JP5222602B2 - Catalyst composition and method for producing aromatic hydrocarbon - Google Patents

Description

  The present invention relates to a catalyst composition suitable for a reaction for producing an aromatic hydrocarbon from a light hydrocarbon, and an aromatic from a light hydrocarbon raw material mainly containing a hydrocarbon having 2 to 7 carbon atoms using the catalyst composition. The present invention relates to a method for producing a group hydrocarbon.

  When using a solid catalyst, it is common to use a molded catalyst for the purposes of handling the catalyst, preventing drift of the reaction fluid, reducing pressure loss, and the like. Conventionally, when a zeolite such as crystalline aluminosilicate is used as a catalyst, since the moldability of the zeolite is very poor, a catalyst composition containing zeolite by blending alumina or the like as a binder can be formed and used. Many. As the binder used at this time, it is required to improve the moldability and the mechanical strength of the molded catalyst composition without adversely affecting the reaction characteristics of the zeolite, but the alumina binder represented by boehmite is molded. Although the effect of improving the mechanical properties and the mechanical strength of the molded product is large, there is a problem caused by the binder itself having an acid property. That is, for example, in a reaction system that tends to cause coking such as dehydrogenation or aromatization of light hydrocarbons having 7 or less carbon atoms, more coking occurs due to the acid nature of the binder, and the catalyst life is reduced. There was a problem. On the other hand, silica as a binder has the disadvantages that it does not have acid properties but has low mechanical strength and poor extrudability.

Various attempts have been made to control the acid properties of alumina (see, for example, Non-Patent Document 1 and Patent Documents 1 to 4 below), all of which have acid properties in order to use alumina as an acid property carrier. Thus far, there has been almost no investigation to suppress the acidity of alumina.
Roberto Rinaldi, Fred Y. Fujiwara, Wolfgang Holderich, Ulf Schuchardt, Journal of Catalysis 244 92-101 (2006) JP 2004-74075 A JP 2004-113898 A Japanese Patent Laid-Open No. 10-296081 Japanese Patent Laid-Open No. 10-174844

As described above, in a catalyst composition containing crystalline aluminosilicate, alumina with sufficient moldability and mechanical strength is used as a binder, and acidity is suppressed, and coking can be sufficiently suppressed during the reaction. And a catalyst composition excellent in reaction activity and selectivity has not been known.

  The present invention has been made in view of the above circumstances, and it is possible to sufficiently suppress coking during the reaction of aromatizing light hydrocarbons by suppressing the acid properties of the catalyst composition containing crystalline aluminosilicate. And providing a catalyst composition having high activity and high selectivity for the reaction, and efficient aromatics using hydrocarbons including light hydrocarbons using such a catalyst composition as a raw material It aims at providing the manufacturing method of hydrocarbon.

  As a result of intensive studies to solve the above problems, the present inventors have found that a catalyst composition comprising a crystalline aluminosilicate containing a specific gallium and a specific alumina contains a light hydrocarbon. In the reaction for aromatization, the inventors have found that deterioration due to coking is greatly suppressed and that the reaction has high activity and high selectivity, and the present invention has been completed.

That is, the present invention is a composition containing a crystalline aluminosilicate containing a gallium atom and alumina, and is a four-dimensional composition determined by a ²⁷ Al-MAS NMR method that constitutes alumina in the composition. ²⁹ Si-MAS NMR method in which the molar ratio of coordinated aluminum atoms to hexacoordinated aluminum atoms is less than 0.5, and the gallium atoms in the composition and the skeleton of the crystalline aluminosilicate in the composition The catalyst composition is characterized in that the molar ratio of aluminum atoms determined by (1) is 0.45 or more.

Further, the present invention is a composition containing a crystalline aluminosilicate containing a gallium atom and alumina, and is quantified by ²⁷ Al-MAS NMR method which constitutes the alumina in the composition. ²⁹ Si in the molar ratio of the coordinated aluminum atom to the hexacoordinated aluminum atom is less than 0.5, and the gallium atom in the composition and the skeleton of the crystalline aluminosilicate used as a raw material of the composition Provided is a catalyst composition characterized in that the molar ratio to aluminum atoms determined by -MAS NMR method is 0.45 or more.

  In the catalyst composition of the present invention, the crystalline aluminosilicate is preferably a pentasil-type zeolite.

  In the catalyst composition of the present invention, the crystalline aluminosilicate has a content of particles having a particle diameter in the range of 0.05 to 20 μm based on the mass of all particles of 80% by mass or more. Is preferred.

  Furthermore, in the catalyst composition of the present invention, the crystalline aluminosilicate is 0.1 to 2.5% by mass of aluminum atoms and 0.1 to 5% of gallium atoms based on the mass of the crystalline aluminosilicate. It is preferable to contain 0.0 mass%.

  In the catalyst composition of the present invention, the crystalline aluminosilicate is preferably a crystalline aluminogallosilicate.

  Moreover, this invention provides the manufacturing method of the aromatic hydrocarbon characterized by including the process which the catalyst composition of the said invention and the raw material containing a C2-C7 hydrocarbon are made to contact. .

  The catalyst composition of the present invention has high activity and selectivity when used in a reaction for producing aromatic hydrocarbons from a raw material mainly composed of light hydrocarbons, and compared with conventional catalyst compositions. Deterioration due to coking is suppressed. In addition, according to the method for producing aromatic hydrocarbons of the present invention, the deterioration of the catalyst due to coking is suppressed, so that the life of the catalyst is greatly extended and efficient production of aromatic hydrocarbons becomes possible. .

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The alumina used in the catalyst composition of the present invention is not particularly limited as long as it can retain the mechanical properties (strength, wear resistance, moldability) as the catalyst composition, but boehmite, cataloid AP (catalyst conversion) Kogyo Co., Ltd. product name).

In the aluminum atoms constituting the alumina contained in the catalyst composition of the present invention, the molar ratio of tetracoordinated aluminum atoms and hexacoordinated aluminum atoms analyzed using ²⁷ Al-MAS NMR (tetracoordinated aluminum atoms / Although it will not specifically limit if 6 coordinated aluminum atom) is less than 0.5, Preferably it is 0.1 or more and less than 0.5, More preferably, 0.3 or more and less than 0.45 are desirable.

²⁷ Al-MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance) analysis can be performed by a known method (for example, see Non-Patent Document 1). The ²⁷ Al-MAS NMR signal attributed to the 4-coordinated aluminum atom and the 6-coordinated aluminum atom derived from alumina in the catalyst composition is observed at around 55-60 ppm and around 0 ppm, respectively, based on the aluminum chloride aqueous solution. From this signal area ratio, the molar ratio of tetracoordinated aluminum atoms and hexacoordinated aluminum atoms can be calculated. Spinning sidebands are not included when calculating the area of each signal.

  The method for setting the molar ratio of tetracoordinated aluminum atoms and hexacoordinated aluminum atoms constituting the alumina contained in the catalyst composition of the present invention to the above range is not particularly limited. For example, boehmite Is used as the alumina precursor, it can be controlled by the firing temperature and time of a molded product obtained from a composition containing crystalline aluminosilicate containing gallium and alumina. The firing temperature and time are preferably 400 to 650 ° C for 0.5 to 10 hours, more preferably 450 to 600 ° C for 1 to 5 hours. Moreover, as an atmosphere at the time of baking, dry air, water vapor-containing air, water vapor, or the like is preferable, and these gases are preferably used under circulation. The flow rates of these gases can be appropriately selected according to the amount of the catalyst composition to be calcined.

