JP2005120366A - Method for producing gasoline base, eco-friendly gasoline and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ECO-friendly gasoline and a method for producing the same, with extremely low sulfur content and reducing effect to the environment, and to provide a method for producing a gasoline base suitable for preparation of ECO-friendly gasoline. <P>SOLUTION: The method for producing the gasoline base having ≤10 mass.ppm of sulfur content, ≥30 mass.% of sulfur content based on thiophenes in the total sulfur content and ≥85 of research octane number, comprises a first process obtaining fluidized catalytically cracked heavy naphtha fraction with 50-120°C of 5% recovered temperature and 150-220°C of 95% recovered temperature by fractionating fluidized catalytically cracked naphtha, and a second process obtaining desulfurized fluidized catalytically cracked heavy naphtha by carrying out a hydrodesulfurization of the fluidized catalytically cracked heavy naphtha fraction having 50-150 mass.ppm of sulfur content and ≤25 vol.% of olefin content obtained in the first process, under a condition which limits reducing rate of olefin content to ≤40%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an environmentally friendly gasoline having a sulfur content reduced to 10 ppm by mass or less in order to reduce the influence on the environment, a method for producing the same, and a method for producing a gasoline base material suitable for the preparation of the environmentally friendly gasoline.

  In recent years, the demand for high-performance gasoline having high driving performance has increased with the improvement in performance of automobiles. On the other hand, environmental pollution due to automobile fuel and its combustion exhaust gas has become a social problem. Therefore, an automobile fuel that maintains high driving performance and has a low environmental impact is desired. In particular, further reduction of sulfur content is desired from the viewpoint of exhaust gas purification and fuel efficiency improvement.

  JIS K 2202 stipulates No. 1 automobile gasoline with a research octane number (RON) of 96 or more and No. 2 automobile gasoline with 89 or more. The former is marketed as high-performance premium gasoline and the latter as regular gasoline. ing. Conventionally, regular gasoline has various base materials such as catalytic reforming gasoline base, alkylate gasoline base, light naphtha base, catalytic cracking gasoline base (catalytic cracking naphtha fraction). It is manufactured by blending.

  The catalytic cracking gasoline base produced by catalytic cracking of a heavy petroleum fraction has an advantage that it can be produced economically compared with other regular gasoline bases, but contains a large amount of sulfur. As a result, most of the sulfur content in the regular gasoline produced as described above was derived from the catalytic cracked gasoline base material.

  The sulfur content of the catalytic cracking gasoline base can be easily reduced by a known technique of hydrotreating in the presence of high-pressure hydrogen and a catalyst. In that case, a large amount of the olefin component having a high RON contained in the catalytic cracking gasoline base material is hydrogenated and the RON of the base material is lowered. Accordingly, it is possible to prevent a decrease in the olefin content as a whole by hydrorefining only a heavy catalytic cracked gasoline base material having a high sulfur content.

  The present inventor examined the hydrorefining of such a heavy catalytic cracking gasoline base material. As a result, an organic sulfur compound not contained in the raw material oil was contained in the refined base material, and this component was an odor. And found to have a significant effect on corrosivity. An object of the present invention is to solve the problem caused by the organic sulfur compound generated after hydrorefining, and to provide an environment-friendly gasoline having an ultra-low sulfur content with reduced environmental impact and a method for producing the same. It is. Another object of the present invention is to provide a method for producing a gasoline base material suitable for preparing the environmentally friendly gasoline.

  As a result of earnest research to solve the above problems, the present inventors have found that organic sulfur compounds are newly generated by the reaction of hydrogen sulfide generated by hydrorefining with olefins in the feedstock. It was found that by limiting the olefin content contained in the hydrorefining feedstock, problems due to hydrocracked catalytic cracked gasoline base materials can be prevented. These findings led to this invention.

That is, the method for producing a gasoline base material having a sulfur content of 10 ppm by mass or less according to the present invention, a sulfur content by thiophenes of 30 mass% or more of the total sulfur, and a research octane number of 85 or more is divided into fluid catalytic cracking naphtha. A first step for obtaining a catalytic cracked heavy naphtha fraction having a 5% distillation temperature of 50 to 120 ° C. and a 95% distillation temperature of 150 to 220 ° C., and the catalytic cracking weight obtained in the first step The sulfur content of the naphtha fraction is 50 to 150 mass ppm, the olefin content is 25% by volume or less, and this catalytic cracked heavy naphtha fraction is hydrodesulfurized under the condition that the reduction rate of the olefin content is 40% or less. A second step of obtaining a desulfurized catalytic cracked heavy naphtha fraction.
Preferably, the sulfur content of the gasoline base is 5 ppm by mass or less, the desulfurization catalytic cracking heavy naphtha fraction is contacted with an alkaline substance, the sulfur content is 3 ppm by mass or less, and the content of thiols. Is 1 mass ppm or less.

