JP4856992B2 - Unleaded gasoline - Google Patents

Description

  The present invention relates to a contact reformed gasoline and an unleaded gasoline using a base material obtained from the same, and more specifically, a contact reformed gasoline that provides unleaded gasoline excellent in cleanliness in an engine such as a combustion chamber and an intake valve, and The present invention relates to unleaded gasoline having the above-mentioned excellent performance using it as a base material.

In recent years, environmental pollution due to exhaust gas from automobiles and the like has been attracting attention from the viewpoint of environmental improvement, and various efforts have been made to reduce exhaust gas from the fuel surface. Specifically, it is considered effective to reduce exhaust gas from automobiles or evaporative gas from fuel.
In general, in order to reduce exhaust gas, it is known that installation of an exhaust gas purification catalyst system in an automobile is effective. It is also known that reducing the sulfur content of the fuel leads to a longer life of the exhaust gas purification catalyst system and is effective in reducing exhaust gas. On the other hand, keeping the inside of the engine clean by improving the fuel oil is also considered effective in reducing exhaust gas. Specifically, it is considered effective to suppress intake valve deposit (IVD) and combustion chamber deposit (CCD).

  In general, reformed gasoline used as a high-octane base material in the production of unleaded gasoline contains a lot of aromatic components, but it is known that IVD tends to increase when a lot of aromatic components are contained ( For example, refer nonpatent literature 1). Generally, a detergent such as polyetheramine or polyisobutene is added to reduce the IVD, but the CCD tends to increase when the detergent is added. In view of this, as a fuel that suppresses both IVD and CCD of a gasoline engine, a fuel that defines the aromatic content and the distillation property of gasoline has been proposed (see, for example, Patent Document 1). However, this technique has a problem in that the gasoline yield decreases because the blending amount of the heavy fraction is reduced in order to make the distillation property of gasoline light.

SAE Paper, Society of Automotive Engineers 922217 JP 2000-204383 A

  An object of the present invention is to provide a catalytic reformed gasoline that enables the production of unleaded gasoline that can suppress both IVD and CCD of a gasoline engine while using a heavy fraction as a high octane base material, and using this It is to provide unleaded gasoline obtained.

  As a result of intensive studies, the present inventors have obtained catalytic reformed gasoline using a desulfurized heavy naphtha fraction having a constant property, and further, the polycyclic aromatic content of the catalytic reformed gasoline is within a certain range. It was found that the above-mentioned object can be achieved by adjusting the content so that the content of the ring is gradually reduced as the number of rings increases.

That is, the present invention is to provide the following non-lead gasoline.
(1) A desulfurized heavy naphtha fraction having a sulfur concentration of 5 mass ppm or less and a nitrogen concentration of 5 mass ppm or less, obtained by desulfurizing a heavy straight-run naphtha having a 90% by volume distillation temperature of 160 ° C. or less. catalytic reforming process and obtained, the following 1) to 5) gasoline components derived from a tangent Sawaaratameshitsu gasoline you satisfy properties listed are formulated 2-40% by volume,
1) Research method octane number is 89-118,
2) Motor method octane number is 79-108,
3) Boiling range is 28-215 ° C,
4) Reed vapor pressure is 20-60kPa,
5) Polycyclic aromatic content index Y represented by the following formula (I) is 20 or less,
Y = (0.002 × 3R-A) + (0.01 × 4R-A) + (0.07 × 5R-A) + (0.2 × 6R + -A)… (I)
[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) shows the mass ppm) at a content of]
Unleaded gasoline, characterized in that it satisfies the properties listed in a) ~ l) below.
a ) Research octane number of 89-97,
b ) Motor method octane number is 79-85,
c ) 50% by volume distillation temperature is 75-110 ° C,
d ) 90% by volume distillation temperature is 180 ° C or less,
e ) Distillation at 70 ° C is 18-40% by volume,
f ) Reed vapor pressure is 45 to 93 kPa,
g ) Gas-liquid ratio at 60 ° C. is 30 to 70,
h ) Density at 15 ° C. of 0.68 to 0.78 g / cm ³ ,
i ) Aromatic content is 40% by volume or less,
j ) Olefin content is 30% by volume or less,
k ) benzene content is 1% by volume or less,
l ) Sulfur content is 10 mass ppm or less ( 2 ) The gasoline base material is a debenzene-catalyzed reformed gasoline obtained by debenzene treatment of the catalytic reformed gasoline ( 1) Unleaded gasoline as described in).

