JP2007177238A - Unleaded gasoline composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide unleaded gasoline composition attaining a high octane rating while containing catalytically cracked gasoline in a high mixing ratio to regular gasoline by enhancing octane rating without producing heavy products of the catalytically cracked gasoline (FCC). <P>SOLUTION: The unleaded gasoline composition comprises ≤10 ppm.mass of sulfur component, 10-25 vol.% of olefinic component, and has ≤96 of research octane number and ≤0.20 of (n-heptane + n-octane)/C6 olefin volumetric ratio. The preferable volumetric ratio of (n-heptane + n-octane)/cyclopentene is less than 5 and volumetric ratio of (n-heptane + n-octane)/methylcyclopentane is less than 0.8. The gasoline composition preferably has ≤1 in silver plate corrosion index, ≤2 ppm.mass of sulfur content derived from thiol, and ≤1 vol.% of benzene and 80-97°C of 50 vol.% distillate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an unleaded gasoline composition used for so-called regular gasoline having a research octane number of less than 96, and more particularly to a gasoline composition having a catalytically cracked gasoline base as a main component and a relatively high octane number.

  In general, regular gasoline is produced by blending gasoline base materials such as catalytically cracked gasoline, reformed gasoline, desulfurized naphtha, isomerized gasoline, alkylate gasoline and isopentane (Patent Document 1).

Background of CO ₂ reduction entry into force of the Kyoto Protocol, enhanced thermal efficiency of the vehicle engine, but to reduce the CO ₂ emissions have been studied, it is effective to increase the octane number of regular gasoline as a strategy Therefore (Non-Patent Document 1).
Japanese Patent Laid-Open No. 9-71789 2004 JCAPII Report

  In general, in order to increase the octane number of regular gasoline, it is necessary to increase the octane number of catalytic cracking gasoline (FCC gasoline), which is the main base material, and it is effective to increase the catalytic cracking reaction temperature. However, when the catalytic cracking reaction temperature is increased, olefins and aromatics increase, resulting in deterioration in oxidation stability, heavy distillation properties, and deterioration in vehicle driving performance and exhaust gas properties due to an increase in benzene content. Will be invited.

  In order to further improve the octane number of regular gasoline, instead of catalytic cracking gasoline, an aromatic base material having a relatively high octane number may be used in many cases. In this case, the aromatic base material has a relatively high boiling point. Since the distillation properties of regular gasoline become heavier and the volatility deteriorates, the drivability of the vehicle is deteriorated particularly when the engine is started. For this reason, 50% distillation temperature, 90% distillation temperature, etc. are lowered by using isopentane or isomerized gasoline having a low boiling point and a relatively high octane number. It is also effective to increase the octane number using an oxygen-containing compound such as ethanol or ETBE.

  However, among these, by increasing the octane number without increasing the weight of catalytic cracking gasoline, the problem of achieving a high octane number while maintaining a high ratio of the catalytic cracking gasoline to regular gasoline is maintained. I can't find what I'm looking at.

  As a result of intensive studies on the above problems, the present inventors have found that the octane number of the catalytic cracking gasoline base material can be improved by fractionating the catalytic cracking gasoline so as to control the ratio of the specific compound. Moreover, this can make the regular gasoline mixing ratio of catalytic cracking gasoline high. Furthermore, according to this method, the distillation property can be reduced.

  The catalytic cracking gasoline base material used in the present invention is a base material by catalytic cracking gasoline, and the ratio (volume ratio) of (n-heptane + n-octane) / (n-nonane + n-decane) is 3 or less and (n -Heptane + n-octane) / (n-pentane + n-hexane) ratio is 0.5 or less. “N-heptane + n-octane” is the sum of the contents of n-heptane and n-octane, and “n-nonane + n-decane” is the sum of the contents of n-nonane and n-decane. “N-pentane + n-hexane” is the sum of the contents of n-pentane and n-hexane. This catalytic cracking gasoline base material (hereinafter referred to as a low (nC7 + 8) catalytic cracking gasoline base material) can be obtained by fractionating and mixing the catalytic cracking gasoline as a raw material.

  The unleaded gasoline composition according to the present invention can be produced by blending 50 to 80% by volume of a low (nC7 + 8) catalytic cracked gasoline base and 50 to 20% by volume of another gasoline base.

