JP2006199754A - Gasoline composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasoline composition ameliorating the adverse effect on fuel-based members due to oxygen-containing compound addition and the aggravation of machine operability in a cool condition and raised in octane number. <P>SOLUTION: The gasoline composition contains 0.1-4.5 mass%, on an oxygen content basis, of an oxygen-containing compound ≥3 in acidity (PHe), has vapor pressure (37.8°C) of 50-90 kPa, a 50% distilling temperature of 85-103°C, an aromatics content of ≤35 vol.%, an isoparaffin content of ≥30 vol.% and a research octane number of ≥91.5, and also meets a specific numerical formula on distilling temperature and oxygen content and a specific numerical formula on the component constitution of aromatic hydrocarbon and isoparaffin. <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, use of gasoline mixed with ethanol defined as renewable energy or ethyl t-butyl ether derived from ethanol (hereinafter abbreviated as ETBE) is considered (for example, see Patent Document 1). . These oxygen-containing compounds are expected to contribute to CO ₂ reduction because they are themselves renewable energy. Furthermore, since the octane number is high, it is possible to increase the engine compression ratio, and at the same time, CO ₂ reduction by improving combustion efficiency is also expected. However, the use of these oxygen-containing compounds increases the proportion of air from the amount of air required to burn a certain amount of fuel (theoretical air-fuel ratio) compared to hydrocarbon compounds, resulting in lean fuel in the combustion chamber. Become. For this reason, the drivability at the time of a cold machine may deteriorate by the case. As an index of deterioration in driving performance, a formula related to DI (Driveability Index) consisting of volatility and oxygen content has been defined by ASTM (American standard test method) and has been further corrected by oxygen content. WWFC (World Wide Fuel Charter) (see Non-Patent Document 1).

Further, the use of oxygen-containing compounds is concerned about the influence on members (metal, rubber, etc.) used in automobiles. For this reason, it is said that ether is preferable to alcohol from a viewpoint of reducing the influence on a motor vehicle member (for example, refer nonpatent literature 2). However, regardless of ether or alcohol, there may be a concern about the influence on automobile members due to impurities mixed in in the production process.
JP 2004-238575 A World-Wide Fuel Charter, December 2002, p.29, Figure 14 Tanaka, "Survey on Ethanol or ETBE Blended Gasoline Overseas", Engine Technology, Vol. 5, No. 5, published by Sankai-do, October 26, 2003, p.40-44

  An object of the present invention is to provide a gasoline composition having an improved octane number by preventing adverse effects on fuel system members due to the addition of oxygen-containing compounds and deterioration of operability during cold operation.

The present inventor uses an oxygen-containing compound having a certain range of acidity (PHe), vapor pressure, 50% distillation temperature (T ₅₀ ), aromatic compound and isoparaffin content, octane number, and aromatic A gasoline composition that adjusts the composition ratio of hydrocarbon and isoparaffin components and satisfies a specific formula for distillation temperature and oxygen content has a high octane number, but does not adversely affect fuel system components due to oxygenated compounds In addition, the inventors have found that the acceleration performance when the vehicle is cold can be maintained, which contributes to CO ₂ reduction, and have come to the present invention.

That is, the gasoline composition according to the present invention contains an oxygen-containing compound having an acidity (PHe) of 3 or more as an oxygen content of 0.1 to 4.5% by mass, a vapor pressure of 50 to 90 kPa, and a 50% distillation. The temperature is 85 to 103 ° C., the aromatic content (AR) is 35% by volume or less, the isoparaffin content is 30% by volume or more, the research octane number (RON) is 91.5 or more, and the following formula (1 ) And (2) are satisfied.
DI = 1.5 × T ₁₀ + 3 × T ₅₀ + T ₉₀ + 11 × OX ≦ 540 (1)
AR / IP ≦ 0.740 (2)
In the formula (1), 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%] is shown. In the formula (2), AR represents the aromatic compound content [volume%], and IP represents the isoparaffin content [volume%].

  Further, in the gasoline composition according to the present invention, the oxygen-containing compound is preferably ethanol and / or a derivative thereof, and further, the sulfur content is 10 mass ppm or less and the sulfur content based on thiols. Is preferably 1.5 ppm by mass or less from the viewpoint of reducing harmful substances, odor, and corrosiveness.

As described above, the gasoline composition of the present invention contains a predetermined amount of an oxygen-containing compound having a certain range of acidity (PHe), 50% distillation temperature and vapor pressure within a predetermined range, isoparaffin and While containing a predetermined amount of aromatic content, and within a certain range of the total aromatic content relative to the isoparaffin content, and satisfying a specific formula relating to the distillation temperature and oxygen content, while having a high octane number, It is also possible to maintain acceleration when the vehicle is cold without adversely affecting the fuel system member due to the oxygen-containing compound.
Furthermore, the improvement in driving performance and fuel efficiency by increasing the octane number is expected to have a significant effect not only on vehicles with the current knock sensor but also on vehicles with high octane number conforming to regular specifications expected in the future.

