Method for producing hydrocarbon compounds

Abstract

To provide a method for producing simultaneously a light hydrocarbon compound and an aromatic compound having excellent activity, selectivity, metal volatilization inhibitory effect and durability from an aliphatic hydrocarbon compound serving as raw material.SOLUTION: A method for producing a hydrocarbon compound is to produce simultaneously a C2-3 light hydrocarbon compound and an aromatic hydrocarbon compound by bringing a C10 or less aliphatic hydrocarbon compound into contact with a metal substituted zeolite catalyst and a metal unsubstituted zeolite catalyst at 400-800°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for simultaneously producing light hydrocarbon compounds and aromatic hydrocarbon compounds. More specifically, by using a metal-substituted zeolite catalyst and a metal-unsubstituted zeolite catalyst, when simultaneously producing light hydrocarbon compounds and aromatic hydrocarbon compounds from aliphatic hydrocarbons, it becomes a method for producing hydrocarbon compounds that is excellent in activity, selectivity, metal volatilization suppression effect, and durability.

Background Art

[0002] Benzene, toluene, xylene (hereinafter, may be collectively referred to as aromatic hydrocarbon compounds in some cases) 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 hydrocarbon compounds from the obtained pyrolysis products by distillation or extraction. In the production of aromatic hydrocarbon compounds by these production methods, aliphatic hydrocarbon compounds (including paraffinic, olefinic, acetylenic, and alicyclic) are included as pyrolysis products other than aromatic hydrocarbon compounds. Therefore, along with the production of aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds are simultaneously produced, so the production volume of aromatic hydrocarbon compounds is adjusted in proportion to the production volume of aliphatic hydrocarbon compounds, and naturally, there is a limit to the production volume. Also, aromatic hydrocarbon compounds can be produced by contacting an aliphatic hydrocarbon compound raw material with a catalyst mainly containing medium-pore-sized zeolite at a temperature of about 400°C to about 800°C (see, for example, Non-Patent Documents 1 to 4). This production method has the advantage that it can produce aromatic hydrocarbon compounds from surplus hydrocarbon compound raw materials, although it has a lower added value compared to the production method of aromatic hydrocarbon compounds by pyrolysis. Therefore, the development of catalysts capable of producing aromatic hydrocarbon compounds from such aliphatic hydrocarbon compounds has been carried out.

[0003] In particular, efforts have been made to improve the activity and selectivity of zeolites by incorporating metals into them. For example, zinc-containing MFI-type zeolites are known to exhibit high catalytic activity in the reaction of producing aromatic hydrocarbon compounds (see, for example, Patent Document 1). Furthermore, medium-pore zeolite catalysts containing zinc and zinc aluminate have been reported as catalysts for producing aromatic hydrocarbon compounds using hydrocarbons containing olefin paraffins, olefins, and naphthenes as raw materials (see, for example, Patent Document 2).

[0004] Furthermore, improving the production efficiency of light hydrocarbon compounds and aromatic hydrocarbon compounds contributes to promoting inclusive and sustainable industrialization, and is one of the technologies necessary for a sustainable society, such as the SDGs, which have been advocated in recent years. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent No. 3813330 [Patent Document 2] Japanese Patent Application Publication No. 10-33987 [Non-patent literature]

[0006] [Non-Patent Document 1] Industrial & Engineering Chemistry Research, Vol. 31, p. 995 (1992) [Non-Patent Document 2] Industrial & Engineering Chemistry Research, Vol. 26, p. 647 (1987) [Non-Patent Document 3] Applied Catalysis Vol. 78, p. 15 (1991) [Non-Patent Document 4] Microporous and Mesoporous Materials, Vol. 47, p. 253 (2001) [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the zinc-containing zeolite catalyst proposed in Patent Document 1 is problematic because the zinc species is reduced to metallic zinc during the reaction, and its high vapor pressure causes it to volatilize, leading to a decrease in catalytic performance due to the reduction of zinc content.

[0008] Furthermore, the method proposed in Patent Document 2 maintains catalytic performance over the long term by including zinc aluminate, which is difficult to reduce. However, this requires including an excess amount of zinc aluminate, making it difficult to reduce the absolute amount of zinc that volatilizes.

