JP2007154151A - Method for producing 6-8c aromatic hydrocarbon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for economically producing 6-8C hydrocarbons such as BTX i.e. benzene, toluene and xylene from heavy oil. <P>SOLUTION: The method for producing 6-8C hydrocarbons, is characterized by decreasing the total concentration of indane, alkylindane, indene, alkylindene, naphthalene and alkylnaphthalene and increasing the total concentration of benzene, toluene and xylene by bringing stock oil into contact with a metal carrier catalyst, which stock oil contains at least one selected from indane, alkylindane, indene, alkylindene, naphthalene and alkylnaphthalene. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to heavy oils produced in petroleum refining processes, especially heavy oils containing alkylbenzene, indane, indene, alkylindane, alkylindene, naphthalene, alkylnaphthalene, and The present invention relates to a method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms (for example, benzene, toluene, ethylbenzene, or xylene (hereinafter referred to as “BTX”)), which is an important petrochemical raw material.

  In general, crude oil is distilled at atmospheric pressure or under reduced pressure, and is divided into various components according to the boiling point, and is used for various applications. Among them, an intermediate boiling point component called naphtha is subjected to high-temperature pyrolysis or catalytic reforming. The route that produces BTX together with the gasoline base is the main. Benzene is used as a monomer for nylon, which is a main polymer, and cyclohexane, which is a raw material for caprolactam, by hydrogenation reaction. In addition, demand for benzene is increasing as a monomer raw material for fine polymers and a raw material for fine chemicals. On the other hand, xylene is further converted to paraxylene and used as a raw material for polyester monomer and terephthalic acid, both of which are the main polymers. This demand is also strong, especially in Asia. Further, toluene is an important raw material for producing benzene and xylene not only as a gasoline base material and a solvent but also in a disproportionation process. Naphtha to meet the increasing demand for BTX is becoming increasingly tight year by year and is now one of the challenges of oil refining.

  As a method for increasing BTX production, one of the heavy oils generated in the previous naphtha reforming process is sometimes referred to as an aromatic hydrocarbon having 9 or more carbon atoms (hereinafter referred to as “aromatic hydrocarbon having 9 or more carbon atoms”). In addition, there is a method of producing benzene or xylene by transalkylation using “aromatic hydrocarbon having n carbon atoms” as a raw material (sometimes referred to as “Cn aromatic hydrocarbon”). In general, it contains indane, alkylindan, indene, alkylindene, naphthalene, and alkylnaphthalene, which are poisoned by the catalyst. From the viewpoint of deterioration of the activity of the catalyst used, conventionally, the catalyst has 10 or more carbon atoms by distillation separation in advance. Aromatic hydrocarbons were removed, and only aromatic hydrocarbons having 9 carbon atoms were used as raw materials. Therefore, heavy oils having 10 or more carbon atoms can only be used as low-value fuel oils such as solvents or heavy oils.

  Another method for increasing BTX production is to increase the throughput of the previous crude oil, but the heavy oil component increases accordingly. Heavy oil components are recovered as active ingredients by upgrading to a gasoline base by fluid catalytic cracking generally called FCC, but the reaction yield is as low as about 40 to 50%, and the remainder is boiling point In descending order, a gas having 3 to 4 carbon atoms, Light Cycle Oil (LCO), Heavy Cycle Oil (HCO), and residue (CSO) are generated, and LCO, HCO, and CSO are Still, it can only be used as a low-value fuel oil such as solvent or heavy oil.

  Therefore, if more benzene, toluene, and xylene can be recovered from the heavy oil as described above, it becomes a new BTX supply source, and a new effective utilization of the heavy oil can be achieved. However, heavy oil contains many so-called catalyst poisoning components that cause a decrease in catalyst activity, such as indane, indene, naphthalene, and high boiling point compounds. For example, the table below is an example of the composition of LCO, one of the heavy oils generated in FCC, but the heavy oils generated in FCC are indan and alkylindane, indene and alkylindene, naphthalene and alkylnaphthalene in particular. It accounts for the majority of the ingredients.

  Usually, when processing such raw materials containing catalyst poisons, for example, in the case of producing BTX from heavy oil containing C9 aromatic hydrocarbons, distillation separation and removal of C10 or higher aromatic hydrocarbons, other raw materials The concentration is reduced by mixing dilution, the ratio of hydrogenation to the raw material is increased, or decomposition and removal are performed by reaction using a metal-supported catalyst. However, even if such measures are taken, the content is allowed to be, for example, about 5% for indane (for example, see Patent Document 1) and about 1% for naphthalene (see Patent Document 2). In actual commercial operation base, the upper limit is 1% and 0.2%, respectively.

As an example of effective utilization of the above LCO, attention is paid to alkylnaphthalene contained in a large amount, and a method for converting it to naphthalene or polymethylnaphthalene, which is used as a raw material for polymers and chemical derivatives by reaction, is disclosed. . For example, an example in which naphthalene is obtained by hydrodealkylating an alkyl side chain by a fluidized bed contact method and a continuous catalyst regeneration method using a single alumina catalyst supporting a hydrogenated metal (for example, Patent Document 3), hydrogenated metal There is an example in which dimethylnaphthalene is obtained by hydrodealkylating the side chain of C2 or more using an acid catalyst supporting dimethylnaphthalene (see, for example, Patent Document 4). Another example is the effective use of LCO by converting it to light oil. After desulfurization of the oil, monocyclic and bicyclic or higher aromatic hydrocarbons that cause cetane number reduction are also hydrogenated. An example of improving the light oil quality by converting the aromatic hydrocarbon to naphthenic paraffin as much as possible by reducing the residual aromatic hydrocarbon concentration by hydrogenated nuclear hydrogenation using a metal-supported acid catalyst (for example, Patent Document 5). However, neither method discloses a method for producing BTX from the LCO, and a method for producing BTX from a raw material containing indane, alkylindane, indene, alkylindene, naphthalene, and alkylnaphthalene is currently in practical use. It has not reached.
JP-A-11-057481 (second page claim 16) Japanese Patent Laid-Open No. 10-045640 (Claim 2 on page 2) JP 02-298347 A (Example 5 on page 5) JP2004-244375 (6th page) JP-A-9-225304 (2nd page)

  This invention makes it a subject to provide the method of manufacturing C6-8 aromatic hydrocarbons, such as BTX, such as benzene, toluene, and a C8 aromatic hydrocarbon, economically from heavy oil.

  In order to achieve the above object, the present invention has the following configuration. That is, indane, alkylindane, indene, alkylindene in a feedstock oil by bringing a raw material containing at least one of indane, alkylindane, indene, alkylindene, naphthalene, and alkylnaphthalene into contact with a metal-supported catalyst. A method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms, characterized in that the total concentration of naphthalene and alkylnaphthalene is reduced and the concentration of benzene, toluene or xylene is increased.

  According to the present invention, a method for producing BTX by contacting a heavy oil comprising indane, alkylindan, indene, alkylindene, naphthalene, and alkylnaphthalene with an acid catalyst in the presence of hydrogen, from the heavy oil. It has become possible to economically produce valuable BTX.

  The feedstock oil used in the present invention contains at least one of indane, alkylindane, indene, alkylindene, naphthalene, and alkylnaphthalene. As such a raw material oil, heavy oil such as LCO generated by FCC and aromatic hydrocarbon oil having 10 or more carbon atoms generated by catalytic reforming can be preferably used.

  In particular, any one of indane, alkylindane, indene, alkylindene, naphthalene, and alkylnaphthalene is present in the feedstock in an amount of 1% by weight or more, more preferably 5% by weight or more, and more preferably 10% by weight or more. preferable. Among them, the total concentration of indane, alkylindane, indene and alkylindene is preferably 1% by weight or more, more preferably 3% by weight or more, further more than 5% by weight, and particularly preferably 10% by weight or more. . Further, the total concentration of naphthalene and alkylnaphthalene in the raw oil is preferably more than 1% by weight, more preferably 3% by weight or more, further 5% by weight or more, and particularly preferably 10% by weight or more.

