340 to 390 ° C., kinematic viscosity (50 ° C.) 3-9 mm ² / s, total sulfur content 3 mass% or less, total nitrogen content 300 mass ppm or less, total aromatic content 36-45% by volume, bicyclic aromatic It is characterized by blending 5-30% by volume of a light oil base having a content of 8-20% by volume and a tricyclic aromatic content of 7% by volume or less.
In addition, another method for producing the fuel composition for external combustion according to the present invention has a density (15 ° C.) of 0.860 g / cm ³ or more and less than 0.880 g / cm ³ , a total sulfur content of 0.5 mass% or less, 70 to 95 volume% of heavy oil base material having a bicyclic aromatic content of 5 to 9 volume%, density (15 ° C.) of 0.880 g / cm ^{3 to} 0.920 g / cm ³ and 90% distillation temperature 340 to 390 ° C., kinematic viscosity (50 ° C.) of 3 to 9 mm ² / s, total sulfur content of 3 mass% or less, total nitrogen content of 300 mass ppm or less, total aromatic content of 36 to 45 volume%, two rings 4 to 15% by volume of a light oil base having an aromatic content of 8 to 20% by volume and a tricyclic aromatic content of 7% by volume or less, and a density (15 ° C.) of 0.870 to 0.900 g / cm ³ , 90 % distillation temperature of 400 ° C. or higher, a kinematic viscosity (50 ° C.) is 5 to 15 mm ² / s, the total sulfur content of 0.5 wt% or less, total nitrogen content A dewaxed desulfurized heavy gas oil base material having 100 mass ppm or less, a total aromatic content of 30 to 45 vol%, a bicyclic aromatic content of 5 to 10 vol%, and a tricyclic aromatic content of 9 vol% or less is 1 It is characterized by blending ˜15% by volume.

  According to the fuel composition for external combustion of the present invention, since the content of the specific component is limited to a specific range, the effect of suppressing the emission of soot and nitrogen oxides during combustion is exhibited. Therefore, according to the present invention, the amount of soot and nitrogen oxides is reduced without blending expensive base materials such as GTL kerosene and fatty acid alkyl esters, which are said to have a considerably small amount of soot. The prepared fuel composition for external combustion can be prepared. As a result, the cost of expensive production equipment for producing GTL kerosene and the enormous energy consumption required for operation can be saved, and fatty acid alkyl esters with high raw material procurement costs are not used. Is economical.

〔density〕
The fuel composition for external combustion of the present invention has a density (15 ° C.) of 0.860 to 0.900 g / cm ³ . When the density of the fuel composition is high, the calorific value per volume increases and the combustion temperature rises, so that the amount of nitrogen oxide emissions increases. The density of the outer燃用fuel compositions of this invention is therefore from the viewpoint of suppressing the emission of nitrogen oxides, and a 0.900 g / cm ³ or less, preferably 0.890 g / cm ³ or less, more preferably Is 0.880 g / cm ³ or less. Meanwhile, since the fuel consumption when the density of the fuel composition is too low to deteriorate, the density of the outer燃用fuel composition of the present invention is 0.860 g / cm ³ or more, preferably 0.870 g / cm ³ or more, More preferably, it is 0.871 g / cm ³ or more.

[90% distillation temperature]
The fuel composition for external combustion of the present invention has a 90% distillation temperature of 340 to 370 ° C. If the 90% distillation temperature is too high, the combustibility deteriorates and soot and nitrogen oxides are likely to be generated. Therefore, the 90% distillation temperature of the fuel composition for external combustion of the present invention is 370 ° C. or less, preferably 368 ° C. or less, more preferably 365 ° C. or less, and particularly preferably 360 ° C. or less. On the other hand, if the 90% distillation temperature is too low, the fuel efficiency is deteriorated. For this reason, the 90% distillation temperature of the fuel composition for external combustion of the present invention is 340 ° C. or higher, preferably 350 ° C. or higher, more preferably 353 ° C. or higher, and particularly preferably 355 ° C. or higher.