[0009] Therefore, there is a need for a manufacturing method that offers excellent activity, selectivity, suppression of metal volatilization, and durability when simultaneously producing light hydrocarbon compounds and aromatic hydrocarbon compounds from aliphatic hydrocarbon compounds. Furthermore, there is a desire for a manufacturing method for hydrocarbon compounds that can be applied not only to petroleum-derived aliphatic hydrocarbon compounds but also to plant-derived and / or chemically recycled aliphatic hydrocarbon compounds. [Means for solving the problem]

[0010] Therefore, the present inventors conducted diligent studies to solve the above problems and found that by using a metal-substituted zeolite catalyst and a metal-non-substituted zeolite catalyst in combination, a manufacturing method is obtained that exhibits excellent performance in terms of activity, selectivity, suppression of metal volatilization, and durability when producing light hydrocarbon compounds and aromatic hydrocarbon compounds from aliphatic hydrocarbon compounds, thus completing the present invention.

[0011] In other words, the present invention relates to a method for producing hydrocarbon compounds, characterized by contacting an aliphatic hydrocarbon compound having 10 or fewer carbon atoms with a metal-substituted zeolite catalyst and a metal-non-substituted zeolite catalyst under conditions of 400 to 800°C, thereby simultaneously producing a light hydrocarbon compound having 2 to 3 carbon atoms and an aromatic hydrocarbon compound.

[0012] The present invention will be described in detail below.

[0013] The present invention provides a method for producing hydrocarbon compounds, which involves contacting an aliphatic hydrocarbon compound as a raw material with a metal-substituted zeolite catalyst and a metal-non-substituted zeolite catalyst as catalysts, thereby simultaneously producing a light hydrocarbon compound and an aromatic hydrocarbon compound.

[0014] The aliphatic hydrocarbon compounds used as raw materials in this process are aliphatic hydrocarbon compounds having 10 or fewer carbon atoms, and any compound belonging to this category is acceptable. Examples include paraffinic compounds such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, and nonane; olefinic compounds such as ethylene, propylene, butene, pentene, hexene, heptene, octane, and nonene; acetylene compounds such as acetylene; and alicyclic compounds such as cyclopropane, cyclobutane, cyclopentane, methylcyclopentane, and cyclohexane. Among these, aliphatic hydrocarbon compounds having 4 to 9 carbon atoms are preferred because they can selectively and efficiently produce benzene. Specifically, examples include paraffinic compounds such as butane, hexane, heptane, octane, and nonane; olefinic compounds such as butene, pentene, hexene, heptene, octane, and nonene; alicyclic compounds such as cyclobutane, cyclopentane, methylcyclopentane, cyclohexane, and methylcyclohexane, as well as mixtures thereof. Here, if the hydrocarbon compound has more than 10 carbon atoms, its selectivity will be inferior to that of benzene. These aliphatic hydrocarbon compounds may be petroleum-derived, such as naphtha, plant-derived, such as bioethanol and bionaphtha, or derived from chemical recycling of resins, such as polyolefins, polyvinyl chloride, acrylics, and polystyrene.

[0015] The light hydrocarbon compound produced by the manufacturing method of the present invention is a light hydrocarbon compound having 2 to 3 carbon atoms, specifically ethane, ethylene, propane, propylene, etc., with ethane or ethylene being particularly preferred. Furthermore, there are no particular restrictions on the aromatic hydrocarbon compound as long as it belongs to the category referred to as an aromatic hydrocarbon compound, for example benzene, toluene, xylene, trimethylbenzene, ethylbenzene, propylbenzene, butylbenzene, naphthalene, methylnaphthalene, etc., with benzene, toluene, and xylene being particularly preferred.

[0016] In the manufacturing method of the present invention, a metal-substituted zeolite catalyst and a metal-unsubstituted zeolite catalyst are used in combination as catalysts. The ratio of the metal-substituted zeolite catalyst to the metal-unsubstituted zeolite catalyst (by weight) is arbitrary, but it is preferable that the production ratio of light hydrocarbon compounds and aromatic hydrocarbon compounds is well-balanced and efficient, so a ratio of metal-substituted zeolite catalyst to metal-unsubstituted zeolite catalyst (by weight) of 10 / 100 to 1000 / 10 is preferred.