As an example of another method in which the molar ratio of tetracoordinated aluminum atoms and hexacoordinated aluminum atoms constituting the alumina contained in the catalyst composition of the present invention is in the above-described range, M _x Al ₃ A binary spinel compound having a structure of _{-xO 4} (M is a divalent metal, Zn, Mg, Mn, Fe, etc., 0 <x ≦ 1) is used as a binder. This is because divalent metal ions occupy the tetracoordinate site to suppress the expression of acid properties. M is not particularly limited as long as it is a divalent metal, but Zn, Mg, Mn, Fe and the like are preferable. Further, x is not particularly limited, but is preferably 0.5 or more, more preferably 0.8 or more.

  As another example of the method in which the molar ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom constituting the alumina contained in the catalyst composition of the present invention is in the above range, a corundum structure is used. It is possible to use α-alumina having a binder. Although it does not specifically limit as a precursor of (alpha) alumina, A diaspore etc. are preferable.

  The structure of the crystalline aluminosilicate containing gallium (hereinafter referred to as “gallium-containing crystalline aluminosilicate”) contained in the catalyst composition of the present invention is not particularly limited, but a pentasil-type zeolite is preferable, and among these, the MFI type And / or zeolite having a MEL type crystal structure is more preferred. MFI-type and MEL-type zeolites belong to a known zeolite structure type of the kind published by “The Structure Commission of the International Zeolite Association” (Atlas of Zeolite Structure. 1978) Distributed by Polycrystalline Book Service, Pittsburgh, PA, USA).

  Examples of the gallium-containing crystalline aluminosilicate according to the catalyst composition of the present invention include those in which gallium atoms are incorporated in the lattice skeleton of the crystalline aluminosilicate (hereinafter referred to as “crystalline aluminogallosilicate”), and crystallinity. Aluminosilicate carrying gallium (hereinafter referred to as “gallium-carrying crystalline aluminosilicate”) or a material containing both of them is used, but preferably it contains at least a crystalline aluminogallosilicate.

The crystalline aluminogallosilicate has a structure in which the SiO ₄ , AlO _4, and GaO ₄ structures are tetrahedrally coordinated in the skeleton. Gel crystallization by hydrothermal synthesis and the lattice skeleton structure of crystalline aluminosilicate It can be obtained by a method of inserting a gallium atom or a method of inserting an aluminum atom into the lattice skeleton structure of crystalline gallosilicate.

  The gel crystallization method is a simple and excellent method for preparing a crystalline aluminogallosilicate because a crystalline aluminogallosilicate can be prepared by simultaneously containing a target amount of aluminum atoms and gallium atoms. Crystalline aluminogallosilicate synthesis by gel crystallization can be obtained by maintaining a slurry-like aqueous mixture containing an alumina source, a silica source, and a gallia source as essential components under hydrothermal synthesis conditions. For example, as the alumina source, aluminum salts such as aluminum sulfate and aluminum nitrate, aluminates such as sodium aluminate, alumina gel, and the like can be used. As the silica source, silicates such as sodium silicate and potassium silicate, colloidal silica, silica powder, dissolved silica, water glass and the like can be used, and as the gallium source, gallium nitrate, gallium chloride, etc. A gallium salt, gallium oxide, or the like can be used. Furthermore, it is also possible to use a solution or hydroxide containing aluminum and gallium obtained in the process of extraction and refining from a deposit such as a bauxite deposit and a zinc deposit as an alumina source and a gallia source. Organic additives, alkali metals, and alkaline earth metal sources can also be used to increase the crystallization speed and purity of the target crystalline aluminogallosilicate. Organic additives include quaternary ammonium salts such as tetrapropylammonium salt, tetrabutylammonium salt and tripropylmethylammonium salt, amines such as propylamine, butylamine, aniline, dipropylamine, dibutylamine and morpholine, ethanol Amino alcohols such as amine, diglycolamine and diethanolamine, alcohols such as ethanol, propyl alcohol, ethylene glycol and pinacol, organic acids, ethers, ketones, amino acids, esters, thioalcohols or thioethers can be used. Furthermore, it is also possible to use compounds that produce the above organic additives under hydrothermal synthesis conditions. As the alkali metal source and alkaline earth metal source, alkali metals such as sodium and potassium, hydroxides, halides, sulfates, nitrates, carbonates and the like of alkaline earth metals such as magnesium and calcium can be used. . In addition to the above-mentioned compounds, the raw material may contain a mineral acid such as sulfuric acid or nitric acid as a pH adjuster. The aqueous raw material mixture containing one or more compounds as each raw material is stirred at a temperature of 140 ° C. or higher, preferably 150 to 250 ° C. under self-pressure for about 1 hour to 7 days, preferably 2 hours to 5 days. The crystallization operation is carried out by holding while holding. By adopting such crystallization conditions, it is possible to efficiently obtain a crystalline aluminogallosilicate having excellent reaction activity. A crystalline aluminogallosilicate having excellent reaction activity can be obtained by increasing the crystallization time even at a crystallization temperature of less than 140 ° C., but this is not economical. In addition, since the zeolite crystal phase of this crystalline aluminogallosilicate is in a metastable phase, if the crystals once generated are subjected to hydrothermal synthesis conditions for a long time, there is a possibility that other phases that are not intended are generated and mixed. For this reason, it is not preferable to leave it under hydrothermal synthesis conditions for a long time.

  One of the chemical properties of crystalline aluminogallosilicate is its acid nature. In general, the amount of acid can be measured by temperature programmed desorption or heat of adsorption using a basic substance such as ammonia or pyridine, but in crystalline aluminogallosilicate, the amount of acid commensurate with the amount of aluminum or gallium is measured. It is shown that aluminum and gallium are in the anionic skeleton structure in the zeolite crystal structure.

  The gallium-supporting crystalline aluminosilicate is obtained by supporting gallium on a crystalline aluminosilicate by a known method such as an ion exchange method or an impregnation method. As the gallium source used for supporting gallium, gallium salts such as gallium nitrate and gallium chloride, gallium oxide, and the like can be preferably used.

  The particle diameter of the gallium-containing crystalline aluminosilicate contained in the catalyst composition of the present invention is 0.05 to 20 μm, preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, particularly preferably 1 to 3 μm. It is desirable that the content of the particles in the range is 80% by mass or more based on the mass of all particles. When the size of the reactive molecule and the pore size of the crystalline aluminosilicate are substantially the same, the diffusion rate of the molecule is slow in the crystalline aluminosilicate pore. Therefore, in the case of a large particle having a particle diameter exceeding 20 μm, it is difficult for the reactive molecule to approach the active site in the deep part of the pore, and the active site is not used effectively during the reaction. Is blocked with coke and the deep part of the pore is not used effectively, and the activity and selectivity are lowered.

  When obtaining crystalline aluminosilicate by hydrothermal synthesis, factors affecting the size of the generated particles include the type of silica source, the amount of organic additives such as quaternary ammonium salts, and inorganic salts as mineralizers. And the amount of base, the amount of base in the gel, the pH of the gel, the heating rate during the crystallization operation, the temperature and the stirring rate, and the like. By appropriately adjusting these conditions, a crystalline aluminosilicate having the above-mentioned particle size range can be obtained.

The catalytic activity for the aromatization reaction of the gallium-containing crystalline aluminosilicate contained in the catalyst composition of the present invention is affected by the composition. In order to obtain high reaction activity, the aluminum atom is preferably contained in an amount of 0.1 to 2.5% by mass, more preferably 0.1 to 2.0% by mass, based on the mass of the crystalline aluminosilicate. Is desirable. Moreover, it is desirable to contain a gallium atom preferably in the range of 0.1 to 5.0% by mass, and more preferably 0.1 to 3.0% by mass. The SiO ₂ / (Al ₂ O ₃ + Ga ₂ O ₃ ) molar ratio is preferably 17 to 600, more preferably 19 to 250, and even more preferably 25 to 200, to keep the reaction activity high for a long time. Desirable above. The molar ratio of SiO ₂ / Al ₂ O ₃ is preferably 32-870, more preferably 35-300, and the molar ratio of SiO ₂ / Ga ₂ O ₃ is preferably 36-2000, particularly preferably 40- 500.