[Kinematic viscosity (30 ° C)]
The fuel composition for external combustion of the present invention has a kinematic viscosity (30 ° C.) of 5.9 to 10 mm ² / s. If the kinematic viscosity at 30 ° C. is high, the fuel particle size at the time of fuel spray becomes large, and soot is likely to be generated due to deterioration in volatility and deterioration in mixing with air. Therefore, the kinematic viscosity of the outer燃用fuel composition of the present invention (30 ° C.) is, 10 mm ² / s or less, preferably 9 mm ² / s or less, more preferably 8 mm ² / s or less, particularly preferably 7 mm ² / s or less. Further, if the kinematic viscosity at 30 ° C. is low, the penetration force at the time of fuel spraying becomes weak and soot tends to be generated due to lack of oxygen. Therefore, the kinematic viscosity (30 ° C.) of the fuel composition for external combustion of the present invention is It is 5.9 mm ² / s or more.

[Kinematic viscosity (50 ° C)]
The fuel composition for external combustion of the present invention has a kinematic viscosity (50 ° C.) of 3.6 to 5.5 mm ² / s. Even if the kinematic viscosity at 50 ° C. is high, the fuel particle size at the time of fuel spray becomes large, and soot is likely to be generated due to deterioration in volatility and mixing with air. Therefore, the kinematic viscosity of the outer燃用fuel composition of the present invention (50 ° C.) is, 5.5 mm ² / s or less, preferably 5 mm ² / s or less, more preferably 4 mm ² / s or less, particularly preferably 3 .8 mm ² / s or less. Further, even if the kinematic viscosity at 50 ° C. is low, the penetration force at the time of fuel spraying becomes weak and soot tends to be generated due to lack of oxygen. Therefore, the kinematic viscosity (50 ° C.) of the fuel composition for external combustion of the present invention is , is 3.6mm ² / s or more.

〔moisture〕
The fuel composition for external combustion according to the present invention has a water content of 120 mass ppm or less. If the moisture is too high, the moisture in the oil is easily released due to a decrease in the outside air temperature, the free water freezes, and the filter for filtration installed in the fuel supply system is clogged. Occurs to form sludge, and the frequency of replacement of the filter for filtration increases. For this reason, the fuel composition for external combustion of the present invention has a water content of 120 mass ppm or less, preferably 100 mass ppm or less, more preferably 80 mass ppm or less, and particularly preferably 70 mass ppm or less.

[Cetane index]
The fuel composition for external combustion of the present invention has a cetane index of 47 to 65. If the cetane index is too low, the ignitability at low temperatures deteriorates, and the amount of nitrogen oxides increases due to rapid ignition and high combustion temperature, so the fuel composition for external combustion of the present invention The cetane index is 47 or more, preferably 50 or more, more preferably 53 or more, and particularly preferably 55 or more. In addition, if the cetane index is too high, the length of the flame of diffusion combustion becomes long and local high temperature spots are likely to be formed. Therefore, the cetane index of the fuel composition for external combustion of the present invention is 65 or less, preferably Is 60 or less, more preferably 58 or less.

[Total sulfur content]
The fuel composition for external combustion of the present invention has a total sulfur content of 0.6% by mass or less. Since the fuel composition for external combustion of the present invention has a total sulfur content of 0.6% by mass or less, an unpleasant odor and an environmental load due to sulfurous acid gas and the like generated by combustion are reduced. The total sulfur content of the fuel composition for external combustion of the present invention is preferably 0.58% by mass or less, more preferably 0.56% by mass or less, and particularly preferably 0.5% by mass from the viewpoint of reducing environmental burden. % Or less.

[Total nitrogen content]
The fuel composition for external combustion of the present invention has a total nitrogen content of 300 mass ppm or less. Since the fuel composition for external combustion of the present invention has a total nitrogen content of 300 ppm by mass or less, the amount of nitrogen oxide generated by combustion is small, and the environmental load is reduced. The total nitrogen content of the fuel composition for external combustion of the present invention is preferably 250 ppm by mass or less, more preferably 240 ppm by mass or less, and particularly preferably 230 ppm by mass or less, from the viewpoint of reducing the environmental load.

