JP2004269871A - Unleaded gasoline composition and preparation process thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unleaded gasoline composition with reduced sulfur content assuring satisfactory mode of operation and a preparation process thereof. <P>SOLUTION: The high octane number unleaded gasoline composition is produced by step 1 of fractional distillation of a catalytically cracked oil to give a catalytically cracked lighter oil fraction with a specific distillation feature, step 2 of desulfurization treatment of the catalytically cracked lighter oil fraction to give desulfurized lighter oil fraction and step 3 of blending the desulfurized lighter oil fraction and the other gasoline base. The unleaded gasoline composition shows 96.0 or over of RON (research octane number), 50 vol% distillation temperatures at 105°C or lower, 10 vol% or over of olefin content and 50 mass% or over of thiophene in total sulfur content as sulfur. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a lead-free gasoline composition with reduced environmental impact and a method for producing the same. In particular, the present invention relates to a lead-free gasoline composition that ensures sufficient operating characteristics while reducing the effect on the environment by reducing the sulfur content and securing a high octane number, and a method for producing the same.

  2. Description of the Related Art In recent years, demand for high-performance gasoline having high driving performance has been increasing along with higher performance of automobiles. On the other hand, environmental pollution due to automobile fuel and its combustion exhaust gas has become a social problem. Therefore, there is a demand for a vehicle fuel that maintains high driving performance and has a low environmental load. In particular, further reduction of sulfur content is desired from the viewpoints of exhaust gas purification and fuel efficiency improvement.

  JIS K 2202 stipulates the first car gasoline with a research octane number (RON) of 96.0 or more and the second car gasoline with a value of 89.0 or more. The former is a high-performance premium gasoline, and the latter is regular. Commercially available as gasoline. Conventionally, premium gasoline has been used in catalytic reforming gasoline bases, bases with more than 100 RONs such as methyl-t-butyl ether (MTBE), alkylate gasoline bases, catalytic cracking gasoline bases such as 93 or more. It is manufactured by blending various base materials, mainly a base material having RON.

  Catalytic cracking gasoline bases produced by catalytic cracking of heavy petroleum fractions have the advantage that they can be produced more economically than other premium gasoline bases, but contain a large amount of sulfur. As a result, most of the sulfur content in the premium gasoline produced as described above comes from the catalytic cracking gasoline base material.

  The reduction of the sulfur content of the catalytic cracking gasoline base material can be easily performed by a known technique of hydrorefining in the presence of high-pressure hydrogen and a catalyst. However, in that case, the catalytic cracking gasoline base material is contained in a large amount, and olefin components having a high RON are hydrogenated to lower the RON of the base material. There was a problem that it could not be obtained. An environmentally friendly gasoline having a low sulfur content of 1 mass ppm or less and sufficient practical performance, and a method for producing the same have not yet been established.

  An object of the present invention is to provide a lead-free gasoline composition which has a reduced sulfur content and secures sufficient operating characteristics under such circumstances, and a method for producing the same.

  The present inventors have conducted intensive studies in order to solve the above problems, and as a result, using only a specific fraction of the catalytic cracking gasoline base material, by using a base material subjected to desulfurization treatment of the fraction, high The present inventors have conceived a lead-free gasoline composition and a method for producing the same, in which the sulfur content is reduced while maintaining the RON and sufficient operating characteristics are secured.

  That is, the method for producing a lead-free gasoline composition having a sulfur content of 1 mass ppm or less and a research octane number of 96.0 or more according to the present invention comprises: A first step of obtaining a catalytic cracked light fraction having a distillation temperature of 25 to 43 ° C and a 95% by volume distillation rate of 55 to 100 ° C, and (2) desulfurizing the catalytic cracked light fraction obtained in the first step. A second step of obtaining a desulfurized light fraction, and (3) mixing the desulfurized light fraction obtained in the second step with another gasoline base material, preferably another gasoline base material having a sulfur content of 0.5 ppm or less. Including a third step.