Further, the composition of the gallium-containing crystalline aluminosilicate contained in the catalyst composition of the present invention is preferably that represented by the following formula (1) depending on the molar ratio of the oxide of the fired product at 500 ° C. or higher.
_{aM x O · bAl 2 O 3} · Ga 2 O 3 · cSiO 2 (1)

In the formula (1), M represents an alkali metal or alkaline earth metal element, x represents 2 when M is an alkali metal, and 1 when M is an alkaline earth metal. Moreover, a-c show the following numbers, respectively.
a: (b + 1) ± 3.0, preferably a positive number of (b + 1) ± 2.0.
b: 0.04 to 62.5, preferably 0.1 to 14.0.
c: 36-2000, preferably 40-500.

MASNMR (Magic Angle Spinning Nuclear Magnetic Resonance) analysis can directly or indirectly obtain useful information about the elements present in the crystal structure of the crystalline silicate and its composition. For example, in crystalline aluminosilicate, information on tetrahedrally coordinated Al in the anionic skeleton structure can be obtained by ²⁷ Al-NMR. In addition, information on four tetrahedrons (TO ₄ ; T = Al, Ga, Si) adjacent to (SiO ₄ ) in the structure is obtained by ²⁹ Si-NMR. Also in the crystalline aluminogallosilicate shown in this specification, the presence of tetrahedrally coordinated Al and Ga in the skeleton structure is shown by ²⁷ Al-NMR and ⁷¹ Ga-NMR, and from the information of ²⁹ Si-NMR analysis. The SiO ₂ / (Al ₂ O ₃ + Ga ₂ O ₃ ) molar ratio in the crystal structure was calculated. This value was in good agreement with the value obtained from the results of elemental analysis.

  One of the chemical properties of crystalline aluminogallosilicate is its acid nature. In general, the amount of acid can be measured by temperature programmed desorption or heat of adsorption using a basic substance such as ammonia or pyridine. In crystalline aluminogallosilicate, the amount of acid commensurate with the amount of aluminum and gallium has been measured, indicating that aluminum and gallium are present in the anionic framework structure in the zeolite crystal structure.

  Further, the gallium-containing crystalline aluminosilicate contained in the catalyst composition of the present invention can be subjected to various activation treatments that are generally applied when crystalline aluminosilicate is used as a catalyst component, as desired. it can. That is, the gallium-containing crystalline aluminosilicate contained in the catalyst composition of the present invention includes not only those produced by the method such as hydrothermal synthesis but also those obtained by modification or activation treatment thereof. Is. For example, after a crystalline aluminogallosilicate is ion-exchanged in an aqueous solution containing ammonium salts such as ammonium chloride, ammonium fluoride, ammonium nitrate, and ammonium hydroxide to form an ammonium type, a metal ion other than alkali metal or alkaline earth metal It is possible to introduce a desired metal other than an alkali metal or an alkaline earth metal by ion exchange in an aqueous solution containing or impregnating the aqueous solution. Further, the ammonium type gallium-containing crystalline aluminosilicate is heated in an atmosphere of air, nitrogen or hydrogen at 200 to 800 ° C., preferably 350 to 700 ° C. for 3 to 24 hours to remove ammonia to remove the acid type The structure can be activated. The acid catalyst may be treated with hydrogen or a mixed gas of hydrogen and nitrogen under the above conditions. Furthermore, you may give the ammonia modification | denaturation which makes an acid type catalyst contact ammonia on dry conditions. In general, the catalyst composition used in the present invention is preferably used after being subjected to the activation treatment before contacting with the hydrocarbon raw material.

  The content of the alumina and the gallium-containing crystalline aluminosilicate in the total mass of the catalyst composition of the present invention is not particularly limited, but alumina is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and still more preferably The gallium-containing crystalline aluminosilicate is preferably 40 to 95% by mass, more preferably 50 to 90% by mass, and still more preferably 60 to 80% by mass.

The molar ratio between the gallium atoms in the catalyst composition of the present invention and the aluminum atoms in the skeleton of the crystalline aluminum silicate contained in the catalyst composition analyzed using ²⁹ Si-MAS NMR is 0.45 or more. Although it will not specifically limit if it exists, Preferably it is 0.45-1.0, More preferably, it is desirable that it is the range of 0.5-0.8.

The molar ratio between the gallium atom in the catalyst composition of the present invention and the aluminum in the skeleton of the crystalline aluminosilicate contained in the catalyst composition analyzed using ²⁹ Si-MAS NMR, The molar ratio of the content of silicon atoms and gallium atoms in the entire catalyst composition determined by chemiluminescence analysis, and silicon atoms / aluminium in the crystalline aluminosilicate skeleton obtained by ²⁹ Si-MAS NMR measurement in the catalyst composition It can obtain | require by the following formula | equation (2) from the molar ratio of an atom.
Gallium atom / aluminum atom in skeleton (molar ratio) = (gallium atom in composition / molar ratio of silicon atom) × (Si / Al ratio in crystalline aluminosilicate)) (2)

In the ²⁹ Si-MAS NMR spectrum of the catalyst composition containing crystalline aluminosilicate, signals in which 0 to 4 aluminum atoms are adjacent to the silicon atom are observed. When these are described as Si (0Al), Si (1Al), Si (2Al), Si (3Al), Si (4Al), the respective signals are -110, -105, based on polydimethylsiloxane. Observed in the vicinity of −100, −95, and −90 ppm. From the area of these signals, the molar ratio of silicon atoms / aluminum atoms in the skeleton of the crystalline aluminosilicate can be calculated by the following formula (3). The spinning sideband is not included when calculating the area of this signal.

  Compositions containing alumina and gallium-containing crystalline aluminosilicates are available in various forms such as granules, spheres, plates, pellets, etc. by methods such as extrusion, spray drying, tableting, rolling granulation, and in-oil granulation. It can be set as a molded body. In molding, it is desirable to use an organic compound lubricant to improve moldability.

  In general, the composition of the alumina and the gallium-containing crystalline aluminosilicate can be formed prior to the ion exchange step of the gallium-containing crystalline aluminosilicate with ammonium ions or the like, or the gallium-containing crystalline aluminosilicate is ionized. It can also be done after replacement.

  Further, the catalyst composition of the present invention may contain an additive in addition to the above-mentioned alumina and gallium-containing crystalline almonosilicate. The additive is not particularly limited, and examples thereof include inorganic oxides such as alumina boria, silica, silica alumina, and aluminum phosphate, clay minerals such as kaolin and montmorillonite, inorganic phosphorus compounds, and organic phosphorus compounds. The addition amount is not particularly limited, but is added to the catalyst composition so as to be 50% by mass or less, more preferably 30% by mass or less, and further preferably 15% by mass or less.

In addition, when the catalyst composition of the present invention contains silicon or a component containing silicon and aluminum as the additive, the crystalline aluminosilicate in the skeleton by ²⁹ Si-MAS NMR analysis of the composition It is difficult to calculate the molar ratio of silicon atom / aluminum atom. In this case, using the molar ratio of silicon atom / aluminum atom in the same skeleton by ²⁹ Si-MAS NMR analysis of the crystalline aluminosilicate used as a raw material of the composition, the gallium atom in the catalyst composition of the present invention and The molar ratio of aluminum in the skeleton of the crystalline aluminosilicate contained in the catalyst composition analyzed using ²⁹ Si-MAS NMR is calculated.

  When the gallium-containing crystalline aluminosilicate contained in the catalyst composition of the present invention contains at least a gallium-supporting crystalline aluminosilicate, the gallium component is supported on the crystalline aluminosilicate before the composition with alumina is formed. It can also be performed, or can be performed on a molded body obtained by molding a composition of crystalline aluminosilicate and alumina. In the latter case, the gallium component is not only supported on the crystalline aluminosilicate, but also partly supported on the alumina. Furthermore, when the catalyst composition of the present invention contains an additive other than crystalline aluminosilicate and alumina, the gallium component may be supported on this additive. In the catalyst composition of the present invention, the description “gallium atom in the composition” refers not only to the gallium atom in the gallium-containing crystalline aluminosilicate, but also to gallium in alumina optionally containing additives as described above. Means containing atoms.

