MFI-type zeolite and hydrocarbon production catalyst containing the same

Abstract

To provide an 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 activity, selectivity, zinc volatilization suppression effect and durability at the time of the simultaneous production, as catalysts for simultaneous production.SOLUTION: An MFI type zeolite satisfies the following characteristics (i) to (vii): (i) containing 0.05-5 wt.% of zinc with respect to zeolite; (ii) containing one or more kinds of metal belonging to Group 8 to 11 elements, in which metal / zinc (weight ratio) that is a content is 0.1 to 0.5; (iii) 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; (iv) having no peak in a range of 0.1-3 degrees in powder X-ray diffraction measurement with a diffraction angle of 2θ; (v) an average particle diameter (PD) of PD≤100 nm; (vi) an outer surface acid amount of 0.01 mmol / g or less; and (vii) an acid amount of 0.02-0.85 mmol / g.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a specific MFI-type zeolite containing zinc and a specific metal. More specifically, it contains zinc and at least one metal selected from Group 8 to 11 elements in a specific ratio and satisfies specific characteristics. The MFI-type zeolite, and further relates to a hydrocarbon production catalyst that is a catalyst for simultaneously producing light hydrocarbon compounds and aromatic compounds with excellent performance in terms of activity, selectivity, zinc volatilization suppression effect, and durability when producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons.

Background Art

[0002] MFI-type zeolite is used as a highly selective catalyst that utilizes the 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 with 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 diameter 2 - 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 its production method have been proposed (see, for example, Patent Document 3). However, there are only a few reports of obtaining specific results by using zeolites with mesopores as catalysts, especially in reactions using relatively small molecules with 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 naturally, there is a limit to the production volume. Also, aromatic compounds can be produced by contacting an aliphatic hydrocarbon raw material with a catalyst mainly containing medium-pore 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 advantages of lower added value compared to the production method of aromatic compounds by pyrolysis and the ability to produce aromatic compounds from surplus hydrocarbon raw materials.

[0007] In addition, the development of catalysts used in the production of these aromatic compounds has also been carried out. In particular, efforts have been made to improve the activity and selectivity by incorporating zinc into zeolite. For example, zinc-containing MFI-type zeolite is known to exhibit high catalytic activity in the aromatic compound production reaction (see, for example, Patent Document 4). Also, as a catalyst for producing aromatic compounds from olefins under a hydrogen atmosphere, a medium-pore zeolite containing zinc and at least one metal selected from the group consisting of Group VIII and Group IB elements is provided (see, for example, Patent Documents 5 and 6). Furthermore, a medium-pore zeolite-based catalyst containing zinc and zinc aluminate has been reported as a catalyst for producing aromatic compounds using a hydrocarbon containing olefin paraffin, olefin, and naphthene as a raw material (see, for example, Patent Document 7).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

[0009] [Non - Patent Document 1] Microporous and Mesoporous Materials, Vol. 137, p. 92 (2011) [Non - Patent Document 2] Industrial & Engineering Chemistry Research, Vol. 31, p. 995 (1992) [Non - Patent Document 3] Industrial & Engineering Chemistry Research, Vol. 26, p. 647 (1987) [Non - Patent Document 4] Applied Catalysis, Vol. 78, p. 15 (1991) [Non - Patent Document 5] Microporous and Mesoporous Materials, Vol. 47, p. 253 (2001) [Summary of the Invention] [Problems to be Solved by the Invention]

[0010] However, in the zinc-containing zeolite catalyst proposed in Patent Document 4, zinc species are reduced during the reaction to form metallic zinc, which volatilizes due to its high vapor pressure. Therefore, deterioration of the catalyst performance due to a decrease in the zinc content has been a problem. In order to suppress this, in the method of suppressing zinc volatilization by introducing at least one metal selected from the group consisting of Group VIII and Group IB elements proposed in Patent Documents 5 and 6, the catalyst performance changes due to the introduction of the second element. Although it is suitable for the production of aromatic compounds, it has problems from the viewpoint of the production of light hydrocarbon compounds, and the durability of the catalyst has not been verified, and a method for suppressing catalyst deterioration due to coking or the like has not been studied.

[0011] In addition, the method proposed in Patent Document 7 is to maintain the catalyst performance for a long time by co-containing zinc aluminate that is difficult to be reduced. However, it is necessary to contain an excessive amount of zinc aluminate, and it is difficult to reduce the absolute amount of volatilized zinc.