  The lead-free gasoline composition according to the present invention has a sulfur content of 10 mass ppm or less, an olefin content of 10 to 25% by volume, a research octane number of less than 96, and an (n-heptane + n-octane) / C6 olefin ratio (volume ratio) of 0. .20 or less. The “C6 olefin” is the total content of unsaturated chain hydrocarbon compounds having 6 carbon atoms. Further, (n-heptane + n-octane) / cyclopentene ratio (volume ratio) is 5 or less, or (n-heptane + n-octane) / methylcyclopentane ratio (volume ratio) is 0.8 or less. Is preferred. Moreover, it is preferable that silver plate corrosion is 1 or less, the sulfur content by thiol is 2 mass ppm or less, benzene content is 1 volume% or less, or 50 volume% distillation temperature is 80-97 degreeC.

  The catalytic cracking gasoline base material or the unleaded gasoline composition using the same according to the present invention can improve the octane number of the catalytic cracking gasoline base material without changing the catalytic cracking process by setting the ratio of the specific compound within a predetermined range. . And since distillation property becomes light, the compounding quantity of the catalytic cracking gasoline base material to an unleaded gasoline composition can be raised.

[Catalytic cracking gasoline]
The process for producing the catalytic cracking gasoline fraction does not particularly limit the catalytic cracking apparatus, the feedstock oil, and the operating conditions, and any known production process can be employed. The catalytic cracker uses a catalyst such as amorphous silica alumina, zeolite, etc., in addition to petroleum fractions from light oil to vacuum gas oil, while being obtained from heavy oil indirect desulfurization equipment, it is obtained directly from delight oil and heavy oil direct desulfurization equipment. This is a device that obtains a high octane gasoline base material by catalytic cracking of degassed oil, atmospheric residue oil and the like. The raw material oil for catalytic cracking uses a fraction whose sulfur content is reduced to 4000 mass ppm or less, more preferably 2000 mass ppm or less, further 1000 mass ppm or less, particularly 500 mass ppm or less by hydrorefining or the like. It is preferable. For example, there are a fluid catalytic cracking method such as UOP catalytic cracking method, flexi cracking method, ultra ortho flow method, Texaco fluid catalytic cracking method, residual oil fluid catalytic cracking method such as RCC method, HOC method, etc. (Non-patent Document 2) ).
Petroleum Society, Petroleum Refining Process, p. 125, Kodansha Scientific (1998)

  The catalytic cracking gasoline base material (low (nC7 + 8) catalytic cracking gasoline base material) according to the present invention is a base material by catalytic cracking gasoline (FCC gasoline): (n-heptane + n-octane) / (n-nonane + n -Decane) ratio (volume ratio) is 3 or less and (n-heptane + n-octane) / (n-pentane + n-hexane) ratio is 0.5 or less. Can be obtained by fractional distillation and mixing. In this fractionation, the fraction taken out from the catalytic cracking apparatus may be fractionated, or a plurality of necessary fractions may be taken out from the fractionation tower inside the catalytic cracking apparatus and mixed.

  In the fractional distillation process, the catalytically cracked gasoline has an (n-heptane + n-octane) / (n-nonane + n-decane) ratio (volume ratio) of 2.5 or less and (n-heptane + n-octane) / (n- It is preferable to fractionate and mix so that the ratio of pentane + n-hexane) is 0.4 or less, more preferably (n-heptane + n-octane) / (n-nonane + n-decane) ratio of catalytically cracked gasoline Fractionation and mixing are performed so that the (volume ratio) is 2 or less and the (n-heptane + n-octane) / (n-pentane + n-hexane) ratio is 0.3 or less. Particularly preferably, the catalytically cracked gasoline has an (n-heptane + n-octane) / (n-nonane + n-decane) ratio (volume ratio) of 1 or less, more preferably 0.6 or less, and (n-heptane + n-octane). ) / (N-pentane + n-hexane) ratio is 0.2 or less, and further, fractional distillation and mixing are performed so that the ratio is 0.1 or less. The content of (n-nonane + n-decane) in the low (nC7 + 8) catalytic cracking gasoline base is preferably 0.1 to 1.0% by volume, particularly preferably 0.2 to 0.7% by volume. In addition, the content of (n-pentane + n-hexane) in the low (nC7 + 8) catalytic cracking gasoline base is preferably 1.0 to 5.0% by volume, particularly 2.0 to 4.0% by volume. . The content of (n-heptane + n-octane) in the low (nC7 + 8) catalytic cracking gasoline base is preferably 1.0% by volume or less, particularly preferably 0.8% by volume or less. The octane number is preferably 90 to 96, particularly 92 to 95.