  Further, the catalyst composition of the present invention can be used with a metal component supported as an auxiliary component. The metal component as the auxiliary component may be supported on gallium-containing crystalline aluminosilicate, or may be supported on alumina or other additives. Further, when the pentasil-type zeolite is molded with alumina, it can be added as a third component. Examples of such auxiliary metal components include metals having dehydrogenation ability and metals having an effect of suppressing carbon deposition. Specific examples of the auxiliary metal component include those that improve catalytic activity, such as magnesium, calcium, strontium, barium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium. , Ytterbium, lutetium, titanium, vanadium, chromium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, zinc, aluminum, indium, germanium, tin, lead , Phosphorus, antimony, bismuth, selenium and the like. These metals can be used alone or in combination of two or more, and the supported amount is 0.1 to 10% by mass in terms of metal. As the metal loading method, known techniques such as an ion exchange method, an impregnation method, and physical mixing can be used. Moreover, an auxiliary component metal can be contained by adding the metal component as an auxiliary component during the synthesis of the pentasil-type zeolite. In addition, as an auxiliary metal component having an effect of suppressing the deposition of coke during the reaction, magnesium, calcium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, One or more metals selected from ruthenium and iridium can be supported, and the supported amount is 0.01 to 5% by mass in terms of metal.

  In the method for producing aromatic hydrocarbons of the present invention, an aromatic hydrocarbon is produced by bringing the catalyst composition described above into contact with a raw material containing a hydrocarbon having 2 to 7 carbon atoms. Here, the raw material used in the present invention contains a light hydrocarbon having 2 to 7 carbon atoms, and the content of the light hydrocarbon having 2 to 7 carbon atoms in the raw material is not particularly limited, but is preferably 20% by mass. As mentioned above, More preferably, it is 40 mass% or more, Especially preferably, it is 60-100 mass%.

  Moreover, although it does not specifically limit as a C2-C7 light hydrocarbon, Any of linear form, a branched form, and cyclic | annular form may be sufficient, and paraffin and olefin may be sufficient. Furthermore, a mixture thereof may be used. Specific examples of such hydrocarbons include linear aliphatic saturated hydrocarbons having 2 to 7 carbon atoms (ethane, propane, normal butane, normal pentane, normal hexane, normal heptane), branched aliphatic saturated hydrocarbons. (Isobutane, 2-methylbutane, 2,2-dimethylbutane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 2,2-dimethylpentane, 2, 3-dimethylpentane, 2,4-dimethylpentane, 2,2,3-trimethylbutane), cycloaliphatic saturated hydrocarbon (cyclopropane, cyclobutane, cyclopentane, 1-methylcyclopentane, 1,1-dimethylcyclopentane 1,2-dimethylcyclopentane, 1,3-dimethylcyclopentane, cyclohexa 1-methylcyclohexane, etc.), linear aliphatic unsaturated hydrocarbons (ethylene, propylene, normal butene, normal pentene, normal hexene, normal heptene, etc.), branched aliphatic unsaturated hydrocarbons (isobutene, 2-methylbutene, Mainly composed of 2-methylpentene, 3-methylpentene, 2-methylhexene, 3-methylhexene, etc.), cycloaliphatic unsaturated hydrocarbons (cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, etc.), propane and butane Liquefied petroleum gas, light fraction (light naphtha) with a boiling point of 100 ° C. or less in naphtha fraction mainly composed of paraffin having 5 to 7 carbon atoms, C4 fraction from fluid catalytic cracking unit (FCC), ethylene cracker Examples include raffinate.

Next, although the manufacturing process of the aromatic hydrocarbon of this invention is not specifically limited, It is preferable to mainly have the following 5 processes.
(A) Conversion reaction step (b) Gas-liquid separation step of reaction bed effluent (c) Hydrogen separation step from separation gas (d) Aromatic hydrocarbon separation step from separation liquid (e) Raw material light hydrocarbon And mixing process of recycled gas

(Conversion reaction process)
In this step, at least n reaction layers holding the above-described catalyst composition are arranged in series, and a heating furnace or the like is provided between the reaction layers as means for heating the effluent from the reaction layer. In this step, a mixture of a light hydrocarbon as a raw material and a recycle gas, which will be described later, is passed through a reaction layer to convert the mixture into an aromatic hydrocarbon. Preferred reaction conditions in this step are a reaction layer inlet temperature of 350 to 650 ° C., a hydrogen partial pressure of 0.5 MPa or less, and a raw material gas space velocity of 100 to 2000 hr ⁻¹ .

  The reaction layer inlet temperature in the conversion reaction step according to the present invention is generally preferably in the range of 350 to 650 ° C, but 450 to 650 ° C when the light hydrocarbon of the raw material is composed mainly of normal paraffin, When isoparaffin is the main component, 400 to 600 ° C., and when olefin is the main component, 350 to 550 ° C. is a more preferable temperature range.

  The reactor used in the conversion reaction step is not particularly limited, and examples thereof include a fixed bed reactor, a CCR reactor, and a fluidized bed reactor. When using a fixed bed or a CCR type reactor, at least n reaction layers holding the catalyst composition described above (n is an integer of 2 or more) are arranged in series, and further between the reaction layers or in the reaction layer, A heating device such as a heating furnace is preferably provided as means for heating the effluent from the previous reaction layer. Of the n reaction layers arranged in series, the catalyst amount in the first-stage reaction layer is 30% by volume or less, preferably 1-30% by volume, more preferably 2-30% by volume of the total catalyst amount. %, More preferably 2 to 28% by volume. When the number n of reaction layers arranged in series is 3 or more, the amount of catalyst in the first-stage reaction layer is preferably 60 / n volume% or less of the total amount of catalyst. Thereby, the aromatic yield finally obtained improves. Further, the number n of the reaction layers is not particularly limited as long as it is 2 or more. However, if the number is too large, the effect is not changed and the economical efficiency is deteriorated. Accordingly, n is preferably 2 or more and 8 or less, more preferably 3 or more and 6 or less.

  Further, in the conversion reaction step according to the present invention, it is possible to operate at a constant reaction layer inlet temperature, and to increase the reaction layer inlet temperature continuously or stepwise so as to obtain a predetermined aromatic yield. You can also drive. When the aromatic yield falls below the specified range or the reaction bed inlet temperature exceeds the specified temperature range, the reactor is switched to a reactor filled with new catalyst or a reactor filled with regenerated catalyst. Continue the reaction. The regeneration of the catalyst can be performed by heat treatment at 200 to 800 ° C., preferably 350 to 700, in an air stream such as air, nitrogen, hydrogen, or a nitrogen / hydrogen mixed gas. The method for producing aromatic hydrocarbons of the present invention is preferably carried out using two series of fixed bed reactors including a reaction layer holding the catalyst composition. In this case, each series of reaction apparatuses is composed of a plurality of reaction layers arranged in series. While the raw material containing light hydrocarbons is introduced into one series of reactors and the reaction proceeds, the catalyst in the other series of reactors is subjected to a regeneration treatment. By performing the reaction / regeneration alternately at intervals of 1 to 10 days in these two series of reactors, for example, continuous operation for one year can be performed. Further, like the cyclic operation, it is possible to continuously perform the reaction by switching a part or all of the series of reactors used for the reaction to another series. And it is preferable to keep the aromatic yield within a predetermined range of 40 to 75% by weight by increasing the reaction temperature continuously or stepwise by about 5 to 20 ° C. for each cycle of the reaction for 1 to 10 days.