[0017] Furthermore, there are no particular restrictions on the zeolites that constitute the catalysts of the metal-substituted zeolite catalyst and the metal-unsubstituted zeolite catalyst, as long as they belong to the category called zeolite. Examples include zeolites such as AEL, CHA, EUO, FER, HEU, IMF, LTF, MEU, MEL, MFI, MOR, NES, and UFI. Zeolites having a 10-membered ring structure are particularly preferred, especially MFI type or MEL type, as they exhibit excellent activity for the simultaneous production of light hydrocarbon compounds and aromatic hydrocarbon compounds. For example, an MFI type can be an aluminosilicate compound belonging to the structural code MFI as defined by the International Zeolite Society. These zeolites are normally referred to as proton type and, since they are not substituted with metal, they can constitute a metal-unsubstituted zeolite catalyst. Furthermore, when constructing a metal-substituted zeolite catalyst, zeolites can be used that have been substituted with metals such as gallium, silver, calcium, platinum, or zinc by methods such as impregnation, ion exchange, or physical mixing, and zeolites substituted with zinc are particularly preferred. When using metal-substituted zeolite catalysts or metal-non-substituted zeolite catalysts, these zeolites and metal-substituted zeolites can be used as catalysts as they are, compressed and molded into specific shapes, or mixed with a binder and molded into specific shapes.

[0018] Then, as the zeolite constituting the metal-substituted zeolite catalyst and the metal-unsubstituted zeolite catalyst, it is desirable to be an MFI-type zeolite having uniform mesopores because it exhibits excellent durability performance. 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. Having uniform mesopores means that the mesopore distribution curve has a peak, and it can be confirmed from the fact that the half-width (hw) of the peak is hw ≦ 20 nm. In particular, it is desirable to have a group of mesopores where the central value (μ) of the peak is 10 nm ≦ μ ≦ 20 nm and the mesopore volume (pv) of the mesopores corresponding to the peak is 0.05 ml / g ≦ pv. 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.

[0019] 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. 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.

[0020] In addition, the MFI-type zeolite preferably comprises a zeolite having a mesopore group with substantially uniform pore diameters. In the present invention, the mesopore group with substantially uniform pore diameters may be referred to as uniform mesopores. Specifically, the uniform mesopores refer to mesopores having a pore diameter within the range of μ ± 2σ (where μ is the central value of the Gaussian function obtained by approximating the maximum peak among the peaks related to the mesopores in the pore size distribution curve with a Gaussian function and 2σ is twice the standard deviation). Further, the pore volume pv of the uniform mesopores can be determined by integrating the amount of nitrogen gas desorbed in the range of μ ± 2σ.

[0021] As the MFI-type zeolite, since it has excellent reaction selectivity, it has a peak in the pore size distribution curve of the mesopores, and it preferably has a substantially uniform mesopore group with a small variation in the pore diameter of the zeolite having a pore diameter of hw ≦ 20 nm or less, particularly preferably hw ≦ 15 nm, and more preferably hw ≦ 10 nm. The lower limit of hw is not particularly set, but it is preferably 1 nm or more because it has better reaction selectivity. Further, since it enables a particularly selective reaction, the proportion (pvr) of the MFI-type zeolite in the total pore volume of pv is preferably 30% ≦ pvr ≦ 100%, and more preferably 40% ≦ pvr ≦ 100%.

[0022] As the MFI-type zeolite, since stable production over a long period is possible, it preferably has an acid amount of 0.02 to 0.85 mmol / g. The acid amount 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, see Catalyst, vol. 42, p. 218 (2000)).

[0023] Furthermore, when the MFI-type zeolite is a metal-substituted MFI-type zeolite, it is preferable that the surface acid content be 0.01 mmol / g or less, as this enables stable production over a long period of time. Here, the surface acid spots of the zeolite refer to acid spots present on the outer surface of the zeolite, as the term suggests. Normally, zeolites have acid spots on their outer surface and within their (micro)pores, and having no acid spots on the outer surface means that acid spots are present only within the (micro)pores. In particular, it is preferable that the metal-substituted MFI-type zeolite has an unmodified surface that is not coated with silicate, dialkylamine reagent, etc., as this results in excellent heat resistance, hot water resistance, and durability. As a method for selectively reducing or removing acid spots on the zeolite surface, one method is to replace part or all of the calcination (heat treatment) process in the production of the zeolite with a hydrothermal (steam) treatment process, and if metal substitution is introduced, to add an ion exchange process before or after the calcination process.

[0024] Furthermore, any method that allows for the confirmation of acid sites on the outer surface of zeolites can be used. For example, they can be confirmed by the adsorption of 2,4-dimethylquinoline, which has adsorption properties for acid sites (see Characterization of acid sites on the external surface of zeolites, Reaction Kinetics and Catalysis Letters, vol.67, p.281 (1999)).