[0012] Therefore, when simultaneously producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, there is a demand for the emergence of a catalyst for simultaneous production of aromatic compounds that can exhibit excellent performance in terms of activity, selectivity, zinc volatilization suppression effect, and durability, and a zeolite applicable thereto. In addition, the emergence of a hydrocarbon production catalyst applicable not only to petroleum-derived but also to plant-derived and / or chemical recycle-derived aliphatic hydrocarbons is desired.

Means for Solving the Problems

[0013] Therefore, as a result of intensive studies to solve the above problems, the present inventors have found that a specific MFI-type zeolite containing zinc and Group 8-11 elements, and the MFI-type zeolite can be used to produce light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons. It has been found that it becomes a catalyst for hydrocarbon production that exhibits excellent performance in terms of activity, selectivity, zinc volatilization suppression effect, and durability, and the present invention has been completed.

[0014] That is, the present invention relates to an MFI-type zeolite characterized by satisfying the following characteristics (i) to (vii). (i) It contains 0.05 to 5% by weight of zinc with respect to the zeolite. (ii) It contains one or more metals belonging to Groups 8 to 11, and the metal / zinc (weight ratio) as the content thereof is 0.1 to 0.5. (iii) 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 mesopore group with a mesopore volume (pv) of the mesopores corresponding to the peak satisfying 0.05 ml / g ≦ pv. (iv) It does not have a peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with the diffraction angle as 2θ. (v) The average particle diameter (PD) satisfies PD ≦ 100 nm. (vi) The amount of acid on the outer surface is 0.01 mmol / g or less. (vii) The amount of acid is 0.02 to 0.85 mmol / g.

[0015] The present invention will be described in detail below.

[0016] The MFI-type zeolite of the present invention contains zinc (hereinafter, may be referred to as Zn in some cases) and one or more metals belonging to Groups 8 to 11 (hereinafter, may be referred to as M in some cases), and is an MFI-type zeolite satisfying the above characteristics (i) to (vii).

[0017] The MFI-type zeolite of the present invention contains 0.05 to 5% by weight of Zn with respect to the zeolite. Here, when the Zn content is less than 0.05% by weight, the productivity of hydrocarbons becomes inferior when the zeolite is used as a catalyst for hydrocarbon production. On the other hand, when the Zn content exceeds 5% by weight, excessive Zn causes by-products such as coke, and the deterioration when used as a catalyst becomes remarkable. Also, as a method for introducing Zn, any of impregnation loading, ion exchange, and physical mixing methods is possible.

[0018] In addition, the MFI-type zeolite of the present invention contains, in addition to zinc, M which is at least one metal selected from Group 8 to 11 elements. Here, examples of M include at least one metal selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, and gold. Among them, copper, cobalt, and / or nickel are preferable. The content of M is such that (ii) M / Zn (weight ratio) = 0.1 to 0.5. Here, when M / Zn is less than 0.1, the volatilization of Zn when the zeolite is used as a catalyst cannot be sufficiently suppressed, and its deterioration becomes remarkable. On the other hand, when M / Zn exceeds 0.5, M becomes excessive, and the selectivity for hydrocarbons deteriorates when used as a catalyst for hydrocarbon production. Also, as a method for introducing the M, any of impregnation loading, ion exchange, and physical mixing methods is possible.

[0019] The MFI-type zeolite of the present invention has (iii) a mesopore distribution curve having a peak, and has a mesopore group with hw ≤ 20 nm, 10 nm ≤ μ ≤ 20 nm, and 0.05 ml / g ≤ pv. The mesopore referred to in the present invention is a mesopore defined by IUPAC and indicates a pore having a pore diameter in the range of 2 to 50 nm. The mesopore 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 mesopore can be obtained. For example, the following method can be used for the analysis.

[0020] Specifically, a method of analyzing the desorption process by the Barret-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pages 373 to 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 mesopore can be obtained.

[0021] 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 of the nitrogen gas desorption amount from the mesopores at the mesopore diameter value (d(V / m) / d(D)), it is possible to obtain the peak of the increase in the nitrogen desorption amount per unit mass at the mesopore diameter.