  The distillation properties of the low (nC7 + 8) catalytic cracking gasoline base material are preferably 10% distillation temperature of 35 to 55 ° C, particularly preferably 40 to 50 ° C, and 90% distillation temperature of 155 to 200 ° C, particularly 170 to 190. ° C is preferred. The difference between the 10% distillation temperature and the 90% distillation temperature is preferably 115 to 160 ° C, particularly preferably 120 to 150 ° C. The diene value is preferably 2.0 g / 100 g or less, particularly preferably 0.5 g / 100 g or less. The saturated content is preferably 30 to 60%, particularly 40 to 50%, the olefin content is 20 to 40%, particularly 20 to 30%, and the aroma content is 15 to 30%, particularly 20 to 25%.

  Catalytic cracking gasoline (n-heptane + n-octane) / (n-nonane + n-decane) ratio (volume ratio) of 3 or less and (n-heptane + n-octane) / (n-pentane + n-hexane) ratio As a preferable method for fractional distillation so that the ratio is 0.5 or less, first, catalytic cracked gasoline is distilled to obtain a light fraction, a medium fraction, and a heavy fraction. At this time, the light fraction has an (n-heptane + n-octane) / (n-nonane + n-decane) ratio (volume ratio) of 3 or less, more preferably 1.5 or less, further 1 or less, particularly 0. .5 or less, the heavy fraction has an (n-heptane + n-octane) / (n-pentane + n-hexane) ratio of 0.5 or less, more preferably 0.3 or less, even more preferably 0.2 or less. Is fractionally distilled so that it becomes 0.1 or less. After fractional distillation, light fraction and heavy fraction are mixed, and (n-heptane + n-octane) / (n-nonane + n-decane) ratio (volume ratio) is 3 or less and (n-heptane + n-octane) ) / (N-pentane + n-hexane) ratio is 0.5 or less, a low (nC7 + 8) catalytic cracking gasoline base is obtained. By this method, the octane number can be improved with almost no change in the sulfur content. In addition, it is preferable to increase the molecular weight of the sulfur content before fractional distillation. The middle fraction obtained here has a low octane number, but the octane number can be increased by catalytic reforming treatment.

The sulfur content of the low (nC7 + 8) catalytic cracking gasoline base is preferably less than 15 ppm by mass, more preferably 10 ppm by mass or less, still more preferably 5 ppm by mass or less, and particularly preferably 1 ppm by mass or less. The method for reducing the sulfur content is not limited, but desulfurization without impairing the olefin contained in the catalytic cracking gasoline is preferable because the octane number does not decrease. Specifically, selective hydrodesulfurization such as the Prime-G + process (Non-patent Document 3) or the detachable sulfur (Patent Document 2) described in known literature is preferable. In order to reduce the sulfur content of the catalytic cracked gasoline to 1 ppm by mass or less without substantially impairing the olefin, a combination of detachable sulfur or selective hydrodesulfurization and detachable sulfur is preferable. Moreover, when making the sulfur content of catalytic cracking gasoline into 10 mass ppm or less, selective hydrodesulfurization or the combination of selective hydrodesulfurization and an absorptive desorption sulfur is mentioned as a preferable method. These desulfurizations may be performed on either catalytically cracked gasoline before fractional distillation or on each fraction after fractional distillation, but preferably only on the heavy fraction after fractional distillation. preferable. Furthermore, the catalytically cracked gasoline is preferably subjected to fractional distillation after a treatment for increasing the molecular weight of the contained sulfur compound. By selectively increasing the molecular weight of sulfur compounds that tend to be heavy, such as thiols, the boiling point of the sulfur-containing compounds is increased, so that the sulfur-containing compounds are transferred into heavy catalytic cracking gasoline in the fractionation step. It is possible to reduce the sulfur content of the light fraction and medium fraction obtained by fractional distillation. As a method of selectively increasing the molecular weight of a sulfur compound, a heavy compound is produced by reacting a sulfur compound with an olefin such as a sweetening process such as the Marlocks method (Non-patent Document 4) or the SHU process (Non-patent Document 3). Is preferably used.
“21st JPI PetroleumRefining Conference“ Recent Progress in Petroleum ProcessTechnology ””, p.37 (2002) International Publication No. 05/44959 Petroleum Refining Technology Handbook 3rd Edition, Sangyo Tosho Co., Ltd. (1981)

