WO2006120898A1

WO2006120898A1 - Process for producing low-sulfur cracked-gasoline base and lead-free gasoline composition

Info

Publication number: WO2006120898A1
Application number: PCT/JP2006/308696
Authority: WO
Inventors: Yasuhiro Araki; Katsuaki Ishida
Original assignee: Japan Energy Corporation
Priority date: 2005-05-06
Filing date: 2006-04-26
Publication date: 2006-11-16
Also published as: JPWO2006120898A1; JP5219247B2

Abstract

A lead-free gasoline composition reduced in sulfur content while ensuring sufficient driving performance; a process for producing the composition; and a process for producing a low-sulfur cracked-gasoline base suitable for preparing the gasoline composition. The process for producing a low-sulfur cracked-gasoline base is characterized by comprising: a step (A) in which cracked-gasoline fractions are obtained; a step (B) in which a heavy cracked-gasoline fraction obtained in the step (A) is hydrodesulfurized; a step (C) in which the whole or part of a light cracked-gasoline fraction obtained in the step (A) and/or the whole or part of the heavy cracked-gasoline fraction reduced in sulfur content obtained in the step (B) is subjected to sorption desulfurization; and a step (D) in which the cracked-gasoline fractions obtained in the steps (A) to (C) are mixed together to obtain a low-sulfur cracked-gasoline base having a specific sulfur content and a specific octane value.

Description

Specification

Method for producing low sulfur cracking gasoline base and unleaded gasoline composition

Technical field

[0001] The present invention relates to a method for producing a low-sulfur cracking gasoline base material with reduced environmental impact, and an unleaded gasoline composition.

Background art

[0002] Cracked gasoline fractions produced by cracking heavy petroleum fractions, such as catalytic cracking and thermal cracking, can be produced more economically than other gasoline bases. ) Has a relatively high olefin content, and is used as a base material for unleaded gasoline compositions. However, the cracked gasoline fraction contains a large amount of sulfur, so if a gasoline composition containing a large amount of the cracked gasoline fraction is used as fuel, the NOx storage type gasoline automobile exhaust gas purification catalyst will work effectively. The problem of not being able to make it happen.

[0003] The sulfur content in the cracked gasoline fraction can be easily reduced by a known technique in which the cracked gasoline fraction is hydrotreated in the presence of high-pressure hydrogen and a catalyst. However, in that case, the olefin component, which is contained in the cracked gasoline fraction and is relatively hydrogenated, is hydrogenated to lower the RON of the base material. The unleaded gasoline composition blended with oil as a base material has the problem that sufficient driving performance cannot be obtained.

[0004] For example, (1) after catalytic cracking gasoline with a sulfur content of 200 mass ppm or less is sweet-junged, it is distilled into a light fraction with a sulfur content of 20 mass ppm or less and a heavy fraction containing the remaining sulfur content. Obtained by the step of separating, (2) the hydrodesulfurization of the heavy fraction so that the decrease in the research octane number is 3 or less and the sulfur content is 20 mass ppm or less, and (3) the step of (1). Mixing the light fraction, the heavy fraction obtained in step (2), and a gasoline base material other than catalytic cracking gasoline with a sulfur content of 10 mass ppm or less, the sulfur content A process for producing a product gasoline of 8 mass ppm or less and a powerful method for producing low sulfur gasoline have been proposed (see Patent Document 1). However, with this method, olefins are hydrogenated and paraffinized. Because it changes to IN, it is not possible to maintain sufficient RON to ensure practical performance.

[0005] On the other hand, a hydrocarbon oil is brought into contact with an adsorbent under specific conditions to adsorb a sulfur compound, and a sulfur compound is desorbed from the adsorbent by passing hydrogen through the adsorbent. By repeating this process, a method has been proposed in which unnecessary reactions such as the hydrogenation reaction of olefins are suppressed, and the sulfur content in hydrocarbon oil that is the base material of gasoline is continuously reduced (patent document). 2). However, the method using such an adsorbent also reduces the sulfur content efficiently and continuously because the adsorption capability of sulfur is hindered because of the specific hydrocarbon compound contained in the feedstock. I couldn't do it, and it wasn't always a satisfactory way. Patent Document 1: Japanese Unexamined Patent Publication No. 2003-183676

Patent Document 2: Japanese Patent Laid-Open No. 2003-277768

Disclosure of the invention

Problems to be solved by the invention

[0006] As described above, a method for producing an unleaded gasoline composition that has reduced sulfur content and maintained sufficient RON to ensure practical performance has not yet been established. Under such circumstances, the present invention uses a method for producing a low-sulfur cracked gasoline base material with reduced sulfur content while ensuring sufficient operating performance, and using the low-sulfur cracked gasoline base material. The challenge is to provide an unleaded gasoline composition.

Means for solving the problem

[0007] As a result of diligent research to solve the above problems, the present inventors have conducted a process of fractionating cracked gasoline and contacting each fraction with a catalyst containing molybdenum or tungsten in the presence of hydrogen. In addition, the present inventors found that the sulfur content of the cracked gasoline base material can be reduced while minimizing the loss of octane number by desulfurization by appropriately combining the treatment with a desulfurization agent containing nickel and zinc in the presence of hydrogen. It was.

That is, the present invention provides:

(1) A fractionation process in which a cracked gasoline fraction is fractionated to obtain a light cracked gasoline fraction and a heavy cracked gasoline fraction (Step A),

A hydrodesulfurization step (step B) in which the heavy cracked gasoline fraction obtained in step A is contacted with a catalyst containing molybdenum and Z or tungsten in the presence of hydrogen to reduce the sulfur content (step B); All or part of the light cracked gasoline fraction obtained in Step A and the heavy cracked gasoline fraction with reduced sulfur content obtained in Z or Step B contains nickel and zinc in the presence of hydrogen. Contact with a porous desulfurizing agent to reduce and remove sulfur to 5 mass ppm or less.

Mixing step of mixing the cracked gasoline fraction obtained in steps A to C to obtain a low sulfur cracked gasoline base material having a sulfur content of 12 mass ppm or less and a research octane number of 85.0 or more (step D)

including

It is a manufacturing method of the low sulfur decomposition gasoline base material characterized by the above-mentioned.

[0009] After the process A and the process B, the preliminary desulfurization control coefficient α expressed by the following formula (1) is 12 to 30

a = (LW X LS + HW X HS) / 100 (1)

(Where LW is the fraction of light cracked gasoline fractionated in process A (volume%), LS is the sulfur content in the light cracked gasoline obtained in process A (mass ppm), and HW is in process A. The fraction (volume%) of the heavy cracked gasoline fractionated in this manner and HS represents the sulfur content (mass ppm) in the heavy cracked gasoline obtained in Step B).