  Furthermore, the present invention includes a blending step of mixing the gasoline base material by the above production method with another gasoline base material having a sulfur content of 10 mass ppm or less, the sulfur content is 10 mass ppm or less, and the research octane number is 89. This is a method for producing environmentally friendly gasoline.

  In addition, the environmentally friendly gasoline according to the present invention has a total sulfur content of 10 mass ppm or less, a total of 50 mass% or more of sulfur content of thiols and sulfur content of thiophenes, and a research octane number of 89 to 96. . Moreover, it is preferable that the sulfur content by thiophene occupies 30 mass% or more of a total sulfur content, and it is further more preferable that olefin content is 10-30 volume%.

According to the present invention, a heavy naphtha fraction containing most of the olefins having 7 or more carbon atoms and most of the olefins having 5 or less carbon atoms, and most of the olefins having 7 or more carbon atoms are contained from the fluid catalytic cracking naphtha. Is divided into light naphtha fractions containing almost no olefins containing 7 or more carbon atoms, and only the heavy naphtha fractions are hydrodesulfurized. Therefore, the refined desulfurized heavy naphtha fraction contains fat with 5 or less carbon atoms. Almost no group thiol is contained, and odor and corrosive problems due to such sulfur compounds can be avoided.
In addition, according to the present invention, by reducing the olefin content in the raw material to be subjected to hydrodesulfurization to 25% by volume or less, mercaptan regeneration reaction by olefin and hydrogen sulfide produced by desulfurization is suppressed, and octane loss is minimized. However, the sulfur content in the product oil can be reduced to 10 ppm by mass or less, and further to 5 ppm by mass or less.

[Forms of thiols produced by hydrorefining]
Hydrogen sulfide is generated when catalytic cracking naphtha is desulfurized by hydrorefining. Since catalytic cracking naphtha contains olefin, olefin and hydrogen sulfide react to generate thiol. Although thiol is originally contained in catalytic cracking naphtha, thiol is very reactive and easily desulfurized by desulfurization by hydrorefining, so thiol contained in desulfurizing catalytic cracking naphtha is sulfided during hydrorefining. Most of them are produced by reaction of hydrogen and olefins. Since the catalytic cracking naphtha usually contains an olefin having 4 to 12 carbon atoms, when the catalytic cracking naphtha is hydrorefined, a thiol having 4 to 12 carbon atoms is generated. Thiols are one of the malodorous substances in gasoline. The lower the boiling point of thiols, the stronger the malodor. Since thiols have a lower boiling point as the carbon number is smaller, thiols having 5 or less carbon atoms have a particularly strong odor. Thiols are easily generated by the reaction of olefin and hydrogen sulfide. Therefore, before hydrocracking the catalytic cracked naphtha, olefins having 5 or less carbon atoms are fractionated and removed as a light naphtha fraction. The generation of thiol having 5 or less carbon atoms in the desulfurization catalytic cracking naphtha can be suppressed.

  The thiols are roughly classified into chain thiols with SH group added to chain paraffin, alicyclic thiols with SH group added to cyclic paraffin, and aromatic thiols with SH group added directly to the aromatic ring. It is done. Of these, chain thiols and alicyclic thiols are generated by hydrorefining treatment, and these are collectively referred to as aliphatic thiols here.

[Catalytic decomposition process]
The process for producing the catalytic cracking naphtha is not particularly limited to the catalytic cracking apparatus, the operating conditions and the catalyst to be used, and any known production process can be adopted. The catalytic cracking unit 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 unit, it can be obtained directly from degassing oil or heavy oil direct desulfurization unit. This is a device that obtains a high octane gasoline base material by catalytic cracking of degassed oil, atmospheric residue oil and the like. For example, UOP catalytic cracking method, flexi cracking method, ultra-orthoflow method, fluid catalytic cracking method such as Texaco fluid catalytic cracking method, RCC method, HOC method, etc. Examples include fluid catalytic cracking. Also, 21st JPI Petroleum Refining Conference “Recent Progress in Petroleum Process Technology”, p.113-158 (2002), Sulfur, 268, 35, (2000), “Production of Low Sulfur Gasoline and Diesel Fuels: Tier 2 and Beyond” , Petroleum Refining Technology Seminar, p.4-24 (August 2001), JP-A-6-277519, catalytic cracking catalyst having high desulfurization effect and additive having desulfurization effect are added to catalytic cracking catalyst It can also be used.

