Metal-containing MFI zeolite and catalyst for producing hydrocarbon compounds containing the same

Abstract

To provide a metal-containing MFI type zeolite which enables simultaneous production of a light hydrocarbon compound and an aromatic compound from aliphatic hydrocarbon, and enables application of a light hydrocarbon compound and an aromatic compound exhibiting performance excellent in productivity, stability and long life at the time of the simultaneous production, as catalysts for simultaneous production.SOLUTION: A metal-containing MFI type zeolite satisfies the following characteristics (i) to (iii), and contains at least metal belonging to a platinum group. (i) a meso pore distribution curve having a peak, and having a meso pore group in which a half-value width (hw) of the peak is hw≤20 nm, a central value (μ) of the peak is 10 nm≤μ≤20 nm, and a meso pore volume (pv) of a meso pore corresponding to the peak is 0.05 ml / g≤pv; (ii) having no peak in a range of 0.1-3 degrees in powder X-ray diffraction measurement with a diffraction angle of 2θ; and (iii) an average particle diameter (PD) of PD≤100 nm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a metal-containing MFI-type zeolite into which a specific metal has been introduced and a catalyst for producing hydrocarbon compounds containing the same. In particular, a specific metal-containing MFI-type zeolite having a relatively uniform mesopore group, and when producing aromatic compounds from aliphatic hydrocarbons, it exhibits excellent performance in productivity, stability, and long life, and at the same time, it relates to a catalyst for simultaneously producing light hydrocarbon compounds and aromatic compounds that enables the simultaneous production of light hydrocarbon compounds typified by ethane.

Background Art

[0002] MFI-type zeolite is used as a highly selective catalyst that utilizes uniform pores derived from the zeolite structure. Examples of using MFI-type zeolite as a catalyst include disproportionation of toluene (see, for example, Patent Document 1) and isomerization of xylene (see, for example, Patent Document 2).

[0003] These reactions mainly utilize the characteristics of the micropores of MFI-type zeolite. The micropores of MFI-type zeolite have an inlet diameter of approximately 0.5 nm and are considered to be an effective reaction field for molecules having a molecular diameter close to this pore diameter.

[0004] Furthermore, research has been conducted on MFI-type zeolites having pores larger than micropores (less than 2 nm), that is, mesopores (pore diameters of 2 to 50 nm) (see, for example, Non-Patent Document 1).

[0005] And as a material promising for industrial use, a novel MFI-type zeolite having uniform mesopores of 10 nm or more and a method for producing the same (see, for example, Patent Document 3) have been proposed. However, there are only a few reports of obtaining specific results by using zeolite having mesopores as a catalyst, particularly in reactions using relatively small molecules having 10 or fewer carbon atoms as raw materials.

[0006] Benzene, toluene, xylene (hereinafter sometimes collectively referred to as aromatic compounds) are often obtained by decomposing a feedstock oil (e.g., naphtha, etc.) obtained by petroleum refining in a pyrolysis reactor and separating and purifying the aromatic compounds from the resulting pyrolysis products by distillation or extraction. In the production of aromatic compounds by these production methods, aliphatic hydrocarbons (including paraffinic, olefinic, acetylenic, and alicyclic) are included as pyrolysis products other than aromatic compounds. Therefore, with the production of aromatic compounds, aliphatic hydrocarbons are simultaneously produced, so the production volume of aromatic compounds is adjusted in proportion to the production volume of aliphatic hydrocarbons, and there is naturally a limit to the production volume. Also, aromatic compounds can be produced by bringing an aliphatic hydrocarbon raw material into contact with a catalyst mainly containing a medium-pore-size zeolite at a temperature of about 400°C to about 800°C (see, for example, Non-Patent Documents 2 to 5). This production method has the advantage that it has a lower added value compared to the production method of aromatic compounds by pyrolysis and can produce aromatic compounds from surplus hydrocarbon raw materials. Also, the development of catalysts used in these aromatic compound productions has been carried out. For example, as a catalyst for producing aromatic compounds using hydrocarbons containing paraffin, olefin, and naphthene as raw materials, a zinc-supported medium-pore-size zeolite-based catalyst with suppressed zinc scattering amount is provided (see, for example, Patent Document 4). Also, as a catalyst used in the production of aromatic compounds using paraffin, olefin, acetylenic hydrocarbons, cyclic paraffin, and cyclic olefin as raw materials, a catalyst obtained by simultaneously supporting platinum and a halogen component on L-type zeolite is provided (see, for example, Patent Document 5). Furthermore, a catalyst for aromatization reaction is provided, which is characterized in that zinc and / or gallium is supported on a structure having a size of 0.1 to 100 mm, crystalline porous aluminosilicate exists in the surface layer part of the structure, and an inorganic support exists in the internal layer excluding the surface layer part of the structure (see, for example, Patent Document 6). In addition, catalysts for producing aromatic compounds using hydrocarbons as raw materials are provided (see, for example, Patent Documents 7 and 8). Also, in recent years, a catalyst for producing aromatic compounds containing a specific MFI-type zeolite (see, for example, Patent Document 9), a silver-containing zeolite having high heat resistance and hydrothermal resistance (see, for example, Patent Document 10).) have been proposed, etc.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Non - Patent Documents

[0008]

Non - Patent Document 1

Non - Patent Document 2

Non - Patent Document 3

Non - Patent Document 4

Non-Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in the methods for producing aromatic compounds using these catalytic reactions proposed in Patent Documents 4 to 8, there were problems with the catalyst life (the time from when the catalyst is in an active state after the start of the reaction until the catalyst is deactivated) from the perspective of production cost. Also, in the proposals of Patent Documents 9 and 10, although there were effects from the perspective of producing aromatic compounds, nothing was examined from the perspective of producing light hydrocarbons.