[0010] In the method for producing a low-sulfur cracked gasoline base material of the present invention, the ratio of supplying to the process C and treating with respect to the total amount of cracked gasoline supplied to the process A is 20% by volume or more and 90% by volume or less. It is preferable.

Prior to Step B or Step C, the whole or part of the cracked gasoline fraction is brought into contact with a catalyst containing at least one metal selected from Group 8 element force in the periodic table in the presence of hydrogen. It is preferable to include a Gen reduction processing step (Process E) that performs Gen reduction processing. Further, it is preferable to include a pretreatment step (step F) that increases the molecular weight of the sulfur-containing compound contained in the cracked gasoline fraction before step A or at the same time as the fractionation step of step A.

[0011] Further, the present invention contains 30% by volume or more of the low sulfur cracking gasoline base material produced by the above method, the research octane number is 89 or more, the sulfur content is 10 mass ppm or less, and the doctor test is negative. It is a lead-free gasoline composition that has a corrosive power of silver plate or less.

Sarako, research method octane number 92 or more, sulfur content 10 mass ppm or less, doctor test A lead-free gasoline composition which is negative and has a silver plate corrosive power ^ or less is preferred.

The invention's effect

[0012] Various cracked gasoline fractions such as catalytically cracked gasoline fractions and pyrolyzed gasoline fractions are rich in high octane olefins. In the present invention, hydrodesulfurization using a catalyst containing molybdenum or tungsten and an appropriate combination of treatment with a porous desulfurization agent containing nickel and zinc in the presence of hydrogen can be used for decomposition while minimizing olefin loss. It is possible to reduce the sulfur content of gasoline. In addition, since the loss of olefins is minimal and neither the octane number nor the octane number decreases, it is possible to reduce the sulfur content to 12 ppm by mass or less without changing the properties such as octane number.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] [cracked gasoline fraction]

The cracked gasoline fraction in the method for producing a low sulfur cracked gasoline base material of the present invention is a petroleum fraction, a refined process oil, a petrochemical process oil, a coal liquefied oil, an oil sand, an oil shale, a polyolefin, a plastic, A hydrocarbon compound with a lower molecular weight, obtained by decomposing hydrocarbons such as waste plastics, and refers to a fraction having a carbon number of 4 or more and a boiling point of 250 ° C or less. Typical processes for obtaining cracked gasoline fractions include catalytic cracking processes and thermal cracking processes. Cracking process power for decomposing hydrocarbon compounds such as gasoline, kerosene, and light oil to obtain olefins such as ethylene and propylene By-product fraction with a carbon number of approximately S4 or more and a boiling point of 250 ° C or less Also, degassing gasoline fractions obtained from catalytic degassing processes that selectively decompose normal paraffin compounds contained in light oil and lubricating oil to improve low-temperature fluidity should be used as cracked gasoline fractions of the present invention. Can do.

In the present invention, two or more cracked gasoline fractions obtained by the above various cracking processes are used in combination.

[0014] As the cracked gasoline fraction in the method for producing a low sulfur cracked gasoline base material of the present invention, a catalytic cracked gasoline fraction can be preferably used. The process for producing the catalytic cracking gasoline fraction can employ any known production process that does not specifically limit the catalytic cracking equipment, feedstock, and operating conditions. Catalytic cracking equipment includes amorphous silica alumina, zeolite, etc. In addition to the oil fraction from diesel oil to vacuum diesel oil, the catalytic cracking of diesel fuel oil obtained from heavy oil indirect desulfurization equipment, direct desulfurization oil obtained from heavy oil direct desulfurization equipment, and atmospheric residual oil This is a device for obtaining a high octane gasoline base material. The catalytic cracking feed oil preferably has a sulfur content of 8000 ppm by mass or less, particularly preferably 4000 ppm by mass or less, more preferably ί or 2000 ppm by mass, or more, or 1000 ppm by mass or less. Use fractions reduced to 500 mass ppm or less by hydrorefining. Specific catalytic cracking methods include, for example, UOP catalytic cracking method, flexi cracking method, ultra-orthoflow method, fluid catalytic cracking method such as Texaco fluid catalytic cracking method, residual oil fluid catalytic cracking such as RCC method and HOC method. (The Petroleum Institute of Japan, Petroleum Refining Process, P. 125, Kodansha Scientific Fukui (1998)).

[0015] A heavy oil pyrolysis gasoline fraction can also be used as the cracked gasoline fraction preferably used in the method for producing a low sulfur cracking gasoline base material of the present invention. Heavy oil pyrolysis A gasoline fraction is a fraction with a carbon number of approximately 4 or more and a boiling point of 250 ° C or less obtained by applying a heat reaction to a heavy oil fraction and mainly a radical reaction. For example, a fraction obtained by a delayed coking method, a visbreaking method or a fluid coking method.

[0016] [Fractionation process (Process A))

Cracked gasoline fractions, particularly catalytic cracked gasoline fractions, contain relatively high RON olefinic compounds in light distillates, but do not contain much sulfur. In contrast, the heavy fraction contains a relatively large amount of sulfur, but does not contain a large amount of olefin compounds with high RON. Therefore, in order to effectively use cracked gasoline fractions, particularly catalytic cracked gasoline fractions, as the base material for unleaded gasoline compositions, the sulfur content in the light cracked gasoline fraction used as the base material is sufficiently low. Thus, it is preferable to carry out fractional distillation. For example, fractional distillation is performed so that the sulfur content is 20 mass ppm or less, particularly 10 mass ppm or less. The light cracked gasoline fraction obtained in this way does not need to be subjected to a hydrodesulfurization step in which it is brought into contact with a hydrodesulfurization catalyst in the presence of high-pressure hydrogen as in step B described later. Since the olefinic compound is not hydrogenated, a decrease in RON of the light cracked gasoline fraction can be avoided. In order to increase the degree of freedom in blending base materials into unleaded gasoline compositions, Further fractionate and subdivide at least one of cracked gasoline fraction and heavy cracked gasoline fraction

The cracked gasoline fraction may be fractionated into three or more fractions. Then, the hydrodesulfurization step (step B) described later is performed on the heavy cracked gasoline fraction containing a relatively large amount of sulfur. As a result, the load on the collection / removal sulfur process (process C) described later can be reduced, and desulfurization can be carried out economically.