  The gasoline composition according to the present invention has a research octane number (RON) of 91.5 or more, preferably 92 to 100, particularly preferably 92.5 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. of 50 to 90 kPa, preferably 52 to 87 kPa, more preferably 55 to 85 kPa. The method for measuring the vapor pressure in this specification is defined in JIS K 2258.

In the gasoline composition according to the present invention, the 10% distillation temperature (T ₁₀ ) is preferably 47 ° C. or more, more preferably 48.0 to 51.5 ° C., and the 50% distillation temperature (T ₅₀ ) is 85 to 85 ° C. 103 ° C, preferably 90-103 ° C, more preferably 92-101 ° C, 70% distillation temperature (T ₇₀ ) is preferably 110-134 ° C, more preferably 115-125 ° C, and The 90% distillation temperature (T ₉₀ ) is preferably 170 ° C. or less, more preferably 155 to 168 ° C. The measuring method of the distillation temperature is 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 ≦ 540 (1)
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.
In addition, DI which does not correct | amend oxygen content is prescribed | regulated to ASTM D4814, and the formula which correct | amended oxygen content is proposed by WWFC.

The aromatic content of the gasoline composition according to the invention is not more than 35% by volume, preferably 20 to 34% by volume, in particular 24 to 33% by volume.
The gasoline composition according to the present invention has an isoparaffin content of 30% by volume or more, preferably 31% by volume or more.

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 and the content of isoparaffin.
AR / IP ≦ 0.740 (2)
Here, AR represents the content [volume%] of the aromatic compound, and IP represents the content [volume%] of isoparaffin.
The AR / IP ratio is 0.740 or less, preferably 0.735 or less. In addition, each composition is prescribed | regulated by the isoparaffin content by JISK2536 "all component test method by gas chromatography", and the aromatic content by the same method.

  The acidity (PHe) of the oxygen-containing compound used in the gasoline composition according to the present invention is preferably 3 or more, particularly preferably 5 or more, and the content thereof is 0.1 to 4.5% by mass as the oxygen content. The preferred content is 0.2 to 4.0 mass%, particularly 1.0 to 3.5 mass% as the oxygen content.

  As the oxygen-containing compound to be used, alcohol or ether is preferable, and ethanol or an ether derivative of ethanol is particularly preferable. Specific examples of preferable oxygen-containing compounds include ethanol, ethyl t-butyl ether (ETBE), t-amyl ethyl ether (TAEE), and the like. Moreover, in order to prevent the corrosion by an oxygen-containing compound, it is preferable to add an appropriate amount of a rust inhibitor as required.

  The sulfur content of the gasoline composition according to the present invention is 10 mass ppm or less, preferably 0.1 to 10 mass ppm, particularly preferably 0.5 to 7 mass ppm. The sulfur content based on thiols is preferably 1.5 mass ppm or less, more preferably 0.1 to 1.0 mass ppm. Moreover, it is preferable that the ratio of the sulfur content based on thiols in the total sulfur content is 30% or less, particularly 20% or less. The sulfur content based on thiols refers to the mass of only sulfur contained in the thiol compound, and is not limited to thiols, where the sulfur content or sulfur content is the content based on only sulfur. (Mass).

Thiols are organic sulfur compounds having 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 compounds of thiols are contained in a relatively large amount in fluid catalytic cracking gasoline bases and pyrolysis gasoline bases, and details of the reduction method are described in Japanese Patent Application No. 2004-178210, which has already been filed by the applicants. It is described in the book.

  When a fluid catalytic cracking gasoline base material is used to prepare the gasoline composition according to the present invention, the sulfur content is sufficiently reduced, and the flow rate is 50% distillation temperature of 85-95 ° C and 90% distillation temperature of 155-170 ° C. It is preferable to use a catalytic cracking gasoline base.

  The preferred blending amount of the gasoline base is 50 to 90% by volume, especially 60 to 80% by volume of the fluid catalytic cracking gasoline base, 5 to 35% by volume, particularly 7 to 25% by volume of the catalytically modified gasoline base. The total of other base materials is 0 to 30% by volume, particularly 5 to 20% 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 composition of the present invention include phenol-based and amine-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organic phosphorus-based compounds. Surface ignition inhibitor, detergent dispersants such as succinimide, polyalkylamine, polyetheramine, anti-icing agent such as polyhydric alcohol or its ether, alkali metal salt or alkaline earth metal salt of organic acid, higher alcohol And a colorant such as an azo dye, an antistatic agent such as an anionic surfactant, a cationic surfactant and an amphoteric surfactant.