[Catalytic cracking feedstock]
An atmospheric distillation residue obtained by atmospheric distillation of crude oil, a vacuum gas oil that is a distillate fraction obtained by vacuum distillation of atmospheric distillation residue, a distillate distillation obtained by atmospheric distillation of crude oil Among the fractions, a pyrolysis heavy gas oil fraction obtained by pyrolyzing a vacuum distillation residue oil obtained by distilling an atmospheric distillation residue oil under reduced pressure, a sulfur content of 4000 mass ppm or less, particularly Is preferably subjected to a hydrorefining treatment so as to have 2000 ppm by mass or less and a nitrogen content of 1000 ppm by mass or less, particularly 500 ppm by mass or less. Further, a light cycle oil having a boiling point higher than that of the gasoline fraction obtained by the catalytic cracking process, a vacuum distillation residue fraction obtained by the hydrocracking process, or a product obtained by hydrotreating them is also preferably used. For crude oils with relatively low sulfur, nitrogen, vanadium, and nickel content, the raw material for catalytic cracking can be obtained without hydrorefining straight-run gas oil, vacuum gas oil, atmospheric distillation residue, or vacuum residue. It can also be used as oil or as part of it.

[First step]
The products obtained after processing in the catalytic cracker are light gas, fluid catalytic cracking naphtha, light cycle oil, heavy cycle oil, coke. Of these products, those other than coke are distilled in a distillation column to obtain each fraction. In the first step of the present invention, a light naphtha fraction containing most of olefins having 5 or less carbon atoms and a heavy naphtha fraction substantially free of olefins having 5 or less carbon atoms are separated from fluid catalytic cracking naphtha. . A light naphtha fraction and a heavy naphtha fraction may be directly fractionated from the product of the catalytic cracker, or after fractionating a fraction containing these fractions, the fraction is further fractionated to obtain a light naphtha fraction. And heavy naphtha fraction.

The catalytic cracked heavy naphtha fraction inevitably contains an olefin, but the olefin content must be 25% by volume or less, preferably 20% by volume or less in order to suppress the octane loss in hydrodesulfurization. .
Further, it is preferable that the heavy naphtha fraction contains 0 to 10% by volume, particularly 0 to 5% by volume, of the olefin having 5 or less carbon atoms contained in the fluid catalytic cracking naphtha, and 7 or more carbon atoms. The olefin is preferably contained in an amount of 50 to 100% by volume, particularly 75 to 100% by volume. It is preferable that the light naphtha fraction contains 90 to 100% by volume or more, particularly 95 to 100% by volume or more of the olefin having 5 or less carbon atoms contained in the fluid catalytic cracking naphtha. It is preferably contained in an amount of 0 to 50% by volume, particularly 0 to 25% by volume.
Usually, the light naphtha fraction has a 5% distillation temperature of 25 to 50 ° C., a 95% distillation temperature of 60 to 120 ° C., particularly 75 to 100 ° C., and a heavy naphtha fraction has a 5% distillation temperature. It is preferable that the temperature is 50 to 120 ° C., particularly 80 to 120 ° C., and the 95% distillation temperature is 150 to 220 ° C., particularly 170 to 220 ° C. If the heavy naphtha fraction contains a large amount of olefins having 5 or less carbon atoms, the heavy naphtha fraction obtained in the second step will contain many thiols having 5 or less carbon atoms. Thiols with 5 or less carbon atoms have a relatively low boiling point, high volatility, and strong odor, so olefins with 5 or less carbon atoms are heavy so that gasoline with 5 or less carbon atoms is not included in gasoline. It is preferable to perform fractional distillation so that it does not enter the naphtha fraction. The olefin having 5 or less carbon atoms in the heavy naphtha fraction is 1.4% by volume or less, particularly 1.0% by volume or less, and further 0.5 volume. % Or less is preferable.

