JP4851198B2 - Method for producing gasoline base material and gasoline composition - Google Patents

Description

  The present invention relates to a method for producing a gasoline base material, and a gasoline composition produced by blending a gasoline base material produced by the method. In particular, skeletal isomerization of low-octane naphtha fractions, low-branch number low-octane compound groups are separated from the resulting isomerization products, and further skeletal isomerization is performed to produce highly branched multi-branched saturated aliphatic carbonization The present invention relates to a method for producing a hydrogen-rich gasoline substrate.

  In recent years, environmental pollution caused by automobile fuel has become a social problem, and automobile fuel with a low environmental load is desired. It is known that the sulfur content in the fuel oil deteriorates the performance of the exhaust gas catalyst at the time of combustion, and there is an increasing demand for reduction to 10 ppm by mass, and further to 1 ppm by mass. In addition, it has been pointed out that aromatics and olefins in gasoline may also adversely affect the environment. As a high-octane fuel, for example, a fuel containing a large amount of aromatics is known, but this fuel increases the amount of aromatic compounds in the exhaust gas. In addition, by reducing the sulfur content of automobile fuels, it is hoped that the environmental burden will be reduced by maintaining the performance of exhaust gas catalysts (especially hydrocarbon (HC), nitrogen oxides (NOx), carbon monoxide (CO), etc. in exhaust gas) It is rare. However, depending on the properties of the base material used and the blend ratio, there is a case where the operation performance of the product is deteriorated due to the low sulfur content.

  Therefore, instead of using aroma and olefin, which are high octane hydrocarbon compounds, it is necessary to produce a gasoline base material containing a branched saturated aliphatic hydrocarbon having a relatively high octane number as a main component. Skeletal isomerization as a method of converting straight-chain saturated aliphatic hydrocarbons with low octane number into branched saturated aliphatic hydrocarbons, or saturated aliphatic hydrocarbons with a small number of branches into saturated aliphatic hydrocarbons with a large number of branches Reaction. In the skeletal isomerization reaction, an acid catalyst has been conventionally used, but this reaction is characterized by the fact that it is governed by thermal equilibrium. The lower the reaction temperature, the more saturated aliphatic hydrocarbons having a larger number of branches. A catalyst that exhibits high activity even at low temperatures has been desired since it exists stably. For example, butane having 4 carbon atoms has two types of isomers: normal butane having a straight octane number of 94 and branched isobutane having a octane number of 101, but the linear / branched ratio at a reaction temperature of 300 ° C. Is 47/53 at 200 ° C., and 30/70 at 100 ° C., and the ratio of branched bodies having a high octane number tends to increase as the temperature decreases (see Non-Patent Document 1). Examples of the isomerization catalyst include a catalyst in which platinum is supported on a solid superacid catalyst such as zirconia sulfate or zirconia tungstate as shown in Non-Patent Document 2. As a method for measuring the acid strength of a solid super strong acid, a method using a Hammett acidity function with a Hammett indicator is often used (Non-patent Document 3).

So far, isomerization reactions using saturated aliphatic hydrocarbons having 6 or less carbon atoms as raw materials have been utilized. In particular, a catalyst in which a noble metal is supported on chlorinated alumina as a catalyst has high activity, and a process using this is already widely used. However, when this process is used, chlorine in the catalyst is desorbed during the reaction, which not only lowers the catalytic activity but also causes chlorine corrosion on the equipment and reduces the stability of the product oil. In addition, it is not preferable for treating waste chlorine without adversely affecting the environment because of the great cost.
On the other hand, when a isomerization reaction is performed using a saturated aliphatic hydrocarbon having 7 or more carbon atoms as a raw material oil, a stable tertiary carbocation is easily generated. Therefore, efficient isomerization has been considered difficult.

As a method for separating a linear saturated aliphatic hydrocarbon having a low octane number, adsorption separation or membrane separation is widely known because of the difference in molecular size from branched saturated aliphatic hydrocarbons.
A method for separating linear saturated aliphatic hydrocarbons, branched saturated aliphatic hydrocarbons and aromatic hydrocarbons has been disclosed (see Patent Document 1), but a fraction having 7 or more carbon atoms was isomerized. There is no disclosure about the separation method of the isomerization reaction product and the like, and it is said that it requires a multi-stage separation step and is particularly difficult. In addition, there are already reported examples of the separation of linear saturated aliphatic hydrocarbons and branched saturated aliphatic hydrocarbons (see Patent Document 2), but no specific isomerization reaction is disclosed in the same manner. Absent. Also disclosed is an isomerization reaction for a fraction having 7 or more carbon atoms and separation of a linear saturated aliphatic hydrocarbon and a branched saturated aliphatic hydrocarbon (see Patent Document 3). Since it uses a liquid catalyst and requires a catalyst separation step, it is not practical, and since the acid strength of the catalyst used is insufficient, it is difficult to obtain an effective high activity at a low temperature. Furthermore, a method for separating one-branched saturated aliphatic hydrocarbon and multi-branched saturated aliphatic hydrocarbon is also disclosed (see Patent Document 4). However, the isomerization reaction itself has practically special effects. It wasn't.
JP 11-236574 A JP 2002-348579 A JP 2003-327972 A Japanese Patent No. 2673907 “The Petrochemical Process 3. Hydrogenation / Dehydrogenation” edited by The Petroleum Society of Japan 193 (1963) Arata, PETROTECH, 733-739, Vol. 19, No. 9 (1996) Arata, Surface, 481-491, Vol.28, No.7 (1990)

  An object of this invention is to provide the manufacturing method of the gasoline base material which manufactures efficiently the gasoline base material which contains many branched saturated aliphatic hydrocarbons which are high octane numbers. Furthermore, by using a high-octane gasoline base material mainly composed of saturated aliphatic hydrocarbons prepared in this way, high-octane gasoline compositions with high environmental impact and reduced olefin content can be efficiently produced. It aims to be well prepared and provided.

Until now, isomerization reactions have been governed by thermal equilibrium, so it is difficult to expect isomerization selectivity above the equilibrium value. The main component is a saturated hydrocarbon compound, which has a high octane number with reduced aromatics and olefins. It has been difficult to produce gasoline bases or gasoline compositions.
The present inventors solved this problem by combining an isomerization step using an appropriate catalyst and a separation step using an appropriate separation method. In other words, if molecular sieves and separation membranes with controlled pore properties are used, linear saturated aliphatic hydrocarbons and branched saturated aliphatic carbonized carbons with low octane numbers may be used due to differences in molecular size or adsorption / permeability. Separation from hydrogen, or separation from one-branched saturated aliphatic hydrocarbon and multi-branched saturated aliphatic hydrocarbon is possible. Compared with saturated aliphatic hydrocarbons with the same number of carbons, the boiling point is generally lower as the number of branches increases, so it is possible to separate compounds with low boiling points and high octane numbers using precision distillation. Thus, it was found that a gasoline base material having an octane number equal to or higher than the thermal equilibrium can be obtained.

Further, the present inventors focused on the fact that the isomerization reaction is an equilibrium reaction, and after separating the high octane compound represented by the multi-branched saturated aliphatic hydrocarbon in the isomerization reaction product oil, it was separated. It was found that by further isomerizing the other low octane compound, a high octane gasoline base material having a multi-branched saturated aliphatic hydrocarbon exceeding the equilibrium in the one-stage isomerization reaction was obtained. In particular, the combination of the reaction column and the separation column is important, and if not paying attention to which fraction is separated and re-reacted, the reverse reaction may be caused in equilibrium in some cases. For example, when reacting a fraction obtained by removing linear saturated aliphatic hydrocarbons from an isomerization product, a reverse reaction from a branched hydrocarbon compound to linear saturated aliphatic hydrocarbons occurs. The result is a lower octane number.
Furthermore, when reacting the isomerized product oil again, a multibranched saturated aliphatic hydrocarbon can be obtained more advantageously in an equilibrium by reacting under a mild temperature condition lower than the previously experienced isomerization conditions. And, it was found that an undesirable decomposition reaction can be suppressed.
The present invention has been completed by skillfully combining these findings.