  According to the contact reformed gasoline and the unleaded gasoline of the present invention, the generation of deposits in the combustion chamber and the intake valve in the engine can be simultaneously suppressed without reducing the gasoline, and the cleanliness in the engine can be improved.

Hereinafter, the contents of the present invention will be described in more detail.
The catalytically reformed gasoline of the present invention is obtained by desulfurizing heavy straight-run naphtha having a 90 vol% distillation temperature of 160 ° C. or less obtained by an atmospheric distillation apparatus, with a sulfur concentration of 5 mass ppm or less and a nitrogen concentration of 5 It can be obtained by catalytic reforming of desulfurized heavy naphtha with mass ppm or less.
The 90 vol% distillation temperature of the heavy straight-run naphtha used for obtaining the desulfurized heavy naphtha is 160 ° C or lower, preferably 135 to 160 ° C, more preferably 140 to 150 ° C. By setting the 90 vol% distillation temperature to 160 ° C or less, it is possible to prevent the catalytic reformed gasoline from becoming heavy. Furthermore, by setting the 90% by volume distillation temperature range to 135 ° C. or higher, the catalytic reformed gasoline when the benzene fraction is removed can be increased in octane number, which is more preferable. This distillation property is a value measured according to JIS K 2254.

In addition, desulfurization treatment of heavy straight-run naphtha is generally performed in the presence of a desulfurization catalyst in which a group VI or VIII metal is supported on an inorganic carrier, with a reaction pressure of 0.1 to 10 MPa, preferably 1 to 3 MPa, and a reaction temperature. The desulfurization reaction is performed at 200 to 450 ° C., preferably 250 to 350 ° C., and the liquid space velocity (LHSV) is 0.1 to 20 hr ⁻¹ , preferably 0.5 to 10 hr ⁻¹ .
The sulfur concentration of the resulting desulfurized heavy naphtha is 5 ppm by mass or less, preferably 1 ppm by mass or less, and the nitrogen concentration is 5 ppm by mass or less, preferably 1 ppm by mass or less. If the sulfur concentration and the nitrogen concentration are each 5 ppm by mass or less, deactivation of the catalytic reforming catalyst can be prevented. The sulfur concentration is a value measured according to JIS K2541 microcoulometric titration method, and the nitrogen concentration is a value measured according to JIS K2609 chemiluminescence method.

The catalytic reformed gasoline of the present invention is obtained by catalytically reforming the above desulfurized heavy naphtha so that the polycyclic aromatic content index Y represented by the following formula (I) is 20 or less.
Y = (0.002 × 3R-A) + (0.01 × 4R-A) + (0.07 × 5R-A) + (0.2 × 6R + -A)… (I)
[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)
The formula (I) of the polycyclic aromatic content index is an empirical formula obtained from the relationship between the content of the polycyclic aromatic content and the deposit amount in the engine, and includes three rings, four rings, five rings, and six rings. The higher the value, the higher the value. 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. The polycyclic aromatic content index Y in the catalytic reformed gasoline is 20 or less, preferably 15 or less, more preferably 12 or less. If it is 20 or less, an increase in harmful components in exhaust gas and an increase in engine deposits can be prevented.