[0022] The MFI-type zeolite of the present invention comprises a zeolite having a group of mesopores with substantially uniform pore diameters. In the present invention, a 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 two times the standard deviation (2σ) from the central value μ of the Gaussian function obtained by approximating the maximum peak among the peaks related to the mesopores in the pore size distribution curve with the Gaussian function. Further, the pore volume pv of the uniform mesopores can be obtained by integrating the nitrogen gas desorption amount in the range of μ ± 2σ.

[0023] The MFI-type zeolite of the present invention has a peak in the pore size distribution curve of mesopores, and has a substantially uniform mesopore group with a small variation in pore diameter of zeolite having a peak of hw ≤ 20 nm, so that it has excellent reaction selectivity. The effect is more remarkable and preferable when hw ≤ 15 nm, particularly hw ≤ 10 nm. The lower limit of hw is not particularly set, but it is preferably 1 nm or more because it has more excellent reaction selectivity. When hw > 20 nm, its reaction selectivity is inferior when used as a catalyst for hydrocarbon production. Further, by including an MFI-type zeolite of 10 nm ≤ μ ≤ 20 nm, it becomes possible to selectively react even larger-sized molecules, and it becomes an excellent catalyst for hydrocarbon production. Furthermore, when pv ≥ 0.05 ml / g, it becomes a long-life catalyst for hydrocarbon production when used as a catalyst, preferably 0.05 ml / g ≤ pv ≤ 0.70 ml / g, particularly preferably 0.10 ml / g ≤ pv ≤ 0.70 ml / g, and 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 is inferior when used as a catalyst for hydrocarbon production.

[0024] Further, since it is suitable as a catalyst for hydrocarbon production that enables a particularly selective reaction, the MFI-type zeolite of the present invention preferably has 30% ≤ pvr ≤ 100%, and more preferably 40% ≤ pvr ≤ 100%.

[0025] The MFI-type zeolite of the present invention does not have a peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with the diffraction angle as 2θ. This indicates that there is no regularity in the arrangement between mesopores and there is no wall separating the mesopores, and when used as a catalyst for hydrocarbon production, mass transfer between mesopores becomes easy, so it becomes a catalyst for hydrocarbon production with excellent reaction efficiency.

[0026] In addition, the MFI-type zeolite of the present invention has a (v) PD ≦ 100 nm. In particular, since it also has excellent thermal stability, it is preferably 3 nm ≦ PD ≦ 100 nm, and more preferably 5 nm ≦ PD ≦ 100 nm. Here, if PD exceeds 100 nm, when the obtained MFI-type zeolite is used in the conversion reaction and isomerization reaction of aliphatic hydrocarbons, the reaction efficiency will be inferior.

[0027] Note that PD can be calculated and obtained from the external surface area of the MFI-type zeolite, for example, 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).) In addition, 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, the measurement points in the range of 0.6 to 1 nm for t are linearly approximated, and the external surface area of the zeolite is obtained from the slope of the obtained regression line.

[0028] The MFI-type zeolite of the present invention has a (vi) external surface acid amount of 0.01 mmol / g or less. Here, the external surface acid sites of the zeolite, as the name implies, indicate the acid sites present on the external surface of the zeolite. Usually, zeolites have acid sites on their external surface and in (micro) pores. If there are no acid sites on the external surface, it can be said that there are acid sites only in the (micro) pores. And, since it is particularly excellent in heat resistance, heat resistance to water, and durability, it is preferably a metal-containing MFI-type zeolite having an unmodified surface not coated with a silicate, a dialkylamine reagent, etc. Here, when the external surface acid amount exceeds 0.01 mmol / g, the catalyst life will be inferior when used as a catalyst for hydrocarbon production.

[0029] And, as for the confirmation of the 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 the acid sites (see Characterization of acid sites on the external surface of zeolites, Reaction Kinetics and Catalysis Letters, vol. 67, p. 281 (1999)).

[0030] The MFI-type zeolite of the present invention has (vii) an acid amount of 0.02 to 0.85 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, Catalysis, vol. 42, p. 218 (2000)). Here, when the acid amount is less than 0.02 mmol / g, the catalytic activity is inferior when used as a catalyst for hydrocarbon production. On the other hand, when it exceeds 0.85 mmol / g, the catalyst deterioration due to coking becomes remarkable when used as a catalyst for hydrocarbon production.

[0031] As a method for producing an MFI-type zeolite satisfying such (vi) and (vii), for example, it can be produced by dealuminating the aluminum in the framework of the MFI-type zeolite, which is a raw material satisfying the above (iii) to (v) 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 still more preferably 500 to 700 °C. The partial pressure of the steam is preferably 0.001 to 5 MPa, particularly preferably 0.01 to 0.5 MPa, and still more preferably 0.05 to 0.2 MPa. The concentration of the 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.