[Total aromatic content]
The fuel composition for external combustion of the present invention has a total aromatic content of 36 to 45% by volume. When the total aromatic content is too low, the fuel consumption increases. Therefore, the fuel composition for external combustion of the present invention has a total aromatic content of 36% by volume or more, preferably 38% by volume or more, more preferably 40%. It is more than volume%. On the other hand, if the total aromatic content is too high, the oxidation reaction rate becomes slow and soot is easily generated. Therefore, the fuel composition for external combustion of the present invention has a total aromatic content of 45% by volume or less, preferably It is 43 volume% or less, More preferably, it is 42 volume% or less.

[Bicyclic aromatic component]
The fuel composition for external combustion of the present invention has a bicyclic aromatic content of 8 to 10% by volume. Here, the bicyclic aromatic component is the content of a compound having two benzene rings, and the benzene rings may be condensed with each other. If the bicyclic aromatic content is too high, the oxidation reaction rate becomes slow and soot is likely to be generated. Therefore, the bicyclic aromatic content of the fuel composition for external combustion of the present invention is 10% by volume or less, preferably It is 9.7 volume% or less, More preferably, it is 9.5 volume% or less. In addition, if the bicyclic aromatic content is too low, it becomes impossible to mix a large amount of medium-sized light oil fraction of a specific petroleum-based fuel containing a large amount of bicyclic aromatic content, and the physical properties of the fuel composition for external combustion It becomes extremely difficult to set the chemical properties within a specific range, resulting in an increase in soot and nitrogen oxide emissions. Therefore, the bicyclic aromatic content of the fuel composition for external combustion of the present invention is 8% by volume or more, preferably 8.3% by volume or more, more preferably 8.5% by volume or more, and particularly preferably 8. 7% or more by volume.

[Tricyclic aromatic component]
The fuel composition for external combustion of the present invention has a tricyclic aromatic content of 3 to 5% by volume. Here, the tricyclic aromatic component is the content of a compound having three benzene rings, and a plurality of benzene rings may be condensed. If the tricyclic aromatic content is too high, the oxidation reaction rate becomes slow and soot is easily generated. Therefore, the tricyclic aromatic content of the fuel composition for external combustion of the present invention is 5% by volume or less, preferably It is 4.5 volume% or less, More preferably, it is 4 volume% or less. In addition, if the tricyclic aromatic content is too low, a large amount of medium-sized gas oil fraction or dewaxed heavy gas oil fraction containing a large amount of tricyclic aromatic content will be mixed into a commercially available A heavy oil base. It becomes extremely difficult to make the physical and chemical properties of the fuel composition for external combustion within a specific range, and as a result, the amount of soot and nitrogen oxide emissions increases. Therefore, the tricyclic aromatic content of the fuel composition for external combustion of the present invention is 3% by volume or more, preferably 3.3% by volume or more, more preferably 3.5% by volume or more, and particularly preferably 3. 7% or more by volume.

[Aniline point]
The fuel composition for external combustion of the present invention has an aniline point of 55 to 65 ° C. If the aniline point is too low, the number of aromatic rings increases, the combustibility deteriorates and smoke (soot) tends to be generated, so the aniline point of the fuel composition for external combustion of the present invention is 55 ° C. or higher. Yes, preferably 58 ° C or higher, more preferably 60 ° C or higher. On the other hand, if the aniline point is too high, the length of the flame becomes longer due to an increase in the paraffin content, the temperature distribution in the combustion chamber becomes easier, the heat generation amount decreases, and the heat of the external combustion engine such as a boiler. Since the transmission efficiency is deteriorated, the aniline point of the fuel composition for external combustion of the present invention is 65 ° C. or lower, preferably 63 ° C. or lower, more preferably 62 ° C. or lower.

[10% carbon residue]
The fuel composition for external combustion of the present invention is not particularly limited, but the residual carbon content of 10% residual oil is preferably 0.8% by mass or less, more preferably 0.5% by mass or less. It is. If the residual carbon content of 10% residual oil is 0.8% by mass or less, clogging of the fuel filter can be sufficiently suppressed.

