JP4913431B2 - Unleaded high octane gasoline - Google Patents

Description

  The present invention relates to a gasoline blended with ethanol and ethyl tertiary butyl ether, and in particular has a specified distillation property and a specified component composition, is environmentally friendly as a fuel for automobiles, and has a startability, The present invention relates to unleaded high octane gasoline with excellent operability and cleanliness of intake valves.

In recent years, fuel oils for gasoline engines have been demanded that have a high octane number and excellent driving performance as well as excellent environmental performance.
In general, as a high-octane gasoline, a high octane number base material having a heavy and high aromatic content and a specific distillation property and component composition are known (see, for example, Patent Document 1).

In the case of this high-octane gasoline, the octane number of the high-boiling fraction is improved because a high-octane base material with a heavy aromatic content is added. However, the gasoline becomes heavier and produces deposits in the engine. In particular, there are concerns about deposits on the intake valves and influence on drivability.
In order to improve the heaviness of gasoline and the adhesion of deposits to the intake valve, it is considered important to add a light and high octane base material.

In addition, gasoline that contains methyl tertiary butyl ether (MTBE), which is an oxygen-containing compound, is known for reducing carbon monoxide (CO), total hydrocarbons (THC), and the like in automobile exhaust gases (for example, Patent Document 2).
However, there is concern about the environmental impact of MTBE, and now production and sales of gasoline containing MTBE are restrained in Japan. Since MTBE is a base material having a high octane number, when the mixing of MTBE is stopped, a high octane number base material is required instead. Among them, oxygen-containing organic compounds other than MTBE, which compensate for the decrease in octane number of gasoline and are considered to have a low environmental load, are attracting attention as new gasoline base materials. Among these, ethanol has a high octane number, does not contain aromatics and olefins, and has an advantage that it can be regarded as a renewable fuel when considered as biomass (see, for example, Non-Patent Document 1).

On the other hand, from the viewpoint of CO ₂ reduction, there is a discussion of mixing ethanol derived from biomass or ETBE derived therefrom with gasoline. However, if ethanol is added to gasoline in order to increase CO ₂ reduction, the azeotropic phenomenon of hydrocarbon and ethanol becomes prominent, and the operability and the like deteriorate due to the distorted distillation curve. It is known that there is. In order to avoid this, it is conceivable to blend ETBE obtained by reacting ethanol with isobutylene into gasoline. From the viewpoint of CO ₂ reduction by biomass mixing, it is necessary to blend a large amount of ETBE into gasoline. This will make the economy of gasoline production inferior.

  As a blend of ethanol and ETBE in gasoline, it contained 1 to 10% by volume of ethanol, 1 to 20% by volume of ethyl tertiary butyl ether, and 5.5% by volume or more of hydrocarbons having 4 carbon atoms. And gasoline compositions containing 1 to 3% by volume of ethanol and 0 to 20% by volume of ethyl tertiary butyl ether (for example, Patent Document 3 and Patent Document 4).

  Patent Document 3 has a problem that the content of light hydrocarbons is not reduced even when ethanol is added because the vapor pressure of ethanol is higher than that of gasoline produced only from conventional petroleum. Patent Document 4 examines the influence of the water content of ethanol, and has a problem of providing gasoline that hardly causes phase separation even when a relatively low concentration of ethanol is added. However, in any case, further improvement is required in terms of startability and acceleration of a vehicle using gasoline containing ethanol and ETBE.

Japanese Unexamined Patent Publication No. 7-207286 Japanese Patent Publication No. 5-53197 JP 2005-29760 JP 2005-29761 A "Automotive Fuels Reference Book" Second Edition, Owen, K.M. and Coley, T .; , P268 (1995)

  The present invention is an unleaded, high-octane gasoline blended with ethanol and ethyl tertiary butyl ether that is excellent in intake valve cleanliness, taking into account the atmospheric environment and suppressing the startability and acceleration of automobiles and the generation of IVD. Is intended to provide.