The sulfur content of thiol in the low (nC7 + 8) catalytic cracking gasoline base is preferably 5 ppm by mass or less, more preferably 2 ppm by mass or less, and even more preferably 1 ppm by mass or less. The method for reducing the sulfur content by thiol is not limited, but treatment by a sweetening process that can remove thiols having 5 or more carbon atoms, such as the MERICAT-II process (Non-patent Document 5), and a detachable sulfur treatment are preferable.
NPRA 2000 Annual Meeting AM-00-54

[Unleaded gasoline composition]
The unleaded gasoline composition of the present invention has a sulfur content of 10 mass ppm or less, preferably 5 mass ppm or less, more preferably 1 mass ppm or less. The olefin content is 10 to 25% by volume, preferably 15 to 25% by volume. When the olefin content is 10% by volume or less, the blending ratio of the catalytic cracking gasoline is limited, which is not preferable. If the olefin content is 25% by volume or more, it is not preferable because deterioration of oxidation stability and rusting of metal are promoted, and evaporated gas causes photochemical smog. The saturated content is preferably 40 to 60% by volume, particularly 40 to 55% by volume. When the saturation is in this range, the coolability is good. The aroma content is preferably 20 to 40% by volume, particularly 25 to 35% by volume. If the aroma content is within this range, the spark plug will not be damaged and the cleanliness of the engine will be good. Here, the saturated content and the aroma content are values obtained by the fluorescent indicator adsorption method of JIS K 2536 “Petroleum product-component test method”.

  The research octane number is less than 96, preferably 89 or more and less than 96, more preferably 92 or more and less than 96. When the research octane number is 96 or more, the blending ratio of the catalytic cracking gasoline is limited, which is not preferable. The silver plate corrosion is preferably 1 or less. The sulfur content by thiol is preferably 2 mass ppm or less, and more preferably 1 mass ppm or less. When the sulfur content by thiol exceeds 2 mass ppm, the member is easily corroded, which is not preferable. The benzene content is preferably 1% by volume or less, more preferably 0.8% by volume or less, and particularly preferably 0.5% by volume or less. The diene value is preferably 1.5 g / 100 g or less, particularly preferably 0.5 g / 100 g or less.

  The (n-heptane + n-octane) / C6 olefin ratio (volume ratio) is 0.20 or less, preferably 0.15 or less, more preferably 0.10 or less, and particularly 0.08 or less. n-Heptane and n-octane have their own research octane number of 0 or less, and it is preferable that these are as small as possible. The (n-heptane + n-octane) / cyclopentene ratio (volume ratio) is preferably 5 or less, more preferably 4 or less, still more preferably 3 or less, and particularly 2 or less. The (n-heptane + n-octane) / methylcyclopentane ratio (volume ratio) is preferably 0.8 or less, more preferably 0.6 or less, still more preferably 0.4 or less, and particularly preferably 0.2 or less. The content of C6 olefin in the unleaded gasoline composition is preferably 2 to 10% by volume, particularly 2 to 7% by volume. The content of cyclopentene is preferably 0.1 to 5.0% by volume, particularly 0.1 to 1.0% by volume. The content of methylcyclopentane is preferably 1 to 20% by volume, particularly 1 to 10% by volume. The content of (n-heptane + n-octane) is preferably 1.0% by volume or less, particularly preferably 0.5% or less.

  The distillation property of the unleaded gasoline composition according to the present invention is such that 10% distillation temperature is 40 to 70 ° C, particularly 40 to 60 ° C, 90% distillation temperature is 130 to 180 ° C, particularly 150 to 175 ° C. preferable. The difference between the 10% distillation temperature and the 90% distillation temperature is preferably 105 to 160 ° C, particularly preferably 110 to 150 ° C. The 50% by volume distillation temperature is preferably 80 to 97 ° C, more preferably 80 to 95 ° C, and particularly preferably 85 to 95 ° C. When the 50% by volume distillation temperature exceeds 97 ° C., it is not preferable because it causes deterioration of operability during cold operation and deterioration of acceleration. Further, if the 50% distillation temperature is 80 ° C. or lower, the fuel efficiency and exhaust gas properties are deteriorated, which is not preferable.