[0010] The present invention provides a novel catalyst for producing hydrocarbon compounds that can simultaneously and selectively produce light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, which are relatively small molecules (especially those having 10 or fewer carbon atoms, preferably 5 to 7 carbon atoms), stably over a long period of time, and a metal-containing MFI-type zeolite that can be used therefor.

Means for Solving the Problems

[0011] As a result of intensive studies to solve the above problems, the present inventors have found that a specific MFI-type zeolite into which a specific metal is introduced can become a catalyst capable of simultaneously producing light hydrocarbon compounds and aromatic compounds selectively and stably from aliphatic hydrocarbons over a long period of time, and have thus completed the present invention.

[0012] That is, the present invention relates to a metal-containing MFI-type zeolite that satisfies the characteristics shown in the following (i) to (iii) and contains at least a metal belonging to the platinum group, and a catalyst for simultaneously producing light hydrocarbon compounds and aromatic compounds comprising the same. (i) It has a mesopore size distribution curve with a peak, the half-width (hw) of the peak satisfies hw ≦ 20 nm, the central value (μ) of the peak satisfies 10 nm ≦ μ ≦ 20 nm, and the mesopore volume (pv) of the mesopores corresponding to the peak satisfies 0.05 ml / g ≦ pv, having a group of mesopores. (ii) It has no peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with the diffraction angle as 2θ. (iii) The average particle diameter (PD) satisfies PD ≦ 100 nm.

[0013] The present invention will be described in detail below.

[0014] The metal-containing MFI-type zeolite of the present invention is a specific MFI-type zeolite into which at least a metal belonging to the platinum group is introduced, and is particularly useful as a catalyst for simultaneously and stably producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons over a long period of time.

[0015] The metal-containing MFI-type zeolite of the present invention satisfies the above (i) to (iii), and is a metal-containing MFI-type zeolite containing at least a metal belonging to the platinum group. By containing at least a metal belonging to the platinum group, it becomes a zeolite that exhibits excellent performance as a catalyst for simultaneously producing light hydrocarbon compounds and aromatic compounds. In particular, since it shows a specific high ethane yield, it is preferable to contain gallium in addition to the metal belonging to the platinum group. Further, since it is suitable as a catalyst for simultaneously and well-balancedly producing ethane and aromatic compounds, the metal belonging to the platinum group is preferably platinum. The content of the metal belonging to the platinum group at that time is preferably 0.05 to 5% by weight. Also, when it contains gallium, its content is preferably 0.05 to 5% by weight. Here, the metal belonging to the platinum group refers to a metal generally called a platinum group element, and examples thereof include ruthenium, rhodium, palladium, osmium, iridium, platinum, etc. Also, as a method for introducing the metal, any of impregnation loading, ion exchange, and physical mixing methods is possible.

[0016] The metal-containing MFI-type zeolite of the present invention satisfies the characteristics shown in the above (i) to (iii). As the MFI-type zeolite, it refers to an aluminosilicate compound belonging to the structure code MFI defined by the International Zeolite Association. Further, the mesopores referred to in the present invention are the mesopores defined by IUPAC and indicate pores with a pore diameter in the range of 2 to 50 nm. And the mesopores can be measured by a general nitrogen adsorption method at liquid nitrogen temperature. Also, by analyzing the measurement results obtained by the nitrogen adsorption method, the value of the pore volume of the mesopores can be obtained. For the analysis, for example, the following method can be used.

[0017] Specifically, a method of analyzing the desorption process by the Barret-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pages 373-380) can be mentioned. For example, by integrating the nitrogen gas desorption amount in the range corresponding to a pore diameter of 2 nm or more and 50 nm or less, the value of the total pore volume of the pores belonging to the mesopores can be obtained.

[0018] Also, first, after obtaining a cumulative curve with the vertical axis being the nitrogen desorption amount per unit mass V / m (mL / g) and the horizontal axis being the mesopore diameter D (nm), by setting the vertical axis to the differential value (d(V / m) / d(D)) at the mesopore diameter value of the nitrogen gas desorption amount from the mesopores, a peak of the increase in the nitrogen desorption amount per unit mass at the mesopore diameter can be obtained.

[0019] The metal-containing MFI-type zeolite of the present invention comprises an MFI-type zeolite having a group of mesopores with substantially uniform pore diameters. In the present invention, the group of mesopores with substantially uniform pore diameters may also be referred to as uniform mesopores. Specifically, the uniform mesopores refer to mesopores having pore diameters within the range of the center value (μ) of a Gaussian function approximating the maximum peak among the peaks related to the mesopores in the pore size distribution curve plus or minus twice the standard deviation (2σ) (μ ± 2σ). Further, the pore volume of the uniform mesopores can be determined by integrating the nitrogen gas desorption amount in the range of μ ± 2σ.