  The raw material oil that can be used in the present invention can be sufficiently used not only for heavy oil generated from FCC such as LCO, but also for heavy oil generated by catalytic reforming, heavy oil generated by naphtha cracking, and the like. In particular, heavy oil generated from catalytic reforming contains a relatively large amount of components having many methyl groups such as trimethylbenzene, ethylxylene, tetramethylbenzene, and pentamethylbenzene. If it is used for all, it can be said that it is an effective heavy oil source that can be converted into lighter BTX in the process of transalkylation of the above reaction.

  When heavy oil is used for part or all of the raw material, it is preferable to remove (preliminarily remove) the sulfur compound and nitrogen compound by contacting with a metal-supported catalyst or adsorbent in advance.

  In the present invention, by bringing such feedstock into contact with the metal-supported catalyst, the total concentration of indane, alkylindane, indene, alkylindene, naphthalene, and alkylnaphthalene in the feedstock is reduced, and benzene, toluene, or xylene. The concentration of (BTX) is increased, which will be described in detail below.

In the present invention, in order to increase the amount of BTX in the above-described raw material oil, a method through at least the following two reaction steps is preferably used.
Reaction step-1: The feedstock is brought into contact with a metal-supported catalyst in the presence of hydrogen, and indane, alkylindane, indene, alkylindene, naphthalene or alkylnaphthalene contained in the feedstock is subjected to nuclear hydrogenation and / or ring opening. The process of converting into tetralin, alkyltetralin, and alkylbenzene by reaction.
Reaction step-2: The intermediate oil obtained in reaction step-1 is brought into contact with an appropriate metal-supported acid catalyst in the presence of hydrogen, and tetralin, alkyltetralin contained in the intermediate oil obtained in reaction step-1, In addition, alkylbenzene having at least one side chain having 2 or more carbon atoms is converted to an aromatic hydrocarbon having 6 to 8 carbon atoms to produce a product oil having a high concentration of 6 to 8 aromatic hydrocarbons. Process.

  First, reaction step-1 will be described. In the reaction step-1, the raw material oil is brought into contact with a metal-supported catalyst in the presence of hydrogen, and a monohydrogenation is performed by a nuclear hydrogenation reaction of two or more aromatic hydrocarbons typified by naphthalene. At this stage, for example, naphthalene is converted to tetralin as shown in the following formula. Alkylnaphthalene is similarly converted to alkyltetralin. Indene and alkylindene are converted to indane and alkylindane by hydrogenation reaction. Here, indane is converted to alkylbenzene by hydrogenation ring-opening reaction of only non-aromatic part as shown in the following reaction formula, and alkylindan is also converted to alkylbenzene in the same manner. Furthermore, dealkylation may occur in some of the alkylbenzene produced by the above reaction and the alkylbenzene originally contained in the raw material.

  As the metal-supported catalyst used in this step, a catalyst having a large surface area such as an oxide typified by aluminum oxide (alumina), amorphous silica / alumina, or zeolite is selected as the support, and a metal-supported catalyst is used. Is done. The metal supported on the catalyst is preferably a hydrogenation active metal, and platinum, palladium, rhenium, nickel, cobalt, molybdenum, tungsten, or the like is preferably used as the hydrogenation active metal. Needless to say, the preferred loading varies depending on the metal to be carried. For example, in the case of molybdenum, it is 0.5 to 30% by weight, more preferably 10 to 20% by weight, and in the case of nickel, 0.5 to 10% by weight is preferably used.

The said catalyst can be performed according to various reaction operation known conventionally. As the reaction method, any of a fixed bed, moving bed, and fluidized bed method can be used, but the fixed bed reaction method is particularly preferable because of the ease of operation. In order to efficiently carry out the nuclear hydrogenation reaction in Reaction Step-1, the reaction is preferably performed at a low temperature and a high pressure. The reaction temperature is 200 to 450 ° C., preferably 250 to 350 ° C., and the pressure is from atmospheric pressure to 10 MPa-G, preferably 3 to 6 MPa-G. The weight hourly space velocity (WHSV) representing the contact time of the reaction is 0.1 to 10 hr ⁻¹ , preferably 0.5 to 4.0 hr ⁻¹ . The ratio of hydrogen to feedstock oil is from 100 to 2000 Nm ³ / m ³ , preferably from 200 to 800 Nm ³ / m ³ . In addition, when using the raw material containing a sulfide and a nitrogen compound among the heavy oil raw materials to be used, these sulfides and the nitrogen compound are hydrocracked by the reaction in the reaction step-1, and gases such as hydrogen sulfide and ammonia are used. In addition, there is an effect of refining the raw material oil such that it is removed by a method of separation by a gas-liquid separation facility such as a separator or a degassing distillation tower.

  In the next reaction step-2, the intermediate oil obtained in the above reaction step-1 is brought into contact with a metal-supported acid catalyst in the presence of hydrogen, and hydrogenated ring-opening reaction of tetralin and alkyltetralin is carried out to convert to alkylbenzene. Of these alkylbenzenes, and the alkylbenzenes originally contained in the feedstock, and further the alkylbenzenes converted in the reaction step-1, the side chain alkyl group having 2 or more carbon atoms is subjected to dealkylation reaction. Convert to basic aromatic hydrocarbons. For example, as shown in the following formula, tetralin is hydrogenated and converted to butylbenzene, and further dealkylated to benzene, and trimethyltetralin is hydrogenated and converted to butyltrimethylbenzene and further dealkylated. To trimethylbenzene. At the same time, indane, indene and alkyl compounds thereof contained in the intermediate oil are also subjected to hydrogen ring-opening and dealkylation of a side chain having 2 or more carbon atoms in the same manner as tetralin to remove only the methyl group. It is converted into an aromatic hydrocarbon (hereinafter referred to as a methyl group aromatic hydrocarbon). As used herein, “methyl group aromatic hydrocarbon” refers to an aromatic hydrocarbon group containing only one or more methyl groups as a substituent.

  Moreover, in the same reaction step-2, the transmethylation reaction of these methyl group aromatic hydrocarbons occurs at the same time, so that aromatics with many methyl groups such as trimethylbenzene, tetramethylbenzene and pentamethylbenzene are further converted into BTX. , BTX can be produced efficiently.

  At this time, in the reaction step-2, benzene and / or toluene is mixed with the above heavy oil and reacted to improve the yield of BTX or change the breakdown of benzene, toluene and xylene in the product. This is also an embodiment.

  The amount of benzene and / or toluene mixed in this case is preferably 0 to 100 parts by weight with respect to 100 parts by weight of the intermediate oil, and the composition of the feedstock, the maximum BTX yield, or the desired BTX in the product It is necessary to change this mixing ratio according to the breakdown of.

As the catalyst used in the reaction step-2, a metal-supported acid catalyst is used. As a catalyst for supporting a metal, an acid-type zeolite can be preferably exemplified. As the zeolite that can be used in the present invention as the acid-type zeolite, a zeolite having a pore having a 12-membered oxygen ring or more is preferable. Examples of zeolites having 12-membered oxygen ring pores include mordenite-type zeolites (for example, Example 1 on page 4-5 of JP-B-2-31006, Example 11 on page 5 of JP-A-55-126529). Examples thereof include beta zeolite (see, for example, Example 1 in column 8 of US Pat. No. 3,308,069), faujasite type zeolite, and the like. An example of a zeolite having 14-membered oxygen ring pores is CFI-type zeolite often referred to as CIT-5 (see, for example, Example 5 in the pamphlet of International Publication No. 99/088961 column 36). MFI type zeolite having pores of 10-membered oxygen rings in these zeolites (see, for example, Example 1 on page 4-5 of JP-B-60-35284 and Example 1 on page 7 of JP-B-46-10064) The BTX yield can be improved by mixing partly. As the zeolite, both natural products and synthetic products can be used, but synthetic zeolite is preferred. Even with the same zeolite structure, the catalytic performance varies greatly depending on the composition, particularly the silica / alumina molar ratio (SiO ₂ / Al ₂ O ₃ molar ratio), the size of the zeolite crystallites, and the like.