  In the third step, it is preferable to mix 10 to 45% by volume of the desulfurized light fraction with 90 to 55% by volume of another gasoline base material. In the second step, desulfurization treatment is preferably performed by bringing a porous desulfurizing agent containing at least one selected from copper, zinc, nickel and iron into contact with a catalytic cracking light fraction, or using an extraction solvent. It is preferable to desulfurize the catalytically cracked light fraction by an extraction treatment. Further, the thiophene content of the catalytically cracked light fraction obtained in the first step is preferably not more than 2.5 ppm by mass in terms of sulfur content. However, it is preferable to perform a pretreatment for increasing the molecular weight of the contained sulfur compound.

  The unleaded gasoline composition according to the present invention has a research octane number of 96.0 or more, a 50% by volume distillation temperature of 105 ° C. or less, an olefin content of 10% by volume or more, and a thiophene ratio of total sulfur content of sulfur. It is 50% by mass or more as a minute.

  The unleaded gasoline composition of the present invention preferably has a total sulfur content of 1 mass ppm or less, and an olefin content in a boiling range of 35 to 80 ° C of 90 vol% or more of the total olefin content. Further, the benzene content is preferably not more than 0.3% by volume.

  The present invention is particularly a method for producing a lead-free gasoline composition using a desulfurized light fraction of a catalytically cracked oil desulfurized while leaving a high octane number olefin component as it is. Can be obtained. Therefore, according to the present invention, an unleaded gasoline composition which has a sufficient operation characteristic and has an environmentally friendly property is provided, especially because the ratio of thiophene in the total sulfur content is large and the sulfur content is extremely low. Is done.

[First step]
In the first step of the method for producing a lead-free gasoline composition of the present invention, the catalytic cracking oil is fractionated and the 5% by volume distillation temperature is 25.0 to 43.0 ° C, preferably 35.0 to 43.0 ° C. And a 95% by volume distillation temperature of 55.0 to 100.0 ° C, preferably 55.0 to 80.0 ° C. If the 5% by volume distillation temperature is less than 25.0 ° C., the vapor pressure of the unleaded gasoline composition will increase. On the other hand, if the 95% by volume distillation temperature is particularly higher than 100.0 ° C., the sulfur content of the desulfurized light fraction increases, or the RON of the gasoline base material decreases, so that a desired lead-free gasoline composition is prepared. Becomes difficult. If the 5% by volume distillation temperature exceeds 43.0 ° C. or the 95% by volume distillation temperature is less than 55.0 ° C., it becomes difficult to adjust the distillation properties of the unleaded gasoline composition, or in the first step. The yield of the resulting catalytic cracked light fraction is reduced, and the cost of the unleaded gasoline composition is increased.

  The thiophene content of the catalytic cracking light fraction obtained in the first step is preferably 0.1 to 2.5 mass ppm in terms of sulfur content. It is even more preferable that the content be 0.1 to 2.0 ppm by mass, more preferably 0.1 to 1.0 ppm by mass. Since thiophene is one of the sulfur compounds most likely to remain in the desulfurized light fraction obtained in the desulfurization treatment in the second step, the catalytically cracked light fraction obtained in the first step has a sulfur content of 2. If the content of thiophene exceeds 5 ppm by mass, the sulfur content is not removed by the desulfurization treatment in the second step, and the flexibility of mixing with another gasoline base material in the next third step is unfavorably reduced. Further, it is preferable that the catalytically cracked light fraction obtained in the first step contains only thiophene having a sulfur content of less than 0.1 ppm by mass, since the yield of the catalytically cracked light fraction is reduced. Absent.

  The total amount of 2-methylthiophene and 3-methylthiophene contained in the catalytic cracking light fraction obtained in the first step is preferably not more than 0.5 ppm by mass in terms of sulfur content. 2-Methylthiophene and 3-methylthiophene, like thiophene, are sulfur compounds most likely to remain in the desulfurized light fraction obtained by the desulfurization treatment in the second step. Therefore, in the first step, it is preferable to reduce 2-methylthiophene and 3-methylthiophene, and it is more preferable that the total sulfur content is 0.1 mass ppm or less. For this purpose, the 95% distillation temperature during fractional distillation is preferably 75.0 ° C or lower, particularly preferably 70.0 ° C or lower.

