JP3441305B2 - gasoline - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a high octane number, which can reduce the ozone generation ability of the gas discharged after combustion, has excellent acceleration performance at low temperatures, and can reduce the deposit in the combustion chamber. It is about gasoline.

[0002]

2. Description of the Related Art Engines for automobiles use nitrogen oxides (NO
x), hydrocarbon (HC), etc. When ultraviolet rays from the sun act on these NOx and HC,
A photochemical oxidant mainly composed of ozone is produced. In order to prevent the generation of photochemical oxidants, the emission amount of NOx, HC, etc. emitted from automobiles has been regulated in the past, and in order to clear this regulation, measures such as mounting an exhaust gas purification catalyst have been implemented. ing.

Further, by reconsidering the properties of gasoline, which is a fuel, it has been devised to suppress the generation of HC and the like. JP-A-6-93275 and JP-A-6-192.
Japanese Patent No. 664 proposes a method for producing gasoline in which components having a high MIR value are removed (that is, the ozone index of the fuel is lowered) in order to reduce the ozone generation ability of exhaust gas.

[0004]

However, in order to lower the ozone index of fuel, "Maximum Incremental Reacti
It is necessary to use a base material that does not contain a component with a high MIR value by the "vity (MIR) method". Gasoline produced using only such a base material is used at low temperatures, which is particularly required for automobile fuel. However, this may cause adverse effects such as impairing the acceleration performance of the engine and increasing the amount of deposit (CCD) in the combustion chamber. When this deposit increases, the volume of the combustion chamber decreases, and the heat insulating effect of the deposit causes knocking.

Therefore, the ozone generation ability of the exhaust gas is low,
There has been a demand for gasoline that can satisfy the acceleration performance at low temperatures and the like that is required as a fuel for automobiles and that does not generate a deposit.

The subject of the present inventor is that (1) the ozone generation ability of exhaust gas is low, and (2) the acceleration performance at low temperature is satisfied,
(3) To provide gasoline with little deposit.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result,
When a gasoline composition having a specific composition / property was used, ozone generation ability of exhaust gas was remarkably reduced, acceleration performance at low temperature was improved, and deposit generation was reduced, and the present invention was reached. did.

The gasoline according to the present invention has specific distillation properties and aromatic hydrocarbon contents. That is, the gasoline according to the present invention has an octane number of 98 or more, a distillation property of gasoline having a 50% distillation temperature of 75 ° C to 95 ° C, a 97% distillation temperature of 155 ° C or less, and an aromatic carbonization. The content of hydrogen is 25 to 35% by volume, the content of aromatic hydrocarbon having 8 or more carbon atoms is 5% by volume or less, and the density is 0.73 to 0.75 g / cm ³ .

The gasoline of the present invention has an octane number of 98 or more, and therefore is a gasoline which can sufficiently exhibit the performance of a high-performance engine having a high compression ratio. This octane number is a value measured by the method specified in "octane number test method" of "JIS K 2280". At present, the upper limit of this octane number is
Usually, it is 104 or less.

The 50% distillation temperature of the gasoline of the present invention is 75 to 95 ° C. from the viewpoint of acceleration performance, particularly in cold weather.
And need to. If the 50% distillation temperature exceeds 95 ° C, the cold acceleration performance will deteriorate. When the 50% distillation temperature is lower than 75 ° C, not only the acceleration performance is deteriorated, but also vapor lock, percolation and the like are generated, which adversely affects the heat resistance performance. From this perspective, 50%
The distillation temperature is more preferably 77 to 95 ° C, further preferably 80 to 93 ° C.

The distillation property of 97% distillation temperature is 155.
It must be below ℃. If the 97% distillation temperature exceeds 155 ° C., the components with poor combustibility increase, and the deposit in the combustion chamber increases. From this viewpoint, it is more preferable that the end point is 180 ° C. or lower. In addition, the end point is 201 ° C. or higher for ordinary gasoline. The distillation property referred to in the present invention means a value measured by a method specified in "Fuel oil distillation test method" of "JIS K 2254".

The gasoline of the present invention contains 2 aromatic hydrocarbons.
It is 5-35% by volume, and the aromatic hydrocarbon having 8 or more carbon atoms is 5% by volume or less. Regarding aromatic hydrocarbons having 8 or more carbon atoms, in order to reduce the ozone generation ability of exhaust gas,
It is necessary to be 5% by volume or less, more preferably 1.5% by volume or less, and even more preferably 1.0% by volume or less. In addition, the case where the aromatic hydrocarbon having 8 or more carbon atoms is not contained (0% by volume) is included. This is 5
When it exceeds the capacity%, the ozone generation ability of the exhaust gas becomes high.
At the same time, reducing the amount of aromatic hydrocarbons having 8 or more carbon atoms has the effect of reducing NOx in the waste gas. In this sense, the amount is 5% by volume or less.