[0032] The MFI-type zeolite of the present invention may be any one as long as its SiO2 / Al2O3 ratio belongs to the category called MFI-type zeolite. Among them, when used in the conversion and isomerization reactions of aliphatic hydrocarbons, since it has excellent efficiency, those with SiO2 / Al2O3 = 20 to 300 are preferred. Particularly, since it has excellent heat resistance, reaction selectivity, and productivity, it is preferably SiO2 / Al2O3 = 30 to 200.

[0033] As a method for producing the MFI-type zeolite of the present invention, any method can be used as long as it can produce a zeolite that satisfies the characteristics described in (i) to (vii) above. And, as a method for selectively reducing or removing acid sites on the surface of the zeolite, that is, a zeolite having an external surface acid amount of 0.01 mmol / g or less, a method can be mentioned in which part or all of the firing (heat treatment) step in producing a zeolite that satisfies the characteristics of (i) to (ii) is used as a hydrothermal (steam) treatment step, and an ion exchange step is added before and after the firing step.

[0034] As a method for producing the MFI-type zeolite of the present invention, for example, it can be produced by containing Zn and M by methods such as impregnation loading, ion exchange, and physical mixing in the MFI-type zeolite.

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

[0036] By using the MFI-type zeolite of the present invention as a catalyst for hydrocarbon production, a catalyst excellent in efficiency such as reaction selectivity and productivity is obtained. For example, by contacting with aliphatic hydrocarbons, particularly aliphatic hydrocarbons having 10 or less carbon atoms, and more particularly aliphatic hydrocarbons having 4 to 6 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 butane, isobutane, pentane, hexane, etc.; olefinic such as butene, isobutene, pentene, hexene, etc.; alicyclic such as cyclohexane, and mixtures thereof, etc. 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, bio-naphtha, etc., 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, since it is an efficient reaction of light hydrocarbon compounds and aromatic compounds that suppresses the generation of by-products and does not require 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, 1 h -1 ~50000 h -1 The space velocity of about can be mentioned. When supplying aliphatic hydrocarbon as the 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, and for example, fixed beds, transport beds, fluidized beds, moving beds, multi-tubular reactors, as well as continuous flow type, batch flow type, and swing reactors, etc. can be used.

[0039] In addition, examples of the light hydrocarbon compounds produced include hydrocarbon compounds having 2 to 3 carbon atoms, specifically, ethane, ethylene, propane, propylene, etc., and ethane is particularly preferred. Further, as for the 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 mentioned, and benzene is particularly preferred.

Advantages of the Invention

[0040] The present invention relates to an MFI-type zeolite containing Zn and M. In particular, when simultaneously producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, it is also possible to obtain a hydrocarbon production catalyst that can specifically achieve a high yield, good balance, and a long catalyst life, and it is very useful industrially.

Examples

[0041] Hereinafter, specific examples of the present invention will be described as examples, but the present invention is not limited to these examples.

[0042] The MFI-type zeolite used in the examples was measured and defined by the following method.

[0043] ~Measurement of Metal Content~ The metal content was measured using an ICP device ((trade name) Optima 8300 manufactured by PerkinElmer Co., Ltd.). After accurately weighing the sample in a 100 ml polymesh flask, hydrofluoric acid, nitric acid, and ultrapure water were added and left to dissolve overnight. After making up the volume, a portion of the sample was taken and measured by ICP-AES, and the metal content was calculated from the calibration curve.

[0044] ~Measurement of Pore Distribution, Pore Diameter, and External Surface Area~ The pore distribution and pore diameter of the zeolite were measured by nitrogen adsorption measurement.

[0045] For the nitrogen adsorption measurement, a general nitrogen adsorption apparatus ((trade name) BELSOAP-max, manufactured by Nippon Bell Co., Ltd.) was used. The adsorption side was measured at intervals of relative pressure (P / P0) of 0.025. The desorption side was measured at intervals of relative pressure of 0.05. The external surface area was determined by the t-plot method by linearly approximating the range of the thickness of the adsorption layer (t = 0.6 to 1.0 nm). For the analysis of the pore distribution curve, BELMaster (ver. 2.3.1) manufactured by Nippon Bell Co., Ltd. was used.