(Catalytic cracking oil)
The process for producing the catalytic cracking oil used in the first step is not particularly limited to the catalytic cracking device, the feedstock, and the operating conditions, and any known production process can be adopted. The catalytic cracking unit uses catalysts such as amorphous silica alumina and zeolite to separate petroleum fractions from gas oil to reduced pressure gas oil, as well as direct gas oil obtained from heavy oil indirect desulfurization unit and direct oil obtained from heavy oil direct desulfurization unit. This equipment mainly obtains high octane gasoline base materials by catalytic cracking of heavy oil, residual oil under normal pressure, and the like. As a catalytic cracking process, for example, a fluid catalytic cracking method such as a UOP catalytic cracking method, a flexicracking method, an ultra-ortho-flow method, a Texaco fluid catalytic cracking method described in "New Petroleum Refining Process" edited by the Japan Petroleum Institute, an RCC method, Fluid catalytic cracking such as HOC method can be used.

  In order to reduce thiophene in the catalytic cracking light fraction, it is preferable to use the petroleum fraction from gas oil to vacuum gas oil as a feed oil of the catalytic cracking unit, particularly one whose sulfur content is 2,000 ppm or less, Further, it is preferable to use a fraction reduced to 1,000 ppm or less, particularly 500 ppm or less by hydrorefining or the like.

(Pretreatment for increasing molecular weight of sulfur compound)
It is preferable that the catalytic cracked oil to be subjected to the first step is subjected to a pretreatment for increasing the molecular weight of the contained sulfur compound and then subjected to the first step. Since the boiling point of the sulfur-containing compound is increased by selectively increasing the molecular weight of the sulfur compound such as thiols, in the first step, the sulfur-containing compound can be removed by being unevenly distributed in the heavy fraction. Thus, the sulfur content of the catalytic cracking light fraction obtained in the first step can be reduced. Specifically, the content of thiols and thiols in the catalytic cracking light fraction is more preferably set to 0.1 mass ppm or less as a sulfur content by a method described later.

  Conventionally, in petroleum refining, sweetening for treating thiols to deodorize products is performed, but a known method for converting thiols to disulfides by an oxidation method or an oxidative extraction method is described in the present invention. Can be applied as a method for increasing the molecular weight of the sulfur compound. Specifically, the Marlox method, the doctor method, and the like disclosed in known literature (Sangyo Tosho Co., Ltd., Petroleum Refining Technology Handbook, 3rd edition, 1981) are preferably used.

  In the present invention, as a method for increasing the molecular weight of the sulfur compound, a method of reacting a sulfur compound contained in a naphtha fraction with an olefin is also suitably used. Specifically, a method of reacting thiols with olefins disclosed in a published patent publication (Japanese Patent Application Laid-Open No. 2001-55584) and a known literature (“Production of Low Sulfur Gasoline and Diesel Fuels: Tier 2 and Beyond”) , Petroleum Refining Technology Seminar August 2001, 11-18) and a method of reacting thiols and thiophenes with olefins.

[Second step]
In the second step of the method for producing a lead-free gasoline composition of the present invention, the catalytically cracked light fraction obtained in the first step is desulfurized to obtain a desulfurized light fraction to be subjected to the third step. The sulfur content of the desulfurized light fraction obtained in the second step is desulfurized to preferably 3 ppm by mass or less, more preferably 2 ppm by mass or less, and further preferably 1 ppm by mass or less. The olefin content of the desulfurized light fraction is preferably 20 to 50% by volume, particularly preferably 25 to 45% by volume.

  The method of the desulfurization treatment in the second step is not particularly limited, but a method of contacting a catalytically cracked light fraction with a desulfurizing agent having a function of adsorbing or sorbing a sulfur compound or selecting a sulfur compound from the catalytically cracked light fraction by extraction. A preferred method is a method of removing it. A method of hydrodesulfurizing the catalytic cracking light fraction in the presence of a desulfurization catalyst and hydrogen can also be mentioned. However, in the presence of high-pressure hydrogen, olefins are easily hydrogenated and the RON of the obtained gasoline base material decreases. It's easy to do. Therefore, the desulfurization treatment is preferably performed in a state where hydrogen is not substantially present, or at a hydrogen partial pressure of less than 1 MPa.

