JP2006213897A - Lead-free high-octane gasoline - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead-free high-octane gasoline which is taken into consideration for air environment and excellent also in startability and operability of automobiles and cleaning property of intake valves. <P>SOLUTION: The lead-free high-octane gasoline contains 1-25 vol.% ethyl tertiary-butyl ether and has (1) 97-105 research octane number, (2) 84-92 motor octane number, (3) 45-93 kPa lead vapor pressure, (4) 75-110°C 50% distillation temperature, (5) 18-40 vol% distillation amount at 70°C, (6) ≤45 vol% aromatic content, (7) ≤25 vol% olefin content, (8) ≤1 vol% benzene content, (9) ≤10 mass ppm sulfur content, (10) 30-70 gas-liquid ratio (V/L) at 60°C and (11) ≤6 polycyclic aromatic index Y. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to unleaded high-octane gasoline, and in particular, has specified distillation characteristics and specified component composition, is environmentally friendly as a fuel for automobiles, and has startability, drivability, and cleanliness of intake valves. It is related to unleaded high octane gasoline excellent in

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).
In order to increase the weight of gasoline, to suppress deposits on the intake valves, and to reduce CO, THC, etc. in automobile exhaust gas, it is possible to use oxygen-containing compounds that are light and have a high octane number. As this oxygen-containing compound, for example, ethyl tertiary butyl ether (ETBE) and tertiary amyl methyl ether (TAME) (SAE 912313) are known in addition to the above-mentioned MTBE.
Gasoline blended with ETBE and blended with ETBE and regulated in terms of distillation properties, reduced emissions of harmful gases such as CO and NOx (see, for example, Patent Documents 3 and 4), distillation properties and steam Gasoline with reduced environmental impact by regulating pressure (see, for example, Patent Document 5), or gasoline with reduced intake valve deposit (IVD) production by regulating distillation properties, olefins, and aromatic content ( For example, Patent Document 6) is also known. However, these gasolines may still be unsatisfactory in terms of reducing deposit adhesion to the intake valve, operability, etc., and further improvements are desired.

Japanese Unexamined Patent Publication No. 7-207286 Japanese Patent Publication No. 5-53197 JP 2004-285204 A JP 2004-285205 A Japanese Patent Laid-Open No. 2004-292511 JP 2004-292510 A

  An object of the present invention is to provide an unleaded high-octane gasoline in which the startability and acceleration of an automobile and IVD generation are suppressed and the intake valve is excellent in cleanliness in consideration of the atmospheric environment.

As a result of intensive research to achieve the above object, the present inventors have selected ethyl tertiary butyl ether (ETBE), which is a light high-octane base material, and specified specific amounts of ETBE and specific component compositions and specifics. By configuring gasoline so as to have the distillation properties of the above, it is possible to obtain gasoline having excellent performance while improving the cleanliness of the intake valve while suppressing the aromatic content in the fuel oil. The inventors have found that the object can be achieved and have completed the present invention.
That is, the present invention provides an unleaded high octane gasoline characterized by containing 1 to 25% by volume of ethyl tertiary butyl ether (ETBE) and satisfying the following properties.
(1) Research octane number (RON) is 97-105
(2) Motor method octane number (MON) is 84 ~ 92
(3) Reed vapor pressure (RVP) 45 ~ 93kPa
(4) 50% distillation temperature (T50) is 75-110 ° C
(5) Distillation at 70 ° C (E70) is 18-40% 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 ) Gas-liquid ratio (V / L) at 60 ℃ is 30 ~ 70
(11) Polycyclic aromatic index represented by the following formula (1) is 6 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 polycyclic aromatics is the content in gasoline and indicates mass ppm.)

  The lead-free high-octane gasoline of the present invention is used in gasoline engines for automobiles and has excellent atmospheric environment conservation, excellent startability and drivability, and is intended to preserve atmospheric environment while maintaining practical performance. It is what 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.
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 1 to 25% by volume, preferably 3 to 20% by volume, more preferably 5 to 18% 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.

  (A) Research method octane number (RON) of unleaded high octane gasoline of the present invention is 97 to 105, preferably 97 to 102, (b) Motor method octane number (MON) is 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) If T50 and E70 are within the above ranges, it is possible to prevent a case where a problem occurs 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.

  The gas-liquid ratio (V / L) at 60 ° C. of the unleaded high octane gasoline of the present invention is 30 to 70, preferably 30 to 60. When this V / L is 30 or more, good startability can be ensured. In addition, by setting V / L to 70 or less, there is a possibility that defects in acceleration and drivability can be reduced. The V / L is a value measured according to ASTM D 2533-93a.

The lead-free high octane gasoline of the present invention has a polycyclic aromatic content index Y represented by the following 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) The content of (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 of 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 dimethylsilicon 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 It 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.

Although there is no restriction | limiting in particular about the base material used in order to manufacture unleaded high octane gasoline which has the above properties, For example, the following various fractions can be used as a 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, etc.) 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.
(G) Oxygenated compounds such as ethanol and propanol.

  The undiluted high-octane gasoline of the present invention can be selected by appropriately selecting the blending amount of the various fractions as described above according to the properties of the various fractions, etc. so as to satisfy the properties, and blending with ETBE as appropriate. Can be manufactured. For example, (I) ETBE 1-25% by volume, (II) RON 100 or more, MON 88 or more, RVP 30kPa or more, boiling point range 30-200 ° C debenzene catalytic reforming gasoline 2-50 capacity % Or (III) RON is 78 or more, MON is 70 or more, RVP is 85 kPa or more, debenzene light catalytic reforming gasoline having a boiling point range of 26-80 ° C is 2-15% by volume, RON is 101 or more, MON is 89 or more, RVP of 3 kPa or more, boiling point range of 90 to 200 ° C debenzene heavy catalytic reforming gasoline 2 to 50% by volume, and (IV) RON of 93 or more, MON of 81 or more, RVP of 90 kPa or more, The lead-free high-octane gasoline of the present invention can be produced by blending 10 to 50% by volume of light catalytic cracking gasoline having a boiling point range of 25 to 110 ° C. so as to satisfy the above properties. In addition, the composition of each substrate as described above has (V) 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, and ETBE were blended in the blending ratios shown in Table 3 to obtain gasolines having the properties listed 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. In this IVD test, the gasolines of Examples 1 and 2 and Comparative Examples 1 and 2 to which 150 ppm by volume of a polyisobuteneamine-based detergent was added were used.
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.

  From the above results, it is clear that the lead-free high-octane gasoline of the present invention is excellent in startability, operation performance, and intake valve cleanliness, and can maintain the atmospheric environment while maintaining practical performance.

Claims (1)

Lead-free high-octane gasoline containing 1 to 25% by volume of ethyl tertiary butyl ether (ETBE) and satisfying the following properties.
(1) Research octane number (RON) is 97-105
(2) Motor method octane number (MON) is 84 ~ 92
(3) Reed vapor pressure (RVP) 45 ~ 93kPa
(4) 50% distillation temperature (T50) is 75-110 ° C
(5) Distillation at 70 ° C (E70) is 18-40% 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 ) Gas-liquid ratio (V / L) at 60 ℃ is 30 ~ 70
(11) Polycyclic aromatic index represented by the following formula (1) is 6 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 polycyclic aromatics is the content in gasoline and indicates mass ppm.)