[Production method of fuel composition for external combustion]
The fuel composition for external combustion of the present invention is not particularly limited in the production method, but as a raw oil, for example, a kerosene oil fraction obtained from an atmospheric distillation apparatus, a catalytic cracking apparatus, a thermal cracking apparatus, etc., that is, an initial boiling point The bottom oil of the atmospheric distillation apparatus is used as a residual coal adjuster for the hydrodesulfurization using a fraction distilled in the temperature range from 140 to 360 ° C. (hereinafter referred to as the boiling range) from the end point to the end point. It is obtained by adding.

In the above hydrodesulfurization, for example, a hydrodesulfurization catalyst containing one or more of Co, Mo and Ni and optionally carrying P is used, and the reaction temperature is 270 to 380 ° C., preferably 295 to 360. ° C, reaction pressure 2.5 to 8.5 MPa, preferably 2.7 to 7.0 MPa, LHSV 0.9 to 6.0 h ⁻¹ , preferably 0.9 to 5.4 h ⁻¹ , hydrogen / oil ratio 130 to The fuel composition for external combustion of the present invention described above is obtained by appropriately selecting within the range of 300 (with a variation of about ± 5 allowed) Nm ³ / kL. In particular, it is preferable that the LHSV, the hydrogen pressure, and the hydrogen / oil ratio are large. The reaction temperature is preferably lowered in order to suppress the formation of styrene compounds and diene compounds having poor oxidation stability.

(Heavy oil base)
The fuel composition for external combustion of the present invention can be easily produced if a heavy oil base is blended in an amount of 70 to 95% by volume, particularly 75 to 90% by volume, based on the total amount of the fuel composition for external combustion. The representative properties of the heavy oil base material have a density (15 ° C.) of 0.860 g / cm ³ or more and less than 0.880 g / cm ³ , particularly 0.865 to 0.870 g / cm ³ and a 90% distillation temperature of 350. To 370 ° C., in particular 350 to 360 ° C., kinematic viscosity (30 ° C.) of 5 to 7 mm ² / s, particularly 5 to 5.5 mm ² / s, kinematic viscosity (50 ° C.) of 3 to 5 mm ² / s, In particular, 3 to 4 mm ² / s, the total sulfur content is 0.5 mass% or less, particularly 0.1 mass% or less, the total nitrogen content is 400 mass ppm or less, particularly 300 mass ppm or less, and the aniline point is 50 to 50 mass%. 70 ° C., in particular 55 to 65 ° C., 10% residual carbon content of 0.21 to 0.80 mass%, in particular 0.25 to 0.70 mass%, total aromatic content of 36 to 45 volume%, in particular Is 38 to 43% by volume, 5 to 9% by volume of bicyclic aromatics, especially 6 to 8% by volume, and 5% by volume of tricyclic aromatics % Or less, particularly 4% by volume or less. The above heavy oil base material is, for example, 60 to 90% by volume of the desulfurized light oil base material of the indirect desulfurization apparatus, 0 to 50% by volume of the catalytic cracking light oil base material, 0 to 30% by volume of the desulfurized light oil base material, It can be produced by blending 0 to 30% by volume and 0 to 1% by volume of atmospheric residual oil.

(Light oil base)
The fuel composition for external combustion of the present invention does not include a light oil base as an essential component, but the light oil base is blended in an amount of 5 to 30% by volume, particularly 10 to 25% by volume, based on the total amount of the fuel composition for external combustion. If it does, it can manufacture easily. When the blending amount of the light oil base is less than 5% by volume, it becomes difficult to bring the physical properties and chemical properties within the desired range. On the other hand, when it exceeds 30% by volume, the total sulfur content increases, thereby reducing the environmental load. Therefore, the blending amount of the light oil base material is 30% by volume or less. The light oil base material has, for example, an initial distillation point of 280 ° C. to 300 ° C. and a 90% distillation temperature of 340 by using a distillation residue oil obtained from a crude oil atmospheric distillation device as a raw material oil and further distilling with a vacuum distillation device. A vacuum gas oil of ˜360 ° C. can be obtained, which can be produced alone or using desulfurized gas oil obtained by further hydrodesulfurization.