[0017] The preferred properties of the fractionated light cracked gasoline fraction are: 5% distillation temperature 35-55 ° C, especially 40-50 ° C, 95% distillation temperature 65-125 ° C, especially is seventy-five to one hundred fifteen ° C, sulfur content L～50ppm, particularly 5 to 20 ppm, Orefin content 30-70 volume ^_0/0, especially from 40-60% by volume. The heavy cracked gasoline fraction is heavier than the light cracked gasoline fraction, and usually has a higher sulfur content and lower olefin content than the light cracked gasoline fraction. Preferred properties of the fractionated heavy cracked gasoline fraction, 5% distillation temperature of 80 to 170 ° C, particularly 95~160 ^o C, 95 ^_0/0 distillation temperature strength S175～215. C, especially ί or 190-220. Is C, sulfur force ^ 20~500ppm, particularly ί or 50~300ppm, old olefin component force 1-35 capacity ^_0/0, is particularly ί or 5-25% by volume.

The fractionation step fractionates the cracked gasoline fraction obtained from a cracking process such as a catalytic cracking process, but the light cracking gasoline fraction directly from the fractionation step included in the final stage of the cracking process. And heavy cracked gasoline fractions can also be obtained.

[0018] [Hydrodesulphurization process (process Β)]

Process IV is a process in which the heavy cracked gasoline fraction obtained in Process IV and the hydrodesulfurization catalyst are brought into contact with each other in the presence of high-pressure hydrogen to separate the sulfur as hydrogen sulfide and hydrodesulfurize it. . Since heavy cracked gasoline fractions contain relatively large amounts of sulfur, all heavy cracked gasoline fractions are usually hydrodesulfurized to supply low sulfur gasoline, but most of them. Specifically, it is preferable to hydrodesulfurize 80% by volume or more, particularly 90% by volume or more. Through the hydrodesulfurization process, the sulfur content of the heavy cracked gasoline fraction can be 5-50 ppm, preferably 10-30 ppm.

[0019] The hydrodesulfurization catalyst contains molybdenum and Z or tungsten, and is preferably one in which molybdenum or tungsten is supported on an inorganic porous carrier such as alumina. The hydrodesulfurization catalyst has a total content of molybdenum and tungsten of 2 to 20% by mass, especially Is preferably 5 to 15% by mass. The content is defined by mass% of the metal element contained in the catalyst. There are no particular restrictions on the component elements other than molybdenum or tungsten contained in the catalyst. Preferred components that may be contained include cobalt, phosphorus, potassium, carbon, nitrogen, and the like. The cobalt content is from 0.5 to 10 mass ^_0/0, especially 1 to 5 wt%, the content of phosphorus 0.1. 2 to: LO wt%, particularly is 5-5 wt% 0.1 Is preferred. Usually, the catalyst is used after sulfiding.

[0020] Preferred reaction conditions include a reaction temperature of 150 to 350 ° C, the reaction pressure 0.1～4.0MPa, liquid hourly space velocity (LHSV) 1.0~10h ^_1, is hydrogen Z oil ratio 50～1000NLZL. Particularly preferred reaction conditions include a reaction temperature of 200 to 300 [° C, the reaction pressure 0.5~2.5MPa, LHSV2.0~6.0h ^_1, is hydrogen Z oil ratio 100～600NLZL. The reaction pressure in this specification is indicated by gauge pressure. The heavy cracked gasoline fraction does not contain a relatively high amount of olefinic compounds with high RON. However, when hydrogenated, the olefinic compounds may be saturated and RON may be reduced. However, operation under conditions where the olefin content is reduced by 20% or more, further 10% or more, particularly 3% or more is not preferable.

[0021] In Step B, hydrogen sulfide produced by hydrodesulfurization reacts with olefins that are usually contained in cracked gasoline to produce thiols, but if gasoline contains thiols, corrosion of gasoline car parts will occur. Cause unpleasant odor. The thiols in the cracked gasoline that has undergone Step B are preferably removed after going through Step C, which will be described later. Although this removal method is not particularly limited, it is preferable to remove thiols by a method of converting thiols typified by acid-sweet jung to disulfide. Furthermore, thiols contained in heavy cracked gasoline usually have about 5 to 10 carbon atoms, and it is preferable to apply an oxidized sweet-jung process that can remove even thiols having a large carbon number. Specific examples include the MERICAT-II process described in NPRA 2000 Annual Meeting AM-00-54. The details of such sweetening will be described later as a method for increasing the molecular weight of the sulfur compound. As another removal method, it is preferable to reduce the thiols in the gasoline base material in advance so that the sulfur content of the thiols in the unleaded gasoline composition is 2 mass ppm or less, and further 1 mass ppm or less. . [0022] [Removal and removal sulfur process (Process C)]

In the present invention, after performing Step A and Step B, in the coexistence of hydrogen, a desulfurization agent containing nickel and zinc and various cracked gasoline fractions obtained in Step A and Step B, that is, Step A The obtained light cracked gasoline fraction and the heavy cracked gasoline fraction and the heavy cracked gasoline fraction obtained in step B are brought into contact with each or all or a part thereof to reduce the sulfur content. Perform a sorption desulfurization step (Step C) to desulfurize to 5 ppm by mass or less, preferably 1 ppm by mass or less.

[0023] In the stage after Step A and Step B, the preliminary desulfurization control coefficient α represented by the following formula (1) is preferably 12-30, more preferably 13-20.

a = (LWX LS + HWX HS) / 100 (1)

Where LW is the fraction (volume%) of the light cracked gasoline fraction fractionated in step A, LS is the sulfur content (mass ppm) in the light cracked gasoline fraction obtained in step A, HW Indicates the fraction (volume%) of the heavy cracked gasoline fraction fractionated in step A, and HS indicates the sulfur content (mass ppm) in the heavy cracked gasoline fraction obtained in step B. The ratio of the light cracked gasoline fraction and the ratio of the heavy cracked gasoline fraction are the ratio to the capacity of 100% by volume of cracked gasoline fractionated in the process A. The ratio HW of the heavy cracked gasoline fraction fractionated in step A is preferably 10 to 80% by volume, particularly 25 to 60% by volume.

This prevents excessive hydrogenation while desulfurizing moderately, so that the decrease in RON can be controlled to a minimum, and desulfurization can be performed economically. If the preliminary desulfurization control coefficient α is less than 12, it is not preferable because the decrease in RON increases. If a exceeds 30, the raw material sulfur concentration in Step C becomes high, and the life of the desulfurizing agent containing nickel and zinc is shortened.