[0020] Among the MFI-type zeolites having a group of substantially uniform mesopores, the metal-containing MFI-type zeolite of the present invention comprises an MFI-type zeolite having a more uniform group of mesopores, where (i) the mesopore distribution curve has a peak, the half-width (hw) of the peak satisfies hw ≦ 20 nm, the center value (μ) of the peak satisfies 10 nm ≦ μ ≦ 20 nm, and the mesopore volume (pv) of the mesopores corresponding to the peak satisfies pv ≧ 0.05 ml / g.

[0021] The metal-containing MFI-type zeolite of the present invention has a pore distribution curve of mesopores with a peak, and the peak has a substantially uniform mesopore group with a small variation in pore diameter of an MFI-type zeolite with hw ≦ 20 nm or less. By including such an MFI-type zeolite, it becomes excellent in reaction selectivity, and the effect becomes more remarkable and preferable when hw ≦ 15 nm, particularly when hw ≦ 10 nm. Although the lower limit of hw is not particularly set, it is preferably 1 nm or more because it becomes more excellent in reaction selectivity. When hw > 20 nm, its reaction selectivity when used as a catalyst for producing hydrocarbon compounds is inferior. Further, by including an MFI-type zeolite with a central value (μ) of 10 nm ≦ μ ≦ 20 nm when the peak is approximated by a Gaussian function, it becomes possible to selectively react even larger-sized molecules, and it becomes an excellent catalyst for producing hydrocarbon compounds. Furthermore, when pv ≧ 0.05 ml / g, it becomes a long-life catalyst for producing hydrocarbon compounds when used as a catalyst. It is preferably 0.05 ml / g ≦ pv ≦ 0.70 ml / g, particularly preferably 0.10 ml / g ≦ pv ≦ 0.70 ml / g, and even more preferably 0.20 ml / g ≦ pv ≦ 0.50 ml / g. Here, when pv < 0.05 ml / g, pores are likely to be blocked due to the accumulation of coke and the like by-produced during the reaction, and the catalyst life when used as a catalyst is inferior.

[0022] Moreover, since it is particularly suitable as a catalyst for producing hydrocarbon compounds that enables a selective reaction, in the metal-containing MFI-type zeolite of the present invention, the ratio (pvr) of pv shown in (i) above to the total pore volume is preferably 30% ≦ pvr ≦ 100%, and more preferably 40% ≦ pvr ≦ 100%.

[0023] The metal-containing MFI-type zeolite of the present invention has no peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with the diffraction angle being 2θ. This indicates that there is no regularity in the arrangement between mesopores and there is no wall separating between mesopores, and when used as a catalyst, the mass transfer between mesopores becomes easy, so it becomes a catalyst for producing hydrocarbon compounds with excellent reaction efficiency.

[0024] The metal-containing MFI-type zeolite of the present invention has (iii) PD ≤ 100 nm, and particularly has excellent heat resistance. Therefore, it is preferable that 3 nm ≤ PD, and more preferably 5 nm ≤ PD. Here, when the zeolite has PD > 100 nm, a substantially uniform mesopore group is not formed, and the reaction selectivity when used as a catalyst for producing hydrocarbon compounds is inferior. Note that PD can be calculated and obtained, for example, from the external surface area using the following formula (1). PD = 6 / S(1 / 2.29×10 6 + 0.18×10 -6 ) (1) (Here, S represents the external surface area (m 2 / g).) Also, the external surface area (S (m 2 / g)) in formula (1) can be obtained from the t-plot method using a general nitrogen adsorption method at liquid nitrogen temperature. For example, when t is the thickness of the adsorption amount, it is a method of linearly approximating the measurement points in the range of 0.6 to 1 nm for t and obtaining the external surface area from the slope of the obtained regression line.

[0025] In addition, as another method for measuring the particle size of the metal-containing MFI-type zeolite, for example, a method of selecting 10 or more arbitrary particles from the photographs of a scanning electron microscope (SEM) or a transmission electron microscope (TEM) and obtaining the surface area average diameter can be mentioned.

[0026] The metal-containing MFI-type zeolite of the present invention is not limited in terms of its SiO2 / Al2O3 (molar ratio). Among them, since it becomes a catalyst for producing hydrocarbons with excellent heat resistance, reaction selectivity, and productivity, the SiO2 / Al2O3 (molar ratio) is preferably 20 or more and 200 or less.

[0027] As the metal-containing MFI-type zeolite of the present invention, since it becomes a catalyst for producing hydrocarbons with excellent reaction selectivity and productivity, it is preferably one that does not contain a structure-directing agent such as tetrapropylammonium salt in the pores.

[0028] Moreover, as a method for producing an MFI-type zeolite which is a raw material satisfying the above characteristics (i) to (iii), for example, the following methods can be mentioned.

[0029] An amorphous aluminosilicate gel is added to an aqueous solution of tetrapropylammonium (hereinafter sometimes referred to as "TPA") hydroxide and sodium hydroxide and suspended. An MFI-type zeolite is added as a seed crystal to the obtained suspension to obtain a raw material composition, and the obtained raw material composition is crystallized and calcined to obtain an MFI-type zeolite.