The properties of the light oil base material used for preparing the fuel composition for external combustion of the present invention have a density (15 ° C.) of 0.880 to 0.920 g / cm ³ , particularly 0.890 to 0.915 g / cm ³ , 90% distillation temperature is 340-390 ° C, especially 350-380 ° C, kinematic viscosity (30 ° C) is 4-18 mm ² / s, especially 4.2-17 mm ² / s, kinematic viscosity (50 ° C) 3 to 9 mm ² / s, especially 3.2 to 8 mm ² / s, total sulfur content is 3% by mass or less, particularly 2.5% by mass or less, total nitrogen content is 300% by mass or less, particularly 200 mass ppm In the following, 10% residual carbon content is 0.0 to 0.60% by mass, especially 0.0 to 0.20% by mass, total aromatic content is 36 to 45% by volume, especially 38 to 42% by volume, aniline The point is 55 to 75 ° C., particularly 60 to 70 ° C., and the bicyclic aromatic content is 8 to 20% by volume, particularly 9 to 20% by volume. 3 aromatic content of 7% by volume or less, particularly equal to or less than 6.5 volume%. The light oil base material satisfying the above properties is preferably blended in an amount of 5 to 30% by volume, particularly 10 to 25% by volume, based on the total amount of the fuel composition for external combustion.

Furthermore, it is preferable to mix a dewaxed desulfurized heavy light oil base together with the above light oil base, and 4 to 15% by volume of the light oil base based on the total amount of the fuel composition for external combustion, dewaxed desulfurized heavy light oil. It is preferable to mix so that it may be 1-15 volume% of base materials, and 70-95 volume% of heavy oil base materials. The above dewaxed desulfurized heavy gas oil base is produced by, for example, hydrotreating a fraction having a boiling point range of 320 to 400 ° C. obtained from an atmospheric distillation apparatus of crude oil after removing the wax with a dewaxing catalyst. Can do. The properties of the dewaxed desulfurized heavy gas oil base material used for the preparation of the fuel composition for external combustion of the present invention have a density (15 ° C.) of 0.870 to 0.900 g / cm ³ , particularly 0.880 to 0.00. 890g / cm ^3, 90% distillation temperature of 400 ° C. or higher, a kinematic viscosity (30 ° C.) is 10 to 30 mm ² / s, in particular 15 to 25 mm ² / s, kinematic viscosity (50 ° C.) is 5 to 15 mm ² / s, in particular 7 to 13 mm ² / s, total sulfur content of 0.5% by mass or less, particularly 0.3% by mass or less, total nitrogen content of 400% by mass or less, particularly 380% by mass or less, 10% residual The carbon content is 0.0 to 0.60% by mass, particularly 0.1 to 0.40% by mass, the total aromatic content is 30 to 45% by volume, particularly 35 to 40% by volume, and the aniline point is 60 to 85%. ° C, especially 65-80 ° C, bicyclic aromatic content is 5-10% by volume, especially 7-9% by volume, tricyclic aromatic content 9 volume%, particularly at most 8% by volume.

  Any antioxidant known to those skilled in the art can be added to the fuel composition for external combustion according to the present invention as necessary. When an antioxidant is added, the amount added can be appropriately adjusted by those skilled in the art according to the target oxidation stability. For example, when the fuel composition contains 0.01% by mass or more of styrenes having 10 or more carbon atoms and dienes having 15 or more carbon atoms, an antioxidant may be added to maintain good oxidation stability. The desired effect can be obtained with an addition amount of about 1 to 10 ppm by mass, but 10 ppm by mass or more may be added.

  As said antioxidant, it can use without a restriction | limiting in particular among a phenolic antioxidant and an amine antioxidant. Specifically, 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2,4-dimethyl-6-t-butylphenol, 2,4,6-tri- phenolic antioxidants such as t-butylphenol, 2-t-butyl-4,6-dimethylphenol, 2-t-butylphenol, N, N′-diisopropyl-p-phenylenediamine, N, N′-di- Examples thereof include amine-based antioxidants such as sec-butyl-p-phenylenediamine, and mixtures thereof. In addition to phenolic and amine compounds, substances with an antioxidative effect are conceivable, but for the sake of clarity, in the present invention, only phenolic and amine compounds are treated as antioxidants to prevent oxidation. When other compounds having an effect are added, they are handled as fuel base materials.