[0024] Hydrocracking a cracked gasoline fraction in the presence of a hydrodesulfurization catalyst and hydrogen to desulfurize it to a sulfur content of 5 mass ppm or less means that the RON of the gasoline base material obtained by hydrogenating olefin is Decreasing and not preferable. Furthermore, since hydrogen sulfide produced by hydrodesulfurization reacts with olefin to regenerate thiols, it is not preferable because it cannot be sufficiently desulfurized. When a porous desulfurization agent containing nickel and zinc is used in the presence of hydrogen, sulfur removed from the organic sulfur compound is fixed on the desulfurization agent and does not generate hydrogen sulfide. React with fins to regenerate thiols.

[0025] The feedstock used in Step C was obtained by contacting the hydrocracked catalyst in the presence of high-pressure hydrogen in Step B or in part or all of the light cracked gasoline fraction obtained in Step A. Use all or part of the heavy cracked gasoline fraction. Alternatively, use a mixture of each in an appropriate ratio.

When the light cracked gasoline fraction obtained in Process A is used in Process C, it is preferable to use 30 to 100% by volume of the light cracked gasoline fraction as the feedstock. When the heavy cracked gasoline fraction obtained in Step B is used in Step C, it is preferable to use 30 to L00 vol% of the heavy cracked gasoline fraction as the feedstock.

[0026] The ratio of treatment in Step C to the total amount of cracked gasoline before being used in Step A is 20% by volume or more and 90% by volume or less, particularly 25% by volume or more and 70% by volume or less. LV preferred. If the rate of treatment in Step C is less than 20% by volume, a sufficient effect of suppressing the decrease in octane number cannot be obtained. If the proportion treated in Step C exceeds 90% by volume, the life of the desulfurizing agent containing nickel and zinc is shortened, which is not preferable.

[0027] The porous desulfurization agent of the present invention contains nickel and zinc. The method for producing a porous desulfurization agent containing nickel and zinc in the present invention is not particularly limited! However, a porous carrier such as alumina is impregnated with metal components such as zinc and nickel, and fired. A preferable method is a production method or a production method in which a metal component such as zinc or nickel is precipitated by filtration and washed by a coprecipitation method, followed by steps such as molding and baking. In addition to nickel and zinc, other elements such as iron and copper may be included. The elemental mass ratio of nickel to zinc is preferably 1 to 50% by mass, particularly preferably 2 to 35% by mass, and more preferably 5 to 30% by mass with respect to 100% by mass of the total elemental mass of zinc and nickel. is there. The nickel content is preferably 33% by mass or less, more preferably 20% by mass or less, based on the total mass of the desulfurizing agent. The zinc content is preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 55% by mass or more with respect to the total mass of the desulfurizing agent. If the nickel content exceeds 50% by mass or the zinc content is less than 30% by mass, the life of the porous desulfurizing agent is shortened, which is not preferable. The sodium content is preferably 1.0% by mass or less based on the total mass of the desulfurizing agent, more preferably 0.5% by mass or less, and further 0 2% by mass or less. If sodium is contained in an amount exceeding 1.0 mass% with respect to the total mass of the desulfurizing agent, the desulfurization performance is lowered, which is not preferable. A preferable desulfurizing agent contains 30 to 85% by mass, particularly 50 to 80% by mass of a metal component such as nickel and zinc. Further, the molded and fired desulfurizing agent may be further impregnated and supported with a metal component and fired. The desulfurizing agent is preferably used after being treated in a hydrogen atmosphere. The specific surface area of the desulfurizing agent is preferably 30 m ² / g or more, particularly preferably 50 to 600 m ² Zg.

[0028] The porous desulfurization agent of the present invention is preferably a porous desulfurization agent having a sulfur sorption function. The porous desulfurization agent having a sulfur sorption function here is to fix the sulfur atom in the organic sulfur compound to the desulfurization agent, and for hydrocarbon residues other than the sulfur atom in the organic sulfur compound. A porous desulfurization agent having a function of desorbing from a desulfurization agent by cleaving a carbon-sulfur bond in an organic sulfur compound. When this hydrocarbon residue is eliminated, hydrogen present in the system is added to carbon whose bond with sulfur has been cleaved. Therefore, organic sulfur-compound strength hydrocarbon compounds from which sulfur atoms are removed are obtained as products. However, hydrocarbon compounds from which sulfur atoms have been removed may give products that have undergone reactions such as hydrogenation, isomerization, and decomposition. Since sulfur is fixed to the desulfurizing agent in the detachable sulfur, it does not generate sulfur compounds such as hydrogen sulfide as a product, unlike hydrorefining. Further, since hydrogen sulfide is not generated, hydrogen sulfide is not included in the recital hydrogen or purge hydrogen, and no facility for removing hydrogen sulfide is required, so that desulfurization can be achieved economically.

[0029] The collection / removal sulfur treatment may be carried out by a notch type or a flow type, but the light cracked gasoline fraction or the heavy cracked gasoline fraction is placed in a fixed bed desulfurization tower filled with a desulfurizing agent. It is preferable to carry out the distribution of the fraction because the separation of the desulfurization agent and the obtained desulfurized cracked gasoline fraction can be easily performed. The temperature in the desulfurization treatment is preferably 100 to 400 ° C, more preferably 200 to 350 ° C, and particularly preferably 250 to 350 ° C. If the reaction temperature is less than 100 ° C, the desulfurization rate decreases, and desulfurization cannot be efficiently performed, which is not preferable. On the other hand, if the reaction temperature exceeds 400 ° C, the desulfurization agent is sintered, and the desulfurization capacity is lowered, which is not preferable. In order to promote desulfurization of thiophenes that are difficult to desulfurize only by contacting with a desulfurizing agent, hydrogen is allowed to coexist. The reaction pressure is preferably 0 to 5. OMPa, more preferably 0 to 3. OMPa, and particularly preferably 0 to 5. 2. It is OMPa. If the reaction pressure exceeds 5. OMPa, hydrogenation of the olefins contained in the hydrocarbon oil tends to proceed and RON may decrease, which is not preferable.