  The preferable range of the silica / alumina molar ratio constituting the zeolite also depends on the zeolite structure. For example, in a synthetic mordenite type zeolite, the preferred silica / alumina molar ratio is 10-50, more preferably 12-35. For beta zeolite, the preferred silica / alumina molar ratio is 15-60, more preferably 15-40. In the faujasite type zeolite, the preferred silica / alumina molar ratio is 4 to 120, more preferably 4 to 60. In the CFI type zeolite, the preferred silica / alumina molar ratio is 30 to 200, more preferably 30 to 120. In addition, the preferred silica / alumina molar ratio is 20 to 60 for MFI type zeolite. The silica / alumina molar ratio of these zeolites can be achieved by controlling the composition ratio during zeolite synthesis. Further, the silica / alumina molar ratio of the zeolite can be increased by removing aluminum constituting the zeolite structure with an acid aqueous solution such as hydrochloric acid or an aluminum chelating agent such as ethylenediaminetetraacetic acid (EDTA). On the contrary, a preferable silica / alumina molar ratio is obtained by increasing the silica / alumina molar ratio of the zeolite by introducing aluminum into the zeolite structure by treatment with an aqueous solution containing aluminum ions, such as an aqueous aluminum nitrate solution or an aqueous sodium aluminate solution. It is also possible to make it. The measurement of the silica / alumina molar ratio can be easily known by atomic absorption method, fluorescent X-ray diffraction method, ICP (inductively coupled plasma) emission spectroscopy or the like.

  The size of zeolite crystallites can be changed to some extent by adjusting the reaction mixture composition ratio, crystallization temperature, crystallization time, stirring speed, and the like, which are zeolite synthesis conditions. Alternatively, the crystallites can be changed to some extent by adding a surfactant, an organic base or other additives to the reaction mixture in zeolite crystallization. For example, as a specific example, in the step of synthesizing synthetic mordenite, by reducing the crystallite from about 0.5 microns to about 0.1 microns by coexisting an organic base such as tetraethylammonium hydroxide. I can do it. The crystallite size of zeolite can be easily known with a device such as a field emission scanning electron microscope (FE-SEM). As the crystallite size decreases, the catalytic activity of the acid-type catalyst prepared from such zeolite increases. In particular, it is preferable to use zeolite having a small crystallite. The crystallite size of the mordenite-type zeolite is mainly preferably 0.5 microns or less, more preferably 0.2 microns or less. The crystallite size of the beta zeolite is preferably mainly 0.2 microns or less. The crystallite size of the CFI-type zeolite is preferably short axis and mainly 0.2 microns or less. The term “mainly” as used herein means that 80% or more of the zeolite crystallites are within the range in the FE-SEM observation drawing performed for measuring the crystallite size.

  Such zeolite is appropriately selected and used as a catalyst.

  Since synthetic zeolite is generally a powder, it is preferably molded for use. Examples of the molding method include a compression molding method, a rolling method, and an extrusion method, and the extrusion method is more preferable. In the extrusion method, binders such as alumina sol, alumina gel, bentonite and kaolin and surfactants such as sodium dodecylbenzenesulfonate, span and twin are added to the synthetic zeolite powder as molding aids and kneaded. . If necessary, a machine such as a kneader is used. Furthermore, depending on the metal added to the catalyst, a metal oxide such as alumina, titania, kaolin, clay or the like is added at the time of molding the zeolite to increase the amount of the metal added to the catalyst or improve the dispersibility. The kneaded material is extruded from the screen. Industrially, for example, an extruder called an extruder is used. The kneaded product extruded from the screen becomes a noodle-like product. The size of the molded body is determined by the screen diameter to be used. The screen diameter is preferably 0.2 to 1.5 mmφ. The noodle-shaped molded body extruded from the screen is preferably treated with a malmerizer to round off the corners. The molded body molded in this way is dried at 50 to 250 ° C. After drying, it is fired at 250 to 600 ° C, preferably 350 to 600 ° C, in order to improve the molding strength.

The molded body thus prepared is subjected to an ion exchange treatment for imparting solid acidity. As a method for imparting solid acidity, ion exchange treatment is performed with a compound containing ammonium ions (for example, NH ₄ Cl, NH ₄ NO ₃ , (NH ₄ ) ₂ SO _4, etc.), and NH ₄ ions are added to the ion exchange site of the zeolite. After that, it is converted into hydrogen ions by drying and calcination, or directly with an acid-containing compound (for example, HCl, HNO ₃ , H ₃ PO _4, etc.) at the ion exchange site of the zeolite. Although there is a method of introducing ions, the latter is preferably subjected to ion exchange treatment with the former, that is, a compound containing ammonium ions, because the latter may destroy the zeolite structure. Alternatively, solid acidity can be imparted to the zeolite by introducing divalent and trivalent metal ions into the zeolite ion exchange site. Examples of divalent metal ions include alkaline earth metal ions Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , and Ba ²⁺ . Examples of the trivalent metal ions include rare earth metal ions such as Ce ³⁺ and La ³⁺ . It can be used in combination with a method of introducing divalent and / or trivalent metal ions and a method of introducing ammonium ions or direct hydrogen ions, and is sometimes more preferable. The ion exchange treatment is usually carried out with an aqueous solution by a batch method or a distribution method. The treatment temperature is usually from room temperature to 100 ° C.

  After the ion exchange treatment in this way, a metal, preferably a hydrogenation active metal is supported. By allowing hydrogen to be present in the catalytic reaction system and supporting a metal, preferably a hydrogenation active metal, it is possible to prevent deterioration of the catalyst with time. As the hydrogenation active metal, platinum, palladium, rhenium, nickel, cobalt, molybdenum, etc. are preferably used. Needless to say, the preferred loading varies depending on the metal to be carried. For example, in the case of platinum, it is 0.005-0.5 weight% with respect to the whole catalyst, More preferably, it is 0.01-0.3 weight%. In the case of palladium, 0.05 to 1% by weight is preferably used. In the case of rhenium, the supported amount is preferably 0.01 to 5.0% by weight, more preferably 0.1 to 2% by weight. When the amount of supported metal is increased, in the reaction step-2, even the aromatic ring portion of the monocyclic aromatic hydrocarbon is nuclear hydrogenated, which is not preferable. These metals are supported by immersing the catalyst in a solution containing platinum, palladium, rhenium or the like, generally in an aqueous solution. For example, if the platinum component is supported, chloroplatinic acid, ammonium chloroplatinate, etc., if the palladium component is supported, palladium acetate, acetylacetone palladium, palladium chloride, palladium nitrate, etc., if the rhenium component is supported, Perrhenic acid, perrhenium ammonium, etc. are used.

  The catalyst thus prepared is dried at 50 to 250 ° C. for 30 minutes or longer, and calcined at 350 to 600 ° C. for 30 minutes or longer prior to use.