  In addition, known fuel additives such as a low-temperature fluidity improver, an abrasion resistance improver, and a cetane number improver may be added. In addition, since the fuel composition for external combustion of the present invention has good low temperature fluidity, it is not necessary to add a low temperature fluidity improver, but when it is added, an ethylene copolymer or the like can be used. Are preferably vinyl esters of saturated fatty acids such as vinyl acetate, vinyl propionate and vinyl butyrate. In addition, as the wear resistance improver, for example, a long-chain fatty acid (12 to 24 carbon atoms) or a fatty acid ester thereof is preferably used, and the wear resistance is sufficiently improved with an addition amount of 10 to 500 ppm, preferably 50 to 100 ppm. To do.

  Hereinafter, the fuel composition for external combustion of the present invention will be described specifically by way of examples. In addition, although this invention is realizable if it implements like the following examples, it is not limited to a present Example.

<Preparation of test fuel (fuel composition for external combustion)>
Test fuel 1: Commercially available LSA heavy oil [boiling point range 210.5-383.0 ° C., 90% distillation temperature: 352.5 ° C., density (15 ° C.) 0.8663 g / cm ³ , kinematic viscosity (30 ° C.) 5.442 mm ² / s, kinematic viscosity (50 ° C.) 3.365 mm ² / s, total sulfur content 0.07 mass%, total nitrogen content 217 mass ppm, 10% residual carbon content 0.34 mass%, total aromatic 40.59% by volume, aniline point 60.0 ° C., bicyclic aromatic content 7.02% by volume, tricyclic aromatic content 3.50% by volume]

Test fuel 2: 80% by volume of commercially available LSA heavy oil of test fuel 1, boiling range of 320 to 400 ° C. (90% distillation temperature: 390.0 ° C.), density (15 ° C.) ) 0.9128 g / cm ³ , kinematic viscosity (30 ° C.) 43.34 mm ² / s, kinematic viscosity (50 ° C.) 10.39 mm ² / s, total sulfur content 2.23 mass%, total nitrogen content 513 mass ppm, 10% residual carbon content 0.69% by mass, total aromatic content 35.64% by volume, aniline point 80.7 ° C., bicyclic aromatic content 9.47% by volume, tricyclic aromatic content 0.50% by volume It was obtained by mixing 20% by volume of a fraction.

Test fuel 3: 80% by volume of commercially available LSA heavy oil of test fuel 1, a boiling range of 289.0 to 375.0 ° C. (90% distillation temperature: 352.0 ° C.) and density distilled from a vacuum distillation apparatus (15 ° C.) 0.9075 g / cm ³ , kinematic viscosity (30 ° C.) 8.919 mm ² / s, kinematic viscosity (50 ° C.) 5.014 mm ² / s, total sulfur content 2.46% by mass, total nitrogen content 199 Mass ppm, 10% residual carbon content 0.01 mass%, total aromatic content 41.20 vol%, aniline point 62.8 ° C, bicyclic aromatic content 19.07 vol%, tricyclic aromatic content 6.23 It was obtained by mixing 20% by volume of a volume fraction.