[0030] When the desulfurization treatment is performed by contacting the desulfurizing agent and the cracked gasoline fraction in a fixed bed flow type, LH SV is preferably more than 2. Oh ^{_ 1} and 50. Oh ^{_ 1} or less, more preferably 2. is a beyond 20. Oh ^{_ 1} below Oh ^_1, particularly preferably 10. Oh ^_1 from more than 2. Oh ^_1. If the LHSV is 2. Oh ^{_ 1} or less, the oil flow rate is limited or the desulfurization reactor becomes too large, and it is not preferable because it cannot economically desulfurize. If the LHSV exceeds 50. Oh ^_1 , a contact time sufficient for desulfurization cannot be obtained, and the desulfurization rate decreases, which is not preferable. Also, when desulfurization treatment is performed by contacting a desulfurization agent and a cracked gasoline fraction in a fixed bed flow system in the presence of hydrogen, the hydrogen Z oil ratio is preferably 1 to 1000 NLZL, more preferably 10 to 500 NLZL. Particularly preferred is 10 to 300 NL / L. Hydrogen may contain impurities such as methane, but the hydrogen purity is preferably 50% by volume or more, more preferably 80% by volume or more, especially 95% by volume or more so that the hydrogen compressor does not become too large. preferable. If a sulfur compound such as sulfur dioxide or hydrogen is contained in hydrogen, the life of the desulfurizing agent is reduced, so that it is preferably less than a certain ratio. Specifically, the sulfur content in hydrogen is preferably 1000 ppm by volume or less, more preferably 100 ppm by volume or less, and particularly preferably 10 ppm by volume or less.

[0031] [Mixing step (Step D): Preparation of low sulfur cracking gasoline base material]

In the mixing step (Step D), the cracked gasoline fraction is treated in Step A, Step B, and Step C, and the base materials obtained in each step are mixed to obtain a sulfur content of 12 mass ppm or less, and RON is 85. Prepare zero or more low sulfur cracking gasoline base. The sulfur content is preferably 10 ppm by mass or less, more preferably 8 ppm by mass or less. RON is preferably 89.0-93.0. In addition, the various base materials obtained in Process A, Process B, and Process C have a sufficient amount of production and the amount used in Process D for preparing a low sulfur cracked gasoline base material. It is economical and preferable to use it frequently.

[0032] Typically, the light cracked gasoline fraction obtained in step A and treated in step C is mixed with the heavy cracked gasoline fraction obtained in step A and treated in step B, or The light cracked gasoline fraction obtained in step A is mixed with the heavy cracked gasoline fraction obtained in step A, treated in step B, and further treated in the same step. Cracked gasoline fraction used as raw material for process A It is preferable to mix various base materials obtained with almost the entire amount, for example, 80% by volume or more, to make a low sulfur decomposition gasoline base material. Further, the mixing in step D may be performed simultaneously with the blending step described later, which is mixing with other gasoline base materials for the preparation of the gasoline composition.

[0033] [Gen reduction treatment process (process E)]

In the method for producing a cracked gasoline base material of the present invention, the whole or part of the cracked gasoline fraction in the pre-process of Step B or Step C is preferably present in the presence of hydrogen, preferably on an inorganic porous support such as alumina. It is preferable to reduce the gen value by contacting with a catalyst supporting at least one metal selected from the group 8 elements in the table. Since cracked gasoline fractions contain sulfur, catalysts with high resistance to sulfur and nickel or cobalt are preferred. There are no particular restrictions on the active component elements other than the Group 8 element contained in the catalyst, but molybdenum, tungsten, and phosphorus are listed as preferred components that may be included. Usually, the catalyst is used after the sulfur treatment. The reaction conditions need to be set so that the hydrogen of the olefins can be significantly reduced and the RON cannot be significantly reduced by reducing the gen number of the cracked gasoline fraction obtained.

[0034] Preferred reaction conditions are a reaction temperature of 40 to 300 ° C, a reaction pressure of 0 to 4 MPa, an LHSV of 1 to: L0h_1, and a hydrogen Z oil ratio of ¹ to 500 NLZL. The gen number of the cracked gasoline fraction obtained by step E is preferably 0.5 gZl00 g or less, more preferably 0.3 gZl00 g, particularly preferably 0. lgZlOOg or less. If the Gen value exceeds 0.5 gZ100 g, desulfurization performance and desulfurization agent life will be greatly impaired in Process B and Process C! /, Preferable! /. Further, in step E, the decrease in olefin content is preferably 10% by volume or less, particularly preferably 5% by volume or less, more preferably 2% by volume or less, and the decrease in RON is preferably 1 or less, more preferably. It is 0.5 or less, more preferably 0.3 or less, and particularly preferably 0.2 or less. In this gen reduction treatment stage, the sulfur content is not substantially reduced. Part of the sulfur content may be converted to hydrogen sulfide, which may be desulfurized in the subsequent step B or step C, and a sulfur hydrogen removal facility is installed in the Jen reduction treatment step. This is not economical. The gen value as used in the present invention refers to the gen value measured by UOP326-82. [0035] The gen number is obtained by bringing a catalyst and catalytically cracked gasoline into contact with each other in the presence of hydrogen and converting gen to mono-olefin or reacting with a sulfur compound coexisting with gen to convert it into sulfides. Is reduced. By using a catalyst containing a Group 8 element and applying the above-mentioned preferred reaction conditions, hydrogenation of olefin can be almost suppressed, so that the gen number can be lowered without significantly reducing RON.

Conventional power In petroleum refining, gen in olefin is selectively hydrorefined, and can be applied as step E in the present invention. Specifically, the IFP Selective Hydrogenation process and the Huies Selective Hydrogenation process are used favorably (edited by the Japan Petroleum Institute, Petroleum Refining Process, p. 62, Kodansha Scientific (199 8)). In addition, as a method of reducing the gen value in the present invention, the SHU process (21st JPI Petroleum Refining and onference 'Recent Progress in Petroleum Process Ί echnology, 37 (2002)) and CD Hydro process (NPRA 2001 Annual Meeting, AM-01- 39 (2001)).

[0037] [Pretreatment step for increasing the molecular weight of the sulfur compound (Step F)]

For cracked gasoline fractions, the pretreatment step (Step F) to increase the molecular weight of the sulfur compounds contained in the cracked gasoline fraction is used for the fractionation step in Step A, or the molecular weight of the sulfur compounds is reduced simultaneously with the fractionation step in Step A. It is preferable to do pretreatment to enlarge. By selectively increasing the molecular weight of the sulfur compound such as thiols, the boiling point of the sulfur compound is increased. Therefore, in the fractionation process, the sulfur compound is contained in the heavy cracked gasoline fraction. The sulfur content of the light cracked gasoline fraction obtained in the fractionation process can be reduced. For example, a catalyst is placed in a distillation column to make the sulfur content heavy, and the heavy sulfur compound moves to the distillate component on the heavy side to reduce the sulfur content of the light fraction. be able to. The CD-Hydro process described below uses this!