[0030] When the metal-containing zeolite of the present invention is used as a catalyst for producing hydrocarbons, catalyst deterioration due to coking and the like hardly occurs, and it has excellent catalyst performance in terms of production efficiency and selectivity. Therefore, (iv) the acid amount on the outer surface is preferably 0.0001 to 0.01 mmol / g. Here, the acid points on the outer surface of the zeolite, as the name implies, indicate the acid points present on the outer surface of the zeolite. Usually, zeolite has acid points on its outer surface and in (micro) pores. Having no acid points on the outer surface means that it can be said to have acid points only in the (micro) pores. And, since it is particularly excellent in heat resistance, hydrothermal stability, and durability, it is preferably a metal-containing zeolite having an unmodified surface that is not coated with a silicate, a dialkylamine reagent, or the like on the surface.

[0031] As for the confirmation of acid sites on the external surface of the zeolite, any method can be used as long as the confirmation is possible. For example, it can be confirmed by the adsorption of 2,4-dimethylquinoline having adsorptivity to acid sites (see Characterization of acid sites on the external surface of zeolites, Reaction Kinetics and Catalysis Letters, vol. 67, p. 281 (1999)).

[0032] When the metal-containing zeolite of the present invention is used as a catalyst for producing hydrocarbon compounds, catalyst deterioration due to coking or the like hardly occurs and it has excellent catalytic activity. Therefore, (v) the acid amount is preferably 0.02 to 0.85 mmol / g, particularly preferably 0.02 to 0.55 mmol / g. As the measurement of the acid amount, it can be measured using a method generally known as a method for measuring the acid amount. For example, it can be measured by a method according to the ammonia-TPD method (measurement of solid acidity by ammonia temperature-programmed desorption method, Catalyst, vol. 42, p. 218 (2000)).

[0033] As a method for producing an MFI-type zeolite satisfying such (iv) and / or (v), for example, it can be produced by dealuminating aluminum in the framework of the MFI-type zeolite, which is a raw material satisfying the above (i) to (iii) characteristics, with steam or the like. The temperature of the steam treatment at that time is preferably, for example, 400 to 900 °C, particularly preferably 450 to 800 °C, and more preferably 500 to 700 °C. The partial pressure of steam is preferably 0.001 to 5 MPa, particularly preferably 0.01 to 0.5 MPa, and more preferably 0.05 to 0.2 MPa. The concentration of steam is preferably, for example, 0.01 to 100 vol% steam / diluent gas. As the diluent gas, an inert gas such as nitrogen, air, oxygen, carbon monoxide, carbon dioxide, or a mixed gas thereof can be used. The steam treatment time can be arbitrarily selected.

[0034] As a method for producing the metal-containing MFI-type zeolite of the present invention, for example, it can be produced by containing a metal belonging to the platinum group by a method such as impregnation loading, ion exchange, or physical mixing on the MFI-type zeolite. When performing impregnation loading or ion exchange, for example, metal salts such as tetraammineplatinum nitrate, platinum nitrate, rhodium nitrate, rhodium sulfate, palladium nitrate, palladium sulfate, and tetraamminepalladium nitrate, and their solutions can be used. When it is also intended to contain gallium, for example, metal salts such as gallium nitrate, gallium sulfate, and gallium hydroxide, and their solutions can be used in combination or sequentially.

[0035] When using the novel metal-containing MFI-type zeolite of the present invention as a catalyst for hydrocarbon production, the form is not limited. For example, the metal-containing MFI-type zeolite powder can be used as the catalyst as it is, compression molding can be performed to obtain a specific-shaped object for use, or it can be mixed with a binder or the like and molded to obtain a specific-shaped object for use. Any of these forms can be used.

[0036] By using the metal-containing MFI-type zeolite of the present invention as a catalyst for hydrocarbon production, a catalyst excellent in efficiency such as reaction selectivity and productivity can be obtained. For example, by contacting with aliphatic hydrocarbons, particularly aliphatic hydrocarbons having 10 or less carbon atoms, and more particularly aliphatic hydrocarbons having 5 to 7 carbon atoms, it is possible to efficiently produce light hydrocarbon compounds and aromatic compounds simultaneously. The aliphatic hydrocarbons at that time include, for example, paraffinic, olefinic, acetylenic, and alicyclic hydrocarbons. Specifically, paraffinic such as propane, butane, isobutane, pentane, hexane, heptane, octane, nonane, etc.; olefinic such as propylene, butene, isobutene, pentene, hexene, heptene, octene, nonene, etc.; alicyclic such as cyclopropane, cyclobutane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, etc. and mixtures thereof can be mentioned. And these aliphatic hydrocarbons may be not only those derived from petroleum typified by naphtha, but also those derived from plants typified by bioethanol and bio-naphtha, and those derived from chemical recycling of resins typified by polyolefin, polyvinyl chloride, acrylic, and polystyrene.