Test fuel 4: 80% by volume of commercially available LSA heavy oil of test fuel 1, a boiling range of 289.0 to 375.0 ° C. (90% distillation temperature: 352.0 ° C.), density (15 ° C.) 0.9075 g / cm ³ , kinematic viscosity (30 ° C.) 8.919 mm ² / s, kinematic viscosity (50 ° C.) 5.014 mm ² / s, total sulfur content 2.46% by mass, total nitrogen content 199 Mass ppm, 10% residual carbon content 0.01 mass%, total aromatic content 41.20 vol%, aniline point 62.8 ° C, bicyclic aromatic content 19.07 vol%, tricyclic aromatic content 6.23 Using a commercially available catalyst carrying Co, Mo, and P after removing wax from a fraction having a boiling point of 320 to 400 ° C. distilled from an atmospheric distillation apparatus with a volume fraction of 10% by volume, and a dewaxing catalyst. , reaction temperature 350 ° C., a reaction pressure 7.2 MPa, a hydrogen / oil ratio 300 ± 5 Nm ³ / k , LHSV1.0H ^-1, dewaxing heavy hydrotreated oil obtained by hydrorefining under the conditions of hydrogen purity of 94%, i.e., boiling range 149.0 ° C. to 400 ° C. or higher (70% distillation temperature: 390.0 ° C., 90% distillation temperature: 400 ° C. or higher), density (15 ° C.) 0.8839 g / cm ³ , kinematic viscosity (30 ° C.) 20.34 mm ² / s, kinematic viscosity (50 ° C.) 9.278 mm ² / s, total sulfur content 0.22 mass%, total nitrogen content 358 massppm, 10% residual carbon content 0.33 mass%, total aromatic content 37.68 vol%, aniline point 74.9 ° C, 2 rings It was obtained by mixing 10% by volume of a dewaxed desulfurized heavy gas oil base material having an aromatic content of 8.66 vol% and a tricyclic aromatic content of 7.01 vol%.

<Test equipment (house heating machine)>
・ Manufacturer: Nepon Corporation
・ Model: HK3025TE
・ Output: 87.2kW
・ Hydraulic pressure: 1.03 MPa
・ Fuel maximum flow rate: 9.7 L / hour

  For each of the above test fuels 1, 2, 3, and 4, the physical properties and composition of the components were measured, and further, a combustion test was conducted with a house warmer, the amount of soot contained in the combustion exhaust gas, nitrogen oxidation Evaluation was made from the amount of waste discharged. The results are shown in Table 1.

In addition, the measuring method and evaluation methods, such as the physical property of Table 1, a component composition, and combustion exhaust gas evaluation, measured and evaluated by the method shown next.
1) Density: The method specified in JIS K2249 “Crude oil and petroleum product density test method”.
2) Distillation property: A method defined in JIS K2254 “Distillation Test Method”.
3) Kinematic viscosity: A method defined in JIS K2283 “Kinematic viscosity test method”.
4) Cetane index: Method defined in JIS K2280 “Method of calculating cetane index” 5) Total sulfur content: Method defined in JIS K2541-6 “Sulfur content test method (ultraviolet fluorescence method)”.
6) Total nitrogen content: A method defined in JIS K2609 “Method for testing nitrogen content”.
7) Moisture: “Karl Fischer-type coulometric titration method” defined in JIS K2275 “Moisture test method”.
8) Total calorific value: The method defined in JIS K2279 “Testing method of calorific value and estimation method by calculation”.
9) Total aromatics, 1-ring aromatics, 2-rings aromatics, 3-rings aromatics: Petroleum Society method JPI-5S-49-97 “Petroleum products—Hydrocarbon type test method—High performance liquid chromatograph method” ”Method.
10) Aniline point: A method defined in JIS K2256 “Petroleum products—Test method for aniline point and mixed aniline point”.
11) 10% residual carbon content: JIS K2270 “Crude oil and petroleum product residual carbon content test method”.

<Combustion test method>
An exhaust gas sampling port is attached to the nearest flue from the can body, the air shutter opening for controlling the amount of combustion air is sequentially changed by 5 to 7 points, and the exhaust gas (O ₂ , CO, CO ₂ and NOx) and baccarax smoke tester (abbreviated as smoke tester). The combustion exhaust gas can simultaneously measure O ₂ , CO, CO ₂ , and NOx by a constant potential electrolysis method. Smoke (煤), according to the manufacturer's instructions, manually swivel the handle 10 times to suck the exhaust gas, the color attached to the white filter paper set in advance of the predetermined scale (10 stages: clean 0-9 contamination) Compare with the color and determine the density (grade number). Each time the air shutter opening is changed while checking the O ₂ concentration and smoke concentration in the exhaust gas. In general, as the air shutter opening is reduced, the amount of combustion air decreases and the efficiency increases, but the smoke increases and increases more rapidly than a certain amount of air. Smoke passes from the can through the flue and is released to the atmosphere, but black smoke will pollute the surrounding environment and cause complaints from the neighborhood. Smoke accumulates on the wall surface of the can body over a long period of operation and reduces the heat transfer efficiency, so the inside of the boiler must be periodically cleaned. Therefore, a fuel for boilers with less smoke is desired.