That is, this invention is the manufacturing method of a gasoline base material as follows, or a gasoline composition.
(1) In a method for producing a gasoline base material having a higher octane number by isomerizing a naphtha fraction, the naphtha fraction is produced in the first isomerization reaction step and the first isomerization reaction step in which the naphtha fraction is isomerized. A second isomerization reaction step in which the first isomerization reaction product is directly or indirectly isomerized, and the first isomerization reaction product is combined with the first low octane compound group and the first isomerization reaction product. The first isomerization step obtained by separating the first octane number compound group into the second isomerization reaction step by separating the first low octane number compound group and / or the second isomerization reaction step. A second separation step of separating the reaction product into a second low-octane compound group and a second high-octane compound group, and a solid having a Hammett acidity function smaller than −12 in the both isomerization reaction steps Using an acid catalyst and the second The reaction temperature in the isomerization reaction step method for producing a gasoline base material which is a low temperature 10 ° C. or higher than the reaction temperature in the first isomerization step of the previous stage.

(2) The solid acid catalyst includes a group IV element of the periodic table, a group VI element of the periodic table, and a group VIII element of the periodic table, and is used in the first isomerization reaction step. And the solid acid catalyst used in the second isomerization reaction step may be the same or different from each other, and the raw material naphtha fraction, the first low octane compound group and / or the second low isomerization compound The method for producing a gasoline base material according to (1), wherein the octane compound group is brought into contact with the solid acid catalyst in the presence of hydrogen.

(3) The group IV element in the periodic table is at least one selected from the group consisting of titanium, zirconium, hafnium, and tin, and the group VI element in the periodic table is from tungsten, sulfur, and molybdenum. And one or more elements selected from the group consisting of platinum, palladium, ruthenium, rhodium, iridium, osmium, iron, cobalt, and nickel. A method for producing a gasoline base material according to (2) above.

(4) The first and second isomerization reaction steps and the first separation step, wherein the first low octane compound group separated in the first separation step is treated in the second isomerization reaction step (1) The manufacturing method of the gasoline base material in any one of (3).

(5) including the first and second isomerization reaction steps and the second separation step, the second low-octane compound group separated in the second separation step together with the first isomerization reaction product The method for producing a gasoline base material according to any one of (1) to (3), wherein the gasoline base material is treated in the isomerization reaction step (2).

(6) The first and second isomerization reaction steps and the second separation step, and the second low octane compound group separated in the second separation step is converted into a naphtha distillate in the first isomerization reaction step. The manufacturing method of the gasoline base material in any one of said (1)-(3) processed with a minute.

(7) The first and second isomerization reaction steps and the first and second separation steps, and the first low octane compound group separated in the first separation step is converted into the second isomerization reaction step. Any one of the above (1) to (3), wherein the second low-octane compound group treated and separated in the second separation step is treated in the second isomerization reaction step together with the first low-octane compound group The manufacturing method of the gasoline base material as described in 2.

(8) The first and second isomerization reaction steps and the first and second separation steps, and the first low octane compound group separated in the first separation step is converted into the second isomerization reaction step. The gasoline group according to any one of (1) to (3), wherein the second low octane compound group that has been treated and separated in the second separation step is treated together with the naphtha fraction in the first isomerization reaction step. A method of manufacturing the material.

(9) A first isomerization reaction product obtained in the first isomerization reaction step, including the first and second isomerization reaction steps, the second separation step, and optionally the first separation step. Or the first low-octane compound group separated in the first separation step is treated in the second isomerization reaction step, and the obtained second isomerization reaction product is directly treated in the second separation step. A second low-octane compound group mainly composed of a chain saturated aliphatic hydrocarbon, a second medium-octane compound group mainly composed of a saturated aliphatic hydrocarbon having a branch number of 1, and a branch number of 2 or more The second high-octane compound group mainly composed of saturated aliphatic hydrocarbons is separated, the second low-octane compound group is treated with the naphtha fraction in the first isomerization reaction step, and the second medium octane compound is obtained. Together with the first isomerization reaction product or the first low octane group Method for producing a gasoline base according to any of the treatment with 2 isomerization reaction step (1) to (3).

(10)
The first and second separation steps are a separation step with an adsorbent containing one or more elements selected from the group consisting of silicon, aluminum and carbon, a separation step with a separation membrane, a separation step with precision distillation, or those The method for producing a gasoline base material according to any one of the above (1) to (9), which is a separation step by a combination of two or more kinds.

(11) The research method octane number obtained by blending the gasoline base material obtained by the method for producing a gasoline base material according to any one of (1) to (10) above, and the sulfur content is 10. A gasoline composition having 0 ppm by mass or less, a 50% by volume distillation temperature of 100 ° C. or less, a vapor pressure of 65 kPa or less, and a linear saturated aliphatic hydrocarbon content of 9.0% by volume or less.

(12) The gasoline composition according to (11), wherein the sulfur content is 1.0 mass ppm or less.

The present invention can provide a method for producing a high-octane gasoline base containing a large amount of branched saturated aliphatic hydrocarbons by the above-described method for producing a gasoline base. That is, by separating the high octane compound from the isomerization reaction product in the separation step, a gasoline base having a high octane number higher than the thermal equilibrium can be obtained, and the multi-branched saturated aliphatic in the isomerization reaction product oil A high octane compound can be obtained in a high yield by separating and removing a high octane compound typified by a hydrocarbon and further isomerizing the low octane compound.
Furthermore, in the second isomerization reaction step, the multi-branched saturated aliphatic hydrocarbon is more favorably balanced by reacting under mild conditions at a lower temperature than the isomerization conditions in the first isomerization reaction step. It can be obtained in high yield and can suppress undesirable decomposition reactions.
In addition, by using a high-octane gasoline base material mainly composed of multi-branched saturated aliphatic hydrocarbons prepared in this way, it does not make heavy use of aromatics and olefins with relatively high environmental impact. A gasoline composition having a high octane number (RON) can be prepared and provided. The term “relatively” means that when the gasoline composition of the present invention is compared with the conventional gasoline composition, if the RON is the same, the gasoline composition of the present invention has less aromatic content and olefin content. If the aromatic content and olefin content are the same, it means that RON can be increased.

  Furthermore, since the gasoline composition obtained from the present invention has a high content of branched saturated aliphatic hydrocarbon compounds, it can be used not only as a fuel for gasoline engines but also as a fuel for fuel cells. It has high energy efficiency and can be used as a common gasoline.

  The method for producing a gasoline base material according to the present invention basically includes two or more isomerization reaction steps, and one or two isomerization reaction products generated therein are separated into a high octane compound group and a low octane compound group. It is a method comprising a separation step, and by combining an appropriate isomerization method and an appropriate separation method in an optimal manner, a high-octane branched saturated aliphatic hydrocarbon restricted by thermal equilibrium in the isomerization step, It is a method of manufacturing more.

  That is, the method for producing a gasoline base material of the present invention includes a first isomerization reaction step of isomerizing a naphtha fraction in a method for producing a gasoline base material having a higher octane number by isomerizing the naphtha fraction, and A second isomerization reaction step in which the first isomerization reaction product produced in the first isomerization reaction step is directly or indirectly isomerized, and the first isomerization reaction product is converted into the first isomerization reaction product. A first separation step in which the first low octane compound group is separated into a first low octane compound group and a first high octane compound group, and the first low octane compound group is sent to the second isomerization reaction step; and / or the second isomerization reaction A second separation step of separating the second isomerization reaction product obtained in the step into a second low-octane compound group and a second high-octane compound group, , Hammett acidity function is less than -12 Used had a solid acid catalyst, and the reaction temperature in the latter stage of the second isomerization step, characterized in that it is a low temperature 10 ° C. or higher than the reaction temperature in the first isomerization step of the previous stage.