  The polycyclic aromatic content is a value obtained by quantification according to the number of rings by the gas chromatographic method shown below, and the quantification method is an absolute calibration curve method using a typical standard sample according to the 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 catalytic reformed gasoline of the present invention has a research octane number (RON) of 89 to 118, preferably 89 to 115, and a motor octane number (MON) of 79 to 108, preferably 79 to 105. If the research method octane number and the motor method octane number are within this range, it is suitable for obtaining an unleaded gasoline composition having a so-called regular grade octane number. The catalytically reformed gasoline of the present invention has a boiling range of 28 to 215 ° C, preferably 28 to 210 ° C, and a Reed vapor pressure (RVP) of 20 to 60 kPa, preferably 25 to 55 kPa. If the boiling point range and the lead vapor pressure are within this range, the unleaded gasoline can be prevented from becoming heavy.

  Contact reforming treatment of desulfurized heavy naphtha is performed by various contact reforming methods (Platform forming method, Magna forming method, Aromaizing method, Reforming method, Food reforming method, Ultra forming method, Power forming method, etc.) The desulfurized heavy naphtha can be subjected to contact treatment with a catalyst (for example, a material in which platinum, rhodium and chlorine are supported on an alumina carrier) in a hydrogen stream under high temperature and pressure.

The method for producing the unleaded gasoline of the present invention using the gasoline base material obtained from the catalytic reformed gasoline of the present invention is not particularly limited, but in general, the unleaded gasoline of the present invention is produced using the following various fractions. can do. Ie;
(A) Debenzene-catalyzed reformed gasoline obtained by removing a benzene fraction from the catalytic reformed gasoline of the present invention by distillation;
(B) The catalytic reformed gasoline of the present invention is divided into a light fraction, a benzene fraction, and a heavy fraction by distillation, and a light fraction (debenzene light catalytic reformed gasoline) and a heavy fraction (dehydrated) are separated. Benzene heavy contact reforming gasoline),
(C) Aromatic main catalytic reformed gasoline mainly composed of toluene or aromatics having 9 or more carbon atoms, obtained by distillation or extraction of the catalytic reformed gasoline of the present invention,
(D) Petroleum fractions ranging from kerosene / light oil to atmospheric residual oil, preferably heavy gas oil or vacuum gas oil, are conventionally known catalytic cracking methods, especially fluid catalytic cracking methods (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. Catalytic cracking gasoline,
(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 at the time of atmospheric distillation of crude oil, crude oil or the like, during the production of reformed gasoline, or during the production of cracked gasoline,
(G) Isomerate obtained by isomerization of linear lower paraffinic hydrocarbon, light naphtha, preferably desulfurized light naphtha, or isopentane obtained by precision distillation of isomerate,
Etc. are used as gasoline base materials.

The following examples are given as specific examples for producing the unleaded gasoline of the present invention by appropriately selecting and using the above various fractions. Ie;
(A ′) Research method octane number is 92 or more, motor method octane number is 82 or more, reed vapor pressure is 28 kPa or more, and boiling range is 28 to 215 ° C. b ') i) 0 to 25% by volume of debenzene light catalytic reformed gasoline having a research octane number of 78 or higher, a motor octane number of 70 or higher, a Reed vapor pressure of 85 kPa or higher, and a boiling point range of 26 to 80 ° C. And ii) 2 to 20% by volume of debenzene heavy catalytic reformed gasoline having a research octane number of 101 or higher, a motor octane number of 89 or higher, a Reid vapor pressure of 3 kPa or higher, and a boiling point range of 90 to 215 ° C., or (C ′) Aromatic substance mainly composed of toluene or aromatics having 9 or more carbon atoms, obtained by distillation or extraction of the catalytically modified gasoline or debenzene-heavy catalytically modified gasoline of the present invention 2-20% by volume of catalytic reformed gasoline, (b ') i) and (d') Research method octane number 87 or more, motor method octane number 76 or more, Reed vapor pressure 40 kPa or more, boiling range 30 10 to 70% by volume of catalytically cracked gasoline at ~ 215 ° C,
(G ′) 10-30% by volume of desulfurized light naphtha having a research octane number of 65 or more, a motor octane number of 62 or more, a reed vapor pressure of 80 kPa or more, and a boiling point range of 25 to 110 ° C.
The unleaded gasoline of the present invention can be produced by blending these so as to have the predetermined properties described later.
In addition, in the formulation of each substrate as described above,
(E ′) 0 to 30% by volume of an alkylate having a research octane number of 93 or higher, a motor octane number of 90 or higher, a lead vapor pressure of 40 kPa or higher, a boiling range of 30 to 210 ° C., and a C8 fraction of 65% by volume or higher. ,
May be further blended.

