JP2010116469A - Gasoline composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasoline composition that contains ETBE and/or ETOH, can reduce a CO discharge amount during a cold engine operation and is slight in the discharge amount of carbon dioxide. <P>SOLUTION: The gasoline composition contains at least either one of ethyl tertiary butyl ether and ethanol, and has a total content of ethyl tertiary butyl ether and ethanol of 1-12 vol.%, a total sulfur content of at most 10 ppm by mass, 20-40 vol.% of an aromatics content, an index X, which is represented by the formula: index X=Ar9/Ar8 [wherein Ar8 is an 8C or lower aromatics content (vol.%); and Ar9 is a 9C or higher aromatics content (vol.%)], of at least 2.0, a Reid vapor pressure of at most 65 kPa, a research octane number of 98-110, and a 50% distillation temperature of 85.0-98.0°C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention contains a gasoline composition, particularly ethyl tertiary butyl ether (ETBE) and / or ethanol (ETOH), reduces carbon monoxide (CO) emissions in exhaust gas when cold, and It relates to gasoline compositions with low carbon emissions.

  CO in the exhaust gas of a gasoline engine is treated as a regulated substance because it adversely affects the human body such as headache, nausea and respiratory problems. On the other hand, with the recent progress of automobile exhaust gas purification technology, the CO emission amount at the time of warm-up is considerably reduced, but the reduction of the CO emission amount at the time of cold-down is not sufficient.

For example, ethyl tertiary butyl ether (ETBE) and ethanol (ETOH), which are oxygen-containing compounds, have a high octane number and have been reported to contribute to the reduction of CO emissions when used as a constituent material for gasoline. Yes. It has also been reported that plant-derived ETBE and ETOH contribute to the reduction of CO ₂ emissions in the sense of carbon neutral (see Patent Document 1 below). However, even if ETBE or ETOH is blended, the reduction of CO emissions and carbon dioxide emissions during cold operation is not sufficient.

On the other hand, aromatic compounds, which are the main constituent components of gasoline, have a high calorific value and a high octane number compared to other hydrocarbons, and are therefore frequently used as important constituent base materials for premium gasoline. However, it is known that when an aromatic compound is mixed in a large amount, exhaust gas properties deteriorate. (See Patent Document 2 below).
JP 2007-270037 A Japanese Unexamined Patent Publication No. 07-207286

  Accordingly, an object of the present invention is to provide a gasoline composition that solves the above-mentioned problems of the prior art, contains ETBE and / or ETOH, can reduce CO emissions during cold operation, and has low carbon dioxide emissions. It is in.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have obtained a gasoline composition containing ETBE and / or ETOH. The present inventors have found that CO emissions and carbon dioxide emissions can be reduced, and have completed the present invention.

That is, the gasoline composition of the present invention contains at least one of ethyl tertiary butyl ether (ETBE) and ethanol (ETOH), the total content of the ethyl tertiary butyl ether and ethanol is 1 to 12% by volume, and the total sulfur The content is 10 mass ppm or less, the aromatic content is 20 to 40% by volume, and the following formula:
Index X = Ar9 ÷ Ar8
[In the formula, Ar8 is an aromatic component (capacity%) having 8 or less carbon atoms, Ar9 is an aromatic component (capacity%) having 9 or more carbon atoms], the index X is 2.0 or more, lead The vapor pressure is 65 kPa or less, the research octane number (RON) is 98 to 110, and the 50% distillation temperature is 85.0 to 98.0 ° C.

  Further, the gasoline composition of the present invention preferably has an olefin content of 13.0% by volume or more.

  ADVANTAGE OF THE INVENTION According to this invention, the gasoline composition which contains at least one of ETBE and ETOH, can reduce CO emission amount at the time of a cold machine, and has little carbon dioxide emission amount can be provided. Furthermore, the gasoline composition of the present invention has the effect of improving the acceleration performance when cold.