  In the present invention, each compound group separated in the separation step is referred to as a low octane compound group or a high octane compound group by relative comparison of the octane values of each compound group. The compounds included in these separated compound groups include (1) a low octane compound containing a linear saturated aliphatic hydrocarbon as a main component, and (2) a saturated aliphatic hydrocarbon having 2 or more branches as a main component. It can be separated into three compounds: a high octane compound containing, and (3) a medium octane compound containing a saturated aliphatic hydrocarbon having 1 branch as the main component. When separating into two components, (3) medium octane compound is divided into (1) low octane compound and (2) high octane compound. The octane number compound group contains saturated aliphatic hydrocarbons having 1 or less branches as the main component, and in the latter case, the high octane compound group contains saturated aliphatic hydrocarbons having 1 or more branches as the main component.

(Isomerization process)
In the isomerization step for converting a saturated aliphatic hydrocarbon having 1 or less branching into a compound having a high degree of branching, the Hammett acidity function is -12 or less, more preferably -13 or less, and particularly preferably -13 as an isomerization catalyst. Use a solid acid catalyst that is less than or equal to .5. Here, when a catalyst having an acidity function larger than -12, that is, a weak acid strength, is used, the temperature required for the isomerization reaction becomes high, which is disadvantageous in terms of thermal equilibrium. Can't get. In the present invention, a solid acid catalyst containing an element of Group IV of the periodic table, an element of Group VI of the periodic table, and an element of Group VIII of the periodic table is preferred.

  Examples of Group IV elements in the periodic table include one or more elements selected from the group consisting of titanium, zirconium, hafnium, and tin, with zirconium being particularly preferred. Examples of Group VI elements in the periodic table include one or more elements selected from the group consisting of tungsten, sulfur, and molybdenum, and sulfur or tungsten is particularly preferable. The one or more elements selected from the group consisting of Group VIII elements in the periodic table are one or more elements selected from the group consisting of platinum, palladium, ruthenium, rhodium, iridium, osmium, iron, cobalt, and nickel. These elements are included. Among these, platinum, palladium, and ruthenium are preferable, and platinum can be particularly preferably used.

  As a solid acid catalyst, specifically, "platinum sulfate zirconia" in which a carrier containing zirconia supports sulfuric acid and platinum, "platinum tungstate zirconia" in which a tungsten oxide component and platinum are supported on a carrier containing zirconia, A solid acid catalyst typified by “platinum sulfate tin oxide” in which a carrier containing tin oxide carries a sulfuric acid content and platinum is preferably used.

  In such a solid acid catalyst, it is preferable to contain 10 to 72 mass%, preferably 15 to 65 mass%, particularly 20 to 60 mass% as a group IV element of the periodic table. This element is not preferable because if it is too much or too little outside the range of the previous period, it becomes impossible to maintain an appropriate acid strength. The ratio of elements in Group VIII of the periodic table (average value of the element content) is 0.01 to 10% by mass, preferably 0.05 to 5% by mass, particularly 0.1 to 3% as the element. % By mass. If the content of the Group VIII element in the periodic table is too small, the catalyst performance improving effect is low, which is not preferable. If the content of this element is too large, the specific surface area and pore volume of the catalyst are reduced, which is not preferable.

  Note that the content of Group VI elements (tungsten, sulfur, molybdenum) in the periodic table varies greatly depending on the individual solid acid catalyst and the Group VI elements used therein. For example, the ratio of the sulfuric acid content in the catalyst is preferably 0.7 to 7% by mass, more preferably 1 to 6% by mass, and particularly preferably 2 to 5% by mass as elemental sulfur in platinum zirconia sulfate. On the other hand, the proportion of tungsten in the catalyst is preferably 2 to 30% by mass, particularly 5 to 25% by mass, and more preferably 10 to 20% by mass as a tungsten metal element in zirconia platinum tungstate. The content of molybdenum is preferably the same as that of tungsten.

  Further, it is preferable that the catalyst contains 5 to 30%, preferably 7 to 28% by mass, particularly 8 to 25% by mass of alumina as an aluminum element. Or you may include as complex metal oxides, such as a zeolite. The zirconia portion is preferably substantially composed of tetragonal zirconia.

The specific surface area of the solid acid catalyst is preferably 50 to 500 m ² / g, more preferably 100 to 300 m ² / g, and particularly preferably 140 to ²⁰⁰ m ² / g. The specific surface area can be measured by the BET method.
With respect to the pore structure of the solid acid catalyst used in the present invention, the pore diameter is preferably 0.002 to 10 μm, and the pore diameter range of 0.002 to 0.05 μm is determined by the nitrogen adsorption method. The range of 10 μm can be measured by mercury porosimetry. The pore volume of the solid acid catalyst having a pore diameter of 0.002~10μm is 0.2 cm ³ / g or more, still more 0.3 cm ³ / g or more, particularly 0.35~1.0cm ³ / g is preferred.
The shape of the solid acid catalyst is not particularly limited, and may be any shape such as powder, pellet, tablet, and bead, but is preferably not a powder but a molded shape. For example, a pellet or an extrude having an irregular column shape (average diameter: about 1.5 mm, length: about 4.0 mm) such as a circular columnar shape or a clover type that can be easily obtained by extrusion molding A so-called solid acid catalyst can be preferably used.

The isomerization reaction proceeds under the reaction conditions of a reaction temperature of 100 to 300 ° C., a reaction pressure of 0.5 to 5 MPa, a hydrogen / raw oil ratio of 0.5 to 20 mol / mol, and a liquid space velocity (LHSV) of 0.3 to 10 h ^−1. Then, the linear saturated aliphatic hydrocarbon is isomerized to increase the branched saturated aliphatic hydrocarbon. Among the above reaction conditions, particularly preferable reaction conditions are, for example, a reaction temperature of 120 to 250 ° C., a reaction pressure of 1 to 3 MPa, a hydrogen / feed oil ratio of 2 to 10 mol / mol, and LHSV: 0.5 to 5 h ⁻¹ . .

  The present invention requires a two-step isomerization reaction, and the catalyst used in each step may be the same or a catalyst having a different activity may be used. The important point here is that the isomerized oil that has been branched to some extent in the subsequent isomerization process is treated again in the subsequent isomerization process, so that the reaction conditions are milder than in the previous isomerization process, and the It is not to cause. Specifically, there are methods such as lowering the reaction temperature and increasing the LHSV to shorten the contact time. In general, it is desirable to lower the reaction temperature. More specifically, the reaction temperature in the subsequent isomerization step is preferably 10 ° C. or lower than the reaction temperature in the previous isomerization step, and depending on the type of catalyst, More preferably, the reaction is performed at a temperature lower by 20 ° C. or more. As a result, not only an undesirable decomposition reaction can be suppressed, but also a low temperature reaction that is advantageous in terms of thermal equilibrium can be performed, and a higher number of isomers having a higher degree of branching and a higher octane number can be obtained. When different types of catalysts are used, it is desirable to select the reaction temperature in consideration of the acid strength of each.