The aromatic yield R is represented by the following formula (4).
R = A / B × 100 (%) (4)
A: Mass of wholly aromatic hydrocarbon in the conversion reaction product B: Mass of C2-C7 aliphatic and / or alicyclic hydrocarbon excluding ethane in the raw material

  When aliphatic and / or alicyclic hydrocarbons are converted to aromatic hydrocarbons, a reaction involving dehydrogenation proceeds. Therefore, under the reaction conditions, a hydrogen partial pressure suitable for the reaction is set without adding hydrogen. Will have. Intentional addition of hydrogen has the advantage of suppressing coke deposition and reducing the frequency of regeneration, but the yield of aromatics is not necessarily advantageous because it decreases rapidly with increasing hydrogen partial pressure. Therefore, the hydrogen partial pressure is preferably suppressed to 0.5 MPa or less.

  In the conversion reaction step according to the present invention, it is desirable to have a light gas containing methane and / or ethane circulated as a recycle gas from the subsequent separation step. By performing the conversion reaction in the presence of the light gas containing methane and / or ethane, coke deposition on the catalyst can be suppressed, and the aromatic yield can be kept high over a long period of time. The circulation amount of the total light gas (recycle gas) circulated to the reaction system is 0.1 to 10 parts by mass, preferably 0.5 to 3 parts by mass, per 1 part by mass of the hydrocarbon feedstock.

(Gas-liquid separation process of reaction bed effluent)
In this step, the effluent from the conversion reaction step is introduced into a gas-liquid separation zone composed of one or more gas-liquid separators, and gas-liquid separation is performed under relatively high pressure, and aromatic hydrocarbons are removed. This is a step of separation into a liquid component (high pressure separation liquid) contained as a main component and a light gas (high pressure separation gas) such as hydrogen, methane, ethane, propane, or butane. As separation conditions, the temperature is usually 10 to 50 ° C., preferably 20 to 40 ° C., and the pressure is usually 0.5 to 8 MPa, preferably 1 to 3 MPa. The reaction bed effluent is cooled by indirect heat exchange with low-temperature raw hydrocarbons before being introduced into the gas-liquid separation process, and, if necessary, hydrogen from the gas-liquid separation process and light gas is separated. In order to reduce the process load, a part of the light gas can be separated.

(Hydrogen separation process from separated gas)
This step is a step of selectively separating hydrogen from the high-pressure separation gas separated in the gas-liquid separation step to obtain a recycle gas containing methane and / or ethane. As a hydrogen separation method in this case, a conventionally known method such as a membrane separation method or a cryogenic separation method is used. From the viewpoint of selective hydrogen separation efficiency, it is preferable to use a membrane separation method. However, when off gas from a cryogenic separation method is used as a recycle gas, unreacted propane is maximized compared to off gas from the membrane separation method. Therefore, there is an advantage that the aromatic hydrocarbon yield can be increased by 1 to 3% by mass. Which method to use is judged from an economic point of view. As the membrane separation device, for example, a device using polyimide, polysulfone, a blend of polysulfone and polydimethylsiloxane as a separation membrane is commercially available. Part of the recycled gas obtained in this step is discharged out of the system in order to keep the total amount of circulating gas within a certain range. In order to recover high-purity hydrogen, a membrane separation device or a PSA (absorption / desorption separation device) is preferably installed as a recovery system in the subsequent stage of the membrane separation device. The selection of the latter device is determined from an economic point of view.

(Separation process of aromatic hydrocarbons from the separation liquid)
This step is a step of separating aromatic hydrocarbon and low boiling point hydrocarbon gas from the high-pressure separation liquid obtained in the gas-liquid separation step, and a stabilizer (distillation tower) is used as the apparatus. The low boiling point hydrocarbon gas separated as the top fraction is composed of C3 to C4 hydrocarbons and is used as a recycle gas.

(Mixing process of raw light hydrocarbons and recycled gas)
In this step, the raw material light hydrocarbon is mixed with the recycle gas containing methane and / or ethane obtained in the hydrogen gas separation step and the low boiling point hydrocarbon gas separated in the aromatic hydrocarbon separation step. It is a process, and this mixing can be performed in a pipe. This mixture is introduced into the conversion reaction step. The mixing ratio of the recycle gas and the low boiling point hydrocarbon gas per 1 part by mass of the raw material light hydrocarbon is 0.1 to 10 parts by mass, preferably 0.5 to 3 parts by mass. Thus, the following effects are acquired by using methane and / or ethane as recycle gas. That is, the aromatization reaction by dehydrocyclization is an endothermic reaction, and therefore the catalyst layer temperature is lowered, which is disadvantageous for the aromatization reaction. Methane and / or ethane is considered an inert gas because it does not aromatize under the reaction conditions. By heating methane and / or ethane, this acts as a heat supply medium, suppresses the temperature drop of the catalyst layer, favorably advances the aromatization reaction, and improves the aromatic hydrocarbon yield. Moreover, the partial pressure of the hydrogen produced | generated by the conversion reaction of a raw material can be reduced by recycling, and an aromatization reaction can be advanced advantageously, As a result, an aromatic hydrocarbon yield can be improved. Furthermore, since the gas velocity in the reaction layer is increased (GHSV is increased), the contact time between the reaction substrate and the catalyst active site is shortened, and the excessive reaction that gives the coke-like substance can be suppressed. As a result, it is possible to suppress the decrease in activity that occurs with the elapsed time of the reaction and maintain the aromatic hydrocarbon yield at a high level. In commercial equipment, the recycle gas ratio must be determined from an economic point of view.

  An example of a flow sheet for carrying out the method for producing aromatic hydrocarbons of the present invention is shown in FIG. A mixture 6 of the raw light hydrocarbon and the recycled light hydrocarbon gas is supplied to the conversion reaction step 1 having a reaction layer in which n catalyst compositions are arranged in series (n is an integer of 2 or more). In the gas-liquid separation step 2, the liquid is then separated into a liquid component (high pressure separation liquid 8) containing aromatic hydrocarbon as a main component and a light gas (high pressure separation gas 9). The high-pressure separation liquid 8 separates and removes the low-boiling hydrocarbon gas 13 in the aromatic hydrocarbon separation step 4 to recover the aromatic hydrocarbon 14.

  An example of the conversion reaction step 1 is shown in FIG. In FIG. 2, a first-stage reactor 16 and a second-stage reactor 17 are arranged in series, and a mixture 18 of raw aliphatic hydrocarbon and light hydrocarbon gas that is a recycle gas (in FIG. Corresponding) is heated by a heating means 19 such as a heating furnace and introduced into the first-stage reactor 16 to carry out a conversion reaction. In the first-stage reactor 16, 30% by mass or less of the total catalyst amount is disposed. The first-stage reactor effluent 21 is reheated by the heating means 20 and introduced into the second-stage reactor 17 so that the conversion reaction is performed again. The reactor effluent 22 from the second-stage reactor 17 may be reheated again by a heating means such as a heating furnace and introduced into the third reactor, or the final reactor. You may introduce into the gas-liquid separation process 2 of the reactor effluent shown in FIG. 1 as an effluent. The reactor 16 and the reactor 17 are provided with another series of reactors 16 ′ and 17 ′, respectively, and the reaction is alternately performed in the two series of reactors and combustion removal of coke deposited on the catalyst is performed. Continuous operation can be performed by performing regeneration.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these Examples.