When using a method of contacting a catalytically cracked light fraction with a desulfurizing agent having an adsorption or sorption function, the desulfurization agent is not particularly limited as long as it has an adsorption or sorption function for sulfur compounds. For example, a porous desulfurizing agent containing at least one metal component selected from copper, zinc, nickel and iron is preferably used. Preferred desulfurizing agents contain 0.5 to 85% by weight, especially 1 to 80% by weight, of the metal component such as copper. The production method of the desulfurizing agent is not particularly limited, but a porous carrier such as alumina is impregnated with a metal component such as copper, supported and baked, or a metal component such as copper and a component such as aluminum by a coprecipitation method. Is preferable as a production method of precipitating and subjecting to steps such as molding and firing. Further, the metal component may be further impregnated and supported on the molded and calcined desulfurizing agent and calcined. As the desulfurizing agent, a fired one may be used as it is, or a desulfurizing agent may be used after a reduction treatment in a hydrogen atmosphere. The specific surface area of the desulfurizing agent, 50 m @ 2 / g or more, and particularly it is preferable 100 m @ 2 / g, even at 200~600m ² / g. The composition and production method of the desulfurizing agent are not particularly limited, but specific examples thereof include desulfurizing agents disclosed in Japanese Patent No. 3324746, Japanese Patent No. 3230864, and JP-A-11-61154.

The desulfurization treatment may be carried out in a batch system or a flow system, but it is possible to carry out the catalytic cracking light fraction in a fixed-bed desulfurization tower filled with a desulfurization agent, and to carry out the desulfurization with the desulfurization agent. It is preferable because light fractions can be easily separated. The temperature for the desulfurization treatment can be selected from the range of 15 to 400 ° C, preferably 80 to 380 ° C. In order to promote desulfurization of thiophenes that are not easily desulfurized only by contacting with a desulfurizing agent, desulfurization treatment may be performed in the presence of hydrogen. However, the hydrogen partial pressure is preferably less than 1 MPa, more preferably less than 0.6 MPa, in order to avoid the olefin being hydrogenated and the RON of the obtained gasoline base material being reduced. When the desulfurization treatment is carried out by bringing the desulfurizing agent and the catalytic cracking light fraction into contact with each other in a fixed bed flow system, the LHSV is preferably selected from the range of 0.01 to 10000 h- ¹ .

  As a method for selectively removing a sulfur compound from a catalytic cracking light fraction by extraction, a publicly known method proposed in, for example, JP-A-2003-531922 and 21st JPI Petroleum Refining Conference “Recent Progress in Petroleum Process Technology”, 159 (2002), etc. As a solvent extraction process, a typical Sulfur-X (registered trademark) process of UOP can be used as a solvent extraction process. Examples of solvents used in these processes include sulfolane, 3-methylsulfolane, 2,4-dimethylsulfolane, 3-ethylsulfolane, diethylene glycol, triethylene glycol, tetraethylene glycol, N-methyl-2-pyrrolidone , N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-formylmorpholine, dimethylsulfoxide, diethylsulfoxide, methylethylsulfoxide, dipropylsulfoxide, ethylene carbonate, propylene carbonate and the like. These solvents may be mixed with water for ease of handling. Particularly, for solvents that can extract thiophene sulfur compounds, benzene having a molecular structure similar to that of the thiophene ring can be extracted at the same time. It becomes. Therefore, the unleaded gasoline composition containing the catalytically cracked light fraction in which the amount of sulfur compounds has been reduced by solvent extraction can also reduce the benzene content as compared with the related art.

[Other gasoline base material used in the third step]
Other gasoline base materials to be mixed in the third step include a catalytic reforming gasoline base material, an alkylate gasoline base material, a base material obtained by desulfurizing a straight-run naphtha, MTBE, ethyl-t-butyl ether (ETBE), Known gasoline base materials such as oxygen-containing gasoline base materials such as t-amylethyl ether (TAEE), ethanol, and methanol can be used. If the sulfur content of the unleaded gasoline composition obtained by mixing with the gasoline base material obtained from the second step is 1 mass ppm or less, the sulfur content of the other gasoline base mixed in the third step is particularly preferable. It is not limited. Preferably, the sulfur content is 0.5 mass ppm or less, more preferably 0.1 mass ppm or less. If the sulfur content of the other gasoline base exceeds 0.5 ppm by mass, the amount of the gasoline base obtained from the second step is restricted, which is not preferable.