[0037] And in the reaction which is the embodiment at that time, the reaction temperature is not particularly limited as long as it is possible to produce light hydrocarbon compounds and aromatic compounds. Among them, in order to suppress the production of by-produced paraffins, olefins or alkanes and enable an efficient reaction of light hydrocarbon compounds and aromatic compounds without requiring a heat-resistant reactor more than necessary, a range of 400 to 800 ° C is desirable. Also, there is no limitation on the reaction pressure, and for example, it can be operated in a pressure range of about 0.05 MPa to 5 MPa. And the supply of the aliphatic hydrocarbon which is the reaction raw material for the catalyst for simultaneous production of light hydrocarbon compounds and aromatic compounds at that time is not particularly limited as the ratio of the volume of the raw material gas to the volume of the catalyst body. For example, 1h -1 ~50000h -1Spatial velocities can be cited. When supplying an aliphatic hydrocarbon as a raw material gas, it can also be used as a single gas, a mixed gas, or a mixture diluted with a single or mixed gas selected from inert gases such as nitrogen, hydrogen, carbon monoxide, and carbon dioxide.

[0038] There is no limitation on the reaction form. For example, not only fixed beds, transport beds, fluidized beds, moving beds, multitubular reactors, but also continuous flow type, batch flow type, and swing reactors can be used.

[0039] Examples of the light hydrocarbon compounds produced include ethane, ethylene, propane, propylene, etc., and ethane is particularly preferred. Also, as for aromatic compounds, there is no particular limitation as long as they belong to the category called aromatic compounds. For example, benzene, toluene, xylene, trimethylbenzene, ethylbenzene, propylbenzene, butylbenzene, naphthalene, methylnaphthalene, etc. can be cited, and particularly, benzene, toluene, and xylene are preferred.

Advantages of the Invention

[0040] The present invention relates to a specific MFI-type zeolite containing a specific metal, and particularly, it is also possible to use it as a catalyst for producing hydrocarbon compounds that can specifically obtain a long catalyst life when simultaneously producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, and it is very useful industrially.

Examples

[0041] Hereinafter, the present invention will be specifically described with reference to examples.

[0042] The performance of the MFI-type zeolite used in the examples and the catalyst for simultaneously producing light hydrocarbon compounds and aromatic compounds was measured and defined by the following methods.

[0043] ~Measurement of Pore Distribution, Pore Diameter, and External Surface Area~ The pore distribution and pore diameter of the MFI-type zeolite were measured by nitrogen adsorption measurement.

[0044] As the nitrogen adsorption measurement at that time, it was measured using a nitrogen adsorption apparatus ((trade name) BELSORP-max, manufactured by MicrotracBEL Corp.). The external surface area was determined by linearly approximating the range of the thickness of the adsorption layer (t = 0.6 to 1.0 nm) by the t-plot method.

[0045] Then, the desorption process of the nitrogen adsorption measurement was analyzed by the Barret-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pages 373 to 380), and a pore size distribution curve of mesopores was obtained, where the horizontal axis is a constant of the pore diameter and the vertical axis is the differential value of the desorption amount of nitrogen gas. The total pore volume of the mesopores was determined by integrating the desorption amount of nitrogen gas in the range of 2 nm or more and 50 nm or less.

[0046] Among the peaks of the differential value (d(V / m) / d(D)) of the nitrogen gas desorption amount from the mesopores at the mesopore diameter value, the maximum peak was analyzed by the intensity approximation of the Gaussian function, and mesopores having a diameter within the range of twice the standard deviation (2σ) from the central value (μ) of the Gaussian function (= μ ± 2σ) were defined as uniform mesopores. The pore volume of the uniform mesopores was determined by integrating the desorption amount of nitrogen gas in the range of ±2σ based on the central value (μ).

[0047] ~Measurement of average particle diameter~ The average particle diameter was calculated using the above formula (1) from the external surface area. In formula (1), S is the external surface area (m 2 / g), and PD is the average particle diameter (m). The external surface area (S (m 2 / g)) in formula (1) was determined by the t-plot method by the nitrogen adsorption method at liquid nitrogen temperature.

[0048] ~Measurement of metal introduction amount~ The amount of metal introduced into the zeolite was determined by dissolving the MFI-type zeolite in an aqueous mixed solution of hydrofluoric acid and nitric acid and measuring it by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a general ICP device ((trade name) OPTIMA 3300DV, manufactured by PerkinElmer).

[0049] ~Measurement of powder X-ray diffraction~ Using an X-ray diffractometer (manufactured by Spectris, (trade name) X’pert PRO MPD), measurements were carried out in the atmosphere using CuKα1 with a tube voltage of 45 kV and a tube current of 40 mA. The range of 0.04 to 5 degrees was analyzed at 0.08 degrees / step and 200 seconds / step. In addition, the background corrected by the absorption rate of the direct beam was removed. The presence or absence of peaks was visually judged.