  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.
DS-LG: straight-run gasoline, obtained by hydrodesulfurizing a naphtha fraction of Middle Eastern crude oil, and distilling and separating the lighter fraction.
FCCG: A light cracked naphtha fraction having a 5% distillation temperature of 25.0 to 43.0 ° C and a 95% distillation temperature of 55.0 to 80.0 ° C is obtained by fractionating a catalytic cracking naphtha fraction. . And after reducing the sulfur content by hydrodesulfurization, the other heavy naphtha fraction fractionated was subjected to thiol reduction treatment by sweetening treatment and mixed with the light naphtha fraction.
ALKG: alkylate gasoline, a fraction containing butylene as a main component and a fraction containing isobutane as a main component were reacted with a sulfuric acid catalyst to obtain a hydrocarbon having a high isoparaffin content.

RFG: A desulfurized heavy naphtha was reacted with a solid reforming catalyst using a moving bed reactor to obtain a fraction (reformed gasoline) reformed to a hydrocarbon having a high aromatic content.
AC7: A relatively light reformate gasoline, and the RFG obtained as described above was further subjected to distillation separation to obtain a fraction containing 95% by volume or more of a hydrocarbon having 7 carbon atoms.
ETBE: Isobutylene and ethanol were reacted with a catalyst to give ethyl t-butyl ether, and a purity of about 95% was used. Two types of PHe values of 1.5 and 5.6 were used.
ETOH: Fermented ethanol (99 degrees first grade) manufactured by Nippon Alcohol Sales Co., Ltd. was used. The PHe value was 7.8.
Table 1 shows the properties of the gasoline base material.

The gasoline base materials shown in Table 1 were blended at the blending ratio shown in the upper part of Table 2 to prepare gasolines that were Examples 1 and 2 and Comparative Examples 1, 2, and 3. In Examples 1 and 2 and Comparative Example 3, 2 ppm of a fatty acid rust inhibitor was added. Table 2 shows the properties of the prepared gasoline.
Regarding the properties in Tables 1 and 2, the research octane number was measured in accordance with JIS K 2202, the vapor pressure in JIS K 2258, and the distillation property in accordance with JIS K 2254. The sulfur content was measured by the microcoulometric titration method of JIS K2541. The thiol sulfur compound content (in terms of sulfur) was measured using a Shimadzu gas chromatograph equipped with a ANTEK sulfur compound luminescence detector that selectively detects and quantifies sulfur compounds by chemiluminescence. The hydrocarbon component composition was measured in accordance with JIS K 2536 “How to obtain all components by gas chromatography” using a PIONA device manufactured by Hured Packard. The PHe measurement was performed according to ASTM D 6423. 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.

In addition, as an acceleration test, two commercial passenger cars with different specifications (test car A and test car B) and chassis dynamo equipment were used, and after leaving the test car at room temperature at 25 ° C for more than 5 hours, the automatic driving device of Horiba (Acceleration time) The acceleration time is measured from the initial speed of 0 (km / hour) to the vehicle speed of 50 (km / hour) when the acceleration is accelerated to 50% by using (ADS7000). The relative improvement rate with Comparative Example 1 was shown. Table 3 shows typical specifications of the test vehicle A and the test vehicle B.
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

  Rust prevention was performed according to ASTM D665 and JIS K2510. Specifically, 300 mL of a sample and 30 mL of purified water are prepared in a predetermined glass container, and a steel round bar test piece is immersed therein, and the mixed solution is stirred at 1000 rpm for 24 hours at 38 ° C. The degree of corrosion of the pieces was evaluated according to the criteria in Table 4.

  The gasoline composition of the present invention has a high octane number by utilizing an oxygen-containing compound having a specific acidity (PHe) and finely adjusting the distillation properties, aromatic hydrocarbons, isoparaffin components, and the like. However, the acceleration performance when the vehicle is cold can be maintained without adversely affecting the fuel system member due to the oxygen-containing compound. Therefore, it is useful as an excellent gasoline composition for automobiles.

Claims (3)

An oxygen-containing compound having an acidity (PHe) of 3 or more is contained in an oxygen content of 0.1 to 4.5% by mass, a vapor pressure at 37.8 ° C. is 50 to 90 kPa, and a 50% distillation temperature is 85 to 103. C., aromatic content is 35% by volume or less, isoparaffin content is 30% by volume or more, research octane number is 91.5 or more, and the following formulas (1) and (2) are satisfied. Gasoline composition,
DI = 1.5 × T ₁₀ + 3 × T ₅₀ + T ₉₀ + 11 × OX ≦ 540 (1)
AR / IP ≦ 0.740 (2)
(In formula _{(1), T 10} 10% distillation temperature _{[℃], T 50} 50% distillation temperature _{[℃], T 90} represents a 90% distillation temperature [° C.], OX oxygen-containing (In the formula (2), AR represents the aromatic compound content [volume%], and IP represents the isoparaffin content [volume%].)   The gasoline composition according to claim 1, wherein the oxygen-containing compound is ethanol and / or a derivative thereof.   The gasoline composition according to claim 1 or 2, wherein the sulfur content is 10 ppm by mass or less, and the sulfur content based on thiols is 1.5 ppm by mass or less.