  It is preferable that olefins having 7 or more carbon atoms are not included in the light naphtha fraction. If olefins with 7 or more carbon atoms are contained in the light naphtha fraction, the sulfur concentration in the light naphtha fraction increases, and desulfurization of the light naphtha fraction is required. At this time, sulfur contained in the light naphtha fraction Since most of the compounds are thiophene sulfur compounds that are not easily desulfurized, it is difficult to desulfurize without loss of octane number. The olefin having 7 or more carbon atoms in the light naphtha fraction is preferably 10% by volume or less, particularly 5% by volume or less, and more preferably 3% by volume or less.

[Treatment to reduce thiols from light naphtha fraction]
As for the light naphtha fraction, if the sulfur content is less than 10 ppm by mass and the sulfur content by thiol is less than 1.5 ppm by mass, no particular treatment is required. When the sulfur content by thiol is 1.5 mass ppm or more, it is preferable to reduce the thiol so that the sulfur content by thiol is less than 1.5 mass ppm. Regarding the treatment for reducing thiol, there are a method of removing sulfur content by thiol and a method of making thiol heavy by another substance that is not thiol.
Extraction-type sweetening process and extraction-oxidation-type sweetening described in Petrotech 17 (11), 974 (1994) and Kodansha Scientific Co., Ltd. “Oil Refining Process” (1998) Examples thereof include a process or a method in which a desulfurization agent having an adsorption or sorption function for sulfur compounds and a catalytically cracked light naphtha fraction are brought into contact with each other. As a method of making thiol into another substance that is not thiol, there is an oxidation-type sweetening process described in Petrotech 17 (11), 974 (1994) and Kodansha Scientific “Oil Refining Process” (1998). In addition, a method of reacting thiols with a diolefin or olefin in catalytic cracking naphtha to make it heavy is a preferable method. The treatment for reducing thiols can be performed either before or after fractional distillation. However, when the thiols are reduced by heavyization, the sulfur content in the light naphtha fraction can be reduced before fractional distillation. Therefore, it is still more preferable.
When the sulfur content of the light naphtha fraction is 10 ppm by mass or more, the sulfur content of the desulfurized catalytic cracked naphtha after mixing with the desulfurized heavy naphtha fraction is 20 ppm by mass or less, preferably 10 ppm by mass or less. It is preferable to perform the desulfurization treatment by the method. The desulfurization treatment is not particularly limited, but there are a method of contacting a light naphtha fraction with a desulfurization agent having adsorption or sorption function of a sulfur compound and a method of selectively removing the sulfur compound from the light naphtha fraction by extraction. It is mentioned as a preferable method. A method of hydrotreating a light naphtha fraction in the presence of a catalyst and hydrogen is also mentioned, but in the presence of high-pressure hydrogen, olefins are easily hydrogenated, and the RON of the resulting gasoline base material is likely to be reduced. . Therefore, the desulfurization treatment is preferably performed in a state where hydrogen is not substantially present or in a hydrogen partial pressure of less than 1 MPa.

[Second step]
In the second step of the present invention, the heavy naphtha fraction obtained in the first step is hydrodesulfurized to obtain a desulfurized heavy naphtha fraction used in the third step. The hydrodesulfurization treatment is performed by bringing the heavy naphtha fraction and the hydrodesulfurization catalyst into contact with each other in the presence of high-pressure hydrogen, and the olefin content reduction rate is 40% or less. As the hydrodesulfurization catalyst, a catalyst in which at least one of molybdenum, nickel, cobalt, and phosphorus is supported on an inorganic porous carrier such as alumina is preferably used. Preferred reaction conditions are a reaction temperature of 150 to 350 ° C., a reaction pressure of 0.1 to 4.0 MPa, LHSV 1.0 to 10 h ⁻¹ , H ₂ / OIL = 50 to 1000 N.
L / L. Particularly preferable reaction conditions are a reaction temperature of 200 to 300 ° C. and a reaction pressure of 1.0 to 1.0.
2.5 MPa, LHSV 2.0 to 6.0 h ⁻¹ , H ₂ / OIL = 100 to 500 NL / L.

  The sulfur content of the heavy naphtha fraction is preferably 50 to 150 mass ppm, particularly 50 to 100 mass ppm. If the heavy naphtha fraction has a high sulfur content, severe hydrorefining is forced and the octane loss is increased, which is not preferable.