As a result of intensive studies to achieve the above object, the present inventors selected ethanol (EtOH) and ethyl tertiary butyl ether (ETBE), which are light high octane base materials, and EtOH and By configuring gasoline so that it has a specific amount of ETBE, a specific component composition and a specific distillation property, it improves the cleanliness of the intake valve while suppressing the aromatic content in the fuel oil, and is excellent It was found that gasoline having various performances was obtained, and that the above-mentioned object could be achieved, and the present invention was completed.
That is, the present invention provides the following lead-free high octane gasoline.
[1] 0.5 to 10.0% by volume of ethanol (EtOH), 0.5 to 15.0% by volume of ethyl tertiary butyl ether (ETBE) , including at least one of the following (i) and (ii) ,
(I) Research method octane number (RON) is 100 or more, motor method octane number (MON) is 88 or more, reed vapor pressure (RVP) is 30 kPa or more, and boiling point range is 30 to 200 ° C. 50% by volume
(Ii) A debenzene heavy catalytic reformed gasoline having a research octane number (RON) of 101 or higher, a motor octane number (MON) of 89 or higher, a Reid vapor pressure (RVP) of 3 kPa or higher, and a boiling point range of 90 to 200 ° C. 2-50% by volume
And the unleaded high octane gasoline characterized by satisfying the following properties.
(1) Research octane number (RON) of 97-105
(2) Motor method octane number (MON) is 84-92
(3) Reed vapor pressure (RVP) is 45 to 93 kPa
(4) 50% distillation temperature (T50) is 75 to 110 ° C
(5) 70 ° C. distillate (E70) is 18 to 40% by volume
(6) Aromatic content 45% or less (7) Olefin content 25% or less (8) Benzene content 1% or less (9) Sulfur content 10 mass ppm or less (10 ) The polycyclic aromatic index represented by the following formula (1) is 3.53 or less Y = (0.002 × 3R−A) + (0.01 × 4R−A) + (0.07 × 5R−A) ) + (0.2 × 6R + −A) (1)
(In the formula, 3R-A represents a 3-ring aromatic content, 4R-A represents a 4-ring aromatic content, 5R-A represents a 5-ring aromatic content, and 6R + -A represents an aromatic having 6 or more rings. (The aromatic content is the content in gasoline and indicates ppm by mass. )

  The lead-free high-octane gasoline of the present invention contains a specific amount of ethanol and ethyl tertiary butyl ether, is used in automobile gasoline engines, has excellent air environment conservation, and excellent startability and drivability. It is intended to preserve the atmospheric environment while maintaining practical performance. In addition, the higher the number of polycyclic aromatic components, the lower the content, and the lower the content, the less the formation of deposits in the engine, in particular, the prevention of deposit adhesion to the intake valve, and the harmful components in exhaust gas. The amount is further reduced.

Hereinafter, the contents of the present invention will be described in more detail.
Ethanol (EtOH) used in the lead-free high-octane gasoline of the present invention has a purity of 92.0% by volume or more, preferably 95.0% by volume or more, more preferably 99.5% by volume or more.
The method for producing ethanol is not particularly limited, and all generally produced ethanol can be used.
The ethanol content is in the range of 0.5% by volume or more and 10.0% by volume or less, preferably 1.0% by volume or more and 7.0% by volume or less, with respect to the total amount of ethanol-blended gasoline. If it is 0.5% by volume or more, the advantage of improving the octane number by blending with ethanol is obtained, and if it is 10.0% by volume or less, the evaporation characteristics may change significantly due to the azeotropic phenomenon with other gasoline base materials. Therefore, it is possible to ensure proper driving performance of gasoline cars.

  Any ethyl tertiary butyl ether (ETBE) used in the unleaded high octane gasoline of the present invention can be obtained from a known production method, and the production method is not particularly limited. The blending amount of ETBE in the unleaded high octane gasoline of the present invention is 0.5 to 15.0% by volume, preferably 1.0 to 10.0% by volume. If the blending amount of ETBE is within the above range, it is possible to reduce CO, THC, etc. in the exhaust gas without fear of an adverse effect on fuel consumption due to a decrease in calorific value.

  The lead-free high-octane gasoline of the present invention has (a) a research octane number (RON) of 97 to 105, preferably 97 to 102, and (b) a motor octane number (MON) of 84 to 92, preferably 84 to 90. If RON is 97 or higher, it is possible to maintain high driving performance, and if MON is 84 or higher, it is possible to prevent a decrease in anti-knock performance during high-speed driving. Note that RON and MON are values measured in accordance with JIS K 2280.

  The lead vapor pressure (RVP) of the unleaded high octane gasoline of the present invention is 45 to 93 kPa, preferably 50 to 90 kPa. By setting the RVP to 93 kPa or less, the amount of evaporative gas can be reduced, and by setting it to 45 kPa or more, it is possible to prevent the low temperature startability and warming performance from being deteriorated. This Reid vapor pressure (RVP) is a value measured according to JIS K 2258.