[0046] The adsorption process of the nitrogen adsorption measurement was analyzed by the Saito-Foley method (AIChE Journal, 1991, Vol. 37, pp. 429 - 436), and a pore distribution curve of micropores was obtained, where the horizontal axis is a constant of the micropore diameter and the vertical axis is the differential value of the desorption amount of nitrogen gas.

[0047] Then, the desorption process of the nitrogen adsorption measurement was analyzed by the Barret-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pp. 373 - 380), and a pore 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.

[0048] Then, among the peaks of the differential value (d(V / m) / d(D)) of the mesopore diameter value of the desorption amount of nitrogen gas from the mesopores, 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).

[0049] ~Measurement of Powder X-ray Diffraction~ Using an X-ray diffractometer (manufactured by Spectris Co., Ltd., (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. Also, the background corrected by the absorption rate of the direct beam was removed.

[0050] The presence or absence of peaks can be confirmed visually, or a peak search program may be used. As the peak search program, a general program can be used. For example, when the measurement results with the horizontal axis being 2θ (degrees) and the vertical axis being intensity (a.u.) are smoothed with the Savitzky & Golay formula and the Sliding Polynomial filter and then second-order differentiation is performed, if there are three or more consecutive negative values, it is determined that a peak exists.

[0051] ~Measurement of average particle diameter~ The average particle diameter was calculated from the external surface area using the above formula (1). 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 from the nitrogen adsorption method at liquid nitrogen temperature.

[0052] ~Measurement of SiO2 / Al2O3 molar ratio~ The SiO2 / Al2O3 molar ratio of the zeolite was measured and determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a general ICP device ((trade name) OPTIMA3300DV, manufactured by PerkinElmer, Inc.) after dissolving the zeolite in a mixed aqueous solution of hydrofluoric acid and nitric acid.

[0053] ~2,4-Dimethylquinoline adsorption infrared absorption spectroscopic measurement~ The measurement of infrared absorption spectroscopy was carried out by combining a general FT-IR measurement device ((trade name) Varian 660-IR, manufactured by Agilent Technologies, Inc.) with parts for an IR measurement device under vacuum ((trade name) multimode cell, manufactured by S.T. Japan Co., Ltd.). After the sample was formed into a disk, it was placed in the cell, and 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 10 minutes, and after evacuating under vacuum 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.

[0054] ~Method for measuring acid amount~ The measurement of the acid amount was carried out using a general NH3-TPD apparatus ((trade name) BELCATII, manufactured by MicrotracBEL Corp.) and a gas analyzer ((trade name) BELMass, manufactured by MicrotracBEL Corp.). The sample was made into granules and then placed in the cell. The temperature was raised to 500 °C at 10 °C / min in a helium atmosphere and held for 1 hour. Then the temperature was lowered to 100 °C, and 0.2% ammonia gas was introduced for 30 minutes. The temperature was raised to 700 °C at 10 °C / min, and the desorbed ammonia was analyzed with a gas analyzer. The acid amount of the sample was calculated from the remaining desorption amount excluding the desorption amount derived from weak acids.

[0055] ~Hydrocarbon production apparatus and durability test method~ The MFI-type zeolite obtained according to the examples and the hydrocarbon production catalyst containing the same were subjected to a durability test in which hydrocarbon production and catalyst regeneration were repeated by the following method, and the evaluation was carried out.

[0056] A fixed-bed gas-phase flow reactor using a stainless steel reaction tube (inner diameter 16 mm, length 500 mm) was used. Hydrocarbon production catalysts were filled in the middle sections of each of the stainless steel reaction tubes, and after heat pretreatment under a dry air flow, the raw material gas was fed. 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 carried out using a ceramic tubular furnace to control the temperature of the catalyst layer. The reaction outlet gas was analyzed using a gas chromatograph.

[0057] The reaction conditions were set as follows.

[0058] (Hydrocarbon production conditions) Catalyst temperature: 600 °C. Flow gas: A mixed gas of 125 ml / min of 1-butene, 75 ml / min of 2-butene, 225 ml / min of isobutene, 50 ml / min of normal butane, 25 ml / min of isobutane, and 25 ml / min of nitrogen. Catalyst weight: 3.0 g. Reaction pressure: 0.1 MPa.

[0059] Also, after the reaction was carried out for a certain period of time, the generated coke was burned under the following conditions to regenerate the catalyst.

