JP2006182981A - Gasoline composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasoline composition that can reduce deterioration in drivability during the cold engine operation in a general gasoline engine (an MPI engine) and also reduce combustion chamber deposits, while distillation properties are adjusted so as to increase heavier gasoline components for the purpose of reducing the risk of malfunction of an injector due to contamination in a direct fuel injection type internal combustion engine. <P>SOLUTION: The gasoline composition has a 10% distillation temperature of 40°C or higher, a 50% distillation temperature of 90-103°C, a 70% distillation temperature of 110-134°C, a 90% distillation temperature of 150-170°C and an aromatic content of 45 vol.% or less, and contains an oxygen-containing compound in an amount of 0.1-2.6 mass% in terms of an oxygen content, and further satisfies specified formulae concerning a distillation temperature, an oxygen content, a composition of the components of aromatic hydrocarbons and a composition of the components of isoparaffins. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gasoline composition produced from a hydrocarbon such as petroleum and an oxygen-containing compound.

As one of the measures to achieve the CO ₂ emission reduction target by ratification of the Kyoto Protocol, fuel efficiency regulations for automobiles will be strengthened from 2010. In order to cope with this, a direct injection gasoline (direct injection) engine is regarded as one of the promising technologies and has attracted attention. However, in the direct injection engine, the injector nozzle is easily damaged, and there is a concern about deterioration of fuel consumption and deterioration of exhaust gas properties (increase of unburned hydrocarbon, NOx, etc.) due to the contamination. As one direction corresponding to this problem, it has been proposed that gasoline is heavier, specifically, that 90% distillation temperature (T ₉₀ ) is defined within a certain range (see Patent Document 1).
However, generally for heavier distillation characteristics including T _90, dirt drivability deterioration and the combustion chamber (combustion chamber deposits) or the like is feared at the time of cold
Special table 2004-513279

  It is an object of the present invention to provide a gasoline composition that can be reduced in weight to reduce injector fouling of a direct-injection engine, while reducing engine cold-time operability and combustion chamber deposits.

  Recent direct-injection engines are not only seeking fuel efficiency improvement measures by the stratified intake system, but also by the so-called stoichiometric direct injection system to reduce exhaust gas, especially NOx, and to improve fuel efficiency by increasing the compression ratio. This high compression ratio type engine is a system that effectively uses a high octane number by using premium gasoline. Therefore, the present inventor increases the mixing amount of the heavy octane base material having a high octane number, raises the octane number and simultaneously reduces injector fouling, and deteriorates the cold-time operability associated with the heavy distillation property. Regarding the combustion chamber deposit, we obtained the idea that adjusting the carbon number distribution of isoparaffin to maintain the accelerating performance during cold operation and reducing the combustion chamber deposit caused by heavy aromatics by adding oxygen-containing compounds. .

That is, the gasoline composition according to the present invention has a research octane number (RON) of 93 or more, a 10% distillation temperature (T ₁₀ ) of 40 ° C. or more, and a 50% distillation temperature (T ₅₀ ) of 90 to 103 ° C. The 70% distillation temperature (T ₇₀ ) is 110 to 134 ° C., the 90% distillation temperature (T ₉₀ ) is 150 to 170 ° C., the aromatic content is 45% by volume or less, and the oxygen-containing compound is used as the oxygen content. It contains 1 to 2.6% by mass and satisfies the following formulas (1), (2), and (3).
DI = 1.5 × T ₁₀ + 3 × T ₅₀ + T ₉₀ + 11 × OX ≦ 530 (1)
A = AC9 ⁺ /AR≧0.40 (2)
B = (IC5 + IC6 + IC7) /IP≧0.45 (3)
Here, T ₁₀ represents 10% distillation temperature [° C.], T ₅₀ represents 50% distillation temperature [° C.], T ₉₀ represents 90% distillation temperature [° C.], and OX represents oxygen content [mass%]. Indicates. AR is the content of aromatic compounds [volume%], AC9 ⁺ is the content of aromatic compounds having 9 carbon atoms [volume%], IP is the content of isoparaffin [volume%], IC5, IC6, and IC7 are The contents [volume%] of isoparaffins having 5, 6 and 7 carbon atoms are shown.

  In addition, the gasoline composition of the present invention preferably has a vapor pressure of 50 to 90 kPa, further has a total sulfur content of 10 mass ppm or less, a sulfur content of thiols of 1.5 mass ppm or less, and a negative doctor test. It is preferable from the viewpoint of reducing harmful substances, odors, and corrosiveness.