(Raw oil)
The naphtha fraction of the feed oil used in the present invention is typically a so-called naphtha fraction that is fractionated by a distillation operation or the like obtained from a petroleum refining process. Naphtha fraction obtained from atmospheric distillation of crude oil, hydrodesulfurization equipment, hydrocracking equipment, catalytic reforming equipment, fluid catalytic cracking equipment, etc. of various distillate oils, and further distillation-separated if necessary. Minutes can be used. In addition, saturated hydrocarbon oils synthesized from coal liquefaction and natural gas, and further hydrocarbon oils obtained by cracking these are also raw materials as long as they are hydrocarbon oils corresponding to a naphtha fraction having distillation properties described later. Can be used as

  As the naphtha fraction, specifically, a light naphtha fraction containing a boiling point component of at least 40 to 50 ° C., preferably 30 to 60 ° C., or a boiling point component of at least 90 to 110 ° C., preferably 90 to 140 ° C. And heavy naphtha fractions. Furthermore, the light naphtha fraction has a 10% by volume distillation temperature of 10 to 50 ° C, particularly 20 to 45 ° C, and a 95% by volume distillation temperature of 50 to 90 ° C, particularly 60 to 80 ° C. Has some distillation properties. The heavy naphtha fraction has a distillation property with a 10% by volume distillation temperature of 80 to 140 ° C., particularly 90 to 120 ° C., and a 95% by volume distillation temperature of 140 to 220 ° C., particularly 140 to 200 ° C. Have. As the naphtha fraction used in the present invention, either a light naphtha fraction or a heavy naphtha fraction, or an appropriate mixture thereof can be used.

(Separation process)
In general, as separation methods of hydrocarbons, adsorption separation, membrane separation, and distillation separation utilizing a difference in boiling points of compounds are known. In the case of distillation separation, hydrocarbons used in petroleum refining are usually a mixture composed of a large number of compounds, and because they have a wide range of carbon numbers, they can be separated by molecular shape (molecular structure or molecular skeleton). There is a limit. In contrast, processes such as adsorption separation and membrane separation that use molecular shape differences are somewhat affected by differences in molecular weight, but are more susceptible to differences in molecular shape. This is a useful technique for separating only linear saturated aliphatic hydrocarbons from multi-component mixed oils.

As the adsorbent used for the adsorption separation, a porous inorganic oxide is preferable. For example, various zeolites represented by A-type zeolite, ZSM-5 type (MFI type) zeolite, Y-type zeolite, X-type zeolite, silica, alumina, Examples thereof include silica alumina, titania, magnesia, zirconia, white clay, diatomaceous earth, activated carbon, and synthetic resin. An adsorbent may be used only by 1 type of the said compound, and may be used in combination of 2 or more type. For example, in the case of A-type zeolite, only a linear saturated aliphatic hydrocarbon having a small molecular size is taken into the pores and adsorbed, and the adsorbed linear saturated aliphatic hydrocarbon has a higher adsorption power. Only linear saturated aliphatic hydrocarbons can be separated by elimination by high compounds. At the time of desorption, desorption can also be performed using a temperature difference or a pressure difference.
In various zeolites, cations that contribute to adsorption separation performance include protons (H), alkali metals such as sodium (Na) and potassium (K), and alkaline earths such as magnesium (Mg) and calcium (Ca). A metal is preferred, but a transition metal may also be used. Specific examples of the transition metal include silver (Ag), platinum (Pt), ruthenium (Ru), rhodium (Rh), nickel (Ni), copper (Cu), and the like. Adsorbents other than zeolite, such as silica, alumina, silica alumina, titania, magnesia, zirconia, clay, diatomaceous earth, activated carbon, synthetic resin, etc. also contain these cations and have improved adsorption performance. It may be. The adsorbent is preferably in the form of powder, pellets, tablets, or beads.

In the adsorptive separation, the pressure is preferably a low pressure from the viewpoint of separability, and particularly preferably 0.1 to 0.5 MPa. Although the separation operation temperature is not particularly limited, it may be obtained by obtaining a suitable temperature from the adsorption rate and adsorption equilibrium, and is generally preferably 0 to 200 ° C, more preferably 20 to 100 ° C. Is done. The space velocity (LHSV in the case of liquid, GHSV in the case of gas) is excessively high, so that the separation ability is lowered. On the other hand, if the space velocity is too low, the apparatus becomes too large. Specifically, in the case of liquid, LHSV is preferably 0.05~10h ^-1, 0.1~5h ^-1 is particularly preferred. Further, when the adsorbed hydrocarbon is desorbed from the adsorbent, a gas such as hydrogen or nitrogen may coexist.

Also in the case of membrane separation, for example, a method in which only a linear saturated aliphatic hydrocarbon having a small molecular size is permeated and separated, such as an MFI type zeolite membrane having a molecular sieve function, a Y type zeolite membrane, and a silica membrane There are methods such as polymer membranes that allow more permeation of specific compounds depending on the adsorption characteristics and dissolution characteristics of the separation membrane material.
As a separation membrane, a porous support represented by alumina or stainless steel is used as a substrate, and an inorganic membrane represented by zeolite membrane or silica alumina membrane or an organic membrane represented by polyimide resin membrane is used as a porous support. A separation membrane formed on the surface or inside the pores can be used. The porous support may be one in which needle-like holes are continuous in a direction perpendicular to the stainless steel surface, or one in which alumina or metal fine particles are bonded. In addition, the material must have high mechanical strength and be stable in material properties in hydrothermal treatment and subsequent heat treatment for forming a zeolite layer. For example, ceramics such as alumina, titania, mullite, stainless steel, etc. Metal such as titanium and glass, glass and the like can be used, and a porous support such as titania and alumina is preferable. The shape of the porous support and the separation membrane may be any shape as long as it is suitable for separating hydrocarbons, for example, a membrane shape, a plate shape, a cylindrical shape, a cylindrical shape, and a honeycomb shape. Etc.

  Membrane separation operations include vapor permeation in which both the supply and permeate sides are in the gas phase, pervaporation in which the supply side is in the liquid phase and the permeate side is in the gas phase, Any method of the liquid phase method in which both sides are in liquid phase may be employed, but more efficiency can be achieved by employing a separation operation method suitable for the state of the isomerization reaction product. Specifically, for example, the vapor permeation method is preferable for the separation operation between the first isomerization reaction step and the second isomerization reaction step. The separation operation temperature is not particularly limited, but a suitable temperature is obtained from the permeation rate and the separation factor, and is preferably 0 to 300 ° C, more preferably 100 to 200 ° C. The pressure is preferably low in order to avoid damage to the separation membrane, and particularly preferably 0.5 kPa to 0.5 MPa as an absolute pressure.

The separation factor in membrane separation is generally represented by the concentration ratio on the permeate side with respect to the concentration ratio on the supply side. For example, if the concentrations (or partial pressures) of the two components A and B on the supply side are Xa and Xb, and the concentrations (or partial pressures) on the transmission side are Ya and Yb, respectively, the separation coefficient α = (Ya / Yb) / ( Xa / Xb). In general, the separation factor α is preferably 40 or more. For example, when Xa = 0.5 and Xb = 0.5 are separated from Ya = 0.98 and Yb = 0.02, the separation coefficient α = (0.98 / 0.02) / (0.5 / 0.5) = 49. In the isomer separation of C ₆ saturated aliphatic hydrocarbons using MFI type zeolite, the separation factor of normal hexane / 2-methylpentane is about 100 and the separation factor of normal hexane / 2,2-dimethylbutane is 100 ° C. It has been shown that the separation factor of 1,000 or more and 2-methylpentane / 2,2-dimethylbutane is several tens or more (for example, Matsukata et al., Petroleum Society 35th Petroleum and Petrochemical Discussion Meeting Abstract) 1B07 (2005)), which is a sufficiently practical separation factor.