The catalyst prepared as described above can be carried out according to various conventionally known reaction operations. As the reaction method, any of a fixed bed, moving bed, and fluidized bed method can be used, but the fixed bed reaction method is particularly preferable because of the ease of operation. In these reaction modes, the catalyst is used under the following reaction conditions. That is, the reaction operation temperature is 200 to 500 ° C, preferably 250 to 450 ° C. The reaction operation pressure is from atmospheric pressure to 10 MPa, preferably 1 to 5 MPa. The weight hourly space velocity (WHSV) representing the contact time of the reaction is 0.1 to 10 hr ⁻¹ , preferably 0.5 to 4.0 hr ⁻¹ . The ratio of hydrogen to feedstock oil is from 100 to 2000 Nm ³ / m ³ , preferably from 200 to 800 Nm ³ / m ³ . The feedstock oil is contacted with the catalyst in the liquid phase or gas phase, but more preferably in the liquid phase. It is presumed that the catalytic activity can be maintained by washing away the high-boiling compounds remaining on the catalyst by-produced by the reaction with the liquid aromatic hydrocarbons.

  The reaction step-1 and the reaction step-2 may be carried out in two steps by filling the respective reactors with a catalyst, or two types of catalysts having respective functions in one reactor. Filling and carrying out as a single step may be performed. Alternatively, the reaction may be performed using one catalyst having two functions, and the reaction steps-1 and 2 may be performed simultaneously. When performing collectively, it is sufficient to select from overlapping portions in each reaction condition.

  The product oil whose BTX concentration has been increased by the above method can usually recover BTX by distillation separation, but can also be recovered by adsorption separation or crystallization separation technology in addition to distillation separation.

  Remaining unreacted components obtained by separating and recovering the product oil containing BTX from the product oil exiting the reaction step-2, for example, tetralin, alkyltetralin, indane, alkylindane, indene, alkylindene, one or more alkyl groups having 2 or more carbon atoms For residual hydrocarbons containing aromatic hydrocarbons and methyl group aromatics having 3 or more methyl groups, it is preferable to recycle again to reaction step-2 in order to increase the recovery rate of BTX. Moreover, when the said residual oil contains many naphthalene and alkyl naphthalene, it is preferable to recycle to the reaction process-1. In the case of recycling, it is preferable to recycle after removing high boiling components that become catalyst poisons such as polycyclic aromatic hydrocarbons having 3 or more rings by distillation separation. One embodiment of a flow preferable for carrying out the above-described present invention is shown in FIG. The contents will be described below. In the figure, 1 is a reaction step-1 in which a nuclear hydrogenation reaction such as naphthalene or alkylnaphthalene mainly contained in the raw material is performed, and 2 is a tetralin contained in the intermediate oil mainly produced from the reaction step-1. This is reaction step-2 in which alkyltetralin, indane, indene, alkylindane, hydrogenated ring opening of alkylindene, dealkylation of an alkyl group having 2 or more carbon atoms, and transalkylation of a methyl group aromatic hydrocarbon are performed. In addition, 1 of “reaction step-1” and 2 of “reaction step-2” include a separator (not shown) for separating off-gas generated by the reaction and a degassing distillation column (not shown). 3 is a BTX recovery distillation column for performing a distillation process for separating and recovering BTX or a low-boiling non-aromatic hydrocarbon containing BTX from the reaction product solution obtained in 2 of “Reaction Step-2”. This is a recycle raw material recovery distillation column that performs a distillation step mainly for separating and removing high-boiling components of three or more aromatic hydrocarbons in order to recycle the residual oil separated and recovered from BTX. First, the feed oil is sent to 1 of “reaction step-1” by the stream 5, and under the addition of hydrogen or a mixed gas containing hydrogen by the stream 6, the nuclear hydrogenation reaction of naphthalene, alkylnaphthalene, etc. An intermediate oil having a low concentration of naphthalene and alkylnaphthalene is obtained, which is sent to “reaction step-2” 2 by stream 7 and rich in BTX concentration by addition of hydrogen or a mixed gas containing hydrogen by stream 9 A reaction product stream 10 is obtained. Here, stream 8 is an additional benzene or toluene feed line for adjusting the recovery or component breakdown of the produced BTX. The reaction product solution 2 of “Reaction Step-2” was recovered from the stream 11 in the distillation step of the BTX recovery distillation column 3 by recovering BTX or a low boiling point component rich in BTX concentration (product oil rich in BTX) from the stream 11. Stream 12 which is a residual oil containing a large amount of tetralin, alkyltetralin, indane, alkylindane, indene, alkylindene, and alkylbenzene in the reaction is sent to recycling column 4 for recycling raw material, which is the next distillation step, and more than three rings The high boiling point component (stream 15) containing the aromatic hydrocarbon is removed by distillation separation, and the unreacted component is recycled to 2 of “reaction step-2” by the stream 13 as a recycle raw material. When a large amount of naphthalene and alkylnaphthalene is contained in the recycled material, it is recycled to 1 in “Reaction Step-1” by the stream 14.

  In the present invention, conventionally, tetralin and alkyltetralin can be converted into decalin and alkyldecalin by nuclear hydrogenation, and then ring-opened as in the above “reaction step-2” to form a monocyclic alkyl group aromatic One of the major features is the conversion to hydrocarbons. Therefore, even if the raw material does not contain naphthalene or alkylnaphthalene, if there is a raw material source containing, for example, tetralin or alkyltetralin, it can be directly charged to “Reaction Step-2” from the beginning, and further if necessary As described above, C6-C8 aromatic hydrocarbons can be more efficiently produced by recycling unreacted components or mixing with benzene / toluene.

  In general, heavy oil represented by LCO contains a high concentration of sulfur compounds in the order of several thousand ppm to several percent. When C6 to C8 aromatic hydrocarbons are recovered as a product, they are considerably high. Concentration to the concentration and concern about contamination. In general, the standard of the sulfur compound concentration when recovering C6-C8 aromatic hydrocarbons as a product is a level of 10 ppm or less to several tens of ppm or less, but in the above reaction step-1 and reaction step-2, Since the metal-supported acid catalyst used has a desulfurization function at the same time, it is possible to desulfurize the feedstock oil or intermediate oil at a high level and depth, and obtain a level that sufficiently satisfies the above standards. .

  The product oil containing the separated and recovered BTX is not only used for chemical raw materials. The product oil has a low concentration of tetralin and alkyltetralin, which are components causing cetane number reduction, and a high octane number BTX concentration. Therefore, by distillation from the product oil, a gas oil fraction having a high cetane number or an octane number It is possible to recover a high gasoline fraction. Therefore, the C6-8 aromatic hydrocarbons produced and separated and recovered by the production method of the present invention can be preferably used for gasoline, kerosene and light oil applications.

(Synthesis of beta-type zeolite)
Tetraethylammonium hydroxide aqueous solution (hereinafter referred to as “TEAOH”) (TEAOH content 20 wt%, H ₂ O content 80 wt%, Sanyo Chemical Industries, Ltd.) 1924 g, sodium aluminate aqueous solution (Al ₂ O ₃ content 18.5) Weight percent, NaOH content 26.1 wt%, H2O content 55.4 wt%, Sumitomo Chemical Co., Ltd.) 336 grams was dissolved in 5082 grams of water. To this solution was added 1052 grams of hydrous silicic acid (SiO ₂ content 91.6 wt%, Al ₂ O ₃ content 0.33 wt%, NaOH content 0.27 wt%, Nipseal VN-3, Nippon Silica Kogyo Co., Ltd.) And stirred to prepare an aqueous mixture slurry. The composition, expressed as a molar ratio, was as follows.
_{SiO 2 / Al 2 O 3:} 25
TEA ⁺ / TEA ⁺ + Na ⁺ : 0.544
OH ⁻ / SiO ₂ : 0.30
H ₂ O / OH ⁻ : 80
(TEA +: tetraethylammonium ion)

  This mixture slurry was put in a 10 L autoclave, sealed, heated to 250 rpm and 160 ° C., and reacted for 11 days with stirring. Thereafter, cooling, filtration and washing with water were repeated 5 times and dried at about 120 ° C. overnight.