(Synthesis Example 1: Synthesis of crystalline aluminogallosilicate)
Sodium silicate [J sodium silicate No. _3, SiO 2: 28 to 30 mass%, Na: 9 to 10 wt%, balance water, manufactured by Nippon Chemical Industrial Co., Ltd.] 1,706.1g and water 2,227. 5 g of solution (A), Al ₂ (SO ₄ ) ₃ · 14 to 18H ₂ O [reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.] 64.2 g, Ga (NO ₃ ) ₃ · nH ₂ O [ Ga: 18.51%, manufactured by Soekawa Rikagaku Co., Ltd.] 32.8 g, tetrapropylammonium bromide 369.2 g, H ₂ SO ₄ (97 mass%) 152.1 g, NaCl ₃ 26.6 g and water 2,975. A solution (B) consisting of 7 g was prepared. Next, the solution (B) was gradually added to the solution (A) while stirring at room temperature. The resulting mixture was vigorously stirred with a mixer for 15 minutes to break up the gel into a milky homogeneous fine state. Next, this mixture was put into a stainless steel autoclave, and a crystallization operation was performed under a self-pressure under the conditions of a temperature of 165 ° C., a time of 72 hours, and a stirring speed of 100 rpm. After completion of this crystallization operation, the product was filtered to recover a solid product, and washing and filtration were repeated 5 times using about 5 liters of water. The solid obtained by filtration was dried at 120 ° C., and further calcined at 550 ° C. for 3 hours under air flow.
The obtained fired product has an MFI structure as a result of X-ray diffraction, and is SiO ₂ / Al ₂ O ₃ (molar ratio), SiO ₂ / Ga ₂ O ₃ (molar ratio) by MAS NMR analysis. , SiO ₂ / (Al ₂ O ₃ + Ga ₂ O ₃ ) (molar ratio) were 64.8, 193.2, and 48.6, respectively. The aluminum element contained in the skeleton structure calculated from the results was 1.32% by mass and the gallium element was 1.16% by mass.
A 30% by mass aqueous ammonium nitrate solution was added to the obtained product at a rate of 5 ml per gram, and the mixture was heated and stirred at 100 ° C. for 2 hours, followed by filtration and washing with water. This operation was repeated four times and then dried at 120 ° C. for 3 hours to obtain an ammonium type crystalline aluminogallosilicate.

Example 1
After the ammonium-type crystalline aluminogallosilicate obtained in Synthesis Example 1 was calcined at 780 ° C. for 3 hours in an air atmosphere, alumina powder [Cataloid AP, manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name] was used as a binder. The mixture was mixed so that the weight ratio of crystalline aluminogallosilicate: alumina powder was 70:30, and further kneaded with water, extruded, dried at 120 ° C. for 3 hours, and then in an air atmosphere. The catalyst composition 1 was obtained by calcining at 550 ° C. for 3 hours and adjusting the size to 16 to 28 mesh.
The catalyst composition was crushed in a mortar, powdered, filled into a 3.2 mmφ MAS-NMR measurement sample tube, and a nuclear magnetic resonance measuring apparatus (VNMRS-500, manufactured by Varian Co., Ltd.) was used. The measurement was performed at 23.8 °, a repetition time of 5 seconds, and the number of integrations of 128 times, and the area ratio (Area _{65 ppm} / Area _{0 ppm} ) of the signal around 65 ppm chemical shift and 0 _ppm was obtained based on 1 mol / l aluminum chloride aqueous solution. However, it was 0.45.
Further, the same powder was filled into a 6 mmφ MAS-NMR measurement sample tube, and using a nuclear magnetic resonance measurement apparatus (Varian, VNMRS-500), the rotation speed was 8000 Hz, the pulse width was 23.8 °, the repetition time was 10 seconds, ²⁹ Si-MAS NMR measurement was performed at 1024 integrations, and signals corresponding to Si (0Al) and Si (1Al) were observed around −110 ppm and −105 ppm, respectively, based on polydimethylsiloxane. From the area of this signal, the Si / Al molar ratio in the skeleton was determined to be 38.
From the fluorescent X-ray analysis of the powder, the contents of silicon atom and gallium atom in the catalyst composition were 29.1 and 0.93% by mass, respectively. Therefore, the molar ratio of the gallium atom to the aluminum atom in the skeleton was calculated to be 0.49.
In addition, using a fixed bed flow type reactor, 3 g of the catalyst composition 1 was charged into the reactor, and a simple life test of the catalyst was performed using normal butane as a raw material. The test conditions were as follows: the reaction temperature was 540 ° C., normal pressure, and GHSV 515 hr ⁻¹ for 1 hour, then the product composition was analyzed by gas chromatograph directly connected to the apparatus, the initial raw material conversion rate, fragrance The group yield was determined. Then, after changing to GHSV 5150hr ⁻¹ and reacting for 4 hours, returning to GHSV 515h ⁻¹ again and reacting for 30 minutes, the composition analysis of the product was performed in the same manner as before, and the raw material after the simple life test Conversion and aromatic yield were determined. Initial raw material conversion rate and aromatic yield Further, the raw material conversion rate after simple life evaluation and the ratio of the aromatic yield to the initial value were determined to be 99.9%, 58.0% by mass, 0.99, 0.92.

(Example 2)
To 100 g of commercially available MFI type zeolite (NaMFI40, Si / Al (molar ratio) = 15, manufactured by Zude Chemie Catalysts, trade name), 500 ml of 30% by mass aqueous ammonium nitrate solution was added, and the mixture was heated and stirred at 100 ° C. for 2 hours, followed by filtration and washing with water. did. This operation was repeated 4 times, followed by drying at 120 ° C. for 3 hours to obtain an ammonium type MFI zeolite. To 50 g of this ammonium-type MFI zeolite, 250 mL of a 0.1 mol / l gallium nitrate aqueous solution was added, heated and stirred at 100 ° C. for 4 hours, filtered, washed with water, dried at 120 ° C. for 3 hours, and then 780 ° C. in an air atmosphere. Calcination was performed for 3 hours to obtain a gallium-supported MFI zeolite. From the fluorescent X-ray analysis, the contents of Si, Al, and Ga elements were 40.5, 2.6, and 1.4% by mass, respectively. Using this gallium-supported MFI zeolite as a binder, alumina powder (Cataloid AP, manufactured by Catalytic Chemical Industry Co., Ltd., trade name) was mixed so that the mass ratio of gallium-supported zeolite: alumina powder was 70:30, After adding water and kneading sufficiently, it is extruded, dried at 120 ° C. for 3 hours, and calcined at 550 ° C. for 3 hours in an air atmosphere. The catalyst composition is adjusted to a size of 16 to 28 mesh. 2 was obtained.
As a result of measuring the molar ratio between the tetracoordinated aluminum atom and the hexacoordinated aluminum atom of the catalyst composition 2 in the same manner as in Example 1, it was 0.46.
The molar ratio between the gallium atoms and the aluminum atoms in the skeleton was measured in the same manner as in Example 1. As a result, it was 0.51.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 99.9%, 58.0% by mass, 0.99, and 0.93, respectively.

(Example 3)
To 100 g of commercially available MFI type zeolite (NaMFI40, Si / Al (molar ratio) = 15, manufactured by Zude Chemie Catalysts, trade name), 500 ml of 30% by mass aqueous ammonium nitrate solution was added, and the mixture was heated and stirred at 100 ° C. for 2 hours, followed by filtration and washing with water. did. This operation was repeated 4 times, followed by drying at 120 ° C. for 3 hours to obtain an ammonium type MFI zeolite. To 50 g of this ammonium-type MFI zeolite, 250 mL of a 0.1 mol / l gallium nitrate aqueous solution was added, heated and stirred at 100 ° C. for 4 hours, filtered, washed with water, dried at 120 ° C. for 3 hours, and then 550 ° C. in an air atmosphere. By calcining for a time, a gallium-supported MFI zeolite was obtained. From the fluorescent X-ray analysis, the contents of Si, Al, and Ga elements were 40.5, 2.6, and 1.4% by mass, respectively. After impregnating 20 g of the obtained gallium-supported MFI zeolite with 5 mL of a 0.1 N sodium hydrogen phosphate aqueous solution, drying at 120 ° C. for 3 hours, and firing in an air atmosphere at 780 ° C. for 3 hours, phosphorus-supported gallium MFI zeolite was obtained. From the fluorescent X-ray analysis, the contents of Si, Al, Ga, and P elements were 40.5, 2.6, 1.4, and 0.7% by mass, respectively. Next, as a binder, alumina powder (Cataloid AP, manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name) is mixed so that the mass ratio of phosphorus-supported gallium MFI zeolite: alumina powder is 70:30, and water is further added. In addition, after kneading sufficiently, it was extruded, dried at 120 ° C. for 3 hours, and then calcined in an air atmosphere at 550 ° C. for 3 hours. This was adjusted to a size of 16 to 28 mesh, and catalyst composition 3 was obtained. Obtained.
As a result of measuring the molar ratio of the tetracoordinate aluminum atom and the hexacoordinate aluminum atom of the catalyst composition 3 in the same manner as in Example 1, it was 0.43.
The molar ratio between the gallium atoms and the aluminum atoms in the skeleton was measured in the same manner as in Example 1. As a result, it was 0.51.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 99.0%, 57.5% by mass, 0.99, and 0.91, respectively.