  Preferred blending amounts are, for example, 10 to 45% by volume, particularly 25 to 40% by volume of the desulfurized light fraction, 25 to 50% by volume, particularly 30 to 45% by volume of the catalytic reforming gasoline base material, and alkylate gasoline. The base material may be blended in an amount of 10 to 40% by volume, particularly 15 to 30% by volume.

(Lead-free gasoline composition)
The unleaded gasoline composition of the present invention has a research octane number of 96.0 or more, preferably 98 to 102, a 50% by volume distillation temperature of 105 ° C or less, preferably 80 to 100 ° C, and an olefin content of 10% by volume or more. Preferably, the content of thiophene is 10 to 20% by volume and the total sulfur content is 65 to 100% by mass as the sulfur content.
Further, the total sulfur content is preferably 1 mass ppm or less, and the ratio of the olefin content in the boiling range of 25 to 100 ° C. to the entire olefin content is preferably 90% by volume or more. If the proportion of the olefin in the boiling range of 25 to 100 ° C., particularly 35 to 80 ° C., is less than 90% by volume, the proportion of the light olefin having a high octane number is reduced, and satisfactory performance is obtained. Can not be. The unleaded gasoline composition preferably contains thiophene in a sulfur content of 0.1 to 1.0 mass ppm. Since thiophene is one of the sulfur compounds most likely to remain in the base material, it is not preferable to make thiophene less than 0.1 mass ppm of sulfur because the cost of the unleaded gasoline composition of the present invention increases.

(Other components)
Further, one or more fuel oil additives known in the art can be added to the gasoline composition of the present invention as needed. The amounts of these additives can be appropriately selected, but it is usually preferable to maintain the total amount of additives at 0.1% by weight or less.
Examples of fuel oil additives that can be used in the gasoline of the present invention include phenol-based, amine-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organic phosphorus-based compounds. 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 flame retardants such as esters, anionic surfactants, cationic surfactants, antistatic agents such as amphoteric surfactants, and coloring agents such as azo dyes.

  The present invention will be described in more detail based on the following examples, but the present invention is not limited to the following examples.

Preparation of desulfurized light fraction 1
Catalytic cracking oil A1 obtained by fluidized bed catalytic cracking using a hydrorefining treatment of a vacuum gas oil fraction of a Middle Eastern crude oil as a main feed oil is subjected to oxidative extraction treatment (sweetening) to obtain catalytic cracking oil B1. Was. The catalytic cracking oil B1 was fractionated, and light and heavy components were removed to obtain a catalytic cracking light fraction C1. The properties of the catalytic cracking oil A1, the catalytic cracking oil B1, and the catalytic cracking light fraction C1 were as shown in Table 1.

  The density was measured according to JIS K 2249, the vapor pressure was measured according to JIS K 2258, and the distillation properties were measured according to JIS K 2254. The sulfur content was measured by the microcoulometric titration oxidation method of JIS K2541. The content of sulfur compounds (in terms of sulfur) was measured by gas chromatography using a gas chromatograph manufactured by Shimadzu Corporation equipped with an ANTEK sulfur chemiluminescence detector for selectively detecting and quantifying the sulfur compounds by chemiluminescence. . The hydrocarbon component composition, benzene content, and RON were measured by gas chromatography using a PIONA apparatus manufactured by Hewlett-Packard Company.

30 mL of this catalytic cracking light fraction C1 was mixed with 10 g of a copper oxide-alumina-based desulfurizing agent (containing 7.6% by mass of copper as a metal atom) in a flask at room temperature for 24 hours. The desulfurizing agent was separated by filtration to obtain a desulfurized light fraction D1.
Light thiols contained in the catalytic cracking oil A1 were converted to higher molecular weight disulfides by the oxidative extraction treatment. The catalytic cracking light fraction C1 contained 5.6 mass ppm of sulfur, but by treating with a desulfurizing agent, a desulfurized light fraction D1 having 0.8 mass ppm of sulfur was obtained. The obtained desulfurized light fraction D1 contained 0.8 mass ppm of thiophene, but did not contain 2-methylthiophene and 3-methylthiophene.