  As a result of measuring the obtained product with an X-ray diffractometer using Cu tube and Kα ray, it was found that the obtained zeolite was a beta zeolite.

  As a result of fluorescent X-ray diffraction analysis, the silica / alumina molar ratio of the beta zeolite was 19.8.

  In order to investigate the size of the crystallite, observation was performed at a magnification of 100,000 times using a field emission scanning electron microscope (FE-SEM). As a result, about 80% of the crystallite was about 0.06 microns. It was found that the above is 80% or more (0.06 ± 0.01 micron).

(Synthesis of mordenite type zeolite-I)
Solid caustic soda (NaOH content 96.0 wt%, H ₂ O content 4.0 wt%, Kirk Corporation) 48.8 g, sodium aluminate solution (Al ₂ O ₃ content 18.5 wt%, NaOH content 26. 1 wt%, H ₂ O content 55.4 wt%, Sumitomo Chemical Co., Ltd.) 835.2 grams, tetraethylammonium hydroxide aqueous solution (TEAOH content 20 wt%, H ₂ O content 80 wt%, Sanyo Chemical Industries, Ltd.) ) 2208 grams was added to 958 grams of distilled water to make a uniform solution. 2620 grams of hydrous silicic acid (SiO ₂ content 91.6% by weight, Al ₂ O ₃ content 0.33% by weight, NaOH content 0.27% by weight, Nipsil VN-3, Nippon Silica Industry Co., Ltd.) Slowly added to prepare a uniform slurry aqueous reaction mixture. The composition ratio (molar ratio) of this reaction mixture was as follows.
_{SiO 2 / Al 2 O 3:} 25
OH ⁻ / SiO ₂ : 0.245
TEAOH / SiO ₂ : 0.075
H ₂ O / SiO ₂ : 30

  The reaction mixture was sealed in a 10 L autoclave and then reacted at 160 ° C. for 7 days with stirring at 250 rpm. After completion of the reaction, washing with distilled water 5 times and filtration were repeated, followed by drying at about 120 ° C. overnight.

  As a result of measuring the obtained product with an X-ray diffractometer using Cu tube and Kα ray, it was found that the obtained zeolite was a mordenite type zeolite.

  The silica / alumina molar ratio of this mordenite zeolite was 21.3 as a result of fluorescent X-ray diffraction analysis.

  As a result of FE-SEM observation at a magnification of 100,000 times, it was found that the crystallites were about 0.1 microns and 80% or more (80% or more were 0.1 ± 0.01 microns).

(Synthesis of mordenite type zeolite-II)
21.3 grams of solid caustic soda (NaOH content 96.0% by weight, H ₂ O content 4.0% by weight, Kirk Co., Ltd.), tartaric acid powder (tartaric acid content 99.7% by weight, H 2 O content 0.3% by weight, stock Company Kirk) 21.3 grams was dissolved in 586.8 grams of distilled water. To this solution was added 29.2 grams of sodium aluminate solution (Al ₂ O ₃ content 18.5 wt%, NaOH content 26.1 wt%, H ₂ O content 55.4 wt%, Sumitomo Chemical Co., Ltd.) A uniform solution was obtained. Hydrous silicic acid (SiO ₂ content 91.6 wt%, Al ₂ O ₃ content 0.33 wt%, NaOH content 0.27 wt%, Nipsil VN-3, Nippon Silica Industry Co., Ltd.) 111.5 Grams were added slowly with stirring to prepare a uniform slurry aqueous reaction mixture. The composition ratio (molar ratio) of this reaction mixture was as follows.
SiO ₂ / Al ₂ O ₃ : 30
OH ⁻ / SiO ₂ : 0.5
A / Al ₂ O ₃ : 2.5 (A: tartrate)
H ₂ O / SiO ₂ : 20

  The reaction mixture was sealed in a 1 L autoclave and then reacted at 160 ° C. for 72 hours with stirring at 250 rpm. After completion of the reaction, washing with distilled water 5 times and filtration were repeated, followed by drying at about 120 ° C. overnight.

  As a result of measuring the obtained product with an X-ray diffractometer using Cu tube and Kα ray, it was found that the obtained zeolite was a mordenite type zeolite.

  The silica / alumina molar ratio of this mordenite zeolite was 18.6 as a result of fluorescent X-ray diffraction analysis.

  As a result of performing FE-SEM observation at a magnification of 10,000, it was found that the crystallite size was about 0.5 microns, which was 80% or more (80% or more was 0.5 ± 0.1 microns).

(Synthesis of CFI type zeolite)
69.8 grams of distilled water and 69.8 grams of 3 wt% aqueous lithium hydroxide solution (LiOH anhydrous primary reagent: Kishida Chemical Co., Ltd.), methylspartenium hydroxide (hereinafter referred to as “MeSPOH”) (MeSPOH solution concentration 1) After adding 187.42 grams of aqueous solution (.51 mmol / g), 5 wt% aqueous solution of aluminum nitrate (Al (NO ₃ ) 3.9H2O reagent special grade: Kirk Co., Ltd.) and ethylenediaminetetraacetic acid (hereinafter referred to as “EDTA”) ) Added 4.32 grams and stirred well for 15 minutes. Next, 18.57 grams of hydrous silicic acid (SiO ₂ content 91.6% by weight, Al ₂ O ₃ content 0.33% by weight, NaOH content 0.27% by weight, Nip Seal VN-3, Nippon Silica Industry Co., Ltd.) Added and stirred for 3 hours. The composition ratio (molar ratio) of this reaction mixture was as follows.
SiO ₂ / Al ₂ O ₃ : 70
LiOH / SiO ₂ : 0.31
MeSPAOH / SiO ₂ : 1.0
EDTA / Al: 1.83
H ₂ O / SiO ₂ : 50

  The reaction mixture was sealed in a 500 ml autoclave and then reacted at 177 ° C. for 11.5 days with stirring at 300 rpm. After completion of the reaction, washing with distilled water 5 times and filtration were repeated, followed by drying at about 120 ° C. overnight.

  FIG. 7 shows the results obtained by measuring the obtained product with an X-ray diffractometer using a Cu tube and Kα rays. The obtained zeolite was found to be CFI type zeolite.

  As a result of fluorescent X-ray diffraction analysis, the silica / alumina molar ratio of this CFI type zeolite was 70.

  As a result of FE-SEM observation at a magnification of 100,000, the crystallite size is 80% or more when the minor axis is about 0.06 microns (80% or more is 0.06 ± 0.001 microns), and the major axis is about 0. It was found that needle-like crystals with a thickness of 3 microns were 80% or more (80% or more were 0.3 ± 0.01 microns).

(Synthesis of MFI type zeolite)
Solid caustic soda (NaOH content 96.0 wt%, H ₂ O content 4.0 wt%, Kirk Co., Ltd.) 7.3 g, tartaric acid powder (tartaric acid content 99.7 wt%, H ₂ O content 0.3 wt% , Kirk Co., Ltd.) 10.2 grams was dissolved in 583.8 grams of water. To this solution was added 35.4 grams of sodium aluminate solution (Al ₂ O ₃ content 18.5 wt%, NaOH content 26.1 wt%, H ₂ O content 55.4 wt%, Sumitomo Chemical Co., Ltd.) A uniform solution was obtained. Hydrous silicic acid (SiO ₂ content 91.6 wt%, Al ₂ O ₃ content 0.33 wt%, NaOH content 0.27 wt%, Nipsil VN-3, Nippon Silica Industry Co., Ltd.) 111.5 Grams were added slowly with stirring to prepare a uniform slurry aqueous reaction mixture. The composition ratio (molar ratio) of this reaction mixture was as follows.
SiO ₂ / Al ₂ O ₃ : 25
OH ⁻ / SiO ₂ : 0.164
A / Al ₂ O ₃ : 1.0 (A: tartrate)
H ₂ O / SiO ₂ : 20

  The reaction mixture was sealed in a 1000 ml autoclave and then reacted at 160 ° C. for 72 hours with stirring at 250 rpm. After completion of the reaction, washing with distilled water 5 times and filtration were repeated, followed by drying at about 120 ° C. overnight.