The reason why the ozone generating ability can be remarkably reduced by setting the content of the aromatic hydrocarbon component having 8 or more carbon atoms to 5% by volume or less can be considered as follows. The aromatic hydrocarbon component having 8 or more carbon atoms has not only a high boiling point but also
Hard to burn. Such a component having a high boiling point is likely to adhere to the intake pipe, the intake valve, and the like. Since the engine speed is increased at the time of acceleration, these components are particularly likely to adhere to the intake pipe, intake valve and the like. When the amount of this adhered substance increases, it is introduced into the engine as a liquid flow, so that the components of gasoline that are unburned and discharged into the atmosphere relatively increase. Therefore, it is considered that the ozone generating ability is increased.

As for the content of aromatic components, the gasoline of the present invention has an aromatic content of 25 to 35% by volume.
The range is. If the content of the aromatic component exceeds 35% by volume, the components used in the gasoline system of the automobile may be adversely affected. Further, by setting the content of the aromatic component to 25% by volume or more, the acceleration performance during cold time is further improved. The content of the aromatic component mentioned here is a value measured by the "fuel hydrocarbon component test method (fluorescent indicator adsorption method)" defined in "JIS K2536".

In order to produce gasoline having such properties, the following base materials can be mixed, for example. The types and properties of the base material suitable for carrying out the present invention will be described. The components of this suitable base material consist of the following four components (A) to (D).

(A) A boiling point of 25 ° C. to 1 obtained by distilling a gasoline fraction obtained by fluid catalytic cracking.
At least one of fluid catalytic light cracking gasoline in the range of 15 ° C and aliphatic hydrocarbon containing isopentane as a main component. (B) alkylate. (C) At least one of a toluene fraction and a catalytically reformed gasoline (reformate). (D) At least one of methyl-t-butyl ether and methyl-t-amyl ether.

The fluid catalytic light cracking gasoline (A) that can be used in the present invention is a wide range of petroleum fractions ranging from kerosene gas oil to atmospheric residual oil, preferably heavy gas oil and vacuum gas oil, which are solid acid decomposed by a fluid catalytic cracking method. It is a light fraction of catalytically cracked gasoline obtained by cracking with a catalyst. Research method octane number 9
It is preferable to use fluid catalytically cracked light cracked gasoline having properties of 2 to 97 and a boiling point range of 25 to 115 ° C.

As the aliphatic hydrocarbon (A) containing isopentane as a main component, research octane number 88 to 88 is obtained.
It may be 95. Particularly, a fraction obtained by precision distillation separation of light naphtha, preferably desulfurized light naphtha can be preferably used. This precision distillation is included in the raw materials 20
The conditions may be appropriately selected such that about pentavol% of isopentane is obtained in a purity range of 90 to 95%. Isopentane mainly acts as a component for adjusting the octane number of the light fraction. The content of the component (A) is preferably 1 to 50% by volume, more preferably 20 to 40% by volume.

The alkylate (B) is obtained by reacting isobutane and a lower olefin (butene, propylene, etc.) in the presence of an acid catalyst (sulfuric acid, hydrofluoric acid, aluminum chloride, etc.). . Although various alkylates can be used in the present invention,
Those containing 60% by volume or more of isooctane are preferable, and among these, those having a research octane number of 92 or more can be preferably used. The content of the component (B) is 1 to 6
It is preferably 0% by volume, particularly preferably 10 to 50% by volume.

If the fraction of 155 ° C. or higher contained in alkylate exceeds 20% by volume, the 97% distillation temperature of the product will be 1%.
It becomes difficult to control the temperature to 55 ° C or lower. Therefore, 155
It is preferable to make the fraction at 0 ° C or higher 0 to 20% by volume,
It is particularly preferable to set it to 0 to 10% by volume.

As the toluene fraction (C), those obtained by catalytic extraction gasoline, or cracked gasoline co-produced during the production of ethylene, etc., by a solvent extraction method such as the sulfolane method can be used. The toluene fraction used in the present invention preferably has a purity of 95% by volume or more.