Preparation of desulfurized light fraction 2
Except that a vacuum gas oil fraction of a Middle Eastern crude oil of another lot was used, the same treatment as in Preparation 1 of the desulfurized light fraction was conducted, and a catalytic cracking light fraction C2 having a different property from the catalytic cracking light fraction C1 was used. Got. 200 mL of the catalytic cracking light fraction C2 was mixed with 15 g of a copper oxide-alumina-based desulfurizing agent (containing 7.6% by mass of copper as a metal atom) in a flask at room temperature for 2 hours. The desulfurizing agent was separated by filtration to obtain a desulfurized light fraction D2. The properties of the catalytic cracking light fraction C2 and the desulfurized light fraction D2 are as shown in Table 2.
The catalytically cracked light fraction C2 contained 6.4 mass ppm of sulfur, but by treating with a desulfurizing agent, a desulfurized light fraction D2 having 1.6 mass ppm of sulfur was obtained. The obtained desulfurized light fraction D1 contained 1.6 mass ppm of thiophene, but did not contain 2-methylthiophene and 3-methylthiophene.

Preparation of desulfurized light fraction 3
Further, another lot was subjected to hydrorefining treatment of a vacuum gas oil fraction of a Middle Eastern crude oil, which was subjected to fluidized bed catalytic cracking in the same manner as in Preparation 1 of the desulfurized light fraction to obtain a catalytic cracking oil A3, Then, it was subjected to an oxidative extraction treatment (sweetening) to obtain a catalytic cracking oil B3, which was further fractionated to obtain a catalytic cracking light fraction C3. 150 mL of this catalytic cracking light fraction C3 was mixed with 600 mL of sulfolane containing 5% by weight of water at room temperature for 1 hour with stirring in a flask to perform an extraction treatment. Raffinate (100 mL which was not extracted by sulfolane) was washed with 100 mL of water to obtain a desulfurized light fraction D3. Table 3 shows the properties of the catalytic cracking oil A3, the catalytic cracking oil B3, the catalytic cracking light fraction C3, and the desulfurizing light fraction D3.

  The catalytic cracking light fraction C3 contained 7.6 ppm by mass of sulfur, but the extraction treatment resulted in a desulfurized light fraction D3 having 1.3 ppm by mass of sulfur. The obtained desulfurized light fraction D3 contained 1.3 mass ppm of thiophene, but did not contain 2-methylthiophene and 3-methylthiophene. The catalytically cracked light fraction C3 contained 1.4% by volume of benzene, but the extraction treatment reduced the desulfurized light fraction D3 to 0.3% by volume or less.

Preparation of Unleaded Gasoline Composition The desulfurized light fraction obtained as described above was mixed with another gasoline base material to prepare an unleaded gasoline composition. As other gasoline base materials, desulfurized naphtha G, catalytic reformed medium oil H, catalytic reformed heavy oil I, and alkylated gasoline J obtained by a known technique other than catalytic cracking were used. Their properties are as shown in Table 4. The catalytic reforming medium oil H is obtained by distilling and separating a fraction containing a large amount of toluene from catalytic reforming gasoline. The catalytic reforming heavy oil I is obtained by distilling and separating aromatics having 9 or more carbon atoms and less than 11 carbon atoms from catalytic reforming gasoline.

  39.5% by volume of the desulfurized light fraction D2 obtained in Preparation 2 of the above desulfurized light fraction, 3.5% by volume of desulfurized naphtha G as another gasoline base material, and 19 0.05% by volume, 15.0% by volume of catalytic reforming heavy oil I, and 23.0% by volume of alkylated gasoline J. Further, a colorant (CL-53 manufactured by Shirad Chemical Co., Ltd.) was used as an additive. ) 2 mg / L, an antioxidant (Sumitomo Chemical Industries Sumilizer 4ML) 20 mg / L, and a detergent / dispersant (BESF Keropur AP-95) 100 mg / L, and a lead-free gasoline composition K1 (Example 1) Was prepared. Further, a lead-free gasoline composition L1 (Comparative Example 1) was prepared in the same manner as in the preparation of the lead-free gasoline composition K1, except that the catalytic cracking light fraction C2 was used instead of using the desulfurized light fraction D2.