[0025] For the metal-substituted MFI type zeolite, it is desirable that the average particle size (PD) be PD ≤ 100 nm, as this enables stable manufacturing. In particular, since it also exhibits excellent thermal stability, it is desirable that the PD be 3 nm ≤ 100 nm, and even more desirable that it be 5 nm ≤ 100 nm.

[0026] Furthermore, PD can be calculated, for example, from the outer surface area of ​​an MFI-type zeolite using the following formula (1). PD = 6 / S(1 / 2.29 × 10 6 +0.18 × 10 -6 ) (1) (Here, S is the external surface area (m²) 2 This indicates / g). Also, the external surface area (S(m)) in equation (1) 2 The amount of nitrogen adsorption ( / g) can be determined using a general nitrogen adsorption method at liquid nitrogen temperature and the t-plot method. For example, when t is the thickness of the adsorbed amount, measurement points in the range of 0.6 to 1 nm are approximated by a straight line, and the outer surface area of ​​the zeolite is determined from the slope of the resulting regression line.

[0027] The acid content of zeolite can be adjusted by dealuminizing the aluminum in the skeleton using steam or the like. The steam treatment temperature is preferably 400 to 900°C, more preferably 450 to 800°C, and even more preferably 500 to 700°C. The partial pressure of the steam is preferably 0.001 to 5 MPa, more preferably 0.01 to 0.5 MPa, and even more preferably 0.05 to 0.2 MPa. The steam concentration is preferably 0.01 to 100 vol% water vapor / dilution gas. The dilution gas can be an inert gas such as nitrogen, air, oxygen, carbon monoxide, carbon dioxide, or a mixture thereof. The steam treatment time can be arbitrarily selected.

[0028] The metal-substituted MFI type zeolite is preferably a zinc-substituted MFI type zeolite because it offers excellent efficiency and stable manufacturing, and it is desirable that it contains 0.05 to 5% by weight of zinc relative to the zeolite. In addition, the metal-non-substituted type zeolite in this invention may be a so-called proton-type zeolite that does not contain any metal.

[0029] The present invention provides a method for producing hydrocarbon compounds, which involves contacting an aliphatic hydrocarbon compound having 10 or fewer carbon atoms with a metal-substituted zeolite catalyst and a metal-unsubstituted zeolite catalyst at 400 to 800°C. Below 400°C, it becomes difficult to efficiently produce light hydrocarbon compounds and aromatic hydrocarbon compounds. Above 800°C, side reactions and carbonization are accelerated. There are no restrictions on the reaction pressure; for example, operation is possible within a pressure range of approximately 0.05 MPa to 5 MPa. Furthermore, the supply of the aliphatic hydrocarbon compound, which is the reaction raw material, to the catalyst is not particularly limited in terms of the ratio of the volume of the raw material gas to the volume of the catalyst; for example, 1 h -1 ~50,000h -1 A certain degree of space velocity can be increased. When supplying aliphatic hydrocarbon compounds as source gases, they can be used as single gases, mixed gases, or diluted with single or mixed gases selected from inert gases such as nitrogen, hydrogen, carbon monoxide, and carbon dioxide.

[0030] Furthermore, there are no restrictions on the reaction type used in manufacturing. For example, fixed-bed reactors, transport-bed reactors, fluidized-bed reactors, moving-bed reactors, multi-tube reactors, as well as continuous-flow reactors, intermittent-flow reactors, and swing-type reactors can be used. However, a fixed-bed gas-phase flow reactor is preferred because it offers excellent productivity and enables stable production.

[0031] Furthermore, there are no restrictions on how the metal-substituted zeolite catalyst and the metal-non-substituted zeolite catalyst are packed into the reactor; they may be mixed and packed together or packed individually. In particular, it is preferable to pack the metal-substituted zeolite catalyst upstream of the raw material supply flow and the metal-non-substituted zeolite catalyst downstream of the metal-substituted zeolite catalyst, as this results in a stable production method that suppresses metal scattering. When multiple reactors are used, the metal-substituted zeolite catalyst may be packed into the upstream reactor and the metal-non-substituted zeolite catalyst into the downstream reactor. Examples of reactors in this case include single-tube reactors and multi-tube reactors.