[0038] Conventional power In petroleum refining, a sweet jung is performed to treat the thiols to make the product non-brominated. A known method for converting thiols to disulfides by an oxidation method or an oxidation extraction method can be applied as a method for increasing the molecular weight of a sulfur compound in the present invention. Specifically, the Marlox method, doctor method, etc. are preferably used (Oil Refining Technology Handbook 3rd Edition, Sangyo Tosho Co., Ltd. (1981)). [0039] In the present invention, as a method of increasing the molecular weight of the sulfur compound, a method of reacting a sulfur compound contained in the cracked gasoline fraction with olefins can also be suitably used. Specifically, SHU process and OATS process (21st JPI Petroleum Refining conference Recent Progress in Petroleum Process Technology, 37 (2002)) In particular, a SHU process capable of simultaneously performing a process for increasing the molecular weight of a sulfur compound and a process for reducing a gen is preferable. Furthermore, a process capable of simultaneously increasing the molecular weight of the sulfur compound and reducing the gen while carrying out fractional distillation is more preferable, and specifically, a CD-hydro process can be mentioned as such a process.

[0040] [Other gasoline base materials other than cracked gasoline fraction]

Other gasoline base materials other than the cracked gasoline fraction mixed in the blending process, which is the final step for preparing a low-sulfur gasoline composition, include catalytic reformed gasoline base materials, alkylate gasoline base materials, straight-run naphtha. Desulfurized base materials, isomeric gasoline base materials, aromatic base materials such as toluene and xylene, and methyl t-butyl ether (MTBE), ethyl t-butyl ether (ETBE), tamyl ether ether (TAEE ), Known gasoline base materials such as oxygen-containing gasoline base materials such as ethanol and methanol can be appropriately used. In particular, ETBE has a higher octane number improvement effect per oxygen content than ethanol and MTBE, and is a preferred base material because it can increase the octane number without deteriorating volatility by mixing ETBE.

[0041] The other gasoline base material mixed in the blending process preferably has a sulfur content of 20 ppm by mass or less, more preferably 10 ppm by mass or less, further 3 ppm by mass or less, particularly 1 ppm by mass. It is as follows. If the sulfur content of other gasoline base materials exceeds 20 mass ppm, the blending amount in the blending process of gasoline base materials is restricted, which is not preferable.

Preferred blending amounts are 30 to 90% by volume of cracked gasoline fraction, especially 40 to 80% by volume, 5 to 50% by volume of catalytically reformed gasoline base, particularly 10 to 45% by volume, alkylate gasoline base 5 to 40% by volume, especially 10 to 30% by volume, and oxygen-containing gasoline base material such as ETBE is 0 to 16% by volume, particularly 1 to 7% by volume.

[0042] [Gasoline composition]

The unleaded gasoline composition of the present invention has a research octane number of 89.0 or more and a total sulfur content. 10 mass ppm or less, doctor test is negative, silver plate corrosion is 1 or less. The research octane number is preferably 90.0 or more and the gen number is preferably 0.1 lg / 100 g or less. If the doctor test is positive or the silver plate corrosion exceeds 1, unpleasant odor of gasoline power is generated, and corrosion of components used in gasoline automobiles is not preferable. RON is preferably 92 or more, more preferably 93 to 102. Having such a high RON is preferable because it can improve the acceleration performance and fuel consumption of a gasoline automobile. Further, the sulfur content is preferably 8 mass ppm or less, more preferably 5 mass ppm or less.

[0043] The lead-free gasoline composition of the present invention preferably has a Reed vapor pressure (RVP) of 93 kPa or less, more preferably 44 to 93 kPa. If it exceeds 93 kPa, the amount of gasoline vapor released into the atmosphere increases, which is preferable. If it is less than 44 kPa, the startability of a gasoline vehicle deteriorates, which is not preferable. More preferably, it is preferable to adjust the RVP according to the season to 44-65 kPa in summer and 70-93 kPa in winter! /.

[0044] The unleaded gasoline composition of the present invention has a 50% by volume distillation temperature of 75 to 105 ° C, more preferably 75 to 100 ° C. If the 50% by volume distillation temperature is less than 75 ° C, the RVP of the unleaded gasoline composition increases, which is not preferable. If it exceeds 105 ° C, the acceleration performance of gasoline automobiles will be poor, which is not preferable. The aromatic content is preferably 40% by volume or less, more preferably 30% by volume or less, and particularly preferably 20 to 30% by volume. When the aromatic content is less than 20% by volume, the blending amount of the cracked gasoline base material is limited, and the production cost of the unleaded gasoline composition becomes high, which is not preferable. If it exceeds 40% by volume, the unflammable gasoline composition has poor flammability, which is preferable.

Furthermore, it is preferable that the olefin content, which is the ratio of the unsaturated carbon number to the total carbon number, is 45% by volume or less, more preferably 20 to 40% by volume, particularly preferably 20 to 30% by volume. is there. When the ratio of unsaturated carbon to total carbon is in such a range, it becomes easy to secure the olefin and aromatic content within the above-mentioned range.

[0045] [Additive]

In the unleaded gasoline composition of the present invention, one or more kinds of fuel oil additives known in the art can be blended as required. These compounding amounts can be appropriately selected. Usually, it is preferable to maintain the total compounding amount of the additives at 0.1% by mass or less. Gasoline of the present invention Examples of fuel oil additives that can be used in water include phenolic and amine-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organophosphorus compounds. Detergents such as surface ignition inhibitors, succinimides, polyalkylamines, polyetheramines, anti-icing agents such as polyhydric alcohols or ethers, alkali metal salts of organic acids or alkaline earth metals Examples thereof include auxiliary agents such as salts and sulfates of higher alcohols, antistatic agents such as anionic surfactants, cationic surfactants and amphoteric surfactants, and colorants such as azo dyes.

[0046] The power described in detail below with reference to examples. The present invention is not limited to these examples.

Example 1

[0047] Fluidized catalytic cracking was performed on hydrodepressurized middle gas oil fractions and hydrodistilled atmospheric distillation residue oil as the main feedstock (sulfur content 3,500ppm). The catalytically cracked gasoline fraction A was processed by an acid-sweet type sweet jung equipment to obtain catalytically cracked gasoline fraction B. Table 1 shows the properties of catalytic cracking gasoline fractions A and B. The oxidation-type sweet-jung equipment is a UOP Merox process, which was operated at a reaction temperature of 42 ° C.