  As a result of measuring the obtained product with an X-ray diffractometer using Cu tube and Kα ray, it was found that the obtained zeolite was MFI type zeolite.

  The silica / alumina molar ratio of this MFI type zeolite was 21.9 as a result of fluorescent X-ray diffraction analysis.

  As a result of FE-SEM observation at a magnification of 100,000, it was found that the crystallite size was about 0.05 microns, which was 80% or more (80% or more was 0.05 ± 0.01 microns).

Example-1
10 g of hydrous alumina having a boehmite structure (manufactured by Sumitomo Chemical Co., Ltd.) on the basis of absolute drying, 30 g on the basis of absolute drying (calculated from loss on ignition when calcined at 500 ° C. for 20 minutes), alumina sol (Al ₂ O 45 g of ₃ content of 10% by weight, manufactured by Nissan Chemical Industries, Ltd.) was added and mixed well. Then, it put into 120 degreeC dryer and dried until it became clay-like water | moisture content. The kneaded material was extruded through a screen having a 1.2 mmφ hole. The extruded product was dried at 120 ° C. overnight, then gradually heated from 350 ° C. to 540 ° C. and fired at 540 ° C. for 2 hours. The alumina molded body was immersed in 40 ml of a chloroplatinic acid aqueous solution containing 2 g of Pt as Pt at room temperature and left for 2 hours with stirring every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to use of the catalytic reaction, calcination was carried out at 540 ° C. for 2 hours to prepare Catalyst-1 for use in Reaction Step-1. As a result of analyzing Pt supported on the catalyst-1 by ICP emission spectroscopic analysis, the supported platinum was 1% by weight as Pt.

Next, hydrated alumina having a pseudo boehmite structure (Sumitomo Chemical Co., Ltd.) having 20 g of mordenite-type zeolite-I synthesized as described above on an absolute dry basis (calculated from loss of ignition when calcined at 500 ° C. for 20 minutes) 10 grams on the absolute dry basis and 45 grams of alumina sol (Al ₂ O ₃ content 10% by weight, manufactured by Nissan Chemical Industries, Ltd.) were added and mixed well. Then, it put into 120 degreeC dryer and dried until it became clay-like water | moisture content. The kneaded material was extruded through a screen having a 1.2 mmφ hole. The extruded product was dried at 120 ° C. overnight, then gradually heated from 350 ° C. to 540 ° C. and fired at 540 ° C. for 2 hours. 20 grams of this mordenite-type zeolite compact was brought into contact with 80 ml of a 10% by weight aqueous NH ₄ Cl solution at 80 ° C. for 1 hour. Thereafter, it was washed with pure water, and again contacted with 80 ml of a 10 wt% aqueous NH ₄ Cl solution at 80 ° C. for 1 hour. This operation was repeated 8 times and washed with pure water 6 times in batches. Twenty grams of a dried product of this ammonium-exchanged mordenite-type zeolite-I compact was immersed in 40 ml of a perrhenic acid aqueous solution containing 80 milligrams of Re at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to use of the catalytic reaction, the catalyst A was calcined at 540 ° C. for 2 hours. As a result of analyzing the Re supported on the catalyst A by ICP emission spectroscopic analysis, the rhenium supported on the catalyst A was 2010 ppm by weight as Re.

  Table 2 shows the composition of the feedstock oil used in the reaction test. The raw material is a model raw material assuming LCO, and prepared by mixing and preparing naphthalene and decalin which is a non-aromatic hydrocarbon as an inert substance that is not converted into BTX, changing the concentration composition of each, Prepared.

7.5 g of a metal-supported catalyst used in the reaction step-1 and catalyst-1 was charged in a reaction tube, and the raw material A was reacted under the following reaction conditions.
WHSV (hr ⁻¹ ): 2.0
Reaction temperature (° C): 350
Reaction pressure (MPa): 4.9
Hydrogen to feedstock ratio (hereinafter referred to as H ₂ / Feed, Nm ³ / m ³ ): 1000

  The reaction product solution was analyzed with a gas chromatograph equipped with an FID detector. Table 3 shows the composition of the reaction product obtained in the reaction step-1.

Here, the liquid yield is a numerical value obtained by dividing the mass of the reaction product obtained by the reaction by the mass of the raw material supplied. From this result, it is understood that the concentrations of naphthalene and methylnaphthalene contained in the raw material are reduced and converted to tetralin and methyltetralin as intermediate products.

  Next, as a reaction stage of the reaction step-2, raw materials having the composition as shown in Table 4 were used, and 7.5 g of catalyst A was charged in a reaction tube and reacted under the following conditions.

In the above raw materials, tetralin, an intermediate in which naphthalene is converted by a nuclear hydrogenation reaction in reaction step-1, or alkylindane or alkylbenzene originally contained in the raw material or produced in reaction step-1 As components, indane, propylbenzene, ethyltoluene, trimethylbenzene and the like are mixed. Moreover, normal decane was mixed as an inert component which is not converted to BTX. Six kinds of raw materials having different concentration compositions were prepared by preparing a mixing ratio of tetralin converted to naphthalene and indane in the reaction step-1.
Reaction conditions WHSV (hr ⁻¹ ): 2.0
Reaction temperature (° C): 400
Reaction pressure (MPa): 3.0
_{^{H 2 / Feed (N-m}} 3 / m 3): 1000

  The reaction product solution was analyzed with a gas chromatograph equipped with an FID detector, and the yields of benzene, toluene and C8 aromatic hydrocarbons (BTX yield) were determined from the liquid composition and the liquid yield.

  From the above two tests, when the concentration of naphthalene and alkylnaphthalene in the raw material increases, in reaction step-1, these are converted to tetralin and alkyltetralin as intermediates, and the concentration of tetralin and alkyltetralin in the reaction product increases. , Naphthalene, alkyl naphthalene concentration decreases. Furthermore, since the tetralin content in the reaction product solution decreases while the yield of BTX increases as the tetralin concentration in the feed solution to the reaction step-2 increases, BTX is converted from naphthalene and alkylnaphthalene. It can be seen that it can be manufactured. In addition, if the indane concentration in the feedstock increases, the indane decreases and the BTX increases, so it can also be seen that indane contributes to BTX production.

Example-2
20 grams of a dried product of an ammonium-exchanged mordenite-type zeolite-I molded body prepared in the same manner as in Example 1 was immersed in 40 ml of a chloroplatinic acid aqueous solution containing 4 milligrams of Pt at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to the use of the catalytic reaction, the catalyst B was calcined at 540 ° C. for 2 hours. As a result of analyzing ICP emission spectroscopic analysis of Pt supported on the catalyst C, platinum supported on the catalyst B was 169 ppm by weight as Pt.

  The catalyst B was used as a catalyst in the reaction step-2, and the reaction was carried out in the same manner as in Example 1 using the feedstock H. As a result, a BTX yield of 25% by weight was obtained, and the total content of indane, tetralin and the like in the reaction product solution was reduced to 0.2% by weight.

Example-3
20 grams of a dried product of ammonium-exchanged mordenite-type zeolite formed in the same manner as in Example-1 was immersed in 40 ml of an aqueous palladium chloride solution containing 40 milligrams of Pd at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to use of the catalytic reaction, calcination was carried out at 540 ° C. for 2 hours to obtain Catalyst C. As a result of analyzing the Pd supported on the catalyst C by ICP emission spectroscopic analysis, the palladium supported on the catalyst C was 1480 ppm by weight as Pd.

