JP5147914B2 - Production method of unleaded gasoline - Google Patents

Description

  The present invention relates to unleaded gasoline, specifically has a specified distillation property and a specified component composition, is environmentally friendly as a fuel for automobiles, and has excellent startability, drivability, and cleanliness of an intake valve. It relates to unleaded gasoline.

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 gas (for example, Patent Document 2).
In order to increase the weight of gasoline, suppress deposit adhesion to the intake valve, and reduce CO, THC, etc. in automobile exhaust gas, it is possible to use an oxygen-containing compound that is light and has 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.
And gasoline blended with ETBE, blended with ETBE, and regulated the distillation properties to reduce 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) produced 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.

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

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

As a result of intensive studies 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 the following method for producing unleaded gasoline.
(I) 1 to 25% by volume of ethyl tertiary butyl ether (ETBE),
(Ii) 2-20% by volume debenzene catalytic reforming gasoline, or (iii) 2-10% by volume debenzene light catalytic reforming gasoline and 2-15% by volume debenzene heavy catalytic reforming gasoline,
(Iv) 30-70% by volume catalytic cracked gasoline, and (v) 5-30% by volume desulfurized light naphtha,
A method for producing unleaded gasoline containing three or more polycyclic aromatic components, wherein the method is adjusted so as to satisfy the following properties.
(1) Research method octane number (RON) of 89 to less than 97 (2) Motor method octane number (MON) of 79 to less than 87 (3) Reed vapor pressure (RVP) of 71 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 is 40 vol% or less (7) Olefin content is 30 vol% or less (8) Benzene content is 1 vol% or less (9) Sulfur content is 10 mass ppm or less (10 ) Gas-liquid ratio (V / L) at 60 ° C. is 50 to 70
(11) The polycyclic aromatic index represented by the following formula (1) is 4 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 ppm by mass.)

  The unleaded gasoline of the present invention is used in a gasoline engine of an automobile, has excellent air environment conservation, excellent startability and drivability, and can maintain the air environment while maintaining practical performance. It is. 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 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 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.

  The lead-free gasoline of the present invention has (a) a research octane number (RON) of 89 or more and less than 97, preferably 89 to 95, and (b) a motor method octane number (MON) of 79 or more and less than 87, preferably 79 to 85. If RON is 89 or more, it is possible to maintain high driving performance, and if MON is 79 or more, it is possible to prevent a decrease in anti-knock property at high speed running. Note that RON and MON are values measured in accordance with JIS K 2280.

  The lead vapor pressure (RVP) of the unleaded gasoline of the present invention is 45 to 93 kPa, preferably 50 to 90 kPa. By setting 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 lowered. In addition, this lead vapor pressure (RVP) is a value measured in accordance with JIS K 2258.

  The distillation properties of the unleaded 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) is 18 to If it is 40 volume%, Preferably it is 20-40 volume% and T50 and E70 are in the said range, the case where a malfunction arises in startability, operativity, and acceleration property can be prevented. These distillation properties are values measured according to JIS K 2254.

  The aromatic content of the unleaded gasoline of the present invention is 40% by volume or less, preferably 5 to 35% by volume. If the aromatic content is within 40% by volume, an increase in harmful components in the exhaust gas can be prevented. In addition, this aromatic content is the value measured based on the Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

  The olefin content of the unleaded gasoline of the present invention is 30% by volume or less, preferably 5 to 27% by volume. If the olefin content is within 30% by volume, a reduction in oxidation stability can be prevented. In addition, this olefin content is the value measured based on the Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

  The benzene content of the unleaded gasoline of the present invention is 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 an increase in the concentration of benzene in the atmosphere can be prevented and environmental pollution can be reduced. In addition, this benzene content is the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

  The sulfur content of the unleaded gasoline of the present invention is 10 mass ppm or less, preferably 8 mass ppm or less. If the sulfur content is within 10 ppm by mass, there is a possibility that it is possible to prevent the exhaust gas purification catalyst from lowering its capacity and to prevent the concentration of NOx, CO and THC in the exhaust gas from increasing. The sulfur content is a value measured according to JIS K2541.

  The gas-liquid ratio (V / L) at 60 ° C. of the unleaded 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. Further, by setting V / L to 70 or less, there is a possibility that problems in acceleration and drivability can be reduced. The V / L is a value measured according to ASTM D 2533-93a.

The unleaded gasoline of the present invention has a polycyclic aromatic content index Y represented by the formula (1) of 4 or less, preferably 3.5 or less, more preferably 3 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 tricyclic 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 deposit in the engine, and is polycyclic, such as 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 4 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 capillary column of dimethyl silicon having 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, injection 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 conditions of an inlet temperature of 300 ° C. and a detector temperature of 350 ° C.