[Gasoline composition]
The gasoline composition of the present invention contains at least one of ETBE and ETOH, and the total content of ETBE and ETOH is 1 to 12% by volume. From the viewpoint of reducing CO in the exhaust gas and improving the research octane number (RON), the total content of ETBE and ETOH needs to be 1% by volume or more, preferably 3% by volume or more, more preferably 5%. It is more than volume%. Further, from the viewpoint of suppressing the increase in NOx in the exhaust gas, and further from the viewpoint of suppressing the influence on the fuel supply system members of the already sold vehicles, the total content of ETBE and ETOH needs to be 12% by volume or less, Preferably it is 10 volume% or less, and especially 8 volume% or less.

  In the gasoline composition of the present invention, the olefin content is preferably 13.0% by volume or more, more preferably 13.5% by volume or more, particularly 14.0% by volume, from the viewpoint of RON improvement effect and acceleration performance during cold operation. That's it. Further, if the olefin content is too much, the oxidation stability of the gasoline composition may be deteriorated and the intake valve deposit may be increased. Therefore, the gasoline composition of the present invention preferably has an olefin content of 25.0% by volume. In the following, it is more preferably 20.0% by volume or less, particularly 18.0% by volume or less.

  The gasoline composition of the present invention has an aromatic content of 20 to 40% by volume. The aromatic component has an effect of improving the octane number. However, if the aromatic component exceeds 40% by volume, the plug is turned up and the volatility is deteriorated, and the acceleration performance during cooling is deteriorated. Further, since the exhaust gas properties are deteriorated when the aromatic content is too much, the aromatic content in the gasoline composition of the present invention is 40% by volume or less, preferably 38% by volume or less, more preferably 35% by volume. It is as follows. Further, if the aromatic content is less than 20% by volume, it is not preferable because the fuel consumption may be deteriorated due to a decrease in the calorific value. From the viewpoint of improving the fuel consumption, the aromatic content in the gasoline composition of the present invention is preferably 25% by volume. % Or more, more preferably 27% by volume or more.

  The benzene content in the gasoline composition is defined as 1% by volume or less according to the Quality Assurance Law, but from the viewpoint of preventing deterioration of exhaust gas properties, the benzene content in the gasoline composition of the present invention is 0.5% by volume. The following is preferable, and 0.4% by volume or less is particularly preferable.

The gasoline composition of the present invention has the following formula (1):
Index X = Ar9 ÷ Ar8 ≧ 2.0 (1)
It is a gasoline composition that satisfies Here, Ar8 is the content (volume%) of an aromatic compound having 8 or less carbon atoms, and Ar9 is the content (volume%) of an aromatic compound having 9 or more carbon atoms.

  The value of the above formula is the result of examining the relationship between the amount of each composition in the gasoline composition and the amount of CO emissions and carbon dioxide emissions during cold operation, and arranging the factors having a high internal correlation between factors as variables, This is an index found by the present inventors. When the value of the formula (1) (that is, the index X) is less than 2.0, the CO emission amount and the carbon dioxide emission amount at the time of cold cooling are greatly deteriorated. Therefore, the gasoline composition of the present invention has an index X of 2.0 or more, preferably 2.5 or more, more preferably 2.7 or more, particularly 3.0 or more. Although not particularly limited, the index X of the gasoline composition of the present invention is preferably 10.0 or less, and more preferably 8.0 or less.

  The gasoline composition of the present invention has a sulfur content of 10 mass ppm or less, preferably 5 mass ppm or less, more preferably 1 mass ppm or less. The sulfur content in the gasoline composition becomes sulfur oxides in the exhaust gas and poisons the nitrogen oxide removal catalyst. Therefore, as the sulfur content increases, more fuel is consumed to form a reducing atmosphere in order to restore the activity of the nitrogen oxide removal catalyst, causing deterioration in fuel consumption. Therefore, the fuel efficiency improves as the sulfur content in the gasoline composition decreases.