<Combustion exhaust gas analyzer specifications>
・ Name: Combustion exhaust gas analyzer ・ Manufacturer name: Hodaka Co., Ltd. ・ Model: HT-1600N
・ Measurement items: O ₂ , CO, CO ₂ , NOx (constant potential electrolysis method)
Exhaust gas temperature, pressure, combustion efficiency

From Table 1, it can be seen that when the oxygen (O ₂ ) concentration in the exhaust gas is constant, in Examples 1 and 2, the soot discharge (smoke) is reduced compared to Comparative Examples 1 and 2. In addition, when the oxygen (O ₂ ) concentration in the exhaust gas is constant, compared to Comparative Examples 1 and 2, Examples 1 and 2 also reduced the nitrogen oxide emissions.

Claims (3)

Density (15 ° C.) is 0.860~0.900g / cm ^3, 90% distillation temperature of three hundred forty to three hundred and seventy ° C., a kinematic viscosity (30 ° C.) is 5.9 ~10mm ² / s, kinematic viscosity (50 ° C.) 3.6 to 5.5 mm ² / s, total sulfur content is 0.6 mass% or less, total nitrogen content is 300 mass ppm or less, total aromatic content is 36 to 45 vol%, aniline point is 55 to 65 ° C. The bicyclic aromatic component is 8 to 10% by volume, the tricyclic aromatic component is 3 to 5% by volume, the water content is 120 mass ppm or less, and the cetane index (JIS-2280) is 47 to 65. Fuel composition for external combustion. A heavy oil base material having a density (15 ° C.) of 0.860 g / cm ³ or more and less than 0.880 g / cm ³ , a total sulfur content of 0.5% by mass or less, and a bicyclic aromatic content of 5 to 9% by volume is 70 95% by volume, density (15 ° C.) of 0.880 g / cm ^{3 to} 0.920 g / cm ³ , 90% distillation temperature of 340 to 390 ° C., kinematic viscosity (50 ° C.) of 3 to 9 mm ² / s The total sulfur content is 3 mass% or less, the total nitrogen content is 300 mass ppm or less, the total aromatic content is 36 to 45 vol%, the bicyclic aromatic content is 8 to 20 vol%, and the tricyclic aromatic content is 7 vol. The method for producing a fuel composition for external combustion according to claim 1, wherein 5 to 30% by volume of a light oil base which is not more than 5% is blended. Density (15 ° C) is 0.860 g / cm ^Three 0.880 g / cm ^Three Less than 70% by mass of a heavy oil base having a total sulfur content of 0.5% by mass or less and a bicyclic aromatic content of 5-9% by volume,
Density (15 ° C) is 0.880 g / cm ^Three 0.920 g / cm ^Three The 90% distillation temperature is 340 to 390 ° C., and the kinematic viscosity (50 ° C.) is 3 to 9 mm. ² / S, total sulfur content is 3 mass% or less, total nitrogen content is 300 massppm or less, total aromatic content is 36 to 45 vol%, bicyclic aromatic content is 8 to 20 vol%, tricyclic aromatic content is 4 to 15 vol% of light oil base that is 7 vol% or less,
Density (15 ° C) is 0.870-0.900 g / cm ^Three The 90% distillation temperature is 400 ° C or higher, and the kinematic viscosity (50 ° C) is 5 to 15 mm. ² / S, total sulfur content is 0.5 mass% or less, total nitrogen content is 400 massppm or less, total aromatic content is 30 to 45 vol%, bicyclic aromatic content is 5 to 10 vol%, tricyclic aromatic The method for producing a fuel composition for external combustion according to claim 1, wherein a dewaxed desulfurized heavy gas oil base having a content of 9% by volume or less is blended in an amount of 1 to 15% by volume.