  The unleaded gasoline of the present invention is a gasoline base obtained from the catalytic reformed gasoline of the present invention, that is, at least one of the above-mentioned examples (a) to (c) (or (a ′) to (c ′)). And the total amount is 2 to 40% by volume, preferably 10 to 40% by volume. If the content is 2% by volume or more, the octane number of the unleaded gasoline can be improved, and if it is 40% by volume or less, the unleaded gasoline can be prevented from becoming heavy. The other undiluted fractions are appropriately selected, and the unleaded gasoline of the present invention is blended by appropriately setting the blending amounts according to the properties of the respective fractions so that the unleaded gasoline obtained has a predetermined property. Gasoline can be produced.

  The unleaded gasoline produced using the catalytic reformed gasoline of the present invention has a research octane number of 89 to 97, preferably 89 to 95, and a motor octane number of 79 to 85, preferably 80 to 84. If the octane number of the research method is 89 to 97, it is possible to maintain high driving performance as a so-called regular-class gasoline of the octane number, and if the octane number of the motor method is 79 to 85, the deterioration of the antiknock property at high speeds is prevented can do. The research method octane number and the motor method octane number are values measured in accordance with JIS K 2280.

  The unleaded gasoline of the present invention has a 50% by volume distillation temperature (T50) of 75 to 110 ° C, preferably 85 to 100 ° C, and a 90% by volume distillation temperature (T90) of 180 ° C or less, preferably 110 to 170. ° C. When the distillation temperature is within the above range, it is possible to prevent a problem in starting performance, operability, and acceleration. These distillation properties are values measured in accordance with JIS K 2254.

  The unleaded gasoline of the present invention has a 70 ° C. distillate (E70) of 18 to 40% by volume, preferably 20 to 40% by volume. If E70 is within the above range, it is possible to prevent a problem in starting performance, drivability and acceleration. These distillation properties are values measured in accordance with JIS K 2254.

  The lead vapor pressure of the unleaded gasoline of the present invention is 45 to 93 kPa, preferably 66 to 93 kPa. By setting the RVP to 93 kPa or less, the amount of evaporating gas can be reduced, and by setting it to 45 kPa or more, it is possible to prevent the low-temperature startability and the warm-up property from being deteriorated. The reed vapor pressure is a value measured according to JIS K 2258.

The density of the unleaded gasoline of the present invention at 15 ° C. is 0.68 to 0.78 g / cm ³ , preferably 0.69 to 0.76 g / cm ³ . When this density is 0.68 g / cm ³ or more, good fuel consumption can be ensured. Further, by setting the density to 0.78 g / cm ³ or less, high-density aromatics can be reduced, and the amount of aromatics discharged into the atmosphere by exhaust gas can be reduced. This density is a value measured in accordance with JIS K 2249.

  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. The aromatic content is a value measured according to the Petroleum Institute method JPI-5S-33-90 (gas chromatographic method).

  The olefin content of the unleaded gasoline of the present invention is 30% by volume or less, preferably 5 to 27% by volume. When the olefin content is within 30% by volume, it is possible to prevent a decrease in oxidation stability. The olefin content is a value measured according to the Japan Petroleum Institute method JPI-5S-33-90 (gas chromatographic 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 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 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 10 mass ppm or less, there is a possibility that the capacity reduction of the exhaust gas purification catalyst can be prevented. The sulfur content is a value measured according to JIS K 2541.

  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. 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.