[0050] ~Measurement of the amount of acid on the outer surface~ The measurement of the amount of acid on the outer surface was carried out by 2,4-dimethylquinoline adsorption infrared absorption spectroscopy. Using an FT-IR spectrometer ((trade name) FT / IR-6700, manufactured by JASCO Corporation), measurements were carried out by the transmission method. Using an MCT detector, a spectrum was obtained with 256 accumulations. The sample was formed into a disk with a diameter of 13 mm and then placed on a disk holder in a quartz vacuum degassing cell, and installed perpendicular to the infrared optical path. As a pretreatment of the sample, the temperature was raised to 400 °C at 10 °C / min under vacuum evacuation and held for 2 hours. After cooling to 150 °C, the infrared absorption spectrum before the adsorption of 2,4-dimethylquinoline was measured. 2,4-Dimethylquinoline gas was introduced and adsorbed for 30 minutes, and after vacuum evacuation at 150 °C for 1 hour, the infrared absorption spectrum after the adsorption of 2,4-dimethylquinoline was measured. The difference between the infrared absorption spectrum after the adsorption of 2,4-dimethylquinoline and the spectrum before adsorption was taken to measure the change in infrared absorption due to adsorption. Among the difference spectra, the peak around 3600 cm -1 is the peak of the absorption spectrum of 2,4-dimethylquinoline adsorbed on the outer surface acid sites (Bronsted acid sites). After obtaining this area intensity, the amount of acid on the outer surface was determined from the following formula (2) by the Lambert-Beer law. Amount of acid (μmol / mg) = A·S / (W·ε) Equation (2) (where A is the peak area intensity (cm -1 ) of the target peak, S is the sample cross-sectional area (cm 2 ), W is the sample weight (mg), and ε is the integrated absorption coefficient, which is 3.7 cm·μmol -1 . Each of these is shown.) ~Measurement of the amount of acid~ The measurement of the amount of acid was carried out by a method according to the ammonia-TPD method (measurement of solid acidity by the ammonia temperature-programmed desorption method, see Catalyst, vol. 42, p. 218 (2000)). The apparatus used was a catalyst analyzer (trade name: BELCATII, manufactured by MicrotracBEL Corporation). After pretreatment at 500 °C for 1 hour under a helium flow, ammonia was adsorbed at 100 °C for 30 minutes. Then, under a helium flow containing water vapor by passing through a bubbler, it was treated at 125 °C for 60 minutes to remove ammonia adsorbed at weak acid sites. Then, after purging at 100 °C under a helium flow, the temperature was raised at 10 °C / min under a helium flow, and the temperature-programmed desorption amount was measured. A quadrupole mass spectrometer (trade name: BELMASS, manufactured by MicrotracBEL Corporation) was used as the detector. The peak derived from the acid site near the desorption temperature of 370 °C in the obtained temperature-programmed desorption curve was fitted with a Gaussian function, and the amount of acid was obtained by determining the ammonia desorption amount from the area.

[0051] ~Hydrocarbon compound production apparatus and its production method~ The MFI-type zeolite obtained by the examples, the catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds containing the same, was used to produce light hydrocarbon compounds and aromatic compounds by the following method and evaluated.

[0052] A fixed-bed gas-phase flow-through reactor using a stainless steel reaction tube (inner diameter 16 mm, length 600 mm) was used. In the middle section of each of the stainless steel reaction tubes, a catalyst for simultaneous production was filled, and after performing a heat pretreatment under a dry air flow, the raw material liquid was supplied together with nitrogen, which was the carrier gas. The stainless steel reaction tube was immediately heated to 200 °C at the inlet so that the raw material liquid reached the catalyst-filled part as a gas. Note that the apparatus conditions and operating conditions of the reactor are not limited to the conditions described in this example and can be appropriately selected. Then, heating was performed using a ceramic tubular furnace to control the temperature of the catalyst layer. The reaction outlet gas and the reaction liquid were collected, and the gas components and the liquid components were analyzed individually using a gas chromatograph. The gas components were analyzed using a gas chromatograph equipped with a TCD detector (manufactured by Shimadzu Corporation, (trade name) GC-14B) and a gas chromatograph equipped with an FID detector (manufactured by Shimadzu Corporation, (trade name) GC-14A). As the packing material of the gas chromatograph equipped with a TCD detector (manufactured by Shimadzu Corporation, (trade name) GC-14B), MS-5A (trade name) manufactured by GL Sciences Inc. was used. As the separation column of the gas chromatograph equipped with an FID detector (manufactured by Shimadzu Corporation, (trade name) GC-14A), CP-Al2O3 / KCl (trade name) manufactured by Agilent Technologies was used. The liquid components were analyzed using a gas chromatograph equipped with an FID detector (manufactured by Shimadzu Corporation, (trade name) GC-2025). As the separation column, TC-1 (trade name) manufactured by GL Sciences Inc. was used.

[0053] The reaction conditions were set as follows.

[0054] (Hydrocarbon compound production conditions) Catalyst temperature: 525 °C. Raw materials: An aliphatic hydrocarbon (a mixed solution of 26% by weight of methylcyclopentane, 16% by weight of hexane, 15% by weight of methylpentane, 8% by weight of cyclopentane, 7% by weight of cyclohexane, 4% by weight of pentane, 4% by weight of methylcyclohexane, 4% by weight of dimethylcyclopentane, 3% by weight of heptane, 3% by weight of methylhexane, 2% by weight of ethylcyclopentane, 1% by weight of butane, 1% by weight of dimethylbutane, 1% by weight of ethylcyclohexane, 1% by weight of octane, 1% by weight of nonane, and 3% by weight of others) was supplied at a rate of 0.136 ml / min, and nitrogen was supplied as a carrier gas at a flow rate of 50 ml / min. Catalyst weight: 3.75 g. Reaction pressure: 0.1 MPa.

[0055] Preparation Example 1 The production of MFI-type zeolite was carried out with reference to JP-A-2013-227203.