  The catalyst C was used as the catalyst in the reaction step-2, and the reaction was carried out in the same manner as in Example 1 using the feedstock H. As a result, a BTX yield of 33% by weight was obtained, and the total content of indane, tetralin and the like in the reaction product solution was reduced to 0.2% by weight.

Example-4
Twenty grams of the beta-type zeolite synthesized as described above was taken on an absolute dry basis (calculated from loss of ignition when calcined at 500 ° C. for 20 minutes), molded in the same manner as in Example 1, and subjected to ammonium ion exchange. Then, 20 grams of the dried ammonium-exchanged beta-type molded article thus prepared was immersed in 40 ml of a perrhenic acid aqueous solution containing 80 milligrams of Re at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to use of the catalytic reaction, it was calcined at 540 ° C. for 2 hours to obtain Catalyst D. As a result of analyzing the Re supported on the catalyst D by ICP emission spectroscopic analysis, the rhenium supported on the catalyst D was 1850 ppm by weight as Re.

  Catalyst D was used as a catalyst for reaction step-2, 7.5 g was charged in a reaction tube, and the reaction was conducted in the same manner as in Example 1 using feedstock H. As a result, a BTX yield of 34% by weight was obtained, and the contents of indane, tetralin and the like in the reaction product solution were reduced to 0.2% by weight.

Example-5
Twenty grams of a dried product of ammonium-exchanged beta zeolite formed in the same manner as in Example 4 was immersed in 40 ml of an aqueous chloroplatinic acid solution containing 4 milligrams of Pt at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to use of the catalytic reaction, it was calcined at 540 ° C. for 2 hours to obtain Catalyst E. As a result of analyzing ICP emission spectroscopic analysis of Pt supported on the catalyst E, platinum supported on the catalyst E was 173 ppm by weight as Pt.

  The catalyst E was used as the catalyst in the reaction step-2, and the reaction was carried out in the same manner as in Example 1 using the feedstock H. As a result, a BTX yield of 33% by weight was obtained, and the total content of indane, tetralin and the like in the reaction product solution was reduced to 0.2% by weight.

Example-6
Take 20 grams of mordenite-type zeolite-II synthesized as described above on the basis of absolute dryness (calculated from the loss of ignition when calcined at 500 ° C. for 20 minutes), molded in the same manner as in Example 1, and ammonium ions Exchanged. This ammonium exchanged mordenite-type zeolite-II molded body was dried at 120 ° C. overnight. 20 grams of a dried product of the mordenite type zeolite-II molded body exchanged with ammonium was immersed in 40 ml of a perrhenic acid aqueous solution containing 80 milligrams of Re at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to use of the catalytic reaction, it was calcined at 540 ° C. for 2 hours to obtain catalyst F. As a result of analyzing the Re supported on the catalyst F by ICP emission spectroscopic analysis, the rhenium supported on the catalyst F was 2100 ppm by weight as Re.

  Catalyst F was used as a catalyst in reaction step-2, 7.5 g was filled in a reaction tube, and the reaction was conducted in the same manner as in Example 1 using feedstock H. As a result, a BTX yield of 33.5% by weight was obtained, and the total content of indane, tetralin and the like in the reaction product solution was reduced to 0.2% by weight. Compared to catalyst A, catalyst F had a lower BTX yield. The reason is considered that the crystallite of mordenite type zeolite-II is larger than the crystallite of mordenite type zeolite-I.

Example-7
15 grams of the CFI type zeolite synthesized as described above was taken on an absolute dry basis (calculated from the loss of ignition when calcined at 500 ° C. for 20 minutes), molded in the same manner as in Example 1, and ammonium ion exchanged. The ammonium exchanged CFI type zeolite compact was dried at 120 ° C. overnight. 15 grams of a dried product of the ammonium exchanged CFI type zeolite compact was immersed in 30 ml of a perrhenic acid aqueous solution containing 60 milligrams of Re at room temperature and left for 2 hours. Stir every 30 minutes. Then, the liquid was cut off and dried at 120 ° C. overnight. Prior to the use of the catalytic reaction, the catalyst G was calcined at 540 ° C. for 2 hours. As a result of analyzing the Re supported on the catalyst G by ICP emission spectroscopic analysis, the rhenium supported on the catalyst H was 1950 ppm by weight as Re.

  The catalyst G was used as a catalyst in the reaction step-22, and the reaction was carried out in the same manner as in Example 1 using the feedstock H. As a result, a BTX yield of 33.5% by weight was obtained, and the total content of indane, tetralin and the like in the reaction product solution was reduced to 0.2% by weight.

Comparative Example-1
MFI-type zeolite synthesized as described above is 20 grams on the absolute dry basis (calculated from the loss on ignition when calcined at 500 ° C. for 20 minutes), hydrous alumina having a pseudo-boehmite structure) on the absolute dry basis 10 grams, 45 grams of alumina sol (Al2O3 content 10% by weight, manufactured by Nissan Chemical Industries, Ltd.) were added and mixed well. Then, it put into 120 degreeC dryer and dried until it became clay-like water | moisture content. The kneaded material was extruded through a screen having a 1.2 mmφ hole. The extruded product was dried at 120 ° C. overnight, then gradually heated from 350 ° C. to 540 ° C. and baked at 540 ° C. for 2 hours. 20 grams of this MFI-type zeolite compact was contacted with 80 ml of a 10 wt% NH4Cl aqueous solution at 80 ° C. for 1 hour. Thereafter, it was washed with pure water, and again brought into contact with 80 ml of 10 wt% NH4Cl aqueous solution at 80 ° C. for 1 hour. This operation was repeated 8 times and washed with pure water 6 times in batches. The ammonium exchanged MFI-type zeolite compact was dried at 120 ° C. overnight. Prior to the use of the catalytic reaction, calcination was carried out at 540 ° C. for 2 hours to obtain catalyst H.

  The catalyst H was used as the catalyst in the reaction step-2, and the reaction was carried out in the same manner as in Example 1 using the feedstock H. As a result, the BTX yield was only 5% by weight, and the total content of indane, tetralin and the like in the reaction product solution was 2.4% by weight and was not reduced at all.

Example-8
A raw material M having a relatively high alkylbenzene concentration as shown in Table 6 was prepared as an intermediate oil obtained in the reaction step-1, and 11 parts by weight of benzene and 49 parts by weight of toluene were mixed with 100 parts by weight of the raw material M. Using the catalyst A prepared in Example-1 and in the same reaction conditions as in Example-1, a test in Reaction Step-2 was performed. As a result, the BTX yield of the raw material M (BTX yield relative to the supply amount of the raw material M) was 52% by weight, and the ratio of C8 aromatic hydrocarbons was 99%. Further, the total content of indane, tetralin and the like in the reaction product liquid was reduced to 0.1% by weight. In Test 1-8 of Example-1, the ratio of C8 aromatic hydrocarbons in BTX was 48%. Thus, depending on the composition of the intermediate oil coming out from Reaction Step-1, benzene and Toluene can be added to adjust the yield of BTX and the breakdown of components.

Example-9
Test No. 1 of Example-1. In 1-8, 1000 ppm by weight of thiophene was added to the raw material H, and the test was performed in the same manner as in Example 1. As a result, most of the thiophene in the reaction solution was decomposed, and the concentration in the reaction product solution was detected ( 10 weight ppm or less), and there was almost no difference in liquid yield and BTX yield. It is considered that the added thiophene was decomposed into gas components such as hydrogen sulfide.

It is a figure which shows one embodiment of the preferable flow for implementing this invention.