[0060] (Catalyst regeneration conditions) Catalyst temperature: 600 °C. Flow gas: 40 ml / min of dry air. Regeneration pressure: 0.1 MPa.

[0061] This hydrocarbon production and catalyst regeneration were repeated 12 times, and the content of each metal in the extracted catalyst was measured according to the above.

[0062] Preparation Example 1 (Preparation of raw material zeolite) The production of MFI-type zeolite was carried out with reference to Japanese Patent Laid-Open No. 2013-227203.

[0063] 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 resulting 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 weight of Al2O3 and SiO2 in the raw material composition. Also, the by-produced ethanol was removed by evaporation.

[0064] 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 = 0.16, OH / Si molar ratio = 0.21, H2O / Si molar ratio = 10.

[0065] 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 mixture. After the crystallization, the slurry-like mixture was solid-liquid separated by a centrifugal sedimentation machine, and the solid particles were washed with a sufficient amount of pure water and dried at 110°C to obtain a dry powder. The obtained dry powder was dispersed in 1 mol / l hydrochloric acid, filtered, and dried. After calcination at 550°C for 1 hour under air, a calcination treatment including steam treatment at 600°C with 50% water vapor for 2 hours was performed. The obtained powder was dispersed in 1 mol / l hydrochloric acid, filtered, and washed to obtain an MFI-type zeolite.

[0066] The obtained MFI-type zeolite had an average particle size of 38 nm, an SiO2 / Al2O3 molar ratio of 55, and a total pore volume of mesopores of 0.45 ml / g. Also, the micropore distribution curve had a maximum value with the largest differential pore volume value at a pore diameter of 0.4125 nm. And the half-width of the peak of the uniform mesopores in the mesopore distribution curve was 16 nm, and the central value was 15 nm. Also, the pore volume of the uniform mesopores was 0.40 ml / g, and the ratio of the pore volume of the uniform mesopores to the total pore volume of the mesopores was 89%. Also, in the powder X-ray diffraction of the obtained MFI-type zeolite, no peak was present in the range of 0.1 to 3 degrees, indicating that the mesopores were irregularly connected. Also, the acid amount of the obtained MFI-type zeolite was 0.20 mmol / g.

[0067] 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 molded body with a diameter of 3 mm. After drying this at 100 °C overnight, it was made into a cylindrical molded body with a length of 4.5 to 7.5 mm (average length 6.0 mm). This was calcined in air at 550 °C for 1 hour. Also, the obtained MFI-type zeolite had an average particle diameter of 34 nm, an external surface acid amount of 0.003 mmol / g, and an acid amount of 0.14 mmol / g.

[0068] Example 1 100 g of the MFI-type zeolite molded body obtained according to Preparation Example 2 was immersed in an aqueous solution consisting of 15.9 g of zinc acetate, 1.2 g of copper(II) acetate monohydrate, and 100 ml of ion-exchanged water for 30 minutes. After filtering off the molded body, the temperature was raised to 110 °C at a heating rate of 10 °C / min and dried overnight, and then calcined at 550 °C for 5 hours under air circulation to obtain a zinc-copper-containing MFI-type zeolite. The zinc content of the obtained zinc-copper-containing MFI-type zeolite was 3.0% by weight, the copper content was 0.5% by weight, the external surface acid amount was 0.003 mmol / g, and the acid amount was 0.08 mmol / g.

[0069] A catalyst for hydrocarbon production containing the obtained zinc-copper-containing zeolite was prepared, and hydrocarbons were produced according to the above, and a durability test of the catalyst was also conducted. Table 1 shows the average yields of each product component between the first and twelfth reactions of the durability test. The average yield of ethane in the first run was 15.6 wt%, the average yield of benzene was 13.8 wt%, the average yield of ethane in the twelfth run was maintained at a high yield of 11.2 wt%, and the average yield of benzene was 14.7 wt%. The zinc content after the durability test was 1.3 wt%, and the copper content was 0.5 wt%. The zinc residual rate was 43%, the volatilization of zinc was suppressed, and it was a catalyst that maintained high catalytic activity and excellent selectivity in the balance between light hydrocarbon compounds and aromatic compounds over a long period. Each result is shown in Table 1. Also, Table 2 shows a graph relatively showing the catalyst life, catalytic activity, and balance of the product compounds based on the test results of the first and twelfth runs of the durability test.