[0056] An amorphous aluminosilicate gel was added to an aqueous solution of tetrapropylammonium (hereinafter sometimes abbreviated as TPA) hydroxide and sodium hydroxide and suspended. An MFI-type zeolite was added as a seed crystal to the obtained suspension to obtain a raw material composition. The addition amount of the seed crystal at that time was 0.7% by weight based on the weights of Al2O3 and SiO2 in the raw material composition. Also, the by-produced ethanol was evaporated and removed.

[0057] The composition of the raw material composition is as follows. SiO2 / Al2O3 molar ratio = 48, TPA / Si molar ratio = 0.05, Na / Si molar ratio = 0.18, OH / Si molar ratio = 0.20, H2O / Si molar ratio = 10 The obtained raw material composition was sealed in a stainless steel autoclave and crystallized for 4 days while stirring at 115°C to obtain a slurry-like mixed solution. After the solid-liquid separation of the slurry-like mixed solution after crystallization with a centrifugal sedimentation machine, the solid particles were washed with a sufficient amount of pure water and dried at 110°C to obtain a dry powder.

[0058] The obtained dry powder was dispersed in 1 mol / l hydrochloric acid at room temperature, filtered, and then the solid particles were washed with a sufficient amount of pure water. After filtration again, it was dried at 100 °C overnight. After calcination at 550 °C for 1 hour under air, it was treated with 30% steam at 600 °C for 2 hours. The obtained powder was dispersed in 1 mol / l hydrochloric acid at room temperature, filtered, and then the solid particles were washed with a sufficient amount of pure water. After filtration again, zeolite was obtained.

[0059] The obtained MFI-type zeolite had an average particle size of 23 nm, an external surface acid amount of 0.003 mmol / g, and an acid amount of 0.28 mmol / g.

[0060] Preparation Example 2 To 100 parts by weight of the MFI-type zeolite obtained in Preparation Example 1, 43 parts by weight of silica (manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex N-30G), 4 parts by weight of cellulose, and 20 parts by weight of pure water were added and kneaded. Then, the kneaded product was made into a cylindrical shape with a diameter of 1.5 mm. After drying this at 100 °C overnight, it was made into a cylindrical molded body with a length of 4.5 to 8.5 mm (average length 6.6 mm). This was calcined at 550 °C for 1 hour under air. The obtained MFI-type zeolite had an average particle size of 23 nm, an external surface acid amount of 0.003 mmol / g, and an acid amount of 0.22 mmol / g.

[0061] Example 1 Ion exchange was carried out by putting 100 g of the MFI-type zeolite molded body obtained in Preparation Example 2 into an aqueous solution consisting of 6.42 g of gallium(III) nitrate n-hydrate and 327 g of water and stirring for 3 hours. Then, filtration and washing with water were carried out. After drying at 120 °C for 1 hour, a gallium-containing MFI-type zeolite catalyst was prepared by calcination at 500 °C for 2 hours. Next, an aqueous solution consisting of 0.172 g of tetraammineplatinum(II) nitrate and 8.2 g of water was dropped onto 10 g of the obtained gallium-containing MFI-type zeolite for loading by the impregnation method. Then, the solution was infiltrated under reduced pressure for 1 hour, dried at 110 °C for 7 hours, and then calcined at 550 °C for 6 hours to adjust the platinum·gallium-containing MFI-type zeolite. The platinum content with respect to the weight of the obtained platinum·gallium-containing MFI-type zeolite molded body was 0.8 wt%, and the gallium content was 0.3 wt%.

[0062] The obtained platinum-gallium-containing MFI zeolite has a 10-membered ring skeletal structure, the mesopore distribution curve in the pore size distribution curve has a peak, the half-width at half maximum of the peak of the uniform mesopores is 14 nm, and μ = 10 nm. Also, the pore volume of the uniform mesopores is 0.13 ml / g, and the ratio of the pore volume of the uniform mesopores to the total pore volume of the mesopores is 44%. In powder X-ray diffraction, there is no peak in the range of 0.1 to 3 degrees, the average particle size is 23 nm, the amount of external surface acid is 0.002 mmol / g, and the acid amount is 0.12 mmol / g.

[0063] The obtained platinum-gallium-containing MFI zeolite was used as a catalyst for hydrocarbon production, and the reaction was carried out for 48 hours according to the above. The average yields of each product component during the reaction are shown in Table 1. The average yield of ethane was 17.2% by weight, and the average yield of aromatic compounds (total of benzene, toluene, and xylene) was 36.3% by weight. It exhibited an excellent balance as a catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds.

[0064] Example 2 An aqueous solution consisting of 0.172 g of tetraammineplatinum(II) nitrate and 8.2 g of water was dropped onto 10 g of the MFI zeolite molded body obtained in Preparation Example 2, and supported by the impregnation method. Then, the solution was infiltrated under reduced pressure for 1 hour, dried at 110 °C for 7 hours, and then calcined at 550 °C for 6 hours to adjust the platinum-containing MFI zeolite. The platinum content based on the weight of the obtained platinum-containing MFI zeolite molded body was 0.7% by weight.