Although there is no restriction | limiting in particular about the base material for manufacturing unleaded 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 from kerosene / light oil to atmospheric residual oil, preferably heavy gas oil or vacuum gas oil, conventionally known catalytic cracking method, especially fluid catalytic cracking method (UOP method, shell two-stage type) Decomposition with solid acid catalyst (for example, 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. Catalytic cracking gasoline.
(D) Desulfurized light naphtha, which is a light fraction obtained by distilling a straight-run naphtha obtained by desulfurizing straight-run naphtha obtained by atmospheric distillation of crude oil into a light fraction and a heavy fraction by distillation.
(E) An alkylate obtained by reacting isobutane with a lower olefin (butene, propylene, etc.) in the presence of an acid catalyst (sulfuric acid, hydrogen fluoride, aluminum chloride, etc.).
(F) C4 fraction 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.
(G) Isomerate obtained by isomerization of straight-chain lower paraffin hydrocarbons, isopentane obtained by precision distillation of isomerate, toluene, xylene obtained from catalytically reformed gasoline, or aroma having 9 or more carbon atoms Ingredients mainly composed of tribes.
(H) Oxygenated compounds such as ethanol and propanol.

  The unleaded gasoline of the present invention is produced by appropriately selecting the blending amounts of the above various fractions according to the properties of the various fractions so as to satisfy the above properties and appropriately blending with ETBE. be able to. For example, (I) ETBE is 1 to 25% by volume, (II) RON is 93 or more, MON is 83 or more, RVP is 30 kPa or more, and boiling point range is 28 to 200 ° C. % 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 to 80 ° C. is 2 to 10% by volume, RON is 101 or more, and MON is 89 or more, RVP is 3 kPa or more, debenzene heavy catalytic reformed gasoline having a boiling range of 90 to 200 ° C. is 2 to 15% by volume, and (IV) RON is 88 or more, MON is 77 or more, RVP is 40 kPa or more, 30 to 70% by volume of catalytically cracked gasoline having a boiling point range of 30 to 210 ° C, RON of 65 or more, MON of 62 or more, RVP of 75 kPa or more, and boiling point range of 25 The 100 ° C. desulfurization light naphtha 5-30 volume%, it is possible the producing unleaded gasoline blending to the present invention so as to satisfy the respective properties. In addition, the composition of each base material 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 gasoline of the present invention can also be produced by blending 3 to 20% by volume of an alkylate or 1 to 10% by volume of a C4 fraction mainly composed of butane and butenes so as to satisfy the above properties. .

  Furthermore, various additives can be appropriately blended in the unleaded 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 fractions (butane, butenes) produced from catalytic cracking equipment, catalytic reforming equipment or atmospheric distillation equipment, debenzene catalytic reforming gasoline, debenzene light catalytic reforming gasoline, debenzene heavy weight with properties shown in Table 2 By blending quality contact reformed gasoline, catalytic cracked gasoline, alkylate, desulfurized light naphtha, and ETBE at the blending ratio shown in Table 3, gasoline having properties described in Table 3 was obtained.

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, catalytic cracked gasoline, alkylate, and By blending desulfurized light naphtha at a blending ratio shown in Table 3, gasoline having properties described in Table 3 was obtained.

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

The startability, drivability, and demerit scores were evaluated under the conditions of a test temperature of 20 ° C. and a humidity of 50% using a vehicle with a displacement of 2 L, a direct injection system (DI), and an automatic transmission (AT).
In addition, the intake valve deposit (IVD) test was performed using a 1.5 L displacement, multipoint injection (MPI) type vehicle, and a chassis dynamo with 60-100 km / h acceleration / deceleration x 1,500 cycles (8,000 km) (Running) conditions.
These evaluations or 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)
After the engine was started, idling was performed for 10 seconds, and the time until the vehicle speed reached 40 km / h at an accelerator opening of 50% was evaluated.
(Demerit points)
Evaluation was performed according to a 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)
It evaluated by the deposit (IVD) weight and IVD score (Rating: CRC No. 16) adhering to the intake valve obtained by weighing the intake valve weight before and after operation. This Rating value indicates that the larger the numerical value, the smaller the IVD amount.

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

Claims (1)

(I) 1 to 25% by volume of ethyl tertiary butyl ether (ETBE),
(Ii) 2-20% by volume debenzene catalytic reforming gasoline, or (iii) 2-10% by volume debenzene light catalytic reforming gasoline and 2-15% by volume debenzene heavy catalytic reforming gasoline,
(Iv) 30-70% by volume catalytic cracked gasoline, and (v) 5-30% by volume desulfurized light naphtha,
A method for producing unleaded gasoline containing three or more polycyclic aromatic components, wherein the method is adjusted so as to satisfy the following properties.
(1) Research method octane number (RON) of 89 to less than 97 (2) Motor method octane number (MON) of 79 to less than 87 (3) Reed vapor pressure (RVP) of 71 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 is 40 vol% or less (7) Olefin content is 30 vol% or less (8) Benzene content is 1 vol% or less (9) Sulfur content is 10 mass ppm or less (10 ) Gas-liquid ratio (V / L) at 60 ° C. is 50 to 70
(11) The polycyclic aromatic index represented by the following formula (1) is 4 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 ppm by mass.)