  In the unleaded gasoline composition according to the present invention, the total content of aromatic compounds having 7 or 8 carbon atoms is preferably 3 to 10% by volume, and more preferably 3 to 7% by volume.

  The unleaded gasoline composition of the present invention is blended with other gasoline bases such as low (nC7 + 8) catalytic cracking gasoline base 50 to 85% by volume, preferably 60 to 85% by volume, more preferably 65 to 80% by volume. Can be manufactured. Other gasoline base materials include (A) catalytic reformed gasoline base material, (C) straight-run naphtha obtained by atmospheric distillation of crude oil, (B) desulfurized naphtha obtained by desulfurizing straight-run naphtha, and (C) light naphtha. Isomerate (isomerized gasoline) that has been subjected to contact treatment and isomerization to increase octane number, (D) butane obtained by precision distillation of LPG fraction and light naphtha recovered from crude oil and various secondary refining equipment, And isopentane.

  As the catalytic reforming gasoline base material, a material obtained by distilling catalytic reforming gasoline and separating a fraction rich in aromatic hydrocarbons having 7 and 9 to 10 carbon atoms can be used. These are usually blended in an amount of 1 to 50% by volume and 2% by volume or more, more preferably 3% by volume or more, and particularly preferably 5% by volume or more from the effect of improving the octane number. From the weight of distillation properties, it is preferably 35% by volume or less, more preferably 25% by volume or less. Further, by using a fraction obtained by separating the catalytic reformed gasoline in an appropriate boiling range, the gasoline composition can be blended and prepared in a fine and flexible manner.

  0-20% by volume of desulfurized light naphtha obtained by desulfurizing naphtha obtained by atmospheric distillation separation of crude oil, and 0-20% by volume of isomerized gasoline whose octane number is increased by isomerization reaction of this desulfurized naphtha. More preferably, 2 to 15% by volume is blended. Further, 0 to 30% by volume of alkylate gasoline, preferably 3 to 28% by volume, more preferably 3 to 25% by volume, and 0 to 20% by volume of ETBE (ethyl-t-butyl ether), preferably 5 to 5% by volume. It is preferable to blend 15% by volume.

  In addition, although it does not specifically limit as another gasoline base material, oxygen-containing gasoline base materials, such as methyl t-butyl ether (MTBE), ethyl s-butyl ether (ESBE), t-amyl ethyl ether (TAEE), ethanol, methanol, etc. A known gasoline base material can be used. The other gasoline base material preferably has a sulfur content of 10 mass ppm or less, preferably 5 mass ppm or less, and particularly preferably 1 mass ppm or less.

[Other additives]
Furthermore, the gasoline of the present invention can be blended with one or more fuel oil additives known in the art as needed. Although these compounding quantities can be selected suitably, it is preferable to maintain the total compounding quantity of an additive to 0.1 weight% or less normally. Examples of fuel oil additives that can be used in the gasoline of the present invention include phenolic, amine-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organic phosphorus-based surfaces. Anti-ignition agent, detergent / dispersant such as succinimide, polyalkylamine, polyetheramine, anti-icing agent such as polyhydric alcohol or its ether, alkali metal salt or alkaline earth metal salt of organic acid, sulfuric acid of higher alcohol Examples include an auxiliary combustor such as an ester, an anionic surfactant, a cationic surfactant, an antistatic agent such as an amphoteric surfactant, and a colorant such as an azo dye.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[Preparation of catalytic cracking gasoline base material]
A gasoline fraction obtained by fluid catalytic cracking using a hydrorefined gas oil fraction of Middle Eastern crude oil as a main feed oil was sweetened to obtain catalytic cracked gasoline A. Catalytic cracking gasoline A was distilled and separated to a ratio of 40:25:35 (volume ratio) to obtain light catalytic cracking gasoline B, medium catalytic cracking gasoline C, and heavy catalytic cracking gasoline D. Heavy catalytic cracking gasoline D was sweetened by desulfurization using a CoMo catalyst at 200 ° C., 1.5 MPa, LHSV = 3 (h ⁻¹ ), H ₂ / Oil = 600 (L / L). Thereafter, it was mixed with light catalytic cracking gasoline B to obtain catalytic cracking gasoline E.

