JP2023055080A - Mfi type zeolite and catalyst for hydrocarbon production containing the same - Google Patents

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

The present invention relates to a specific MFI-type zeolite containing zinc and a specific metal, more specifically zinc and at least one metal selected from Groups 8 to 11 elements in a specific ratio. and excellent in activity, selectivity, zinc volatilization suppression effect, and durability when producing light hydrocarbon compounds and aromatic compounds from MFI type zeolite that contains and satisfies specific characteristics, and also aliphatic hydrocarbons. The present invention relates to a catalyst for producing hydrocarbons, which is a catalyst for simultaneous production of light hydrocarbon compounds and aromatic compounds exhibiting excellent performance.

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).

These reactions mainly take advantage of the micropore characteristics of MFI-type zeolites. The micropores of MFI-type zeolite have an entrance diameter of approximately 0.5 nm, and are considered to be effective reaction fields for molecules having molecular diameters close to this pore diameter.

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

As a promising material 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 that specific results were obtained by using zeolite having mesopores as a catalyst, particularly in reactions using relatively small molecules having 10 or less carbon atoms as raw materials.

Benzene, toluene, and xylene (hereinafter sometimes collectively referred to as aromatic compounds) are often decomposed in a thermal cracking reactor from raw oil (for example, naphtha) obtained by petroleum refining. Then, the aromatic compound is separated and purified from the obtained thermal decomposition product by distillation or extraction. In the production of aromatic compounds by these production methods, thermal decomposition products other than aromatic compounds include aliphatic hydrocarbons (including paraffinic, olefinic, acetylenic, and alicyclic hydrocarbons). Therefore, since aliphatic hydrocarbons are produced simultaneously with the production of aromatic compounds, the production of aromatic compounds is adjusted according to the production of aliphatic hydrocarbons, and the production volume is naturally limited. It was something. In addition, an aromatic compound can be produced by contacting an aliphatic hydrocarbon raw material with a catalyst mainly containing medium pore size zeolite at a temperature of about 400° C. to about 800° C. (for example, non-patented References 2 to 5.). This production method has the advantage of being less value-added and capable of producing aromatic compounds from surplus hydrocarbon raw materials, as compared with a method of producing aromatic compounds by thermal decomposition.

In addition, development of catalysts used for producing these aromatic compounds is also underway. In particular, attempts have been made to improve the activity and selectivity of zeolites by incorporating zinc into them. For example, zinc-containing MFI-type zeolite is known to exhibit high catalytic activity in aromatic compound production reactions (see, for example, Patent Document 4). In addition, as a catalyst for producing aromatic compounds of olefins in a hydrogen atmosphere, a zeolite with medium pore diameter containing zinc and at least one metal selected from the group consisting of VIII and IB group elements is provided (e.g. , see US Pat. Furthermore, a medium pore size zeolite catalyst containing zinc and zinc aluminate has been reported as a catalyst for producing aromatic compounds using hydrocarbons containing olefin paraffins, olefins, and naphthenes as raw materials (for example, Patent Document 7. reference.).

Patent No. 4014279 Patent No. 2598127 JP 2013-227203 A U.S. Pat. No. 3,813,830 JP-A-54-24835 U.S. Pat. No. 4,167,293 JP-A-10-33987

Microporous and Mesoporous Materials Vol.137, p.92 (2011) Industrial & Engineering Chemistry Research Vol.31, p.995 (1992) Industrial & Engineering Chemistry Research Vol.26, p.647 (1987) Applied Catalysis Vol.78, p.15 (1991) Microporous and Mesoporous Materials Vol.47, p.253 (2001)

However, in the zinc-containing zeolite catalyst proposed in Patent Document 4, the zinc species are reduced during the reaction to become metallic zinc, which volatilizes due to its high vapor pressure. It has become. 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 IB elements proposed in Patent Documents 5 and 6, the introduction of a second element Although the catalyst performance changes and it is suitable for the production of aromatic compounds, there are problems from the viewpoint of the production of light hydrocarbon compounds, and the durability of the catalyst has not been verified, and catalyst deterioration due to coking etc. is suppressed. The method was not considered.

In addition, the method proposed in Patent Document 7 maintains the catalytic performance for a long period of time by containing zinc aluminate that is difficult to reduce, but it is necessary to contain an excessive amount of zinc aluminate, It was difficult to reduce the absolute amount of volatilized zinc.

Therefore, when simultaneously producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, it is possible to produce aromatic compounds that can exhibit excellent performance in terms of activity, selectivity, zinc volatilization suppression effect, and durability. The advent of co-production catalysts and zeolites applicable thereto is desired. In addition, there is a demand for a catalyst for producing hydrocarbons that can be applied not only to petroleum-derived but also to plant-derived and/or chemically recycled-derived aliphatic hydrocarbons.

Therefore, the present inventors have made intensive studies to solve the above problems, and as a result, a specific MFI-type zeolite containing zinc and Groups 8 to 11 elements, the MFI-type zeolite is an aliphatic hydrocarbon A carbonization catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds that exhibits excellent performance in terms of activity, selectivity, zinc volatilization suppression effect, and durability when producing light hydrocarbon compounds and aromatic compounds from The present inventors have found that it can be used as a catalyst for hydrogen production, and have completed the present invention.