[0070] Example 2 100 g of the MFI-type zeolite formed body obtained in Preparation Example 2 was immersed in an aqueous solution consisting of 15.9 g of zinc acetate, 2.3 g of cobalt nitrate hexahydrate, and 100 ml of ion-exchanged water for 30 minutes. After filtering off the formed body, the temperature was raised to 110 °C at a heating rate of 10 °C / min and dried overnight, and then calcined at 550 °C for 5 hours under air circulation to obtain zinc-cobalt-containing MFI-type zeolite. The zinc content of the obtained zinc-cobalt-containing MFI-type zeolite was 3.0 wt%, the cobalt content was 0.5 wt%, the external surface acid amount was 0.003 mmol / g, and the acid amount was 0.09 mmol / g.

[0071] A catalyst for hydrocarbon production containing the obtained zinc-cobalt-containing zeolite was prepared, and hydrocarbons were produced according to the above, and a durability test was also conducted. Table 1 shows the average yields of each product component between the first and twelfth reactions of the durability test. The average yield of ethane in the first run was 14.7 wt%, the average yield of benzene was 12.3 wt%, the average yield of ethane in the twelfth run maintained a high yield of 10.4 wt%, and the average yield of benzene was 13.7 wt%. The zinc content after the durability test was 1.2 wt%, and the cobalt content was 0.5 wt%. The zinc residual rate was 40%, the volatilization of zinc was suppressed, and it was a catalyst having selectivity to maintain high catalytic activity and excellent selectivity in the balance between light hydrocarbon compounds and aromatic compounds over a long period. Each result is shown in Table 1. Also, Table 2 shows a graph relatively showing the catalyst life, catalytic activity, and balance of the produced compounds based on the test results of the first and twelfth runs of the durability test.

[0072] Example 3 100 g of the MFI-type zeolite molded body obtained by Preparation Example 2 was immersed in an aqueous solution consisting of 15.9 g of zinc acetate, 2.3 g of nickel nitrate hexahydrate, and 100 ml of ion-exchanged water for 30 minutes. After filtering off the molded body, the temperature was raised to 110 °C at a heating rate of 10 °C / min and dried overnight, and then calcined at 550 °C for 5 hours under an air flow to obtain a zinc-nickel-containing MFI-type zeolite. The zinc content of the obtained zinc-nickel-containing MFI-type zeolite was 3.0 wt%, the nickel content was 0.4 wt%, the external surface acid amount was 0.003 mmol / g, and the acid amount was 0.09 mmol / g.

[0073] A catalyst for hydrocarbon production containing the obtained zinc-nickel-containing zeolite was prepared, and hydrocarbons were produced according to the above, and a durability test was also conducted. Table 1 shows the average yields of each product component between the first and twelfth reactions of the durability test. The average yield of ethane in the first reaction was 14.6 wt%, the average yield of benzene was 13.2 wt%, the average yield of ethane in the twelfth reaction maintained a high yield of 9.5 wt%, and the average yield of benzene was 14.3 wt%. After the durability test, the zinc content was 1.2 wt% and the nickel content was 0.4 wt%. The zinc residual rate was 40%, the volatilization of zinc was suppressed, and it was a catalyst having selectivity to maintain high catalytic activity and excellent selectivity in the balance of light hydrocarbon compounds and aromatic compounds over a long period. Each result is shown in Table 1. Also, Table 2 shows a graph relatively showing the catalyst life, catalytic activity, and balance of product compounds based on the test results of the first and twelfth durability tests.

[0074] Comparative Example 1 100 g of the MFI-type zeolite formed body obtained by Preparation Example 2 was immersed in an aqueous solution consisting of 15.9 g of zinc acetate and 100 ml of ion-exchanged water for 30 minutes. After filtering off the formed body, the temperature was raised to 110 °C at a heating rate of 10 °C / min and dried overnight, and then calcined at 550 °C for 5 hours under air circulation to obtain zinc-containing MFI-type zeolite. The zinc content of the obtained zinc-containing MFI-type zeolite was 3.1 wt%, the external surface acid amount was 0.003 mmol / g, and the acid amount was 0.08 mmol / g.