Further, the (C) catalytically reformed gasoline is obtained by catalytically treating heavy straight run naphtha and the like with a catalyst in a hydrogen stream under high temperature and pressure by a conventionally known catalytic reforming method. It is obtained by doing. In the present invention, a fraction having a research octane number of 95 or more and 155 ° C. or more is 1
Those of 0% by volume or less can be preferably used. If the fraction above 155 ° C exceeds 10% by volume, it will be difficult to keep the 97% distillation temperature of the product below 155 ° C. Therefore, 1
The fraction at 55 ° C. or higher is preferably 0 to 10% by volume, particularly preferably 0 to 5% by volume. The content of component (C) is 1
〜50% by volume, preferably 10-40% by volume
Is particularly preferable.

(D) Methyl-t-butyl ether (MT
As BE), it is preferable to use the one produced by reacting methanol and isobutene in the presence of an acid catalyst. Further, (D) methyl-t-amyl ether (TAME) is preferably prepared by reacting methanol and isopentene in the presence of an acid catalyst. These components (D) are mainly used as octane number improving components, but they have the effect of reducing the concentration of unburned hydrocarbons in the exhaust gas. By containing this component (D) in gasoline, the concentration of aromatic compounds can be reduced.

The same effect can be obtained by using either MTBE or TAME alone or by mixing both. The component (D) is usually added in the range of 3 to 15% by volume.

Of course, each of the above-mentioned components can be used regardless of the manufacturing method, as long as they have equivalent properties.

In addition to the above components, in order to secure a certain amount of vapor pressure and to maintain good engine startability, a fraction having 4 carbon atoms can be added in an amount of 0 to 8% by volume.

Further, the gasoline of the present invention may be blended with one or more fuel oil additives known in the art, if necessary. The blending amount of these can be appropriately selected, but it is usually preferable to maintain the total blending amount of the additives at 0.1% by weight or less. Examples of fuel oil additives that can be used in the gasoline of the present invention include phenol-based, amine-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organic phosphorus-based compound surfaces. Ignition inhibitor, detergent / dispersant such as succinimide, polyalkylamine and polyetheramine, antifreezing agent such as polyhydric alcohol or its ether, alkali metal salt or alkaline earth metal salt of organic acid, sulfuric acid of higher alcohol Combustion improver such as ester, anionic surfactant, cationic surfactant,
Examples thereof include antistatic agents such as amphoteric surfactants and colorants such as azo dyes.

[0028]

EXAMPLES The constitution and effects of the present invention will be described in more detail with reference to the following examples and comparative examples, but these do not limit the present invention in any way.

[Exhaust gas test] Of the test vehicle types shown in Table 1, a bluebird manufactured by Nissan Motor Co., Ltd. was used.
The exhaust gas test was conducted in the 10/15 mode and the 11 mode. The measurement items were ozone generating ability, carbon monoxide, total hydrocarbons, and NOx concentration. The ozone generation capacity is
ximum Incremental Reactivity (MIR) method ”was used for the calculation.

[0030]

[Formula 1] Ozone generation capacity (gO ₃ / gNMOG) = Σ [NMOGi (g
/ Mile) × MIRi (gO ₃ / gNMOG)] / ΣNMOGi (g / mile)

In the formula, "NMOGi" is the amount of the component i of non-methane organic gas (abbreviated as NMOG). Here, the non-methane organic gas means a hydrocarbon compound having 12 or less carbon atoms and not containing oxygen, excluding methane in exhaust gas, and an oxygen-containing hydrocarbon compound having 5 or less carbon atoms (ketone, aldehyde, alcohol,
Ether etc.) is a general term. “MIRi” is the MIR of each component i and is determined by the type of each component. The amount “NMOGi” of each non-methane organic gas component i is
It was quantified by gas chromatography and high performance liquid chromatography, respectively.

[0032]

[Table 1]

[Acceleration Test] The roadster manufactured by Mazda Motor Corporation shown in Table 1 was used. For cold acceleration, a test vehicle was placed in a temperature-controlled room and allowed to stand overnight at a constant temperature of 25 ° C. After that, start the engine of the test car on the chassis dynamo (load condition is set to road load), and
The time required to accelerate from 0 to 120 km / h at the throttle opening was measured and evaluated. The warm-up acceleration is
After sufficient warming up, the engine was restarted and tested as above.