  As described above, the distillation property is kept within a certain numerical value related to the oxygen-containing compound content as defined in the formula (1), and the number of carbon atoms in the total aromatic content as defined in the formula (2) is 9 or more. Direct injection by increasing the proportion of aromatic compounds of the above, increasing the proportion of C5-C7 isoparaffins in the total isoparaffin as defined in formula (3), and adding a predetermined amount of oxygen-containing compound While preventing the nozzle from being polluted, it is possible to suppress the increase in deposits in the combustion chamber and maintain acceleration and driving force when the vehicle is cold. In particular, it has a great effect in a straight-line engine in which the deposits in the injection nozzle part and the combustion chamber are said to be serious as compared with general gasoline (MPI) engines.

  The gasoline composition according to the present invention has a research octane number (RON) of 93 or more, preferably 94 to 100, particularly preferably 95 to 100. The measuring method of the research method octane number is defined in JIS K2202.

  The gasoline composition according to the present invention has a vapor pressure at 37.8 ° C. within the range of JIS standard (JIS K 2202: 44 to 93 kPa), preferably 50 to 90 kPa, more preferably 52 to 87 kPa, and particularly preferably. 55 to 85 kPa. The method for measuring the vapor pressure in this specification is defined in JIS K 2258.

The gasoline composition according to the present invention has a 10% distillation temperature (T ₁₀ ) of 40 ° C. or higher, preferably 47.5 to 50.0 ° C., and a 50% distillation temperature (T ₅₀ ) of 89 to 103 ° C., preferably 90-103 ° C., 70% distillation temperature _{(T 70)} is one hundred ten to one hundred and thirty-four ° C., preferably 112~125 ℃, 90% distillation temperature _{(T 90)} is 155 to 175 ° C., preferably 155-170 ° C. The distillation properties are defined in JIS K 2254.

Further, the gasoline composition according to the present invention needs to satisfy the following relational expression (1).
DI = 1.5 × T ₁₀ + 3 × T ₅₀ + T ₉₀ + 11 × OX ≦ 530 (1)
Here, T ₁₀ represents a 10% distillation temperature [° C.], T ₅₀ represents a 50% distillation temperature [° C.], T ₉₀ represents a 90% distillation temperature [° C.], and OX contains a blended oxygen-containing compound. The amount is expressed as oxygen content [% by mass].
DI is preferably 525 or less.

The aromatic content of the gasoline composition according to the invention is not more than 45% by volume, preferably 25 to 45% by volume, in particular 27 to 41% by volume.
Further, the gasoline composition according to the present invention needs to satisfy the following relational expression (2) with respect to the content of the aromatic compound.
A = AC9 ⁺ /AR≧0.40 (2)
In the above formula, AR represents the total aromatic compound content [volume%], and AC9 ⁺ represents the aromatic compound content [volume%] of 9 or more carbon atoms.
The AC9 ⁺ / AR ratio is preferably 0.42 to 0.55.
Moreover, as an aromatic compound, it is preferable to make content of benzene into 1 volume% or less from a viewpoint of a harmful substance reduction.
In addition, content of each aromatic compound is measured by the method prescribed | regulated to "How to obtain | require all the components by gas chromatography" of JISK2536-2, and C9 or more aromatic content and total aromatic compound of The content (aromatic content) was calculated.

Furthermore, in the gasoline composition according to the present invention, the proportion of the content of isoparaffin having 5 to 7 carbon atoms [volume%] in the content of isoparaffin [volume%] must satisfy the following relational expression (3). It is.
B = (IC5 + IC6 + IC7) /IP≧0.45 (3)
The (IC5 + IC6 + IC7) / IP ratio is preferably 0.50 or more. The isoparaffin content is preferably 20 to 60% by volume, particularly 30 to 50% by volume. Here, content of isoparaffin is prescribed | regulated by the isoparaffin measurement value measured by JISK2536-2 "how to obtain | require all the components by gas chromatography".

  The gasoline composition according to the present invention contains an oxygen-containing compound in an oxygen content of 0.1 to 2.7% by mass. A preferable content of the oxygen-containing compound is 0.5 to 2.5% by mass, particularly 0.6 to 2.3% by mass. As the oxygen-containing compound to be used, alcohol or ether is suitable. Specific examples of preferable alcohols include methanol, ethanol, and propanol. Examples of ethers include methyl t-butyl ether (MTBE), ethyl t-butyl ether (ETBE), and t-amyl ethyl ether (TAEE). .