  As the feed oil used for the hydrodesulfurization treatment, other gasoline equivalent fraction oil containing a high concentration of sulfur can be selected in addition to catalytic cracking naphtha. Specifically, straight naphtha distilled from an atmospheric distillation unit, thermal naphtha distilled from a pyrolysis unit, dewaxed naphtha distilled from a dewaxing device, direct desulfurization naphtha distilled from a direct desulfurization unit, For example, denaphtha is used while distilling from the indirect desulfurization unit. These may be mixed with the catalytic cracking naphtha before fractionation, or may be mixed with the heavy naphtha fraction after fractionation, but the sulfur content of the heavy naphtha fraction is 200 mass ppm or less, It is preferable to mix so that it may become 150 mass ppm or less. When performing the process which reduces thiols before fractional distillation, it is preferable to mix before that.

The sulfur content of the desulfurized heavy naphtha fraction is 10 ppm by mass or less. By sulfur compound, the thiols are preferably 10 ppm by mass or less, particularly 3 ppm by mass or less, and more preferably 1.5 ppm by mass or less. The aliphatic thiol having 7 or more carbon atoms is preferably from 0.1 to 10 ppm by mass, particularly preferably from 0.1 to 2.5 ppm by mass. The aliphatic thiol having 6 or less carbon atoms is preferably 0.1 to 10 ppm by mass, particularly preferably 0.1 to 2 ppm by mass. When the aliphatic thiol in the desulfurized heavy naphtha fraction is less than 0.1 mass ppm, RON in the hydrorefining treatment is remarkably lowered, which is not preferable.

[Treatment to reduce thiols from desulfurized heavy naphtha fraction]
The method for reducing thiols from the desulfurized heavy naphtha fraction is not particularly limited, but is a method other than hydrodesulfurization, and it is preferable to selectively reduce thiols. Specifically, a method of sweetening thiols in a desulfurized heavy naphtha fraction by contacting with an alkaline substance, or a desulfurizing agent having a sulfur compound adsorption or sorption function and a desulfurized heavy naphtha fraction are contacted. A preferable method is a method of selectively removing thiols by a method.

Conventionally, in petroleum refining, sweetening has been performed to treat thiols to make the product non-brominated, such as Petrotech 17 (11), 974 (1994) and Kodansha Scientific “Oil Refining Process”. The Marlox method described in (1998) is preferably used. In sweetening, since olefins are retained as they are, RON does not decrease. However, the desulfurized heavy naphtha fraction contains a lot of heavy thiols with 7 or more carbon atoms, but such thiols have low reactivity by the conventional Marlox method and may not be converted sufficiently. There is. In that case, it is necessary to select a sweetening process capable of removing heavy thiols. Specifically, MERIC described in NPRA 2000 Annual Meeting AM-00-54
AT-II process and the like.

Thiols are converted to disulfides by the presence of alkaline substances such as caustic soda and ammonia. At this time, conversion efficiency can be improved by using an additive and a catalyst. In addition, since the extraction type sweetening process allows thiols to react with an alkaline substance and be separated from the oil, the sulfur content in the oil can be reduced.
In addition, when the process which reduces thiols from a desulfurization heavy naphtha fraction is performed, the sulfur content contained in the desulfurization heavy naphtha fraction after the thiol reduction treatment is 10 mass ppm or less, more preferably 5 mass ppm or less. 3 mass ppm or less is preferable. Further, the content of thiols is preferably 3 mass ppm or less, more preferably 2 mass ppm or less, and particularly preferably 1 mass ppm or less.

[Treatment with porous desulfurization agent]
The desulfurization agent in the case of using a method of contacting a desulfurization agent having an adsorption or sorption function with a desulfurized heavy naphtha fraction is not particularly limited as long as it has an adsorption or sorption function for a sulfur compound. A porous desulfurization agent containing at least one selected from copper, zinc, nickel and iron is preferably used. A preferred desulfurizing agent is 0.5 to 85% by weight of a metal component such as copper,
In particular, 1 to 80% by weight is contained. The method for producing the desulfurizing agent is not particularly limited, but a metal component such as copper and a component such as aluminum by a production method or a coprecipitation method in which a porous carrier such as alumina is impregnated with a metal component such as copper and supported. A preferable method is a production method in which the above is precipitated and subjected to steps such as molding and baking. Alternatively, the molded and fired desulfurizing agent may be further impregnated and supported with a metal component and fired. The desulfurization agent may be used as it is, or may be used after being treated in a hydrogen atmosphere. The specific surface area of the desulfurizing agent, ^{50 m} 2 / g or more, particularly 200~600m ² / g are preferred. The composition and production method of the desulfurizing agent are not particularly limited, and preferred desulfurizing agents are those disclosed in Japanese Patent No. 3324746, Japanese Patent No. 3230864, and Japanese Patent Laid-Open No. 11-61154.