  On the other hand, in the distillation method, when the reflux ratio is increased and the separation performance is increased, separation can be performed even with a very small difference in boiling point. In the case of the same number of carbon atoms, a compound having a larger number of branches generally tends to have a lower boiling point. Therefore, it is a useful method for separating each branch number. For example, octane with 8 carbon atoms has many isomers, but the normal boiling point of normal normal octane and 1-methyl 3-methylheptane are 126 ° C and 119 ° C, respectively. Bibranched 2,4-dimethylhexane and tribranched 2,2,4-trimethylpentane are 110 ° C. and 99 ° C., respectively, and the boiling point tends to decrease as the number of branches increases. The octane numbers of these four types of compounds having 8 carbon atoms are -22, 27, 65, and 100, respectively, and the octane number increases as the degree of branching increases. Considering the characteristics of these compounds, when separating multibranched saturated aliphatic hydrocarbons, if the separation efficiency in molecular form is poor, saturated aliphatics with the same number of carbon atoms with different branching numbers can be obtained by applying a precision distillation method. It becomes possible to separate hydrocarbons.

  As such a precision distillation method, specifically, a distillation column packed with a filler is used, and the reflux ratio is set to at least 1/1, preferably 3/1, more preferably 5/1, and the more the number of theoretical plates is. Preferably, it is at least 15 stages, preferably 30 stages or more, more preferably 50 stages or more. The filler is not particularly limited, but stainless steel, metal, refractory inorganic materials, etc. are widely used so as not to damage the shape due to heat history, moisture, or the like. Examples of the shape include a cylindrical shape, a saddle shape, a honeycomb shape, and a mesh shape, and shapes obtained by improving them. Specific examples include Raschig rings, helipacks, Dixon packing, and Goodroll packing. Distillation temperature and pressure conditions are not limited because they vary depending on the raw material to be separated by distillation. The feedstock temperature, tower top temperature, reflux temperature and vacuum of the distillation tower are used so that the target compound can be obtained by distillation separation. The degree or the like may be set as appropriate.

  The separation method used in the separation step of the present invention may be any of the above-described separation method using an adsorbent, separation method using a separation membrane, and separation method using precision distillation, or a separation method combining two or more methods. I do not care. In addition, the separation method in the first separation step and the second separation step of the present invention may be the same separation method or different.

According to the method for producing a gasoline base material of the present invention, not only is the naphtha raw material isomerized to increase the content of the high octane compound, but the obtained isomerization reaction product is further separated by the above method, A compound having a high octane number can be obtained.
The octane number can be increased by further isomerization of the low octane compound containing the linear saturated aliphatic hydrocarbon as a main component separated in the present invention. It can also be extracted outside and used for other purposes such as petrochemical raw materials.

(Process flow example)
The method for producing a gasoline base material according to the present invention basically includes two or more isomerization reaction steps, and one or two isomerization reaction products generated therein are separated into a high octane compound group and a low octane compound group. This method consists of a separation step, and will be described in detail below using a process flow.

FIG. 1 shows a basic process flow of a method for producing a gasoline base material according to the present invention. In FIG. 1, R1 and R2 represent a first isomerization reaction step 2 and a second isomerization reaction step 4, respectively, in which an isomerization reaction is performed using a solid catalyst, and S1 represents a first isomer produced by R1. 2 shows a first separation step 6 for separating the isomerization reaction product 3 into the first high octane compound group 7 and the first low octane compound group 8, S2 being the second isomerization reaction product produced by R2 5 shows a second separation step 9 for separating 5 into a second high octane compound group 10 and a second low octane compound group 11. The first low-octane compound group 8 separated in S1 is sent to R2 and isomerized at a temperature 10 ° C. or more lower than R1, and a compound from which the high-octane compound is removed is used as a raw material. As a result, the degree of branching is further increased, and a high octane compound can be obtained effectively.
Finally, as a gasoline base material, when (a) S1 and S2 are present, first and second high octane compound groups (7 and 10) are obtained, and (b) when only S1 is present, The first high octane compound group 7 and the second isomerization reaction product 5 are obtained, and when only (c) S2 is present, the second high octane compound group 10 is obtained. When S2 is present (in the case of (a) and (c)), the second low-octane compound group 11 is also obtained, but this is not preferable as a gasoline base material because of its low octane number, and will be described later. You may return to R1 and R2 and reprocess, or you may send out of the system and use for applications other than a gasoline base material, for example, a petrochemical raw material.
Further, in FIG. 1, the first separation step (S1) 6 and the second separation step (S2) 9 may be provided in both of S1 and S2, although they are enclosed in broken brackets. One of them is required and the other is not necessarily required.

  FIG. 2 shows that in the first separation step (S1) 6 installed after the first isomerization reaction step (R1) 2, the first isomerization reaction product 3 is mixed with the first high octane compound group 7 and 1 to obtain a second isomerization reaction product 5 by separating the first low octane compound group 8 into a second isomerization reaction step (R 2) 4. The manufacturing method of a base material is shown. The first low octane compound group 8 may contain a linear saturated aliphatic hydrocarbon as a main component or a saturated aliphatic hydrocarbon having 1 or less branches as a main component. , R2 is treated at a temperature lower than R1, and since the first high-octane compound group 7 is separated, the reaction equilibrium is shifted and the isomerization reaction proceeds more effectively in R2. As a gasoline base material, the 1st high octane compound group 7 and the 2nd isomerization reaction product 5 correspond, and both can also be mixed and used.

  FIG. 3 shows a process flow including a first isomerization reaction step (R1) 2, a second isomerization reaction step (R2) 4, and a second separation step (S2) 9, and the second separation step ( The second low octane compound group 11 separated in S2) is returned to the first isomerization reaction step 2 to be isomerized again (FIG. 3 (b)), or the second isomerization reaction. The process is returned to step 4 and isomerized again (FIG. 3 (a)). Basically, only the second high octane compound group 10 is produced as a gasoline base material. When returning the 2nd low octane compound group 11 to R1, it is preferable to isolate | separate and return as a low octane compound which contains a linear saturated aliphatic hydrocarbon as a main component.

  FIG. 4 is a process flow showing a method for producing a gasoline base material in which two isomerization reaction steps (R1 and R2) and two separation steps (S1 and S2) are combined. It differs from the flow of FIG. 3 in that the first separation step 6 is included. That is, in the second isomerization reaction step, the first low octane compound group 8 obtained by separating the first isomerization reaction product 3 in the first separation step (S1) is isomerized. Similarly to FIG. 3, is the second low octane compound group 11 separated in the second separation step (S2) returned to the first isomerization reaction step 2 and subjected to isomerization again (FIG. 4)? (B)), or returned to the second isomerization reaction step 4 and isomerized again (FIG. 4 (a)). As the gasoline base material, only the high octane compound of the first high octane compound group 7 and the high octane compound of the second high octane compound group 10 can be produced, and both can be obtained by mixing.

FIG. 5 is a process flow showing a method for producing a gasoline base material in which two isomerization reaction steps (R1 and R2) and one separation step (S2) are combined, and there is another separation step (S1). (FIG. 5 (b)) or not (FIG. 5 (a)). In particular, in the second separation step 9, in addition to the second high octane compound group 10 and the second low octane compound group 11, a compound group having an intermediate octane number (second The middle octane compound group 12) is separated into three components, and the second low octane compound group 11 and the second medium octane compound group 12 are divided into a first isomerization reaction step 2 and a second isomerization reaction step 4, respectively. The point is to isomerize again.
In the second separation step 9, the three components of the low, medium and high octane compound groups are separated, but the order of separating the three components may be any order. Specifically, the three components are, specifically, the low octane compound group 11 includes a linear saturated aliphatic hydrocarbon as a main component, and the medium octane compound group 12 includes a one-branched saturated aliphatic hydrocarbon as a main component. In addition, the high octane compound group 10 preferably contains two or more branched saturated aliphatic hydrocarbons as main components.
The second low octane compound group 11 is treated again with the naphtha fraction in the first isomerization reaction step 2, and the second medium octane compound group 12 is processed in the second isomerization reaction step 4 in the first isomerization reaction. The product is isomerized again together with the product (FIG. 5A) or with the first low octane compound group 8 (FIG. 5B). Since the low and medium octane compound groups to be recycled have a structure close to that of the saturated aliphatic hydrocarbon of the raw material to be treated in the first and second isomerization reaction steps, the isomerization reaction is more efficiently performed. Advances. 5A, the second high octane compound group 10 is produced as a gasoline base material having a high octane number, and the first and second high octane compound groups 7 and 10 are produced in FIG. 5B.