Example 4
(Synthesis of ZnAl ₂ O ₄ binder)
0.2 mol of aluminum nitrate and 0.1 mol of zinc nitrate were dissolved in 1 L of water, 100 g of ethanol was added with stirring, and the mixture was further stirred to obtain a mixed solution. To this mixed solution, 57.8 g of 25% aqueous ammonia containing 0.85 mol of ammonia was added to form a precipitate. After removing water and ethanol from the liquid containing the precipitate, the obtained solid was calcined at 400 ° C. for 5 hours and further calcined at 700 ° C. for 5 hours to obtain a powder.
(Preparation of molded catalyst using ZnAl ₂ O ₄ binder)
The ammonium-type crystalline aluminogallosilicate obtained in Synthesis Example 1 is mixed with the powder obtained above so that the mass ratio of crystalline aluminogallosilicate: powder is 70:30, and water is further added. After being sufficiently kneaded, it was extruded, dried at 120 ° C. for 3 hours, and then calcined at 780 ° C. for 3 hours in an air atmosphere. This was adjusted to a size of 16 to 28 mesh to obtain catalyst composition 4. .
The ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom in the catalyst composition 4 was measured in the same manner as in Example 1. As a result, it was 0.05.
Further, the molar ratio of the gallium atom to the aluminum atom in the skeleton was measured in the same manner as in Example 1, and as a result, it was 0.49.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 99.9%, 58.0% by mass, 0.99, and 0.92, respectively.

(Example 5)
(Synthesis of diaspore)
30% by mass of Chinese diaspore ore as a seed crystal was added to gibbsite (manufactured by Nippon Light Metal Co., Ltd., BHP39) and hydrothermally synthesized in a 1N NaOH aqueous solution at 390 ° C. for 13 days. The precipitated solid was washed with water, dried and then fired at 550 ° C. for 5 hours to obtain a powder.
(Preparation of molded catalyst using diaspore binder)
The powder obtained above is mixed with the ammonium-type crystalline aluminogallosilicate obtained in Synthesis Example 1 so that the mass ratio of crystalline aluminogallosilicate: powder is 70:30, and water is further added to sufficiently After being kneaded, the mixture was extruded, dried at 120 ° C. for 3 hours, and then calcined at 780 ° C. for 3 hours in an air atmosphere. This was adjusted to a size of 16 to 28 mesh to obtain catalyst composition 5.
As a result of measuring the molar ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom of the catalyst composition 5 in the same manner as in Example 1, it was 0.01.
Further, the molar ratio of the gallium atom to the aluminum atom in the skeleton was measured in the same manner as in Example 1, and as a result, it was 0.49.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 99.9%, 58.0% by mass, 0.99, and 0.93, respectively.

(Comparative Example 1)
The ammonium type crystalline aluminogallosilicate obtained in Synthesis Example 1 was used as a binder with alumina powder (Cataloid AP, manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name), and the weight ratio of crystalline aluminogallosilicate: alumina powder was 70. : 30, and after adding water and kneading sufficiently, extrusion molding, drying at 120 ° C. for 3 hours, baking at 780 ° C. for 3 hours in an air atmosphere, The catalyst composition 4 was obtained in accordance with the size of 28 mesh.
As a result of measuring the molar ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom of the catalyst composition 4 in the same manner as in Example 1, it was 0.52.
Further, the molar ratio of the gallium atom to the aluminum atom in the skeleton was measured in the same manner as in Example 1, and as a result, it was 0.49.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial stage was determined, they were 99.0%, 58.0% by mass, 0.96, and 0.88, respectively.

(Comparative Example 2)
The ammonium type crystalline aluminogallosilicate obtained in Synthesis Example 1 was used as a binder with alumina powder (Cataloid AP, manufactured by Catalytic Kasei Kogyo Co., Ltd., trade name), and the crystalline aluminogallosilicate: alumina powder mass ratio was 70. : 30, and after adding water and kneading sufficiently, extrusion molding, drying at 120 ° C. for 3 hours, baking at 550 ° C. for 3 hours in an air atmosphere, The catalyst composition 7 was obtained in accordance with the size of 28 mesh.
The ratio of tetracoordinated aluminum atoms to hexacoordinated aluminum atoms in the catalyst composition 7 was measured in the same manner as in Example 1. As a result, it was 0.45.
Further, the molar ratio of the gallium atom to the aluminum atom in the skeleton was measured in the same manner as in Example 1, and as a result, it was 0.32.
In addition, using a fixed bed flow type reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, as well as raw material conversion rate after simple life evaluation, aroma When the ratio of the group yield to the initial value was determined, they were 97.0%, 48.0% by mass, 0.99, and 0.92, respectively.

(Comparative Example 3)
To 100 g of commercially available MFI type zeolite (NaMFI40, Si / Al (molar ratio) = 15, manufactured by Zude Chemie Catalysts, trade name), 500 ml of 30% by mass aqueous ammonium nitrate solution was added, and the mixture was heated and stirred at 100 ° C. for 2 hours, followed by filtration and washing with water. did. This operation was repeated four times and then dried at 120 ° C. for 3 hours to obtain an ammonium type MFI zeolite. To 50 g of this ammonium-type MFI zeolite, 250 mL of 0.1 mol / l gallium nitrate aqueous solution was added, heated and stirred at 100 ° C. for 4 hours, filtered, washed with water, dried at 120 ° C. for 3 hours, and then 550 ° C. in an air atmosphere. Was calcined for 3 hours to obtain a gallium-supported MFI zeolite. From the fluorescent X-ray analysis, the contents of Si, Al, and Ga elements were 40.5, 2.6, and 1.4% by mass, respectively. Using this gallium-supported MFI zeolite as a binder, alumina powder (Cataloid AP, manufactured by Catalytic Chemical Industry Co., Ltd., trade name) is mixed so that the mass ratio of gallium-supported zeolite: alumina powder is 70:30, After adding water and kneading sufficiently, it is extruded, dried at 120 ° C. for 3 hours, and calcined at 780 ° C. for 3 hours in an air atmosphere. The catalyst composition is adjusted to a size of 16 to 28 mesh. 8 was obtained.
As a result of measuring the molar ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom of the catalyst composition 8 in the same manner as in Example 1, it was 0.53.
The molar ratio between the gallium atoms and the aluminum atoms in the skeleton was measured in the same manner as in Example 1. As a result, it was 0.51.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 99.9%, 58.5% by mass, 0.96, and 0.89, respectively.