  The distillation properties of the lead-free high-octane gasoline of the present invention are as follows: (a) 50% distillation temperature (T50) is 75 to 110 ° C, preferably 75 to 105 ° C, (b) 70 ° C distillation amount (E70) When the T50 and E70 are within the above ranges, it is possible to prevent the occurrence of problems in startability, drivability, and acceleration. These distillation properties are values measured in accordance with JIS K 2254.

  The aromatic content of the unleaded high octane gasoline of the present invention is 45% by volume or less, preferably 5 to 45% by volume. When the aromatic content is within 45% by volume, an increase in harmful components in the exhaust gas can be prevented. The aromatic content is a value measured in accordance with the Petroleum Institute Method JPI-5S-33-90 (gas chromatographic method).

  The olefin content of the unleaded high octane gasoline of the present invention is 25% by volume or less, preferably 5 to 25% by volume. When the olefin content is within 25% by volume, a decrease in oxidation stability can be prevented. The olefin content is a value measured in accordance with the Petroleum Institute method JPI-5S-33-90 (gas chromatographic method).

  The lead-free high octane gasoline of the present invention has a benzene content of 1% by volume or less, preferably 0.8% by volume or less. If the benzene content is within 1% by volume, there is a possibility that the increase in benzene concentration in the atmosphere can be prevented and environmental pollution can be reduced. The benzene content is a value measured according to the Petroleum Institute method JPI-5S-33-90 (gas chromatographic method).

  The lead content of the lead-free high octane gasoline of the present invention is 10 ppm by mass or less, preferably 8 ppm by mass or less. If the sulfur content is within 10 ppm by mass, there is a possibility that the exhaust gas purification catalyst capacity can be prevented from being lowered and the concentration of NOx, CO and THC in the exhaust gas can be prevented from increasing. The sulfur content is a value measured according to JIS K 2541.

  In the lead-free high-octane gasoline of the present invention, the ratio of aromatics having 9 or more carbon atoms to the total aromatics (hereinafter also referred to as (C9 + A) / TA) is 0.80 or less, preferably 0.10 to 0.00. 80. It is preferable that the ratio of the aromatic component having 9 or more carbon atoms and the total aromatic component is 0.80 or less because it is possible to prevent the smoldering property of the plug from being lowered. The aromatic content is a value measured in accordance with the Petroleum Institute Method JPI-5S-33-90 (gas chromatographic method).

The lead-free high octane gasoline of the present invention has a polycyclic aromatic content index Y represented by the formula (1) of 6 or less, preferably 5.5 or less, more preferably 5 or less.
Y = (0.002 × 3R-A) + (0.01 × 4R-A) + (0.07 × 5R-A) + (0.2 × 6R + -A) ... (1)
[In the formula, 3R-A is a 3-ring aromatic content, 4R-A is a 4-ring aromatic content, 5R-A is a 5-ring aromatic content, 6R + -A is an aromatic content of 6 or more rings (both in gasoline) (Ppm by mass)
Here, the polycyclic aromatic index Y is an empirical formula obtained from the relationship between the content of polycyclic aromatics and the amount of deposits in the engine, and is composed of three rings, four rings, five rings, six rings or more. The higher the value is. This indicates that the increase in harmful components in the exhaust gas and the generation of deposits in the engine become higher as the polycycle increases.
If the index Y is 6 or less, it is possible to prevent an increase in harmful components in the exhaust gas and an increase in the generation of deposits in the engine. The polycyclic aromatic content is a value determined by the number of rings by the gas chromatographic method shown below, and the quantitative method is an absolute calibration curve method using typical standard samples by number of rings. . That is, a dimethyl silicon capillary column with a length of 30 m and an inner diameter of 0.25 mm is used as the column, the detector is a hydrogen ionization detector (FID), the carrier gas is helium at a flow rate of 1.3 ml / min, splitless injection, inlet temperature This is a value measured by raising the column temperature from the initial temperature of 50 ° C. to the final temperature of 350 ° C. under the conditions of 300 ° C. and detector temperature of 350 ° C.