[0032] Furthermore, improving the production efficiency of light hydrocarbon compounds and aromatic hydrocarbon compounds contributes to promoting inclusive and sustainable industrialization and is one of the technologies necessary for a sustainable society, such as the SDGs, which have been advocated in recent years. In particular, it can contribute to achieving SDG Goal 9 (Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation). [Effects of the Invention]

[0033] The present invention relates to a method for simultaneously producing light hydrocarbon compounds and aromatic hydrocarbon compounds. More specifically, by using a metal-supported zeolite catalyst and a metal-unsupported zeolite catalyst, the present invention provides a method for producing hydrocarbon compounds that are excellent in activity, selectivity, zinc volatilization inhibition effect, and durability when producing light hydrocarbon compounds and aromatic hydrocarbon compounds from aliphatic hydrocarbon compounds. [Examples]

[0034] The following describes specific examples of the present invention, but the present invention is not limited to these examples.

[0035] The zeolites used in the examples were measured and defined by the following method.

[0036] ~Measurement of metal content~ The amount of metal supported was measured using an ICP instrument (product name Optima 8300, manufactured by PerkinElmer, Inc.). After accurately weighing the sample into a 100 ml polyvolume flask, hydrofluoric acid, nitric acid, and ultrapure water were added and allowed to stand overnight to dissolve. After making up the volume, the sample was divided and measured by ICP-AES, and the metal content was calculated from the calibration curve.

[0037] ~Measurement of pore distribution, pore diameter, and outer surface area~ The pore distribution and pore diameter of the zeolite were measured by nitrogen adsorption measurement.

[0038] For nitrogen adsorption measurements, a general nitrogen adsorption apparatus (product name BELSOAP-max, manufactured by Nippon Bell Co., Ltd.) was used. The adsorption side was measured at 0.025 intervals of relative pressure (P / P0), and the desorption side was measured at 0.05 intervals of relative pressure. The outer surface area was determined by linear approximation of the adsorption layer thickness (t=0.6~1.0 nm) using the t-plot method. For pore distribution curve analysis, BELMaster (ver.2.3.1) manufactured by Nippon Bell Co., Ltd. was used.

[0039] The adsorption process for nitrogen adsorption measurements was analyzed using the Saito-Foley method (AIChE Journal, 1991, Vol. 37, pp. 429-436), and a pore distribution curve of micropores was obtained, with the horizontal axis representing the constant of the pore microdiameter and the vertical axis representing the differential value of the nitrogen gas desorption amount.

[0040] The desorption process of nitrogen adsorption measurements was then analyzed using the Barret-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pp. 373-380), and a pore distribution curve of mesopores was obtained, with the x-axis representing the constant of pore diameter and the y-axis representing the differential value of nitrogen gas desorption. The total pore volume of the mesopores was determined by integrating the nitrogen gas desorption amounts in the range of 2 nm to 50 nm.

[0041] Then, the largest peak among the differential values ​​(d(V / m) / d(D)) of nitrogen gas desorption from mesopores with respect to the mesopore diameter was analyzed using the intensity approximation of a Gaussian function. Mesopores with diameters within a range of 2 times the standard deviation (2σ) from the center value (μ) of the Gaussian function (=μ±2σ) were defined as uniform mesopores. The pore volume of uniform mesopores was determined by integrating the nitrogen gas desorption amounts within a range of ±2σ from the center value (μ).

[0042] ~Measurement of average particle diameter~ The average particle diameter was calculated from the outer surface area using the above equation (1). In equation (1), S is the outer surface area (m²). 2 The outer surface area (S(m²)) is given by equation (1), where PD is the average particle diameter (m). 2 The g (g) was determined by t-plot analysis using the nitrogen adsorption method at liquid nitrogen temperature.

[0043] ~Measurement of SiO2 / Al2O3 molar ratio~ The SiO2 / Al2O3 molar ratio of the zeolite was determined by dissolving the zeolite in a mixed aqueous solution of hydrofluoric acid and nitric acid, and then measuring it using inductively coupled plasma atomic emission spectroscopy (ICP-AES) with an ICP instrument (product name OPTIMA3300DV, manufactured by PerkinElmer).