[0075] A catalyst for hydrocarbon production containing the obtained zinc-containing zeolite was prepared, and hydrocarbons were produced according to the above, and a durability test was also conducted. Table 1 shows the average yields of each product component between the first and twelfth reactions of the durability test. The average yield of ethane in the first reaction was 15.9 wt%, the average yield of benzene was 13.1 wt%, the average yield of ethane in the twelfth reaction decreased to 7.6 wt%, and the average yield of benzene was 14.8 wt%. After the durability test, the zinc content was 0.73 wt%. The zinc residual rate was 22%, the volatilization of zinc progressed significantly, and it was a catalyst inferior in terms of catalyst life. Each result is shown in Tables 1 and 2.

[0076] Comparative Example 2 100 g of the MFI-type zeolite molded body obtained by Preparation Example 2 was immersed in an aqueous solution consisting of 15.9 g of zinc acetate, 4.8 g of copper(II) acetate monohydrate, and 100 ml of ion-exchanged water for 30 minutes. After filtering off the molded body, the temperature was raised to 110°C at a rate of 10°C / min and dried overnight, and then calcined at 550°C for 5 hours under air circulation to obtain a zinc-copper-containing MFI-type zeolite. The zinc content of the obtained zinc-copper-containing MFI-type zeolite was 2.9% by weight, the copper content was 1.8% by weight, the external surface acid amount was 0.003 mmol / g, and the acid amount was 0.08 mmol / g.

[0077] A catalyst for hydrocarbon production containing the obtained zinc-copper-containing zeolite was prepared, and hydrocarbons were produced according to the above method, and a durability test was also conducted. Table 1 shows the average yields of each product component between the first and twelfth reactions of the durability test. The average yield of ethane in the first reaction was as low as 13.0% by weight, the average yield of benzene was 15.7% by weight, the average yield of ethane in the twelfth reaction further decreased to 8.5% by weight, and the average yield of benzene was 14.1% by weight. After the durability test, the zinc content was 1.3% by weight and the copper content was 1.8% by weight. The zinc residual rate was 41%, and although the volatilization of zinc was suppressed, the ethane yield was generally low, and it was a catalyst inferior in terms of selectivity. The respective results are shown in Tables 1 and 2.

[0078]

Table 1

[0079]

Table 2

Industrial Applicability

[0080] When the MFI-type zeolite of the present invention is used as a catalyst for hydrocarbon production, for example, when simultaneously producing light hydrocarbon compounds and aromatic compounds, it is possible to achieve excellent productivity for each and a stable production method, and its industrial value is extremely high.

Claims

1. An MFI-type zeolite characterized by satisfying the following characteristics (i) to (vii). (i) Containing 0.05 to 5% by weight of zinc with respect to the zeolite. (ii) Containing one or more metals belonging to Group 8 to 11 elements, and the metal / zinc (weight ratio) which is the content thereof being 0.1 to 0.

5. (iii) The mesopore distribution curve has a peak, the half-width (hw) of the peak being hw ≦ 20 nm, the central value (μ) of the peak being 10 nm ≦ μ ≦ 20 nm, and having a mesopore group in which the mesopore volume (pv) of the mesopores corresponding to the peak is 0.05 ml / g ≦ pv. (iv) Having no peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with the diffraction angle as 2θ. (v) The average particle diameter (PD) being PD ≦ 100 nm. (vi) The external surface acid amount being 0.01 mmol / g or less. (vii) The acid amount being 0.02 to 0.85 mmol / g.

2. SiO ２ / Al ２ O ３ The MFI-type zeolite according to claim 1, characterized in that the ratio of

3. The MFI-type zeolite according to Claim 1 or 2, characterized in that the metal belonging to Group 8 to 11 elements is copper, cobalt and / or nickel.

4. A catalyst for simultaneous production of light hydrocarbon compounds and aromatic compounds, comprising the MFI-type zeolite according to any one of Claims 1 to 3.

5. A method for producing hydrocarbon compounds, characterized by contacting an aliphatic hydrocarbon having 4 to 6 carbon atoms in the presence of the catalyst for simultaneous production of light hydrocarbon compounds and aromatic compounds according to Claim 4 to obtain light hydrocarbon compounds having 2 to 3 carbon atoms and aromatic compounds.

6. The method for producing hydrocarbon compounds according to Claim 5, characterized in that the light hydrocarbon compound is ethane and the aromatic compound is one or more selected from the group consisting of benzene, toluene and xylene.

7. The method for producing hydrocarbon compounds according to Claim 5 or 6, characterized in that the aliphatic hydrocarbon having 4 to 6 carbon atoms contains an aliphatic hydrocarbon derived from plants and / or chemical recycling.

Images