Explanation of symbols

1: Reaction step-1
2: Reaction step-2
3: BTX recovery distillation column 4: Recycled raw material recovery distillation column 5: Stream 6: Stream 7: Stream 8: Stream 9: Stream 10: Stream 11: Stream 12: Stream 13: Stream 14: Stream 15: Stream

Claims (32)

Indane, alkyl indane, indene, alkyl indene, naphthalene in raw material oil by contacting a raw material oil containing at least one of indane, alkyl indane, indene, alkyl indene, naphthalene and alkyl naphthalene with a metal-supported catalyst. A method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms, comprising reducing the total concentration of alkylnaphthalene and increasing the concentration of the aromatic hydrocarbon having 6 to 8 carbon atoms. 2. The carbon according to claim 1, wherein a heavy oil containing at least one of indane, alkylindane, indene, alkylindene, naphthalene, and alkylnaphthalene is used as a raw material oil and undergoes at least the following two reaction steps. A method for producing an aromatic hydrocarbon of formula 6-8.
Reaction step-1: The feedstock oil was brought into contact with a metal-supported catalyst in the presence of hydrogen, and the total concentration of naphthalene or alkylnaphthalene contained in the feedstock oil was reduced by a nuclear hydrogenation reaction and / or a ring-opening reaction. A process for producing intermediate oil.
Reaction step-2: The total concentration of tetralin and alkyltetralin contained in the intermediate oil obtained in reaction step-1 by contacting the intermediate oil obtained in reaction step-1 with a metal-supported acid catalyst in the presence of hydrogen. And reducing the total concentration of alkylbenzenes having at least one side chain having 2 or more carbon atoms and increasing the concentration of aromatic hydrocarbons having 6 to 8 carbon atoms to produce a product oil.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 2, wherein the total concentration of indane, alkylindane, indene, and alkylindene in the raw material oil is 1% by weight or more.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 2, wherein the total concentration of indane, alkylindane, indene, and alkylindene in the raw material oil is 3% by weight or more.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 2, wherein the total concentration of indane, alkylindane, indene and alkylindene in the raw material oil is more than 5% by weight.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 2, wherein the total concentration of indane, alkylindane, indene, and alkylindene in the raw material oil is 10% by weight or more.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 1 to 6, wherein the total concentration of naphthalene and alkylnaphthalene in the raw material oil is more than 1% by weight.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 1 to 6, wherein the total concentration of naphthalene and alkylnaphthalene in the raw material oil is 5% by weight or more. The aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 1 to 6, wherein the concentration of at least one component of naphthalene or alkylnaphthalene in the feedstock is 10% by weight or more. Manufacturing method.   The metal-supported catalyst used in the reaction step-1 contains at least one metal selected from platinum, palladium, rhenium, nickel, cobalt, molybdenum, and tungsten. A method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms.   The metal-supported acid catalyst used in the reaction step-2 contains at least one metal selected from platinum, palladium, rhenium, nickel, cobalt, molybdenum, and tungsten. The manufacturing method of C6-C8 aromatic hydrocarbon of description.   The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 11, wherein the metal-supported acid catalyst used in the reaction step 2 contains rhenium.     The metal-supported acid type catalyst used in the reaction step-2 contains a zeolite composed of at least one of mordenite, zeolite β, faujasite, and CFI type zeolite. The manufacturing method of C6-C8 aromatic hydrocarbon of description.   The metal-supported acid-type catalyst used in the reaction step-2 contains a mordenite-type zeolite having a silica / alumina molar ratio of 10 to 50 and a crystallite size of mainly 0.5 microns or less. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 13.   The metal-supported acid-type catalyst used in the reaction step-2 contains a mordenite-type zeolite having a silica / alumina molar ratio of 10 to 50 and a crystallite size of mainly 0.2 microns or less. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 12.   The metal-supported acid catalyst used in the reaction step-2 is characterized by containing a beta zeolite having a silica / alumina molar ratio of 15 to 60 and a crystallite size of mainly 0.2 microns or less. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 13.   The metal-supported acid catalyst used in the reaction step-2 is characterized by containing a beta zeolite having a silica / alumina molar ratio of 15 to 40 and a crystallite size of mainly 0.2 microns or less. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 13.   The metal-supported acid type catalyst used in the reaction step 2 contains a CFI type zeolite having a silica / alumina molar ratio of 30 to 120 and a crystallite size of short axis and mainly 0.2 microns or less. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 13.   The aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 13, wherein the metal-supported acid catalyst used in the reaction step 2 contains a faugersite type zeolite. A method for producing hydrocarbons.   The metal-supported acid catalyst contains a metal oxide selected from at least one of alumina, titania, kaolin, and clay, and has 6 to 8 carbon atoms according to any one of claims 2 to 19. A method for producing aromatic hydrocarbons.   21. The mixture according to claim 2, wherein 0 to 100 parts by weight of benzene and / or toluene are mixed with 100 parts by weight of the intermediate oil produced from the reaction step-1 and supplied to the reaction step-2. A method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to one item.     After separating the product oil containing C6-C8 aromatic hydrocarbons from the product oil obtained in the reaction step-2, the residual oil whose concentration of C6-C8 aromatic hydrocarbons is reduced The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 21, wherein the process is added again to reaction step-1 or reaction step-2 and recycled. .   When the residual oil contains a high-boiling component containing three or more aromatic hydrocarbons, the high-boiling component containing three or more aromatic hydrocarbons contained in the residual oil is removed by distillation separation and then recycled. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 22.     A product oil containing an aromatic hydrocarbon having 6 to 8 carbon atoms separated from the product oil obtained in the reaction step-2 is used for any of gasoline, kerosene and light oil applications. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 2 to 22.   25. The carbon number of 6 to 25 according to any one of claims 2 to 24, wherein, in the reaction step-1, the raw material oil contains a sulfur compound and a nitrogen compound, which are removed by hydrogenolysis. A method for producing an aromatic hydrocarbon according to 8.   The raw material oil contains heavy oil, and sulfur compounds and nitrogen compounds are previously removed by contacting with a metal-supported catalyst or adsorbent. The manufacturing method of C6-C8 aromatic hydrocarbon as described in any one of these. By bringing a raw material containing at least one of tetralin and alkyltetralin into contact with a metal-supported acid catalyst in the presence of hydrogen, the total concentration of tetralin and alkyltetralin in the raw material is reduced, and an aromatic having 6 to 8 carbon atoms. A method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms, characterized by increasing the concentration of the aromatic hydrocarbon. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 27, wherein the metal-supported acid catalyst is at least one selected from the metal-supported acid catalysts according to claims 10 to 20. By bringing a raw material containing at least one of tetralin and alkyltetralin into contact with a metal-supported acid catalyst in the presence of hydrogen, the total concentration of tetralin and alkyltetralin in the raw material is reduced, and the carbon number is 6 to 8. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 27 or 28, wherein the sulfur compound contained in the raw material is simultaneously decomposed when the concentration of the aromatic hydrocarbon is increased.   A product oil containing an aromatic hydrocarbon having 6 to 8 carbon atoms is separated from a product oil obtained by bringing the raw material into contact with the metal-supported acid catalyst in the presence of hydrogen. 30. The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to any one of claims 27 to 29, wherein the residual oil whose concentration of the aromatic hydrocarbon having 8 is reduced is also recycled.   When the residual oil contains a high-boiling component containing three or more aromatic hydrocarbons, after removing the high-boiling component containing three or more aromatic hydrocarbons contained in the residual oil by distillation separation, The method for producing an aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 30, wherein the aromatic hydrocarbon is recycled.     The product oil containing the separated aromatic hydrocarbon having 6 to 8 carbon atoms is used for any of gasoline, kerosene, and light oil applications. A method for producing aromatic hydrocarbons.

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