[0044] ~Infrared absorption spectroscopy measurement of 2,4-dimethylquinoline adsorption~ Infrared absorption spectroscopy measurements were performed using an FT-IR analyzer (product name: Varian 660-IR, manufactured by Agilent Technologies, Inc.) combined with a vacuum-operated IR analyzer component (product name: Multimode Cell, manufactured by ST Japan Co., Ltd.). After forming the sample into a disk, it was placed in the cell and heated to 400°C at a rate of 10°C / min under vacuum evacuation, and held for 2 hours. After cooling to 150°C, the infrared absorption spectrum before 2,4-dimethylquinoline adsorption was measured. 2,4-dimethylquinoline gas was introduced and adsorption was allowed for 10 minutes. After vacuum evacuation at 150°C for 1 hour, the infrared absorption spectrum after 2,4-dimethylquinoline adsorption was measured. The difference between the infrared absorption spectrum after 2,4-dimethylquinoline adsorption and the spectrum before adsorption was taken to measure the change in infrared absorption due to adsorption.

[0045] ~Method for measuring acid content~ Acid content was measured using an NH3-TPD instrument (product name BELCATII, manufactured by Microtrac-Bell Co., Ltd.) and a gas analyzer (product name BELMass, manufactured by Microtrac-Bell Co., Ltd.). The sample was granulated, placed in a cell, and heated to 500°C at 10°C / min under 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 ammonia released was analyzed using a gas analyzer. The acid content of the sample was calculated from the remaining amount of released ammonia after excluding the amount released from weak acids.

[0046] ~Hydroxide Compound Manufacturing Apparatus and Durability Testing Method~ Durability tests were conducted by repeatedly producing hydrocarbon compounds and regenerating catalysts using the zeolite obtained from the preparation example and the catalyst containing it, and the results were evaluated.

[0047] A fixed-bed gas-phase flow reactor was used, consisting of stainless steel reaction tubes (16 mm inner diameter, 900 mm length). In each of the middle sections of the stainless steel reaction tubes, a metal-supported zeolite catalyst was packed in the upper section and a metal-unsupported zeolite catalyst in the lower section. After pre-treatment with heating under dry air flow, the raw material gas was fed in from the top. Note that the reactor's equipment and operating conditions are not limited to those described in this example and can be selected as appropriate. Heating was performed using a ceramic tubular furnace to control the catalyst layer temperature. The reaction outlet gas was analyzed using a gas chromatograph.

[0048] The reaction conditions were set as follows.

[0049] (Hydrogen compound manufacturing conditions) Catalyst temperature: 530℃. Flowing gas: A mixed gas of 1-butene 125 ml / min, 2-butene 75 ml / min, isobutene 225 ml / min, n-butane 50 ml / min, and isobutane 25 ml / min. Catalyst weight: 70.0g. Reaction pressure: 0.1 MPa.

[0050] Furthermore, after the reaction was carried out for a certain period of time, the catalyst was regenerated by burning the generated coke under the following conditions.

[0051] (Catalyst regeneration conditions) Catalyst temperature: 530℃. Flowing gas: Dry air 570 ml / min. Regeneration pressure: 0.1 MPa.

[0052] The production of this hydrocarbon compound and catalyst regeneration were repeated six times, and the content of each metal in the extracted catalyst was measured according to the above procedure.

[0053] Preparation Example 1 (Preparation of Base Zeolite) We manufactured MFI-type zeolite with reference to Japanese Patent Publication No. 2013-227203.

[0054] An amorphous aluminosilicate gel was added to an aqueous solution of tetrapropylammonium (hereinafter sometimes abbreviated as TPA) hydroxide and sodium hydroxide and suspended. MFI-type zeolite was added to the resulting suspension as a seed crystal to prepare the raw material composition. The amount of seed crystal added was 0.7% by weight relative to the weight of Al2O3 and SiO2 in the raw material composition. The by-product ethanol was removed by evaporation.

[0055] The composition of the raw material 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.

[0056] The obtained raw material composition was sealed in a stainless steel autoclave and crystallized at 115°C with stirring for 4 days to obtain a slurry mixture. After crystallization, the slurry mixture was separated into solid and liquid components using a centrifugal sedimentation machine, the solid particles were washed with a sufficient amount of pure water, and the mixture was 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.

[0057] 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 0.45 ml / g for the mesopores. The micropore distribution curve showed a maximum value with the largest differential pore volume at a pore diameter of 0.4125 nm. The full width at half maximum of the uniform mesopore peak in the mesopore distribution curve was 16 nm, and the central value was 15 nm. The pore volume of these uniform mesopores was 0.40 ml / g, and the proportion of the pore volume of uniform mesopores to the total pore volume was 89%. Powder X-ray diffraction of the obtained MFI-type zeolite showed no peaks in the range of 0.1 to 3 degrees, indicating that the mesopores were irregularly connected. The acid content of the obtained MFI-type zeolite was 0.20 mmol / g.