[Blend process]
The gasoline composition of the present invention can be produced by blending the isomerized gasoline obtained by the above-described treatment with other gasoline bases in an appropriate ratio.
The other gasoline base refers to a gasoline base used in addition to the isomerized gasoline when preparing the gasoline composition of the present invention, and a gasoline base used in conventional gasoline production can be used. Specifically, after hydrodesulfurizing the naphtha fraction, the desulfurized straight-run naphtha fraction obtained by distillation separation of the light fraction, alkylate gasoline obtained by alkylating the butylene fraction and the isobutane fraction, contact Catalytic cracked light naphtha fraction (FL) obtained by distillation of cracked naphtha fraction (FCCG), reformed gasoline obtained by reforming desulfurized heavy naphtha with solid reforming catalyst, and distillation thereof A specific gasoline fraction and a rich gasoline reformate fraction obtained (eg, AC7 rich in aromatics having 7 carbons, AC9 rich in aromatics having 9 carbons, etc.), Examples thereof include gasoline fractions by-produced from various refining processes of crude oil, and isolated butane and pentane, and aromatic compounds such as so-called BTX. Further, so-called “oxygen compounds” of alcohols such as ethanol and ethers and esters which are derivatives from alcohols such as ethanol may be used.

  As the oxygen-containing compound, for example, alcohols having 2 to 5 carbon atoms and ethers having 4 to 8 carbon atoms are suitable. Specifically, alcohols such as ethanol, propyl alcohols, butyl alcohols, Examples thereof include ethers such as ethyl isopropyl ether, ethyl tertiary butyl ether, ethyl secondary butyl ether, diisopropyl ether, and tertiary amyl ethyl ether, and esters such as ethyl acetate and ethyl propionate, which are derivatives from alcohols.

  These oxygenated compounds are used in an amount of 1 to 15% by volume, preferably 3 to 12% by volume, more preferably 5 to 10% by volume, based on the total gasoline composition. This is because if the amount is too small, the effect of addition is small, and if the amount is too large, impurities such as moisture are accompanied, causing troubles such as corrosion of pipes and sealing materials. For example, since ethanol dissolves water infinitely, if it is contained in a large amount in fuel, water may be concentrated and accumulated in an automobile fuel tank, which may have an adverse effect. Furthermore, when there are many oxygenated compounds in the fuel oil, for example, if the amount exceeds 15% by volume, it will deviate from the optimum value of the air / fuel ratio of the existing engine, resulting in an excess of oxygen. There is a drawback that the amount of nitrogen oxide (NOx) increases. Further, since oxygen-containing compounds generally have a lower calorific value than other gasoline base materials and may reduce fuel consumption, it is not preferable to use too much.

[Gasoline composition]
The gasoline composition of the present invention is a gasoline composition obtained by blending the gasoline base material isomerized and separated by the above method, the research method octane number is 90 or more, and the sulfur content is 10.0 mass ppm or less. The 50% by volume distillation temperature is 100 ° C. or less, the vapor pressure is 65 kPa or less, and the content of linear saturated aliphatic hydrocarbon is 9.0% by volume or less. The octane number is preferably 93 or more, more preferably 95 or more, and the sulfur content is preferably 1.0 mass ppm or less, more preferably 0.5 mass ppm or less. The sulfur content in gasoline becomes sulfur oxides in the exhaust gas, poisoning the nitrogen oxide removal catalyst and lowering the catalytic activity. The poisoned nitrogen oxide removal catalyst is regenerated in a reducing atmosphere to recover its activity. At this time, fuel is usually used to form a reducing atmosphere, which causes a deterioration in fuel consumption. Therefore, the fuel efficiency improves as the sulfur content in gasoline decreases. The 50% by volume distillation temperature is preferably 98 ° C. or less, more preferably 96 ° C. or less, from the viewpoint of low temperature operability. The vapor pressure is preferably 62 kPa or less, and more preferably 60 kPa or less. When the RVP is high, problems such as an increase in evaporation loss, a concern about vapor lock, and an increase in danger are likely to occur.

The content of the linear saturated aliphatic hydrocarbon is preferably 1.0% by volume or more and 7.0% by volume or less, more preferably 2.0% by volume or more and 6.0% by volume or less, and further preferably 2.% by volume. It is preferably 0% by volume or more and 5.5% by volume or less. Here, when the content of the linear saturated aliphatic hydrocarbon exceeds 9% by volume, the aromatic content may adversely affect the environment in order to maintain the conventional distillation properties, vapor pressure and octane number. And a large amount of base material containing a large amount of olefin is unavoidable.
Furthermore, the gasoline composition of the present invention preferably has as little aromatic content as possible from the viewpoint of maintaining exhaust gas properties and low-temperature operability, and is preferably 5.0% by volume or more and 35.0% by volume or less. Is preferably 5.0% by volume or more and 32.0% by volume or less. On the other hand, the olefin content is preferably 5.0% by volume or more and 30.0% by volume or less, more preferably 10.0% by volume or more and 25.0% by volume from the viewpoint of RON maintenance, fuel consumption, light stability and storage stability. It is as follows. Furthermore, since silver is partially used in the fuel tank level gauge of gasoline vehicles, it is desirable that the corrosion of the silver plate is 1 or less.

〔Additive〕
As a preferred embodiment of the gasoline composition of the present invention, a known fuel additive can be further blended as necessary. Although these compounding quantities can be chosen suitably, it is usually preferable to set it as 0.1 volume% or less as a total amount of an additive. Additives that can be used in the gasoline composition of the present invention include amine-based, phenol-based, aminophenol-based antioxidants, Schiff-type compounds, metal deactivators such as thioamide-type compounds, and organic phosphorus-based compounds. Surface ignition inhibitor, detergent dispersants such as succinimide, polyalkylamine, polyetheramine, anti-icing agent such as polyhydric alcohol and its ether, alkali metal salt or alkaline earth metal salt of organic acid, higher alcohol Auxiliary agents such as sulfuric acid esters, anionic surfactants, cationic surfactants, antistatic agents such as amphoteric surfactants, rust inhibitors such as alkenyl succinates, discriminating agents such as quinizarin and coumarin, azo dye And the like.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1
(Isomerization process)
The first reactor is filled with a zirconia platinum tungstate catalyst (catalyst A), normal hexane is passed through the first reactor as a naphtha fraction of the feedstock, and an isomerization reaction is performed. Isomerization reaction product A was obtained. The reaction conditions were as follows: reaction temperature: 200 ° C., reaction pressure: 1.0 MPa, LHSV: 1.5 h ⁻¹ , H _{2 /} Oil: 5.0 mol / mol. The catalyst A used was in the form of a pellet having an outer diameter of about 1.5 mm and a height of about 4.0 mm, 1.6% by mass of platinum, 37.6% by mass of zirconium, 15.5% by mass of tungsten, and aluminum. It contained 13.7% by mass, and the Hammett acidity function by the Hammett indicator was -13.75.
Table 1 shows the properties of the first isomerization reaction product A. Since the normal heptane of the raw material has an octane number of 0, as is clear from Table 1, the octane number was improved to 55.6 by the isomerization reaction.