  The lead vapor pressure of the gasoline composition of the present invention is 65 kPa or less, more preferably 60 kPa or less, and particularly preferably 58 kPa or less for reducing evaporative gas. Here, the vapor pressure is a vapor pressure at 37.5 ° C. measured according to JIS K 2258 “Crude oil and fuel oil—Vapor pressure test method—Reed method”. Although not particularly limited, the lead vapor pressure of the gasoline composition of the present invention is preferably 45 kPa or more, and more preferably 50 kPa or more.

  The research method octane number (RON) of the gasoline composition of the present invention is 98 to 110, preferably 99 or more, and more preferably 100 or more, from the viewpoint of fuel efficiency improvement effect. In addition, if the RON is too high, the exhaust gas quality deteriorates due to an increase in aromatic content, or the distillation properties become heavier, which adversely affects the acceleration performance when cold, so the RON of the gasoline composition of the present invention Is 110 or less, preferably 105 or less, more preferably 101 or less, and particularly 100 or less.

  The 50% distillation temperature in the distillation properties of the gasoline composition of the present invention is 98.0 ° C. or less, preferably 97.0 ° C. or less, more preferably 96, from the viewpoints of acceleration during cooling and properties of exhaust gas. 0.0 ° C. or lower, particularly 95.0 ° C. or lower. Further, if the 50% distillation temperature is too low, the fuel efficiency is deteriorated. Therefore, the gasoline composition of the present invention has a 50% distillation temperature of 85.0 ° C or higher, preferably 87.0 ° C or higher, more preferably. 90.0 ° C or higher.

  The method for preparing the gasoline composition of the present invention described above is not particularly limited, and a known gasoline group such as desulfurized straight-run light naphtha, alkylate gasoline, catalytic cracked gasoline, or the like so as to satisfy the above-described component contents and physical properties. It can be prepared by appropriately blending ETBE or ETOH with the material.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  The gasoline base materials used in preparing the gasoline compositions as Examples and Comparative Examples are as follows.

DS-LG: A straight desulphurization naphtha obtained by hydrodesulfurizing a naphtha fraction of Middle Eastern crude oil and distilling off the light fraction.

IMFL: Gasoline fraction of 100 ° C or less obtained by catalytic cracking of indirect desulfurized gas oil obtained by hydrorefining a Middle Eastern crude oil with a fluidized bed reactor using a solid catalyst The fraction was obtained by distillation separation.

ALKG: A so-called alkylate gasoline obtained by alkylating a fraction containing butylene as a main component and a fraction containing isobutane as a main component using a sulfuric acid catalyst, and having a high carbon content of isoparaffin having 8 carbon atoms. Is the main component.

RFG: catalytic reforming gasoline derived from Middle Eastern crude oil.

-TOL: 99.5% purity toluene reagent product [Wako Pure Chemical Industries, Ltd.] was used.

AC-7: Desulfurized heavy naphtha is reformed with a solid catalyst using a moving bed reactor to obtain a hydrocarbon having a high aromatic content, that is, reformed gasoline. This is a light fraction obtained by distillation separation, that is, light reformed gasoline (AC-7), and contains 95% by volume or more of hydrocarbons having 7 carbon atoms.

AC-9: Heavy fraction obtained by distillation separation of reformed gasoline obtained by catalytic reforming of desulfurized heavy naphtha, that is, heavy reformed gasoline (AC-9), carbon The number 9 and 10 hydrocarbons are contained in 90% by volume or more, and the content of hydrocarbons having 11 or more carbon atoms is 5% by volume or less.

-ETBE: 95% pure reagent product [manufactured by Wako Pure Chemical Industries, Ltd.] was used.

-ETOH: Brazilian bioethanol was used.