[0058] Preparation Example 2 (Base Zeolite Molded Body) 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., product name Snowtex N-30G), 4 parts by weight of cellulose, and 20 parts by weight of pure water were added and kneaded. The kneaded mixture was then molded into a cylindrical body with a diameter of 3 mm. After drying this at 100°C overnight, it was molded into cylindrical bodies with a length of 4.5 to 7.5 mm (average length 6.0 mm). This was then calcined in air at 550°C for 1 hour. The resulting zeolite molded body had an average particle size of 34 nm, an outer surface acid content of 0.003 mmol / g, an acid content of 0.16 mmol / g, and contained MFI-type zeolite with a uniform mesopore distribution curve, a half-width of 16 nm, a central value of 15 nm, and a mesopore volume of 0.40 ml / g.

[0059] Preparation Example 3 3.00 kg of the MFI-type zeolite molded body obtained according to Preparation Example 2 was immersed for 30 minutes in an aqueous solution consisting of 148 g of zinc acetate and 3750 ml of deionized water. After filtering the molded body, it was heated 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-substituted MFI-type zeolite molded body. The obtained zinc-substituted zeolite molded body contained zinc content of 1.1 wt%, outer surface acid content of 0.003 mmol / g, acid content of 0.08 mmol / g, and average particle size of 32 nm. The full width at half maximum of the peak of uniform mesopores in the mesopore distribution curve was 16 nm, the central value was 15 nm, and it contained zinc-substituted MFI-type zeolite with a mesopore volume of 0.40 ml / g.

[0060] Example 1 Using 46.7 g of zinc-substituted zeolite molded material obtained by Preparation Example 3 and 23.3 g of metal-unsubstituted zeolite molded material obtained by Preparation Example 2, hydrocarbon compounds were produced according to the above procedure, and a catalyst durability test was conducted. Table 1 shows the average yield of each product between the first and sixth reactions of the durability test. In the first reaction, the average yield of ethane was 10.7% by weight, and the average yield of benzene was 13.3% by weight. In the sixth reaction, the average yield of ethane was 7.2% by weight, and the average yield of benzene was 15.4% by weight, maintaining high yields. The average zinc content of the entire catalyst layer after the durability test was 0.66% by weight. The average zinc retention rate of the entire catalyst layer was 90%, indicating that zinc volatilization was suppressed, and high catalytic activity, excellent selectivity in the balance between light hydrocarbon compounds and aromatic hydrocarbon compounds, and excellent zinc retention rate were maintained over a long period. The results for each are shown in Table 1. In addition, Table 2 shows a graph that relatively shows the catalyst life, catalytic activity, and balance of product compounds based on the results of the first and sixth durability tests.

[0061] Example 2 Using 35.0 g of zinc-substituted zeolite molded material obtained by Preparation Example 3 and 35.0 g of metal-unsubstituted zeolite molded material obtained by Preparation Example 2, hydrocarbon compounds were produced according to the above procedure, and a catalyst durability test was conducted. Table 1 shows the average yield of each product component between the first and sixth reactions of the durability test. In the first reaction, the average yield of ethane was 10.0% by weight, and the average yield of benzene was 13.8% by weight. In the sixth reaction, the average yield of ethane was 6.5% by weight, and the average yield of benzene was 15.8% by weight, maintaining high yields. The average zinc content of the entire catalyst layer after the durability test was 0.50% by weight. The average zinc retention rate of the entire catalyst layer was 91%, indicating that zinc volatilization was suppressed, and high catalytic activity, excellent selectivity in the balance between light hydrocarbon compounds and aromatic hydrocarbon compounds, and excellent zinc retention rate were maintained over a long period. The results for each are shown in Table 1. In addition, Table 2 shows a graph that relatively shows the catalyst life, catalytic activity, and balance of product compounds based on the results of the first and sixth durability tests.