  In the unleaded gasoline of the present invention, various additives can be appropriately blended 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. , Detergent dispersants such as polyisobutyleneamine, friction modifiers (FM) such as long chain alkylamines, amides, imides and derivatives thereof, anti-icing agents such as polyhydric alcohols and ethers thereof, alkali metals and alkaline earths of organic acids Metal salts, auxiliary agents such as sulfates of higher alcohols, anionic surfactants, cationic surfactants, antistatic agents such as amphoteric surfactants, rust inhibitors such as alkenyl succinates, and azo dyes Known fuel additives such as colorants can be used. 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.

  Furthermore, in the unleaded gasoline of the present invention, if necessary, an oxygen-containing compound such as ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary amyl ethyl ether (TAEE), or ethanol, Tertiary butyl alcohol (TBA) can be blended.

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

Examples and Comparative Examples Table 1 shows properties of desulfurized heavy naphtha, and Table 2 shows properties of catalytic reformed gasoline obtained by catalytic reforming of the desulfurized heavy naphtha. In Tables 1 and 2, desulfurized heavy naphtha α and catalytically reformed gasoline 1 obtained therefrom satisfy the properties of the present invention. On the other hand, desulfurized heavy naphtha β and catalytically reformed gasoline 2 obtained therefrom deviate from the properties of the present invention.
And each gasoline base material shown to Table 3, 4 was mixed in the ratio shown to Table 5, 6, unleaded gasoline was manufactured, and the various performance evaluation tests described below were done.
The density in the table was measured by JIS K 2249, and the aromatic content, olefin content, and benzene content were measured by the Petroleum Institute method JPI-5S-33-90 (gas chromatographic method).

  Intake valve deposit (IVD) test and combustion chamber deposit (CCD) test using a 1.5L displacement, multipoint injection (MPI) type vehicle with 60-100km / h acceleration / deceleration x 1,500 cycles The test was carried out under the conditions of (8,000 km travel). The method is described below, and the results are shown in Tables 5 and 6.

(IVD test)
Evaluation was made based on the weight of the deposit (IVD) attached to the intake valve and the IVD score (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.
(CCD test)
After the IVD test, the deposit (CCD) adhered to the cylinder head and the piston top was collected and weighed.

As specifically shown in the examples, deposits are particularly prevented from adhering to the intake valves. Therefore, the unleaded gasoline of the present invention is excellent in cleanliness inside the engine and can maintain the air environment while using heavy contact reformed gasoline as a high octane base material.

Claims (2)

Catalytic reforming of desulfurized heavy naphtha fraction with sulfur concentration of 5 mass ppm or less and nitrogen concentration of 5 mass ppm or less, obtained by desulfurization of heavy straight-run naphtha with 90 vol% distillation temperature of 160 ° C or less processing obtained are the following 1) to 5) gasoline components derived from a tangent Sawaaratameshitsu gasoline you satisfy properties listed are formulated 2-40% by volume,
1) Research octane number is 89-118
2) Motor method octane number is 79-108
3) Boiling range is 28 ~ 215 ℃
4) Reed vapor pressure is 20-60kPa
5) Polycyclic aromatic content index Y represented by the following formula (I) is 20 or less
Y = (0.002 × 3R-A) + (0.01 × 4R-A) + (0.07 × 5R-A) + (0.2 × 6R + -A)… (I)
[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)
An unleaded gasoline characterized by satisfying the properties listed in the following a) to l).
a) Research octane number of 89-97
b) Motor method octane number is 79-85
c) 50% volume distillation temperature is 75-110 ° C
d) 90% volume distillation temperature is 180 ° C or less
e) Distillation at 70 ° C is 18-40% by volume
f) Reed vapor pressure is 45 ~ 93kPa
g) Gas-liquid ratio at 60 ° C is 30 to 70
h) Density at 15 ° C. is 0.68 to 0.78 g / cm ³
i) Aromatic content is 40% or less
j) Olefin content is 30% by volume or less
k) Benzene content 1% or less
l) Sulfur content is 10 mass ppm or less The unleaded gasoline according to claim 1 , wherein the gasoline base material is debenzene contact reformed gasoline obtained by debenzene treatment of the contact reformed gasoline.