(Distillation separation process)
Next, the obtained first isomerization reaction product A was used as a distillation tower having a tower height of 4200 mmH and a tower diameter of 42.8 mmφ packed with a packing made by Tokyo Special Wire Mesh Co., Ltd. and GOODROLL TYPE D (made by SUS304). The reflux ratio is 3/1 to 5/1 (theoretical plate number is 85), the set pressure is distilled at 0.1 MPa (first separation step), and the top temperature of the fraction (gas component) up to 68 ° C. A fraction of 68 to 88 ° C. (light fraction, ie, the first high octane compound B) and a remaining fraction of 88 ° C. or higher (heavy fraction, ie, the first low octane compound C) were obtained. The respective yields were 9.0% by volume for gas, 42.6% by volume for first high octane compound B, and 48.4% by volume for first low octane compound C. Table 1 shows the properties of the first high-octane compound B and the first low-octane compound C after the distillation separation together with the properties of the first isomerization reaction product A before the distillation.

Next, the first low octane compound C obtained as described above was supplied to the second reactor to carry out the second isomerization reaction. The second isomerization reaction uses catalyst A under the reaction conditions of reaction temperature: 180 ° C., LHSV: 1.5 h ⁻¹ , H _{2 /} Oil: 5.0 mol / mol, and reaction pressure: 1.0 MPa. The second isomerization reaction product D was obtained.
The second isomerization reaction product D was mixed with the gas component obtained in the first separation step and the first high-octane compound B having a light content to obtain a gasoline base H.

Examples 2-4
Using the first low octane compound C prepared in Example 1, a second isomerization reaction was carried out by changing the catalyst and reaction conditions, and the second isomerization reaction products E (Example 2), F ( Except for obtaining Example 3) and G (Example 4), gasoline base materials I (Example 2), J (Example 3) and K (Example 4) were produced in the same manner as in Example 1. Was prepared. The properties of the obtained second isomerization reaction products E to G and gasoline base materials I to K are the same as those of the second isomerization reaction product D and gasoline base material H of Example 1, respectively. It shows in Table 3 and Table 4.
In Examples 1 to 4, in the first and second isomerization reactors, the catalyst used, the temperature of the reactor (reaction temperature) and LHSV were carried out under the conditions shown in Table 2, and the other conditions in Examples 2 to 4 Was carried out under the same conditions as in Example 1.
Catalyst B is a pellet-shaped platinum sulfate zirconia catalyst having an outer diameter of about 1.5 mm and a height of about 4.0 mm. Platinum is 0.4 mass%, zirconium is 42.1 mass%, and sulfur is 2.5. It contained 15.5% by mass of aluminum and 15.5% by mass of aluminum, and the Hammett acidity function with a Hammett indicator was -16.0.

Comparative Examples 1-3
As a comparative example, in order to obtain a high octane hydrocarbon, a decomposition-oriented operation of a one-stage reaction was performed. As overdecomposition type reaction conditions, the reaction pressure was 1.0 MPa, H _{2 /} Oil: 5.0 mol / mol, and the catalyst used, reaction temperature, and LHSV were the conditions shown in the upper part of Table 5.
In Comparative Example 1 and Comparative Example 2, a platinum sulfate zirconia catalyst (Catalyst B) was used. In Comparative Example 1, the octane number was the same level as in Example 1, and in Comparative Example 2, C5 + The reaction temperature was adjusted so that the fraction was at the same level as in Example 3. In Comparative Example 3, a platinum tungstate zirconia catalyst (Catalyst C) was used as the catalyst, and the reaction temperature was adjusted so that the C5 + fraction was at the same level as in Example 3.
Catalyst C is a pellet-shaped catalyst having an outer diameter of about 1.5 mm and a height of about 4.0 mm. As metal elements, platinum is 0.5% by mass, zirconium is 41.8% by mass, and tungsten is 12.8% by mass. %, 14.5% by mass of aluminum, and the Hammett acidity function according to the Hammett indicator was -13.75.
As a result, properties of the obtained overdecomposition isomerization reaction products L (Comparative Example 1), M (Comparative Example 2), and N (Comparative Example 3) are shown in Table 5.

  As is clear from comparison between Tables 4 and 5, when the octane number is increased, the C5 + fraction obtained as a liquid is less than 50% by volume as shown in Comparative Example 1. On the other hand, in Example 1, although the octane number is slightly low, a large amount of 80% by volume or more C5 + fraction, that is, a liquid fraction useful as a gasoline base material is obtained. Moreover, when it is going to raise a liquid yield like the comparative example 2 and the comparative example 3, an octane number will not reach 50 and the high octane number of about 60 or more like Examples 1-4 may not be obtained.

Examples 5-9, Comparative Examples 4-8
As the gasoline base material obtained in the present invention, the first high octane compound B in Example 1, the second isomerization reaction product F in Example 3, the overdecomposition isomerization reaction product M in Comparative Example 2, and The gasoline compositions of Examples 5 to 9 and Comparative Examples 4 to 8 were prepared by blending at a mixing ratio shown in the upper part of Table 7 using a conventional gasoline base. The properties of the gasoline base used are shown in Table 6, and the properties of the obtained gasoline composition are shown in the lower part of Table 7.

In addition, the conventional gasoline base material used what was prepared as follows.
Catalytic cracking light naphtha fraction (FL)
Desulfurized gas oil or desulfurized heavy oil is used as a raw material oil, and in the presence of a solid catalyst, a catalytic cracking reaction in a fluidized bed reactor is used to obtain a catalytically cracked naphtha fraction (FCCG) with a high olefin content. It is a light fraction (FL) obtained by distilling into a fraction.

Desulfurization cracking naphtha fraction (DS-FCCG)
Hydrocarbon oil with low sulfur content was obtained by collecting and removing the FCCG. After sulfiding a catalyst carrying 20% by mass of nickel on alumina, the reaction temperature: 250 ° C., reaction pressure: normal pressure, LHSV: 4 h ⁻¹ , H ₂ / oil ratio: 340 NL / L, Middle East Diene reduction treatment was carried out by passing a catalytic cracked naphtha fraction (FCCG) obtained by fluid catalytic cracking using a hydrorefined fraction of a crude oil of reduced pressure as the main feedstock. Furthermore, after reducing the copper-zinc-aluminum composite oxide (copper content 35 mass%, zinc content 35 mass%, aluminum content 5 mass%) prepared by the coprecipitation method, the diene-treated contact was performed. The cracked gasoline was passed for 20 hours under the conditions of a reaction temperature of 100 ° C., a reaction pressure of normal pressure, LHSV of 2.0 h ⁻¹ , an H ₂ / oil ratio of 0.06 NL / L, and a desulfurized cracked naphtha fraction (DS-FCCG fraction). )

Catalytic reforming gasoline (AC9)
By reacting desulfurized heavy naphtha with a solid reforming catalyst using a moving bed reactor, it is reformed into a hydrocarbon with a high aromatic content to obtain catalytic reformed gasoline. The reformed gasoline can be used as it is, but here, a fraction (AC9) containing 85% or more of aromatic hydrocarbons having 9 carbon atoms was obtained by distillation separation.

Ethyl tertiary butyl ether (ETBE)
Using an ion exchange resin catalyst (Amberlyst-15), ethanol and isobutylene were reacted and then purified by distillation to obtain ETBE having a purity of 95% or more.

Ethanol (EtOH)
Commercially available fermented ethanol (99 degrees first grade, manufactured by Nippon Alcohol Sales Co., Ltd.) was used.