  Table 1 shows the properties of the gasoline base material. These gasoline base materials were blended at a mixing ratio (volume%) shown in the upper part of Table 2, and gasoline compositions of Examples 1-2 and Comparative Examples 1-3 (referred to as test gasolines 1-5, respectively). Were prepared, and the exhaust gas properties and the acceleration performance during cold cooling were evaluated.

  In addition, the property of the gasoline base material shown in Table 1 and Table 2, and the property of the gasoline composition of an Example and a comparative example were measured with the following method.

Density: JIS K 2249 "Crude oil and petroleum products-Density test method"
-Octane number (RON): JIS K 2280 "Petroleum products-Fuel oil-Octane number and cetane number test method and cetane index calculation method" research method octane number test method-Vapor pressure (RVP): JIS K 2258 "Crude oil and fuel oil- Vapor Pressure Test Method-Lead Method "
・ Distillation properties: JIS K 2254 "Petroleum products-Distillation test method"
Composition component (hydrocarbon compound: olefin content, total aromatic content, aromatic content having 8 or less carbon atoms and aromatic content having 9 or more carbon atoms): Gas chromatography according to JIS K 2536 “Petroleum products-component test method” Law

  In addition, as for the technical standards related to the safety standards for road transport vehicles (October 1, 1981, Automobile No. 899), the vehicle was run based on the “Technical Standards for Gasoline Vehicle 10-Mode and 11-Mode Exhaust Gas Measurement” and discharged. The gas was measured. In Table 2, the value is described as 11 mode.

Furthermore, in order to evaluate the acceleration performance at the time of cold (hereinafter referred to as acceleration time), the gasoline composition of Examples 1 and 2 and Comparative Examples 1 to 3 was subjected to an acceleration performance test by an MPI test vehicle using a chassis dynamo device. Carried out. In the test, after the vehicle was kept 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 speed was 0 to 50 ( km / hour) until the vehicle speed was reached. The results (acceleration time increase rate) were compared based on the difference in acceleration time relative to the arrival time when commercial premium gasoline was used. The results are also shown in Table 2. The rate of increase in the acceleration time of the test gasoline is as follows:
Acceleration time increase rate (%) = (arrival time of test gasoline-arrival time of commercial premium gasoline) / (arrival time of commercial premium gasoline) x 100
Determined by

  From Table 2, in Examples 1 and 2, the index X described above was as large as 2.0 or more, and the carbon monoxide emission and the carbon dioxide emission were very low. On the other hand, in Comparative Examples 1 to 3, the index X is as low as less than 2.0, and it can be seen that the carbon monoxide emission and the carbon dioxide emission are larger than those in Examples 1 and 2.

  Examples 1 and 2 were accelerated because the aromatic content was 40% by volume or less, the RON was 110 or less, the 50% distillation temperature was 98.0 ° C. or less, and the olefin content was 13.0% by volume or more. The rate of time increase was a very low value, and the acceleration performance when cold was very good. On the other hand, in Comparative Example 3, the 50% distillation temperature exceeds 98.0 ° C. and the olefin content is less than 13.0% by volume, so that the acceleration time increase rate is extremely high compared to Examples 1 and 2. It can be seen that the acceleration performance when cold is bad.

Claims (2)

It contains at least one of ethyl tertiary butyl ether and ethanol, the total content of the ethyl tertiary butyl ether and ethanol is 1 to 12% by volume, the total sulfur content is 10 mass ppm or less, and the aromatic content is 20 to 40% by volume. And the following formula:
Index X = Ar9 ÷ Ar8
[In the formula, Ar8 is an aromatic component (capacity%) having 8 or less carbon atoms, Ar9 is an aromatic component (capacity%) having 9 or more carbon atoms], the index X is 2.0 or more, lead A gasoline composition having a vapor pressure of 65 kPa or less, a research octane number of 98 to 110, and a 50% distillation temperature of 85.0 to 98.0 ° C.   The gasoline composition according to claim 1, wherein the olefin content is 13.0% by volume or more.