[0048] In this specification, density «JIS K 2249, vapor pressure (Lead method) ¾ JIS K 2258, distillation properties« JIS K 2254 (normal pressure method), hydrocarbon component composition «JIS K 2536 (fluorescent indicator adsorption method) ), Gen number was measured according to UOP326-82, and sulfur content was measured according to ASTM D 5453 (ultraviolet fluorescence method). RON was measured by a gas chromatograph method using a PIONA apparatus manufactured by Hewlett-Packard Company. Silver plate corrosion «JIS K2513 (Petroleum product copper plate corrosion test method: Corresponding ASTM D130) cylinder method (jet fuel). Instead of copper plate, JIS Κ2276 (Petroleum product aviation fuel oil test method)" 14. Silver plate corrosion The silver plate used in “Test method” was used for evaluation. The test temperature is 50 ° C and the test time is 3 hours. The doctor test was measured according to JIS K 2276.

[0049] This catalytic cracking gasoline fraction B was fractionated to obtain a light catalytic cracking gasoline fraction C and a heavy catalytic cracking gasoline fraction D. The ratio of light fraction C and heavy fraction D was 68:32 (volume ratio). Table 1 shows the properties of light catalytic cracking gasoline fraction C and heavy catalytic cracking gasoline fraction D. Shown in

[0050] A catalyst having 20% by mass of nickel supported on alumina is charged into a fixed bed flow reactor and subjected to sulfiding treatment, and then the reaction temperature is 250 ° C, the reaction pressure is normal pressure, and LHSV = 4.

Under the condition of hydrogen Z oil ratio 340NLZL, light catalytic cracking gasoline fraction C was passed through and subjected to the reduction of gen to obtain light catalytic cracking gasoline E.

[0051] A solution in which 106 g of sodium carbonate was dissolved in water was heated to 60 ° C, and 58 g of nickel nitrate hexahydrate was added to the solution in which 179 g of zinc nitrate hexahydrate was dissolved in water. The food was dripped. The resulting precipitate was filtered and washed with water. Thereafter, after drying at 120 ° C. for 16 hours, calcination was performed at 350 ° C. for 3 hours to obtain a desulfurizing agent Z. The desulfurizing agent Z had a nickel content of 17.9% by mass, a zinc content of 58.7% by mass, a sodium content of 0.02% by mass and a specific surface area of 80 m ² Zg. The ratio of nickel to zinc was 30.4% by mass. Light catalytic cracking gasoline fraction E is desulfurized using desulfurizing agent Z under the conditions of reaction temperature 300 ° C, reaction pressure normal pressure, LHSV = 2.5 h ~ hydrogen / oil ratio 180NL / L, and light catalytic cracking Got gasoline F. Table 1 shows the properties of light catalytic cracking gasoline fractions E and F.

[0052] A catalyst having cobalt, molybdenum and phosphorus supported on alumina (cobalt content 2.4% by mass, molybdenum content 9.4% by mass, phosphorus content 2.0% by mass) was charged into a fixed bed flow reactor and subjected to sulfurization treatment. After that, under the conditions of reaction temperature 225 ° C, reaction pressure 1.0MPa, LHSV = 5.0h "\ hydrogen Z oil ratio = 307NLZL, heavy catalytic cracking gasoline fraction D was passed through and hydrodesulfurized. Further, it was treated with an oxidized sweet jung equipment to obtain heavy catalytic cracking gasoline G. The oxidized sweet jung equipment is a MERICAT-IV process manufactured by Merichem, and the reaction temperature was 41 ° C. Drove in.

Light catalytic cracking gasoline F and heavy catalytic cracking gasoline G were mixed together to obtain a low sulfur decomposition gasoline base H. Table 1 shows the properties of heavy catalytic cracking gasoline G and low sulfur cracking gasoline base H. The value of the preliminary desulfurization control coefficient α in Example 1 was 18. Since the sulfur content does not change before and after sweet jung, the sulfur content of heavy catalytic cracked gasoline G after hydrocatalyzed desulfurization of heavy catalytic cracked gasoline fraction D and then sweet jung is defined as HS. The preliminary desulfurization control coefficient α was calculated.

[0053] [Table 1]

Example 2

[0054] Half of the light catalytic cracking gasoline fraction C obtained by the same method as in Example 1 was subjected to a gen removal treatment and a desulfurization treatment with a desulfurizing agent Z in the same manner as in Example 1 to obtain a light catalytic cracking gasoline F. Got.

A heavy catalytic cracking gasoline fraction D obtained in the same manner as in Example 1 was converted to a catalyst in which cobalt, molybdenum and phosphorus were supported on alumina (cobalt content 2.4% by mass, molybdenum content 9.4% by mass, phosphorus Content 2.0% by mass) in a fixed bed flow reactor and treated with sulfur, reaction temperature 240 ° C, reaction pressure 1.0MPa, LHSV =

Under conditions of hydrogen Z oil ratio = 307NLZL, hydrodesulfurization was carried out by passing oil, and further, it was treated with an acid type sweetening device to obtain heavy catalytic cracked gasoline I.

Half of the light catalytic cracking gasoline C, all of the light catalytic cracking gasoline F and all of the heavy catalytic cracking gasoline I were mixed together to obtain a low sulfur cracking gasoline base J. Table 2 shows the properties of the low sulfur cracking gasoline base J and the properties of the intermediate substrate. The preliminary desulfurization control coefficient ex in Example 2 was 14.

[0055] [Table 2]

Example 3

[0056] The heavy catalytic cracking gasoline G total amount obtained in the same manner as in Example 1, a desulfurizing agent Z reaction temperature 300 ° C using a reaction pressure ^{0. 5MPa, LHSV = 2. 5h _} 1, hydrogen Heavy catalytic cracking gasoline K was obtained by desulfurization treatment under the condition of Z oil ratio 20NLZL. Light sulfur cracked gasoline C obtained in the same manner as in Example 1 and heavy catalytic cracked gasoline C were mixed together to obtain a low sulfur gasoline substrate L. Table 3 shows the properties of the low-sulfur cracking gasoline base material L and the properties of the above-mentioned intermediate base material. The preliminary desulfurization control coefficient α in Example 3 was 18.