[0065] The obtained platinum-containing MFI zeolite has a 10-membered ring framework structure, the mesopore distribution curve in the pore size distribution curve has a peak, the half-width at half-maximum of the peak of the uniform mesopores is 14 nm, and μ = 10 nm. Also, the pore volume of the uniform mesopores is 0.13 ml / g, and the ratio of the pore volume of the uniform mesopores to the total pore volume of the mesopores is 44%. In powder X-ray diffraction, there is no peak in the range of 0.1 to 3 degrees, the average particle size is 23 nm, the amount of acid on the outer surface is 0.001 mmol / g, and the amount of acid is 0.14 mmol / g.

[0066] The obtained platinum-containing MFI zeolite was used as a catalyst for hydrocarbon production, and the reaction was carried out for 48 hours according to the above. The average yields of each product component during the reaction are shown in Table 1. The average yield of ethane was 6.8 wt%, and the average yield of aromatic compounds (total of benzene, toluene, and xylene) was 35.3 wt%. It exhibited an excellent balance as a catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds.

[0067] Comparative Example 1 Ion exchange was carried out by adding 100 g of the MFI zeolite molded body obtained in Preparation Example 2 to an aqueous solution consisting of 6.42 g of gallium(III) nitrate n-hydrate and 327 g of water and stirring for 3 hours. Then, filtration and washing with water were carried out, followed by drying at 120°C for 1 hour and then calcination at 500°C for 2 hours to prepare a gallium-containing MFI zeolite. The gallium content based on the weight of the obtained gallium-containing MFI zeolite molded body was 0.3 wt%.

[0068] The obtained gallium-containing MFI zeolite has a 10-membered ring framework structure, the mesopore distribution curve in the pore size distribution curve has a peak, the half-width at half-maximum of the peak of the uniform mesopores is 14 nm, and μ = 10 nm. Also, the pore volume of the uniform mesopores is 0.13 ml / g, and the ratio of the pore volume of the uniform mesopores to the total pore volume of the mesopores is 47%. In powder X-ray diffraction, there is no peak in the range of 0.1 to 3 degrees, the average particle size is 23 nm, the amount of acid on the outer surface is 0.001 mmol / g, and the amount of acid is 0.14 mmol / g.

[0069] The obtained gallium-containing MFI-type zeolite was used as a catalyst for hydrocarbon production, and the reaction was carried out for 48 hours according to the above. The average yields of each product component during the reaction are shown in Table 1. The average yield of ethane was 3.5% by weight, and the average yield of aromatic compounds (total of benzene, toluene, and xylene) was 45.1% by weight. Although the yield of aromatic compounds was high, the ethane yield was low, and the yield balance between light hydrocarbon compounds and aromatic compounds was poor.

[0070] Comparative Example 2 The MFI-type zeolite obtained in Preparation Example 2 was used as a catalyst for hydrocarbon production, and the production of light hydrocarbon compounds and aromatic compounds was carried out according to the above. The results are shown in Table 1. The average yield of ethane was 5.4% by weight, and the average yield of aromatic compounds (total of benzene, toluene, and xylene) was 36.1% by weight. The ethane yield was low, and the yield balance between light hydrocarbon compounds and aromatic compounds was poor.

[0071]

Table 1

Industrial Applicability

[0072] The novel MFI-type zeolite of the present invention contains at least a metal belonging to the platinum group and is characterized by mesopores. For example, when simultaneously producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, it is possible to achieve excellent productivity for each and a stable production method, and it is very useful industrially as a catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds.

Claims

1. A metal-containing MFI-type zeolite that satisfies the characteristics shown in the following (i) to (iii) and contains at least a metal belonging to the platinum group. (i) The mesopore distribution curve has a peak, the half-width (hw) of the peak satisfies hw ≤ 20 nm, the central value (μ) of the peak satisfies 10 nm ≤ μ ≤ 20 nm, and it has a group of mesopores with a mesopore volume (pv) of the mesopores corresponding to the peak satisfying 0.05 ml / g ≤ pv. (ii) It has no peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with the diffraction angle as 2θ. (iii) The average particle size (PD) satisfies PD ≤ 100 nm.

2. The metal-containing MFI-type zeolite according to Claim 1, further containing gallium.

3. The metal-containing MFI-type zeolite according to Claim 1 or 2, further satisfying the characteristics shown in the following (iv) and / or (v). (iv) The external surface acid amount is 0.0001 to 0.01 mmol / g. (v) The acid amount is 0.02 to 0.85 mmol / g.

4. The metal-containing MFI-type zeolite according to any one of Claims 1 to 3, wherein the content of the metal belonging to the platinum group is 0.05 to 5 wt%.

5. A catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds, comprising the metal-containing MFI-type zeolite according to Claims 1 to 4.

6. A method for producing a hydrocarbon compound, characterized in that an aliphatic hydrocarbon having 10 or less carbon atoms is contacted in the presence of the catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds according to Claim 5 and converted into light hydrocarbon and aromatic compounds.

7. The method for producing a hydrocarbon compound according to Claim 6, wherein the aliphatic hydrocarbon contains at least one selected from aliphatic hydrocarbons having 5 to 7 carbon atoms, the light hydrocarbon is ethane, and the aromatic compound is at least one selected from the group consisting of benzene, toluene, and xylene.

8. The method for producing a hydrocarbon compound according to Claim 6 or 7, wherein the aliphatic hydrocarbon contains aliphatic hydrocarbons derived from plants and / or chemical recycling.

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