Catalytic cracking gasoline A was distilled and separated to a ratio of 50:25:25 (volume ratio) to obtain light catalytic cracking gasoline F, medium catalytic cracking gasoline G, and heavy catalytic cracking gasoline H. Heavy catalytic cracking gasoline H was desulfurized and sweetened by using a CoMo catalyst at 200 ° C., 1.5 MPa, LHSV = 3 (h ⁻¹ ), H ₂ / Oil = 600 (L / L). Thereafter, it was mixed with light catalytic cracking gasoline F to obtain catalytic cracking gasoline I. Further, after desulfurization of heavy catalytic cracked gasoline H using a CoMo catalyst at 200 ° C., 1.5 MPa, LHSV = 3 (h ⁻¹ ), H ₂ / Oil = 600 (L / L), Ni— After desulfurization and sweetening treatment under conditions of 300 ° C., 1.0 MPa, LHSV = 2.5 (h ⁻¹ ), H ₂ / Oil = 90 (L / L) using Zn composite oxide, Mixing with catalytic cracking gasoline F, catalytic cracking gasoline J was obtained.

Catalytic cracked gasoline A was distilled and separated to a ratio of 60:40 (volume ratio) to obtain light catalytic cracked gasoline K and heavy catalytic cracked gasoline L. Heavy catalytic cracking gasoline L was sweetened by desulfurization using a CoMo catalyst at 200 ° C., 1.5 MPa, LHSV = 3 (h ⁻¹ ), H ₂ / Oil = 600 (L / L). Thereafter, it was mixed with light catalytic cracking gasoline K to obtain catalytic cracking gasoline M.

  Characteristics of catalytic cracking gasoline A, light catalytic cracking gasoline B, heavy catalytic cracking gasoline D, light catalytic cracking gasoline F and heavy catalytic cracking gasoline H are shown in Table 1, light catalytic cracking gasoline K and heavy catalytic cracking. Properties such as properties of gasoline L are shown in Table 2. Table 3 shows properties such as properties of catalytic cracked gasoline M and catalytic cracked gasoline E, catalytic cracked gasoline I, and catalytic cracked gasoline J which are low (nC7 + 8) catalytic cracked gasoline base materials. In the table below, n-C5 is n-pentane, n-C6 is n-hexane, n-C7 is n-heptane, n-C8 is n-octane, n-C9 is n-nonane, and n-C10 is n -Decane and C9 + aroma represent aromatics with 9 or more carbon atoms.

  From this result, it can be seen that the catalytic cracking gasoline E and the catalytic cracking gasoline I can improve the octane number and change the distillation properties lightly compared with the catalytic cracking gasoline M with almost no change in the sulfur content. Furthermore, it can be seen that catalytic cracked gasoline J can reduce the sulfur content to 1 mass ppm or less and improve the octane number to make the distillation properties light.

  [Preparation of Gasoline Composition] A gasoline base material was prepared as shown in Table 4 and blended at a blending ratio (volume%) shown in Table 5 to prepare gasoline compositions as Examples and Comparative Examples. The properties of these gasoline compositions are shown in Tables 6 and 7. From this result, it can be seen from this result that the gasoline of Examples 1 and 2 has a higher octane value while maintaining a higher ratio of catalytically cracked gasoline that can be produced economically than the gasoline of Comparative Examples 1, 2 and 3. It can be seen that the distillation properties can be reduced by maintaining the same level.

  The following gasoline base was used. Butane is a butane fraction derived from crude oil.

Isomerized gasoline:
Desulfurized straight-run light naphtha obtained by desulfurizing straight-run light naphtha obtained by distillation of crude oil was isomerized using a platinum sulfate zirconia catalyst to obtain isomerized gasoline.

AC7:
Light reformed gasoline. When obtaining the desulfurized straight-run light naphtha (DS-LG), after desulfurization, the heavy fraction (desulfurized heavy naphtha) is distilled and separated. This desulfurized heavy naphtha was reformed with a solid catalyst using a moving bed reactor to obtain a hydrocarbon with a high aromatic content, that is, reformed gasoline. This was subjected to distillation separation to obtain a fraction (AC7) containing 95% by volume of C7 aromatic hydrocarbon (toluene).