[0062] Comparative Example 1 Using 70.0 g of the zinc-substituted zeolite molded body obtained by Preparation Example 3, hydrocarbon compounds were produced according to the above procedure, and a catalyst durability test was conducted. Table 1 shows the average yields of each product between the first and sixth reactions of the durability test. The average yield of ethane in the first reaction was 10.1% by weight, and the average yield of benzene was 14.1% by weight. Although high yields were maintained, with an average yield of 8.0% by weight for ethane and 14.5% by weight for benzene in the sixth reaction, the average zinc content of the entire catalyst layer after the durability test was 0.80% by weight. The average zinc retention rate of the entire catalyst layer was 73%, which is low and suggests the possibility of catalyst degradation, resulting in inferior durability.

[0063] Comparative Example 2 Using 70.0 g of the metal-unsubstituted zeolite molded body obtained by Preparation Example 2, hydrocarbon compounds were produced according to the above procedure, and a catalyst durability test was conducted. Table 1 shows the average yields of each product between the first and sixth reactions of the durability test. In the first reaction, the average yield of ethane was 7.0% by weight and the average yield of benzene was 10.1% by weight. In the sixth reaction, the average yield of ethane was 6.0% by weight and the average yield of benzene was 10.3% by weight, both lower than the yield of aromatic hydrocarbon compounds. The results for each reaction are shown in Table 1. Furthermore, Table 2 shows a graph that relatively illustrates the catalyst lifetime and the balance between catalytic activity and the product compounds based on the results of the first and sixth durability tests.

[0064] [Table 1]

[0065] [Table 2] [Industrial applicability]

[0066] The present invention provides a method for producing hydrocarbon compounds that simultaneously manufactures light hydrocarbon compounds and aromatic hydrocarbon compounds. This method offers excellent activity, selectivity, metal volatilization inhibition, and durability, making it of extremely high industrial value.

Claims

1. A method for producing hydrocarbon compounds, comprising contacting an aliphatic hydrocarbon compound having 10 or fewer carbon atoms with a metal-substituted zeolite catalyst and a metal-non-substituted zeolite catalyst under conditions of 400 to 800°C, thereby simultaneously producing a light hydrocarbon compound having 2 to 3 carbon atoms and an aromatic hydrocarbon compound, For a supply flow of aliphatic hydrocarbon compounds with 10 or fewer carbon atoms, the catalyst is first brought into contact with a metal-substituted zeolite catalyst upstream, and then into contact with a metal-unsubstituted zeolite catalyst. A method for producing hydrocarbon compounds, characterized in that the metal-substituted zeolite catalyst is a zinc-substituted MFI-type zeolite or a catalyst containing the same, and the metal-unsubstituted zeolite catalyst is a proton-type MFI-type zeolite or a catalyst containing the same.

2. A method for producing a hydrocarbon compound according to claim 1, characterized in that the ratio of a metal-substituted zeolite catalyst to a metal-unsubstituted zeolite catalyst is 10 / 100 to 1000 / 100 (by weight).

3. A method for producing a hydrocarbon compound according to claim 1 or 2, characterized in that the metal-substituted zeolite catalyst is an MFI-type zeolite or catalyst containing the same that satisfies the following characteristics (i) to (v), and the metal-unsubstituted zeolite catalyst is an MFI-type zeolite or catalyst containing the same that satisfies the following characteristics (i) to (ii). (i) The mesopore distribution curve has a peak, the full width at half maximum (hw) of the peak is hw ≤ 20 nm, the center value (μ) of the peak is 10 nm ≤ μ ≤ 20 nm, and the mesopore volume (pv) of the mesopore corresponding to the peak is 0.05 ml / g ≤ pv. (ii) The acid content is 0.02 to 0.85 mmol / g. (iii) The amount of acid on the outer surface is 0.01 mmol / g or less. (iv) The average particle size (PD) is PD ≤ 100 nm. (v) Contains 0.05 to 5% by weight of zinc relative to the zeolite.

4. A method for producing a hydrocarbon compound according to any one of claims 1 to 3, characterized in that the light hydrocarbon compound having 2 to 3 carbon atoms is ethane, and the aromatic hydrocarbon compound is one or more selected from the group consisting of benzene, toluene, and xylene.

5. A method for producing a hydrocarbon compound according to any one of claims 1 to 4, characterized in that the aliphatic hydrocarbon compound having 10 or fewer carbon atoms includes aliphatic hydrocarbon compounds derived from plants and / or from chemical recycling.

6. The method for producing a hydrocarbon compound according to any one of claims 1 to 5, characterized in that the hydrocarbon compound is produced using a fixed-bed gas-phase flow reactor.

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