The base material other than EtOH and ETBE for producing unleaded high octane gasoline having the above-described properties is not particularly limited. For example, the following various fractions can be used as the base material.
(B) Hydrogen stream by contact reforming method (Platforming method, Magnaforming method, Aromaizing method, Reforming method, Food reforming method, Ultraforming method, Powerforming method, etc.) for heavy straight-run naphtha, etc. In which the benzene fraction is removed by distillation from a reformed gasoline obtained by contact treatment with a catalyst (for example, platinum, rhodium and chlorine supported on an alumina carrier) at high temperature and pressure. Quality gasoline.
(B) The reformed gasoline obtained by contact treatment by the above catalytic reforming method is separated into light fraction, benzene fraction, and heavy fraction by distillation. Gasoline) and heavy fractions (debenzene heavy catalytic reforming gasoline).
(C) Petroleum fraction ranging from kerosene / light oil to atmospheric residual oil, preferably heavy gas oil or vacuum gas oil, is conventionally known catalytic cracking method, especially fluid catalytic cracking method (UOP method, shell two-stage type) Decomposition with a solid acid catalyst (eg, silica / alumina blended with zeolite) by the method, flexi cracking method, ultra ortho flow method, texaco method, Gulf method, ultra cat cracking method, RCC method, HOC method, etc. Light catalytic cracking gasoline obtained by distilling the catalytic cracking gasoline obtained in this way.
(D) An alkylate obtained by reacting isobutane and a lower olefin (butene, propylene, etc.) in the presence of an acid catalyst (sulfuric acid, hydrogen fluoride, aluminum chloride, etc.).
(E) C4 fractions mainly composed of butane and butenes obtained by distillation during the atmospheric distillation of crude oil or crude oil, during the production of reformed gasoline, or during the production of cracked gasoline.
(F) Isomerate obtained by isomerization of straight-chain lower paraffin hydrocarbons, or isopentane obtained by precision distillation of isomerate, toluene, xylene obtained from catalytically reformed gasoline, or fragrance having 9 or more carbon atoms Ingredients mainly composed of tribes.

  The unleaded high-octane gasoline of the present invention can be obtained by appropriately blending the various fractions as described above according to the properties of the various fractions so as to satisfy the properties and appropriately blending with EtOH + ETBE. Can be manufactured. For example, (I) EtOH is 0.5-10.0% by volume, (II) ETBE is 0.5-15.0% by volume, (III) RON is 100 or more, MON is 88 or more, RVP is 30kPa or more, and the boiling point range is 30 to 200 ° C. 2 to 50% by volume of debenzene-catalyzed reformed gasoline, or (IV) 2 or more of debenzene light-catalyzed reformed gasoline with RON of 78 or more, MON of 70 or more, RVP of 85 kPa or more, and boiling point range of 26-80 ° C 15% by volume, RON is 101 or more, MON is 89 or more, RVP is 3kPa or more, 2-50% by volume of debenzene heavy catalytic reforming gasoline with a boiling range of 90-200 ° C, and (V) RON is 93 or more , MON is 81 or more, RVP is 90 kPa or more, and light catalytic cracking gasoline having a boiling point range of 25 to 110 ° C. is blended so as to satisfy the above properties, and the unleaded high octane gasoline of the present invention is produced. be able to. In addition, the composition of each substrate as described above has (VI) RON of 93 or more, MON of 90 or more, RVP of 40 kPa or more, boiling range of 30 to 210 ° C., and C8 fraction of 65% by volume or more. The lead-free high-octane gasoline of the present invention is produced by blending 5 to 30% by volume of alkylate or 1 to 10% by volume of C4 fraction mainly composed of butane and butenes so as to satisfy the above properties. You can also.

  Furthermore, various additives can be appropriately blended in the lead-free high octane gasoline of the present invention as necessary. Such additives include phenolic and amine antioxidants, metal deactivators such as thioamide compounds, surface ignition inhibitors such as organophosphorus compounds, succinimides, polyalkylamines, polyetheramines. Detergents such as polyisobutylene amine, anti-freezing agents such as polyhydric alcohols and ethers thereof, organic metal alkali metal and alkaline earth metal salts, auxiliary alcohols such as higher alcohol sulfates, anionic surfactants, Known fuel additives include antistatic agents such as cationic surfactants and amphoteric surfactants, rust inhibitors such as alkenyl succinates, and colorants such as azo dyes. These can be added singly or in combination. The addition amount of these fuel additives is arbitrary, but usually the total addition amount is preferably 0.1% by mass or less.

  The content of the present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1 and 2
C4 fraction (butane, butenes) produced from catalytic cracking equipment, catalytic reforming equipment or atmospheric distillation equipment, debenzene catalyzed reformed gasoline, debenzene light catalytic reformed gasoline, debenzene heavy weight with properties shown in Table 2 Gasoline reforming gasoline, light catalytic cracking gasoline, alkylate, ETBE, and EtOH were blended at the blending ratios shown in Table 3 to obtain gasoline having the properties shown in Table 3.