The desulfurization treatment may be performed in a batch system or a flow system, but it is possible to obtain a desulfurization agent by performing a desulfurization heavy naphtha fraction through a fixed bed desulfurization tower filled with a desulfurization agent. This is preferable because the desulfurized heavy naphtha fraction can be easily separated. The temperature for the desulfurization treatment can be selected from the range of 15 to 400 ° C, and preferably from the range of 80 to 380 ° C. The desulfurization treatment may be performed in the presence of hydrogen. However, the hydrogen partial pressure is preferably less than 1 MPa, and more preferably less than 0.6 MPa in order to avoid hydrogenation of the olefin and a decrease in RON of the resulting gasoline base material. When the desulfurization treatment is performed by contacting the desulfurizing agent and the light naphtha fraction in a fixed bed flow type, the LHSV is preferably selected from the range of 0.01 to 10,000 h ⁻¹ .

[Other gasoline base materials used in the third step]
In the present invention, as other gasoline base materials mixed in the third step with light naphtha fraction and desulfurized heavy naphtha fraction, catalytic reforming gasoline base material, alkylate gasoline base material, straight-run naphtha is desulfurized. Treated base materials and known gasoline base materials such as methyl t-butyl ether (MTBE), ethyl t-butyl ether (ETBE), t-amyl ethyl ether (TAEE), and oxygen-containing gasoline base materials such as ethanol and methanol are used. be able to. The other gasoline base material to be mixed preferably has a sulfur content of 10 mass ppm or less, and more preferably 5 mass ppm or less. When the sulfur content of other gasoline bases exceeds 10 ppm by mass, the blending amount into the light naphtha fraction and the desulfurized heavy naphtha fraction is restricted, which is not preferable.

  Preferred blending amounts are 20 to 60% by volume of light naphtha fraction, particularly 30 to 50% by volume, 25 to 65% by volume of desulfurized heavy naphtha fraction, particularly 35 to 55% by volume, and a catalytically modified gasoline base. 5 to 50% by volume, particularly 10 to 40% by volume, and 50% by volume or less of other base materials such as desulfurized straight run naphtha, particularly 5 to 35% by volume.

[Other ingredients]
Furthermore, the gasoline composition of the present invention may contain 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.

[Environmentally friendly gasoline]
The environmentally friendly gasoline according to the present invention has a total sulfur content of 10 mass ppm or less, preferably 5 mass ppm or less, and preferably the total sulfur content of thiols and sulfur content of thiophenes is 50 mass% or more of the total sulfur content. Furthermore, it is preferable that the sulfur content by thiophenes occupy 30% by mass or more of the total sulfur content. Moreover, the sulfur content by aliphatic thiol having 7 or more carbon atoms occupies 50 mass% or more of the sulfur content by thiols, and the research octane number is 89-96. Preferably, the doctor test is negative and / or the antioxidant is contained in an amount of 30 ppm by mass or more, and the evaluation by the copper plate corrosion test is 1 or less.

Preferably, the 50 volume% distillation temperature is 105 ° C. or less, preferably 80 to 100 ° C., and the olefin content is 10 volume% or more, preferably 10 to 30 volume%. Sulfur content is 0.1
10 mass ppm is preferred. For each sulfur compound, the thiols are preferably 3.0 ppm by mass or less, particularly 1.5 ppm by mass or less. The aliphatic thiol having 7 or more carbon atoms is preferably 50% by mass or more of all thiols. Setting the aliphatic thiol having 7 or more carbon atoms to less than 50% by mass in the total thiols is not preferable because RON is significantly impaired. The aliphatic thiol having 6 or less carbon atoms is preferably 1.5 mass ppm or less, particularly preferably 1.0 mass ppm or less.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto. In this example, the density was measured according to JIS K 2249, the distillation property was measured according to JIS K 2254, and the vapor pressure was measured according to JIS K 2258. The sulfur content was measured by the microcoulometric titration method of JIS K2541. The content of sulfur compounds (in terms of sulfur) was measured by gas chromatography using a Shimadzu gas chromatograph equipped with an ANTEK sulfur chemiluminescence detector that selectively detects and quantifies sulfur compounds by chemiluminescence. . The hydrocarbon component composition and RON were measured by a gas chromatograph method using a PIONA device manufactured by Hewlett-Packard Company. Doctor test is JIS K
In 2276, copper plate corrosion was measured according to JIS K2513.