  Further, similarly to the preparation of the lead-free gasoline composition K1, the desulfurized light fraction D3 was 40% by volume, the desulfurized naphtha G was 2% by volume, the catalytically modified medium oil H was 11% by volume, and the catalytically modified 21% by volume of high-quality oil I and 26% by volume of alkylated gasoline J. As additives, a colorant (CL-53 manufactured by Shirad Chemical) 2 mg / L, an antioxidant (Sumilyzer 4ML manufactured by Sumitomo Chemical Co., Ltd.) ) 20 mg / L and 100 mg / L of a detergent / dispersant (Keropur AP-95 manufactured by BFSF) were added to prepare a lead-free gasoline composition K2 (Example 2). Further, a lead-free gasoline composition L2 (Comparative Example 2) was prepared in exactly the same manner as in the preparation of the lead-free gasoline composition K2 except that the catalytic cracking light fraction C3 was used instead of using the desulfurized light fraction D3. .

  Table 5 shows the properties of the lead-free gasoline compositions K1, K2, L1, and L2 prepared as Examples and Comparative Examples, respectively. The olefin content in the boiling range of 25 to 100 ° C. in the total olefin content was 100% by volume in all of K1, K2, L1 and L2.

  From Table 5, it can be seen that the unleaded gasoline compositions provided by the present invention (K1 and K2) have little change in other properties compared to the unleaded gasoline compositions provided by the prior art (L1 and L2). It is clear that the sulfur content can be reduced to 1 mass ppm or less, and the benzene content can be reduced to 0.3 volume% or less.

Claims (10)

A first step of fractionating the catalytic cracking oil to obtain a catalytic cracking light fraction having a 5% by volume distillation temperature of 25 to 43 ° C and a 95% by volume distillation temperature of 55 to 100 ° C;
A second step of desulfurizing the catalytically cracked light fraction obtained in the first step to obtain a desulfurized light fraction, and a second step of mixing the desulfurized light fraction obtained in the second step with another gasoline base material. A method for producing a lead-free gasoline composition having a sulfur content of 1 mass ppm or less and a research octane value of 96.0 or more, including three steps.   The method for producing a lead-free gasoline composition according to claim 1, wherein in the third step, 10 to 45% by volume of the desulfurized light fraction and 90 to 55% by volume of another gasoline base material are mixed.   The lead-free gasoline composition according to claim 1 or 2, wherein in the second step, a porous desulfurizing agent containing at least one selected from copper, zinc, nickel and iron is brought into contact with a catalytic cracking light fraction to perform desulfurization treatment. Production method.   The method for producing a lead-free gasoline composition according to claim 1 or 2, wherein in the second step, the catalytic cracking light fraction is subjected to desulfurization treatment by an extraction treatment using an extraction solvent.   The method for producing a lead-free gasoline composition according to any one of claims 1 to 4, wherein the thiophene content of the catalytic cracking light fraction is 2.5 mass ppm or less as a sulfur content.   The method for producing a lead-free gasoline composition according to any one of claims 1 to 5, wherein a pretreatment for increasing the molecular weight of a sulfur compound contained in the catalytic cracking oil is performed before the fractionation in the first step.   Research method Octane number is 96.0 or more, 50% by volume Distilling temperature is 105 ° C or less, olefin content is 10% by volume or more, and the ratio of thiophene to total sulfur content is 50% by mass or more as a sulfur content. Unleaded gasoline composition.   The unleaded gasoline composition according to claim 7, wherein the total sulfur content is 1 mass ppm or less.   9. The unleaded gasoline composition according to claim 7, wherein the olefin content in the boiling range of 25 to 100 [deg.] C. in the total olefin content is 90% by volume or more.   The unleaded gasoline composition according to any one of claims 7 to 9, wherein the benzene content is 0.3% by volume or less.