Comparative Examples 1-3
C4 fraction (butane, butenes) described in Examples 1 and 2, debenzene catalytic reformed gasoline, debenzene light catalytic reformed gasoline, debenzene heavy catalytic reformed gasoline, light catalytic cracked gasoline, and alkylate Were blended at the blending ratios shown in Table 3 to obtain gasoline having the properties shown in Table 3.

  Various performance evaluation tests described below were performed using the gasoline obtained in the above Examples and Comparative Examples.

Startability, drivability, and demerit scores were evaluated using a 2L displacement, direct injection (DI), automatic transmission (AT) vehicle at a test temperature of 20 ° C and humidity of 50%.
In addition, the intake valve deposit (IVD) test was performed using a 1.5-liter, multi-point injection (MPI) type vehicle, and a chassis dynamo with 60-100 km / h acceleration / deceleration x 1,500 cycles (8,000 km travel). I went there.
These evaluations and test methods are described below, and the results are shown in Table 3.

(Startability)
It was evaluated by the time from the start of cranking to the complete explosion (time until the engine can continue to rotate on its own).
(Acceleration)
The engine was idled for 10 seconds after the engine was started, and the time until the vehicle speed reached 40 km / h with an accelerator opening of 50% was evaluated.
(Demerit points)
Evaluation was performed according to the CRC (Coordinating Research Council) Report No. 483 evaluation method.
The evaluation method was determined by the demerit score given by the degree of the phenomenon that occurred (Σ = demerit score × defect coefficient).
Note that stalls during idling and running were not calculated, and the respective coefficients were added. The smaller the score, the better the performance.

(IVD test)
Evaluation was made based on the weight of the deposit (IVD) adhering to the intake valve and the IVD rating (Rating: CRC No. 16) obtained by weighing the intake valve weight before and after operation. The rating value indicates that the larger the numerical value, the smaller the IVD amount.

(Plug smoldering test)
Using a vehicle with a total displacement of 2L, MPI method, automatic transmission (AT), and a test temperature condition of -10 ° C, about 30 minutes per cycle (engine start ⇒ 10-20 km / h acceleration / deceleration repeated 10 times ⇒ 28 The degree of fouling of the plug was measured by measuring the insulation resistance of the plug. It was determined that plug smoldering occurred when the plug insulation resistance value was 100 MΩ or less.

  From the above results, the lead-free high-octane gasoline of the present invention is blended with a specific amount of ethanol and ethyl tertiary butyl ether, and is excellent in startability, operation performance and cleanliness of the intake valve, while maintaining practical performance while maintaining the atmospheric environment It is clear that can be achieved.

Claims (1)

0.5 to 10.0% by volume of ethanol (EtOH), 0.5 to 15.0% by volume of ethyl tertiary butyl ether (ETBE) , including at least one of the following (i) and (ii)
(I) Research method octane number (RON) is 100 or more, motor method octane number (MON) is 88 or more, reed vapor pressure (RVP) is 30 kPa or more, and boiling point range is 30 to 200 ° C. 50% by volume
(Ii) A debenzene heavy catalytic reformed gasoline having a research octane number (RON) of 101 or higher, a motor octane number (MON) of 89 or higher, a Reid vapor pressure (RVP) of 3 kPa or higher, and a boiling point range of 90 to 200 ° C. 2-50% by volume
And the unleaded high octane gasoline characterized by satisfying the following properties.
(1) Research octane number (RON) of 97-105
(2) Motor method octane number (MON) is 84-92
(3) Reed vapor pressure (RVP) is 45 to 93 kPa
(4) 50% distillation temperature (T50) is 75 to 110 ° C
(5) 70 ° C. distillate (E70) is 18 to 40% by volume
(6) Aromatic content 45% or less (7) Olefin content 25% or less (8) Benzene content 1% or less (9) Sulfur content 10 mass ppm or less (10 ) The polycyclic aromatic index represented by the following formula (1) is 3.53 or less Y = (0.002 × 3R−A) + (0.01 × 4R−A) + (0.07 × 5R−A) ) + (0.2 × 6R + −A) (1)
(In the formula, 3R-A represents a 3-ring aromatic content, 4R-A represents a 4-ring aromatic content, 5R-A represents a 5-ring aromatic content, and 6R + -A represents an aromatic having 6 or more rings. (The amount of aromatics is the content in gasoline and indicates ppm by mass.)