  A naphtha fraction A obtained by fluid catalytic cracking using a hydrorefined gas oil fraction of Middle Eastern crude oil hydrotreated and a hydrorefined residue of atmospheric distillation residue as the main feed oil, is an oxidized sweet The naphtha fraction B was obtained by processing with a ning apparatus. The properties of these fractions are shown in Tables 1 and 2. Naphtha fraction B was fractionated to obtain light naphtha fraction C and heavy naphtha fraction D. The properties of these fractions are shown in Tables 3 and 4. Here, the sweetening process was performed by the Marlocks process of UOP.

This heavy naphtha fraction D is a catalyst in which cobalt, molybdenum and phosphorus are supported on alumina (cobalt content 2.4% by mass, molybdenum content 9.4% by mass, phosphorus content 2.0% by mass)
Is used for hydrodesulfurization under conditions of a reaction temperature of 250 ° C., a reaction pressure of 1.0 MPa, LHSV = 5.0 h ⁻¹ , H ₂ / OIL = 307 NL / L, and a desulfurized heavy naphtha fraction G is obtained. It was. Properties of this fraction are shown in Tables 7 and 8.

  This desulfurized heavy naphtha fraction G, light naphtha fraction C, and other gasoline base materials having properties shown in Table 9 (desulfurized naphtha L, catalytic reforming medium oil M, catalytic reforming heavy oil N, al Chelated gasoline O) was blended in the blending amounts shown in Table 10, and 10 mass ppm of antioxidant, a colorant and a cleaning dispersant were added to obtain an unleaded gasoline composition P. As the antioxidant, AO-550 manufactured by ACTEL was used. Properties of the unleaded gasoline composition P are shown in Tables 11 and 12.

  Hydrodesulfurization was performed in the same manner as in Example 1 except that the same heavy naphtha fraction D as in Example 1 was set at a reaction temperature of 240 ° C., and a desulfurized heavy naphtha fraction H was obtained. This desulfurized heavy naphtha fraction H, light naphtha fraction C, and another gasoline base material similar to that of Example 1 were blended in the blending amounts shown in Table 10, antioxidant 100 mass ppm, colorant, detergent dispersant Was added to obtain an unleaded gasoline composition Q. Properties of desulfurized heavy naphtha fraction H and unleaded gasoline composition Q are shown in Tables 7, 8, 11 and 12.

  Desulfurized heavy naphtha fraction H100 cc obtained by the same method as in Example 2 was added to 100 cc of 12N sodium hydroxide solution and brought into contact with stirring at room temperature for 30 minutes, and then the oil was extracted and desulfurized heavy. A quality naphtha fraction I was obtained. This desulfurized heavy naphtha fraction I, light naphtha fraction C, and another gasoline base material similar to that in Example 1 were blended in the blending amounts shown in Table 10, and 10 mass ppm of antioxidant as in Example 1, A colorant and a detergent / dispersant were added to obtain an unleaded gasoline composition R. Properties of desulfurized heavy naphtha fraction I and unleaded gasoline composition R are shown in Tables 7, 8, 11 and 12.

Desulfurized heavy naphtha fraction H100cc obtained by the same method as in Example 2 and 20 g of a copper oxide-alumina desulfurizing agent (containing 7.6% by mass of copper as a metal atom) at room temperature for 2 hours in a flask Then, the desulfurization agent was filtered off to obtain a desulfurized heavy naphtha fraction J. This desulfurized heavy naphtha fraction J, light naphtha fraction C, and another gasoline base material similar to that in Example 1 were blended in the blending amounts shown in Table 10, and in the same manner as in Example 1, 10 mass ppm of antioxidant, A colorant and a detergent / dispersant were added to obtain an unleaded gasoline composition S. Properties of the desulfurized heavy naphtha fraction J and the unleaded gasoline composition S are shown in Tables 7, 8, 11 and 12.

Comparative Example 1

  The same naphtha fraction B as in Example 1 was fractionated to obtain a light naphtha fraction E and a heavy naphtha fraction F. Tables 5 and 6 show properties and composition of light naphtha fraction E and heavy naphtha fraction F. Among these, the heavy naphtha fraction F was hydrodesulfurized in the same manner as in Example 2 to obtain a desulfurized heavy naphtha fraction K. This desulfurized heavy naphtha fraction K, light naphtha fraction E, and another gasoline base material similar to that in Example 1 were blended in the blending amounts shown in Table 10, antioxidant 100 mass ppm, colorant, detergent dispersant Was added to obtain an unleaded gasoline composition T. Properties of desulfurized heavy naphtha fraction K and unleaded gasoline composition T are shown in Tables 7, 8, 11 and 12.