(Comparative Example 4)
To 100 g of commercially available MFI type zeolite (NaMFI40, Si / Al (molar ratio) = 15, manufactured by Zude Chemie Catalysts, trade name), 500 ml of 30% by mass aqueous ammonium nitrate solution was added, and the mixture was heated and stirred at 100 ° C. for 2 hours, followed by filtration and washing with water. did. This operation was repeated four times and then dried at 120 ° C. for 3 hours to obtain an ammonium type MFI zeolite. To 50 g of this ammonium-type MFI zeolite, 250 mL of 0.1 mol / l gallium nitrate aqueous solution was added, heated and stirred at 100 ° C. for 4 hours, filtered, washed with water, dried at 120 ° C. for 3 hours, and then 550 ° C. in an air atmosphere. Was calcined for 3 hours to obtain a gallium-supported MFI zeolite. From the fluorescent X-ray analysis, the contents of Si, Al, and Ga elements were 40.5, 2.6, and 1.4% by mass, respectively. Using this gallium-supported MFI zeolite as a binder, alumina powder (Cataloid AP, manufactured by Catalytic Chemical Industry Co., Ltd., trade name) is mixed so that the mass ratio of gallium-supported zeolite: alumina powder is 70:30, After adding water and kneading sufficiently, it is extruded, dried at 120 ° C. for 3 hours, and calcined at 550 ° C. for 3 hours in an air atmosphere. The catalyst composition is adjusted to a size of 16 to 28 mesh. 9 was obtained.
The molar ratio of the tetracoordinated aluminum atom to the hexacoordinated aluminum atom in the catalyst composition 9 was measured in the same manner as in Example 1. As a result, it was 0.46.
Further, the molar ratio between the gallium atom and the aluminum atom in the skeleton was measured in the same manner as in Example 1, and as a result, it was 0.27.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 98.4%, 42.0% by mass, 0.99, and 0.93, respectively.

(Comparative Example 5)
To 100 g of commercially available MFI type zeolite (NaMFI40, Si / Al (molar ratio) = 15, manufactured by Zude Chemie Catalysts, trade name), 500 ml of 30% by mass aqueous ammonium nitrate solution was added, and the mixture was heated and stirred at 100 ° C. for 2 hours, followed by filtration and washing with water. did. This operation was repeated four times and then dried at 120 ° C. for 3 hours to obtain an ammonium type MFI zeolite. To 50 g of this ammonium-type MFI zeolite, 250 mL of a 0.1 mol / l gallium nitrate aqueous solution was added, and the mixture was heated and stirred at 100 ° C. for 4 hours, filtered, washed with water, dried at 120 ° C. for 3 hours, and then heated to 550 ° C. in an air atmosphere. And calcining for 3 hours to obtain a gallium-supported MFI zeolite. From the fluorescent X-ray analysis, the contents of Si, Al, and Ga elements were 40.5, 2.6, and 1.4% by mass, respectively. After impregnating 20 g of the obtained gallium-supported MFI zeolite with 5 ml of a 0.1 N sodium hydrogen phosphate aqueous solution, drying at 120 ° C. for 3 hours, and firing in an air atmosphere at 550 ° C. for 3 hours, phosphorus-supported gallium MFI Zeolite was obtained. From the fluorescent X-ray analysis, the contents of Si, Al, Ga, and P elements were 40.5, 2.6, 1.4, and 0.7% by mass, respectively. Next, as a binder, alumina powder (Cataloid AP, manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name) is mixed so that the mass ratio of phosphorus-supported gallium MFI zeolite: alumina powder is 70:30, and water is further added. In addition, after being sufficiently kneaded, extruded, dried at 120 ° C. for 3 hours, and calcined in air at 780 ° C. for 3 hours. Obtained.
As a result of measuring the molar ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom of the catalyst composition 10 in the same manner as in Example 1, it was 0.54.
Further, the molar ratio between the gallium atoms and the aluminum atoms in the skeleton was measured in the same manner as in Example 1, and as a result, it was 0.51.
In addition, using a fixed bed flow reactor, initial activity evaluation and simple life evaluation are performed in the same manner as in Example 1. Initial raw material conversion rate and aromatic yield, raw material conversion rate after simple life evaluation, aromatic When the ratio of the yield to the initial value was determined, they were 98.5%, 55.5% by mass, 0.96, and 0.88, respectively.

  The results of Examples 1 to 5 and Comparative Examples 1 to 5 are summarized in Table 1. When the molar ratio of the tetracoordinated aluminum atom and the hexacoordinated aluminum atom is less than 0.5 and the molar ratio of the gallium atom to the aluminum atom in the skeleton is 0.45 or more, a high aromatic yield can be obtained. It is clear from Table 1 that the decrease in activity after the life test is small.

It is a figure which shows an example of the flow sheet in the case of implementing the method of this invention. It is a figure which shows an example of the conversion reaction process in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Conversion reaction process 2 ... Gas-liquid separation process 3 of reactor effluent 3 ... Hydrogen separation process 4 from high pressure separation gas 4 ... Separation process of aromatic hydrocarbon from high pressure separation liquid 5 ... Raw material aliphatic hydrocarbon 6 ... Raw material Mixture of aliphatic hydrocarbon and light hydrocarbon gas as recycle gas 7 ... Reactor effluent 8 ... High-pressure separation liquid 9 separated in gas-liquid separation process ... High-pressure separation gas 10 separated in gas-liquid separation process ... Hydrogen separation Gas 11 mainly composed of hydrogen separated in the process ... Off-gas 12 separated in the hydrogen separation process ... Gas 13 discharged out of the system in order to keep the total circulating gas amount within a certain range ... Separated from the high-pressure separation liquid Low boiling point hydrocarbon gas 14 ... aromatic hydrocarbon 15 separated from high-pressure separation liquid ... recycle gas 16 ... first stage reactor 16 '... another series of reactors 17 in first stage reactor 17 ... second stage Reactor 17 'for the second stage Reactor 18 in another series of reactors ... Mixture 19 of raw aliphatic hydrocarbon and light hydrocarbon gas as recycle gas 19, 20 ... Heating means 21 such as heating furnace ... Reactor outflow from first stage reactor Item 22 ... Reactor effluent from the second-stage reactor

Claims (7)

A composition containing crystalline aluminosilicate containing gallium atoms and alumina,
The molar ratio of tetracoordinated aluminum atoms and hexacoordinated aluminum atoms, which is quantified by ²⁷ Al-MAS NMR method, constituting the alumina in the composition is less than 0.5,
The molar ratio between the gallium atom in the composition and the aluminum atom in the skeleton of the crystalline aluminosilicate in the composition determined by ²⁹ Si-MAS NMR method is 0.45 or more. A catalyst composition for producing aromatic hydrocarbons from light hydrocarbons . A composition containing crystalline aluminosilicate containing gallium atoms and alumina,
The molar ratio of tetracoordinated aluminum atoms and hexacoordinated aluminum atoms, which is quantified by ²⁷ Al-MAS NMR method, constituting the alumina in the composition is less than 0.5,
The molar ratio of the gallium atom in the composition to the aluminum atom quantified by ²⁹ Si-MAS NMR method in the skeleton of the crystalline aluminosilicate used as a raw material of the composition is 0.45 or more. A catalyst composition for producing aromatic hydrocarbons from light hydrocarbons .   The catalyst composition according to claim 1 or 2, wherein the crystalline aluminosilicate is a pentasil-type zeolite.   The crystalline aluminosilicate has a particle content of a particle diameter in the range of 0.05 to 20 µm based on the mass of all particles, and is 80% by mass or more. The catalyst composition according to claim 1.   The crystalline aluminosilicate contains 0.1 to 2.5% by mass of aluminum atoms and 0.1 to 5.0% by mass of gallium atoms based on the mass of the crystalline aluminosilicate. The catalyst composition according to any one of claims 1 to 4.   The catalyst composition according to any one of claims 1 to 5, wherein the crystalline aluminosilicate is a crystalline aluminogallosilicate.   A process for producing an aromatic hydrocarbon, comprising the step of bringing the catalyst composition according to any one of claims 1 to 6 and a raw material containing a hydrocarbon having 2 to 7 carbon atoms into contact with each other. .

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