[0057] [Table 3]

Example 4

The catalytically cracked gasoline fraction B obtained in Example 1 was fractionally distilled to a volume ratio of 47:53 to obtain a light catalytic cracked gasoline fraction M and a heavy catalytic cracked gasoline fraction N. 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 charged into a fixed-bed flow reactor and subjected to sulfidation, and then reacted. Under the conditions of temperature 225 ° C, reaction pressure 1.0MPa, LHSV = 5.0h "\ hydrogen Z oil ratio = 307NLZL, heavy catalytic cracking gasoline fraction N was passed through and hydrodesulfurization was conducted. Heavy catalytic cracking gasoline O was obtained.

Half of the heavy catalytic cracked gasoline O was desulfurized with the desulfurizing agent Z, and heavy catalytic cracked gasoline P was obtained.

The total amount of light catalytic cracking gasoline M, the half amount of heavy catalytic cracking gasoline O and the total amount of heavy catalytic cracking gasoline P were mixed to obtain a low sulfur cracking gasoline base material Q. Table 4 shows the properties of the low sulfur decomposition gasoline substrate Q and related intermediate substrates. The preliminary desulfurization control coefficient ex in Example 4 was 14.

[Table 4]

Comparative Example 1

[0060] The heavy catalytic cracking gasoline fraction D obtained in Example 1 was used as a catalyst (cobalt content 2.4 mass%, molybdenum content 9.4 mass%, phosphorus content). 2.0 mass%) into a fixed bed flow reactor and treated with sulfur, then reaction temperature 300 ° C, reaction pressure 3.0 MPa, LHSV =

Under conditions of hydrogen Z oil ratio = 307NLZL, hydrodesulfurization was conducted by passing oil, and heavy catalytic cracking gasoline R was obtained.

The light catalytic cracking gasoline fraction C obtained in Example 1 was mixed with the entire heavy catalytic cracking gasoline R to obtain cracked gasoline base material S. Table 5 shows the properties of the cracked gasoline base material 3 and the related intermediate base material.

[0061] [Table 5]

[0062] Gasoline base materials obtained by known techniques other than catalytic cracking include desulfurized straight-run naphtha T, catalytically reformed medium oil U, catalytically reformed heavy oil V, alkylate gasoline W, ethyl tbutylbutyl X The properties are as shown in Table 6. Catalytically modified medium oil U is obtained by distilling and separating a toluene-rich fraction from catalytically modified gasoline. Catalytically modified heavy oil V is obtained by distillation separation of aromatics having 9 or more carbon atoms and less than 11 from catalytically reformed gasoline.

[0063] [Table 6]

Example 5

Desulfurization straight-run naphtha T 15%, catalytic reforming medium oil U 5%, catalytic reforming heavy oil V 5%, alkylate gasoline W 5% by volume Gasoline base material Η 70% by volume was prepared to prepare an unleaded gasoline composition AA. Table 7 shows the properties.

[0065] [Table 7]

Example 6

[0066] Desulfurization straight-run naphtha T, 10% by volume, catalytic reforming medium oil U, 10% by volume, catalytic reforming heavy oil V, 6 capacity ⁰ alkylate gasoline W, 10 capacity ⁰ ethyl t butyl ether X, 7 Mixing 57% by volume of cracked gasoline base H described in Example 1 and unleaded gasoline composition A product BB was prepared. Table 7 shows the properties.

Example 7

[0067] 15% by volume of catalytically modified medium oil U, 15% by volume of catalytically modified heavy oil V, 16% by volume of alkylate gasoline W, 7% by volume of ethyl t-butyl ether X, Example 4 An unleaded gasoline composition CC was prepared by blending 22% by volume of the cracked gasoline base material Q described above and 25% by volume of the light catalytic cracked gasoline base material M described in Example 4. Table 7 shows the properties.

Comparative Example 2

[0068] Comparative Example 1 with 15% by volume of desulfurized straight-run naphtha T, 5% by volume of catalytically modified medium oil U, 5% by volume of catalytically modified heavy oil V, and 5% by volume of alkylate gasoline W Undecomposed gasoline composition DD was prepared by blending 70% by volume of the cracked gasoline base S described. Table 7 shows the properties.

Claims

The scope of the claims

[1] A fractionation process (Step A) for fractionating the cracked gasoline fraction to obtain a light cracked gasoline fraction and a heavy cracked gasoline fraction.

A hydrodesulfurization step (Step B) in which the heavy cracked gasoline fraction obtained in Step A is brought into contact with a catalyst containing molybdenum and Z or tungsten in the presence of hydrogen to reduce the sulfur content (Step B). Contact with a porous desulfurization agent containing nickel and zinc in the presence of hydrogen in the presence or absence of hydrogen cracked light gasoline fraction and heavy cracked gasoline fraction with reduced sulfur content obtained in Z or Step B The sulfur removal and removal process (process C), which reduces the sulfur content to 5 mass ppm or less,

A process for producing a low sulfur decomposition gasoline base material, comprising:

[2] The preliminary desulfurization control coefficient α expressed by the following formula (1) is 12 to 30 after the process A and the process B

a = (LW X LS + HW X HS) / 100 (1)

(Where LW is the fraction of light cracked gasoline fractionated in process A (volume%), LS is the sulfur content in the light cracked gasoline obtained in process A (mass ppm), and HW is in process A. (The percentage of heavy cracked gasoline fractionated by volume (volume%), HS indicates the sulfur content (mass ppm) in the heavy cracked gasoline obtained in Step B.)

The method for producing a low-sulfur cracking gasoline base material according to claim 1.

[3] The low sulfur decomposition according to claim 1 or 2, wherein a ratio of supplying to the process C and processing to the total amount of cracked gasoline supplied to the process A is 20 vol% or more and 90 vol% or less. A method for producing a gasoline base material.

[4] Prior to Step B or Step C, all or part of the cracked gasoline fraction is contacted with a catalyst containing at least one metal selected from Group 8 element force in the periodic table in the presence of hydrogen. The method for producing a low-sulfur cracking gasoline base material according to any one of claims 1 to 3, further comprising a jen reduction treatment step (step E) for performing a jen reduction treatment.

[5] The method according to claim 1, further comprising a pretreatment step (step F) for increasing the molecular weight of the sulfur compound contained in the cracked gasoline fraction before step A or simultaneously with the fractionation step of step A. The manufacturing method of the low sulfur decomposition gasoline base material in any one of -4.

[6] Claims 1 to 5, containing at least 30% by volume of low-sulfur cracking gasoline base material manufactured according to any of the above, research octane number of 89 or more, sulfur content of 10 mass ppm or less, doctor test is negative An unleaded gasoline composition with a silver plate corrosion of 1 or less.

7. The unleaded gasoline composition according to claim 6, having a research octane number of 92 or more.