  The same heavy naphtha fraction D as in Example 1 was hydrodesulfurized in the same manner as in Example 2 to obtain a desulfurized heavy naphtha fraction H. The desulfurized heavy naphtha fraction H, the light naphtha fraction C, and another gasoline base material similar to that in Example 1 were blended in the blending amounts shown in Table 10, and 10 mass ppm of antioxidant as in Example 1, A colorant and a cleaning dispersant were added to obtain an unleaded gasoline composition U. Properties of the desulfurized heavy naphtha fraction H and unleaded gasoline composition U are shown in Tables 7, 8, 11 and 12.

  The desulfurized heavy naphtha fraction G used in Example 1 was further sweetened by the same method as in Example 3, that is, desulfurized heavy naphtha fraction G100 cc was added to 100 cc of 12N sodium hydroxide solution, Then, the oil component was extracted to obtain a desulfurized heavy naphtha fraction X with further reduced sulfur content. This desulfurized heavy naphtha fraction X, light naphtha fraction C, and other gasoline base materials in Table 9 were blended in the blending amounts in Table 10, and 10 mass ppm of antioxidant and colorant in the same manner as in Example 1. Then, a detergent dispersant was added to obtain an unleaded gasoline composition V. Tables 7, 8, 11 and 12 show the properties and component compositions of desulfurized heavy naphtha fraction X and unleaded gasoline composition V.

  As can be seen by comparing the examples and comparative examples, by fractionating so that 5% or less of the C5 olefin in the catalytic cracking naphtha is contained in the heavy naphtha fraction, by desulfurizing only the heavy naphtha fraction, The thiols contained in the desulfurized catalytic cracking naphtha are 50% or more of aliphatic thiols having a relatively weak odor and having 7 or more carbon atoms. Therefore, gasoline mixed with this has a weaker odor than gasoline containing a large amount of aliphatic thiols having 6 or less carbon atoms. The doctor test is also negative. Even if it is positive as in Example 5, it can be easily made negative by adjusting the amount of addition of antioxidant as shown in Example 2, and the environmental impact of the present invention was reduced. The product value of environmentally friendly gasoline with ultra-low sulfur content can be improved.

Claims (7)

In a first step and a first step, a fluid catalytic cracking naphtha is fractionated to obtain a catalytic cracking heavy naphtha fraction having a 5% distillation temperature of 50 to 120 ° C and a 95% distillation temperature of 150 to 220 ° C. The obtained catalytic cracked heavy naphtha fraction has a sulfur content of 50 to 150 mass ppm and an olefin content of 25% by volume or less. The catalytic cracked heavy naphtha fraction has an olefin content reduction rate of 40% or less. Including a second step of hydrodesulfurizing under conditions to obtain a desulfurized catalytic cracking heavy naphtha fraction, the sulfur content is 10 mass ppm or less, the sulfur content by thiophenes is 30 mass% or more of the total sulfur, and the research octane number is The manufacturing method of the gasoline base material which is 85 or more.   The method for producing a gasoline base material according to claim 1, wherein the sulfur content is 5 ppm by mass or less.   The method for producing a gasoline base material according to claim 1 or 2, wherein the desulfurization catalytic cracking heavy naphtha fraction is brought into contact with an alkaline substance so that the contained sulfur content is 3 mass ppm or less and the thiol content is 1 mass ppm or less. .   A sulfur content of 10 mass ppm or less, comprising a blending step of mixing the gasoline base material according to any one of claims 1 to 3 with another gasoline base material with a sulfur content of 10 mass ppm or less, and research. A method for producing environmentally friendly gasoline with an octane number of 89 or more.   An environmentally friendly gasoline having a total sulfur content of 10 ppm by mass or less, a total sulfur content of thiols and a sulfur content of thiophenes accounting for 50 mass% or more of the total sulfur content, and a research octane number of 89 to 96.   The environmentally friendly gasoline according to claim 5, wherein the sulfur content of thiophenes accounts for 30% by mass or more of the total sulfur content.   Furthermore, the environmentally friendly gasoline according to claim 5 or 6, wherein the olefin content is 10 to 30% by volume.