[Deposit (CCD) generation test] A commercially available engine shown in Table 1 was installed on an engine bench, and a total of 5
After repeating the following driving cycle continuously for 0 hours,
The deposit accumulated in the combustion chamber was collected and weighed. The running mode was 240 seconds per cycle. The load condition was load. Initially, the engine speed is set to 1800 rpm, the engine speed is increased from 1800 rpm to 3000 rpm in the first 50 seconds, and from 3000 rpm to 180 rpm from 50 seconds to 100 seconds.
The speed was reduced to 0, and the speed was set to 1800 from the 100th to the 240th.

[Production of Gasoline and Test Results] The gasoline base materials shown in Table 2 were mixed at the mixing ratios shown in Tables 3 and 4 to produce gasolines of Examples and Comparative Examples. Tables 5 and 6 show the density, distillation property, research octane number, aromatic hydrocarbon ratio, and aromatic hydrocarbon ratio of 8 or more carbon atoms for each gasoline.

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

[Table 5]

[0040]

[Table 6]

The above-mentioned exhaust gas test, acceleration test and deposit generation test were carried out on the gasolines of these Examples and Comparative Examples, respectively. However, "acceleration test"
For clarifying the effect of 50% distillation temperature,
The regular gasolines of Test Examples 1 to 4 (research method octane number of about 90) were also tested. Table 7 shows the density and distillation properties of the gasoline of Test Examples 1 to 4. The test results are shown in Tables 8, 9 and 10.

[0042]

[Table 7]

[0043]

[Table 8]

[0044]

[Table 9]

[0045]

[Table 10]

As is clear from Table 8, the aromatic component having 8 or more carbon atoms in gasoline is within the range of the present invention and is 97%.
By setting the distillation temperature to 155 ° C. or lower, carbon monoxide (CO) and hydrocarbon (H
C) and ozone-forming ability were significantly reduced. In particular, the ozone production capacity of the gasoline of Example 1 was 2.6 g / test.
And contains a large amount of aromatic components having 8 or more carbon atoms, 97%
The value was remarkably low as compared with the gasoline of the comparative example whose distillation temperature exceeded 155 ° C.

Table 9 shows the results of acceleration performance.

Examples 1 and 2, Comparative Example 1, Comparative Examples 6-8,
From the results of using the gasolines of Test Examples 1 to 4 having the properties shown in Table 7, the 50% distillation temperature was 75 to 95.
℃, preferably 77 to 95 ℃, more preferably 80 to 9
Good cold acceleration is obtained in the range of 3 ° C. Similar results are obtained with the gasoline of the present invention.

As can be seen from these results, the gasoline of the present invention has excellent accelerating performance both during cold and warm-up, and particularly during cold. Further, as can be seen from Table 10, the temperature of the end point greatly affects the deposit (CCD) together with the amount of the aromatic hydrocarbon having 8 or more carbon atoms. That is, when the 97% distillation temperature increased, the deposit amount increased remarkably.

[0050]

INDUSTRIAL APPLICABILITY The present invention provides a gasoline having a specific aromatic component composition and a specific distillation property. As a result, the acceleration performance at low temperature is better than that of conventional gasoline. Exhaust gas ozone generation capacity is low,
It became extremely advantageous for pollution control. Therefore, the gasoline of the present invention can be expected to be widely and effectively used as a fuel oil for a gasoline engine having low pollution and high performance.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-4-117492 (JP, A) JP-A-7-179868 (JP, A) JP-A-7-97582 (JP, A) JP-A-6- 192664 (JP, A) JP-A-6-93275 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C10L 1 / 06,1 / 18

Claims (2)

(57) [Claims] 1. A gasoline having an octane number of 98 or more, the distillation property of which is 50% at a distillation temperature of 75 ° C.
Is to 95 ° C., and 97% distillation temperature is at 155 ° C. or less, the content of the aromatic hydrocarbon is 25 35 vol%, the content of number 8 or more aromatic hydrocarbon carbon 5 volume %
Hereinafter der is, density, characterized in 0.73-0.75g / cm ³ der <br/> Rukoto, gasoline. 2. The boiling point of (A), which is obtained by distilling the gasoline fraction obtained by fluid catalytic cracking, is from 25.degree.
At least one of a fluid catalytic light cracking gasoline in the range of 115 ° C. and an aliphatic hydrocarbon containing isopentane as a main component, (B) an alkylate, (C) at least one of a toluene fraction and a catalytically reformed gasoline, and (D) Methyl-
The gasoline according to claim 1, which contains at least one of t-butyl ether and methyl-t-amyl ether.