  The sulfur content of the gasoline composition according to the present invention is preferably 10 ppm by mass or less, particularly preferably 0.5 to 5 ppm by mass. The sulfur content by thiols is preferably 1.5 ppm by mass or less, particularly preferably 0.1 to 1.2 ppm by mass, and the proportion of sulfur by thiols in the sulfur content is 30% or less, particularly 10 to 30%. It is preferable that

  Moreover, it is preferable that a doctor test result is negative. Thiols are organic sulfur compounds containing SH groups, chain thiols with SH groups added to chain paraffins, alicyclic thiols with SH groups added to cyclic paraffins, and SH groups added directly to aromatic rings. Containing aromatic thiols.

  Sulfur containing thiol in gasoline is contained in a relatively large amount in fluid catalytic cracking gasoline base and pyrolysis gasoline base, and details of the reduction method are described in Japanese Patent Application No. 2004-178210, which has already been filed by the inventors. No. ".

  The gasoline composition according to the present invention preferably contains less than 80% by volume, particularly 30 to 70% by volume, more preferably 40 to 70% by volume, of other gasoline substrates in the catalytically modified gasoline substrate. As other gasoline base materials, fluid catalytic cracking gasoline base materials, alkylate gasoline base materials, base materials obtained by desulfurizing straight-run naphtha, and the like can be used. Moreover, an oxygen-containing compound is mix | blended so that it may contain 0.1-2.7 mass% as oxygen content.

  The preferred blending amount of these gasoline base materials is 20 to 40% by volume, especially 30 to 40% by volume of fluid catalytic cracking gasoline base, 10 to 30% by volume of light reformed gasoline base, heavy reformed gasoline base 10 to 20% by volume of material, oxygen-containing gasoline base material (in the case of ETBE) about 0.5 to 10% by volume (within the range of 0.1 to 2.7% by mass as oxygen content), total of other base materials 0 to 35% by volume.

  Furthermore, the gasoline composition of the present invention may contain one or more fuel oil additives known in the art as needed. Although these compounding quantities can be selected suitably, it is preferable to maintain the total compounding quantity of an additive to 0.1 mass% or less normally. Examples of fuel oil additives that can be used in the gasoline of the present invention include phenolic, amine-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organic phosphorus-based surfaces. Anti-ignition agents, detergent dispersants such as succinimides, polyalkylamines and polyetheramines, anti-icing agents such as polyhydric alcohols or their ethers, anionic surfactants, cationic surfactants, amphoteric surfactants, etc. And anti-static agents and colorants such as azo dyes.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

In order to prepare the gasoline compositions of Examples and Comparative Examples, the following gasoline base materials were prepared.
ETBE: Commercially available ETBE having a purity of about 95% (manufactured by Chevron Chemical).
ETOH: Commercial fermented ethanol (99 degrees first grade, manufactured by Nippon Alcohol Sales Co., Ltd.).
BB: A butane fraction obtained by petroleum refining including a butane fraction obtained by steam distillation of crude oil and a butane fraction by-produced from a catalytic reformer or a catalytic cracker.
FCCGL: Light catalytic cracking naphtha having a 5% distillation temperature of 25.0 to 43.0 ° C and a 95% distillation temperature of 55.0 to 80.0 ° C obtained by fractionating a catalytic cracking naphtha fraction Fraction.
ALKG: A hydrocarbon having a high isoparaffin content (alkylated gasoline) obtained by reacting (alkylating) a fraction mainly containing butylene and a fraction mainly containing isobutane with a sulfuric acid catalyst.
AC7: Light reformed gasoline obtained by reacting desulfurized heavy naphtha with a solid catalyst using a moving bed reactor, reforming it into a hydrocarbon with high aromatic content, and distilling it off. And 95% or more of C7 hydrocarbons.
AC9: Heavy reformed gasoline obtained by distillation separation of high aromatic hydrocarbons obtained by reforming the above desulfurized heavy naphtha, containing 95% or more of hydrocarbons having 9 or more carbon atoms To do.
Table 1 shows the properties of the gasoline base material.