In addition, the property of the gasoline base material and the gasoline composition was measured by the following method.
The density was measured by the vibration type density test method of JIS K 2249, the vapor pressure was measured by the Reed method vapor pressure test method of JIS K 2258, and the distillation property was measured by the atmospheric pressure method of distillation test of JIS K 2254. The sulfur content was measured by the sulfur content test method of JIS K2541. Silver plate corrosion is the cylinder method (jet fuel) of JIS K2513 (Petroleum products-Copper plate corrosion test method: corresponding ASTM D130). Instead of the copper plate, “14. Silver plate of JIS K2276 (Petroleum product-Aviation fuel oil test method)” The silver plate used in the “corrosion test method” was evaluated. The component composition of various hydrocarbons such as an aromatic component, an olefin component, and a saturated hydrocarbon component was measured by an all component test method based on a gas chromatographic method of JIS K2536. The octane number was measured by gas chromatography using a PIONA device manufactured by Hured Packard.

  As shown in Table 7, the octane number-improved gasolines of Examples 5-9 produced by blending gasoline base materials produced by the method of the present invention were isomerized as compared with the conventional gasolines of Comparative Examples 4-8. By using isomerized gasoline obtained by optimally combining the process and the separation process, the content of linear saturated aliphatic hydrocarbon is low, so the vapor pressure is low and the octane number is high. That is, the octane number-improved gasolines of Examples 5 to 9 have a high octane number and a low vapor pressure even when the sulfur content and the distillation properties are similar to those of Comparative Examples 4 to 8, and excellent practical use. It can be seen that it has performance.

  According to the method for producing a gasoline base material of the present invention, it becomes possible to increase the content of a branched saturated aliphatic hydrocarbon having a high octane number. By effectively utilizing the high octane number of saturated aliphatic hydrocarbons, it is not necessary to use a large amount of aromatics and olefins that have been conventionally used to increase the octane number. Gasoline compositions with low aromatic content and olefin content are not only preferred as fuel for gasoline engines from the standpoint of environmental protection, but also as fuel for fuel cells, they have high combustibility and energy efficiency. It has performance and is expected to be used as a common gasoline.

It is a basic process flow which shows the outline of the manufacturing method of the gasoline base material of this invention. Both of the two separation steps (S1, S2) are not essential, and any one of them may be present. It is a process flow which shows one embodiment of the manufacturing method of the gasoline base material of this invention. Only the first separation step is included. It is a process flow which shows one embodiment of the manufacturing method of the gasoline base material of this invention. Only the second separation step is included. FIG. 3 (a) recycles the second low-octane compound group to the second isomerization reaction step (R2), and FIG. 3 (b) recycles to the first isomerization reaction step (R1). Yes. It is a process flow which shows one embodiment of the manufacturing method of the gasoline base material of this invention. Includes only two separation steps. FIG. 4 (a) recycles the second low octane compound group to the second isomerization reaction step (R2), and FIG. 4 (b) recycles to the first isomerization reaction step (R1). Yes. It is a process flow which shows one embodiment of the manufacturing method of the gasoline base material of this invention. In the second separation step, the octane compound group is separated into three groups of high, medium and low, and the low octane compound group is recycled to the first isomerization reaction step (R1), and the medium octane compound group is second isomerized. Recycle to reaction step (R2). FIG. 5A has no first separation step, and FIG. 5B has a first separation step.

Explanation of symbols

1 Naphtha fraction 2 First isomerization reaction step (R1)
3 First isomerization reaction product 4 Second isomerization reaction step (R2)
5 Second isomerization reaction product 6 First separation step (S1)
7 1st high octane compound group 8 1st low octane compound group 9 2nd separation process (S2)
10 second high octane compound group 11 second low octane compound group 12 second medium octane compound group

Claims (9)

In a method for producing a gasoline base material having a higher octane number by isomerizing a naphtha fraction, a first isomerization reaction step for isomerizing the naphtha fraction, and a first isomerization reaction step produced by the first isomerization reaction step A second isomerization reaction step in which the isomerization reaction product is directly or indirectly isomerized, and the first isomerization reaction product is divided into a first low octane compound group and a first high octane compound. The first isomerization reaction product obtained in the first separation step and / or the second isomerization reaction step, wherein the first low octane compound group is separated into a group and sent to the second isomerization reaction step Is separated into a second low-octane compound group and a second high-octane compound group, and the periodic table IV in which the Hammett acidity function is less than −12 is obtained in the both isomerization reaction steps. Group elements and periodic table group VI elements and white Using a solid acid catalyst containing gold , the naphtha fraction and further the first low octane compound group and / or the second low octane compound group in the presence of hydrogen, reaction temperature of 100 to 300 ° C., reaction pressure of 0. 5 to 5 MPa, hydrogen / feed oil ratio 0.5 to 20 mol / mol, liquid space velocity (LHSV) 0.3 to 10 h ⁻¹ , contacted with the solid acid catalyst, and the second isomer in the latter stage A method for producing a gasoline base material, characterized in that the reaction temperature in the isomerization reaction step is 10 ° C. or more lower than the reaction temperature in the first isomerization reaction step in the preceding stage. The group IV element of the periodic table is at least one selected from the group consisting of titanium, zirconium, hafnium, and tin, and the group VI element of the periodic table is from the group consisting of tungsten, sulfur, and molybdenum. method for producing a gasoline base according to claim 1 der one or more elements Ru selected. A first and second isomerization step comprises a first separation step, according to claim 1 or a first low octane compounds separated in the first separation step is treated with a second isomerization step 2. A method for producing a gasoline base material according to 2 . The first and second isomerization reaction steps and the second separation step, and the second low octane compound group separated in the second separation step is mixed with the second isomerization product together with the second isomerization product. The method for producing a gasoline base material according to claim 1 or 2, wherein the gasoline base material is treated in the chemical reaction step. The first and second isomerization reaction steps and the second separation step, and the second low octane compound group separated in the second separation step is treated together with the naphtha fraction in the first isomerization reaction step A method for producing a gasoline base material according to claim 1 or 2 . Including the first and second isomerization reaction steps and the first and second separation steps, and treating the first low octane compound group separated in the first separation step in the second isomerization reaction step; The method for producing a gasoline base material according to claim 1 or 2, wherein the second low octane compound group separated in the second separation step is treated together with the first low octane compound group in the second isomerization reaction step. . Including the first and second isomerization reaction steps and the first and second separation steps, and treating the first low octane compound group separated in the first separation step in the second isomerization reaction step; The method for producing a gasoline base material according to claim 1 or 2, wherein the second low-octane compound group separated in the second separation step is treated together with the naphtha fraction in the first isomerization reaction step. A first isomerization reaction product obtained in the first isomerization reaction step, comprising a first and second isomerization reaction step, a second separation step, and optionally a first separation step; or The first low octane compound group separated in the first separation step is treated in the second isomerization reaction step, and the obtained second isomerization reaction product is linearly saturated in the second separation step. A second low-octane compound group mainly composed of aliphatic hydrocarbons, a second medium-octane compound group mainly composed of saturated aliphatic hydrocarbons having 1 branch, and a saturated aliphatic group having 2 or more branches The second high-octane compound group is separated into the second high-octane compound group mainly composed of hydrocarbon, the second low-octane compound group is treated with the naphtha fraction in the first isomerization reaction step, and the second medium-octane compound group is Second isomerization reaction product or first low octane compound group together with the second Method for producing a gasoline base according to claim 1 or 2 is treated with sexual reaction step. The first and second separation steps are a separation step with an adsorbent containing one or more elements selected from the group consisting of silicon, aluminum and carbon, a separation step with a separation membrane, a separation step with precision distillation, or those The method for producing a gasoline base material according to any one of claims 1 to 8 , which is a separation step by a combination of two or more kinds.

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