AC9:
It is a heavy reformed gasoline, and in the distillation separation of the reformed gasoline prepared as described above, hydrocarbons having 11 or more carbon atoms are contained in 5% by volume or less, and hydrocarbons having 9 or 10 carbon atoms in 90% by volume or more. Fraction (AC9) was obtained. The content of aromatic hydrocarbon having 9 carbon atoms is 90% by volume.

ALKG:
A hydrocarbon having a high isoparaffin content was obtained by reacting a fraction mainly composed of butylene and a fraction mainly composed of isobutane with a sulfuric acid catalyst or a solid phosphoric acid catalyst.

The measurement of this example was performed by the following method.
Distillation properties: JIS K 2254 "Petroleum products-Distillation test method"
Vapor pressure (RVP): JIS K 2258 "Crude oil and fuel oil-Vapor pressure test method-Reed method"
Octane number (RON): Research method octane number test method of JIS K 2280 "Petroleum products-Fuel oil-Octane number and cetane number test method and cetane index calculation method" Total sulfur content: In accordance with ASTM D 5453 (ultraviolet fluorescence method), Obtained up to one decimal place.
Sulfur content by thiol: JIS K 2276 "Oil test-Aviation fuel oil test method-Mercaptan sulfur content test method (potentiometric titration method)"
Density: JIS K 2249 "Crude oil and petroleum products-Density test method"

Composition component: Gas chromatography method of JIS K 2536 “Petroleum products-component test method” Material: Methyl silicone, column tank conditions: initial temperature 5 ° C., holding time 10 minutes, heating rate 2 ° C./min, final temperature 140 ° C. Gas conditions: flow rate 2 ml / min, split ratio 50: 1, makeup volume 50 ml / min, sample injection volume: 0.5 μL

  Diene number: According to UOP method 326-82, the number of grams of iodine equivalent to maleic anhydride reacting with 100 g of sample was determined. Both compounds detected by the diene number are contained in a large amount in catalytically cracked gasoline and pyrolyzed gasoline and have a specific odor. In particular, when the diene number is high, the oxidation stability of gasoline is deteriorated.

Silver plate corrosion: JIS K 2513 “Petroleum products-Copper plate corrosion test method: Corresponding (ASTM D130)” cylinder method (jet fuel), instead of copper plate, JIS K2276 “Petroleum product-aviation fuel oil test method” “14. The silver plate used in the “silver plate corrosion test method” was evaluated. The test temperature is 50 ° C. and the test time is 3 hours.

Nitrogen content: JIS K 2606 "Testing method for nitrogen content (chemiluminescence method)"
Benzene: Gas chromatographic method of JIS K 2536 “Petroleum products-Component test method” (same as above)
Saturated content, olefin content, aroma content: Fluorescence indicator adsorption method (FIA method) of JIS K 2536 “Petroleum products-component test method”

Claims (6)

  Unleaded gasoline composition having a sulfur content of 10 mass ppm or less, an olefin content of 10 to 25% by volume, a research octane number of less than 96, and an (n-heptane + n-octane) / C6 olefin ratio (volume ratio) of 0.20 or less. .   The unleaded gasoline composition according to claim 1, wherein the ratio (n-heptane + n-octane) / cyclopentene (volume ratio) is 5 or less.   The unleaded gasoline composition according to claim 1 or 2, wherein (n-heptane + n-octane) / methylcyclopentane ratio (volume ratio) is 0.8 or less.   It is a base material by catalytic cracking gasoline, and (n-heptane + n-octane) / (n-nonane + n-decane) ratio (volume ratio) is 3 or less and (n-heptane + n-octane) / (n-pentane) The unleaded gasoline composition according to claims 1 to 3, comprising 50 to 80% by volume of a low (nC7 + 8) catalytic cracked gasoline base material having a ratio of + n-hexane) of 0.5 or less.   The lead-free gasoline composition according to claims 1 to 4, wherein the corrosion of silver plate is 1 or less, the sulfur content by thiol is 2 mass ppm or less, and the benzene content is 1 vol% or less. The unleaded gasoline composition according to any one of claims 1 to 5, wherein the 50 vol% distillation temperature is 80 to 97 ° C.