The gasoline base material shown in Table 1 was blended at the blending ratio shown in the upper part of Table 2 to prepare gasolines for Comparative Example 1 and Examples 1 and 2. Table 2 shows the properties of the prepared gasoline.
Regarding the properties in Tables 1 and 2, the research octane number was measured according to JIS K 2202, the vapor pressure was measured according to JIS K 2258, and the distillation property was measured according to JIS K 2254. The sulfur content was measured by the microcoulometric titration method of JIS K2541. The sulfur compound content (sulfur equivalent) was measured by gas chromatography using a Shimadzu gas chromatograph equipped with an ANTEK sulfur chemiluminescence detector that selectively detects and quantifies sulfur compounds by chemiluminescence. . The hydrocarbon component composition of aromatic and isoparaffin was measured in accordance with JIS K 2536-2 “How to obtain all components by gas chromatography” using a PIONA device manufactured by Hured Packard. The doctor test was measured according to JIS K 2276.
The oxygen content was calculated by multiplying the blending amount of the oxygen-containing compound (after mass conversion) by the proportion of oxygen contained in the oxygen-containing compound.

Furthermore, an acceleration performance test was conducted using three commercially available passenger cars (test cars A, B and C) using the chassis dynamometer apparatus using the gasolines of Examples 1 and 2 and Comparative Example 1. Table 3 shows the engine specifications of the test vehicles A, B and C.
In the acceleration performance test, after the vehicle was held in a cold machine (25 ° C.) state, when the accelerator opening was accelerated up to 50% by the automatic driving device (Horiba Seisakusho, ADS7000), the initial acceleration was 0. It was measured by the time required to reach a vehicle speed of 50 (km / hour). The result (acceleration time reduction rate) was compared based on the difference in acceleration time relative to the arrival time when the fuel of Comparative Example 1 was used. The results are also shown in Table 2. The acceleration time reduction rate of the test gasoline was obtained from the following equation.
Acceleration time reduction rate = (arrival time of comparative example 1−arrival time of test gasoline) ÷ (arrival time of comparative example 1) × 100

  The engine cleanliness test was conducted using the gasoline of Example 1 and Comparative Example 1. Specifically, using an engine having the specifications shown in Table 4, after operating under the conditions of Table 5, the intake valve deposit (IVD) attached to the intake valve and the combustion chamber deposit (CCD) attached to the combustion chamber Each mass was measured. In Table 4, PFI of the fuel supply system indicates a port fuel injection system. In Table 5, “State” indicates the state of the engine speed, “Fixed” indicates that the engine speed is maintained for a predetermined time, and “SLOPE” indicates that the engine speed is maintained for a predetermined time. Is proportionally changed to a predetermined rotational speed. The results are shown in Table 6.

  The gasoline composition of the present invention utilizes a heavy aromatic component and an oxygen-containing compound, and finely adjusts the distillation properties, the composition of the isoparaffin component, etc. While preventing injector fouling, it is possible to prevent intake valve deposits and combustion chamber deposits and maintain performance such as cold acceleration of the vehicle. Therefore, it is useful as an excellent gasoline composition for automobiles.

Claims (3)

10% distillation temperature is 40 ° C or higher, 50% distillation temperature is 90 to 103 ° C, 70% distillation temperature is 110 to 134 ° C, and 90% distillation temperature is 150 to 170 ° C,
The aromatic content is 45% by volume or less,
Containing oxygen-containing compound in an oxygen content of 0.1 to 2.6% by mass,
Satisfying the following formulas (1), (2) and (3), and
A gasoline composition having a research octane number of 93 or more,
DI = 1.5 × T ₁₀ + 3 × T ₅₀ + T ₉₀ + 11 × OX ≦ 530 (1)
A = AC9 ⁺ /AR≧0.40 (2)
B = (IC5 + IC6 + IC7) /IP≧0.45 (3)
(Here, T ₁₀ represents a 10% distillation temperature [° C.], T ₅₀ represents a 50% distillation temperature [° C.], T ₉₀ represents a 90% distillation temperature [° C.], and OX represents an oxygen content [mass%]. AR represents the content [volume%] of the aromatic compound, AC9 ⁺ represents the content [volume%] of the aromatic compound having 9 or more carbon atoms, and IP represents the content [volume%] of isoparaffin. IC5, IC6, and IC7 indicate the content [volume%] of isoparaffins having 5, 6, and 7 carbon atoms, respectively.   Furthermore, the gasoline composition according to claim 1 whose vapor pressure is 50-90kPa. The gasoline composition according to claim 1 or 2, wherein the total sulfur content is 10 ppm by mass or less, the sulfur content by thiols is 1.5 ppm by mass or less, and the doctor test result is negative.