That is, the present invention relates to an MFI-type zeolite characterized by satisfying the following properties (i) to (vii).
(i) Zinc is contained in an amount of 0.05 to 5% by weight based on the zeolite.
(ii) It contains one or more metals belonging to Groups 8 to 11, and the metal/zinc content (weight ratio) is 0.1 to 0.5.
(iii) The mesopore distribution curve has a peak, the half width (hw) of the peak is hw≦20 nm, and the central value (μ) of the peak is 10 nm≦μ≦20 nm, corresponding to the peak It has a mesopore group with a mesopore volume (pv) of 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 a diffraction angle of 2θ.
(v) The average particle diameter (PD) is PD≦100 nm.
(vi) The outer surface acid content is 0.01 mmol/g or less.
(vii) acid amount is 0.02 to 0.85 mmol/g;

The present invention will be described in detail below.

The MFI-type zeolite of the present invention contains zinc (hereinafter sometimes referred to as Zn) and one or more metals belonging to Groups 8 to 11 (hereinafter sometimes referred to as M), It is an MFI-type zeolite that satisfies the properties (i) to (vii).

The MFI-type zeolite of the present invention contains (i) 0.05 to 5% by weight of Zn relative to the zeolite. Here, if the Zn content is less than 0.05% by weight, the productivity of hydrocarbons is inferior when the zeolite is used as a catalyst for producing hydrocarbons. On the other hand, when the Zn content exceeds 5% by weight, excessive Zn causes by-products such as coke, resulting in remarkable deterioration of the catalyst. Zn can be introduced by any of impregnation, ion exchange, and physical mixing.

Further, the MFI-type zeolite of the present invention contains, in addition to zinc, at least one metal M selected from Groups 8 to 11 elements. Here, M is, for example, at least one metal selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver and gold. and/or nickel, and the content of M is (ii) M/Zn (weight ratio) = 0.1 to 0.5. Here, when M/Zn is less than 0.1, volatilization of Zn cannot be sufficiently suppressed when zeolite is used as a catalyst, resulting in significant deterioration. On the other hand, when M/Zn exceeds 0.5, M becomes excessive, and when used as a catalyst for hydrocarbon production, the hydrocarbon selectivity is poor. In addition, as a method for introducing the M, any method of impregnation support, ion exchange, or physical mixing can be used.

The MFI-type zeolite of the present invention has (iii) a mesopore distribution curve with a peak, hw ≤ 20 nm, 10 nm ≤ μ ≤ 20 nm, and a mesopore group of 0.05 ml / g ≤ pv. have. The mesopores referred to in the present invention are mesopores defined by IUPAC, and indicate pores having a pore diameter in the range of 2 to 50 nm. And mesopores can be measured by a general nitrogen adsorption method at liquid nitrogen temperature. In addition, the pore volume of mesopores can be obtained by analyzing the measurement results obtained by the nitrogen adsorption method. For the analysis, for example, the following method can be used.

Specifically, a method of analyzing the desorption process by the Barrett-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pp. 373-380) can be mentioned. By accumulating the nitrogen gas desorption amount in the range corresponding to , the value of the total pore volume of the pores belonging to the mesopores can be obtained.

Also, first, after obtaining a cumulative curve in which the vertical axis is the nitrogen desorption amount per unit mass V / m (mL / g) and the horizontal axis is the mesopore diameter D (nm), the vertical axis is the mesopore By taking the differential value (d (V / m) / d (D)) of the nitrogen gas desorption amount from the mesopore diameter value, the increase in the nitrogen desorption amount per unit mass at the mesopore diameter peak can be obtained.

The MFI-type zeolite of the present invention comprises a zeolite having a mesopore group with substantially uniform pore diameters. They are sometimes called pores. Specifically, uniform mesopores are obtained by approximating the maximum peak among the peaks related to mesopores in the pore distribution curve with a Gaussian function, and the standard deviation from μ, which is the central value of the Gaussian function. Mesopores with pore diameters within the range (μ±2σ) of twice (2σ). Further, pv, which is the pore volume of uniform mesopores, can be obtained by accumulating the amount of nitrogen gas desorption within the range of μ±2σ.

The MFI-type zeolite of the present invention has a pore distribution curve of mesopores with a peak, and the peak is hw ≤ 20 nm or less. When hw≤15 nm, particularly hw≤10 nm, the effect becomes more remarkable and preferable. Although the lower limit of hw is not particularly set, it is preferably 1 nm or more because the reaction selectivity is more excellent. When hw>20 nm, the reaction selectivity when used as a hydrocarbon production catalyst is inferior. In addition, by including MFI zeolite of 10 nm≦μ≦20 nm, it becomes possible to selectively react even molecules with a larger size, resulting in an excellent catalyst for hydrocarbon production. Further, when pv≧0.05 ml/g, the catalyst becomes a long-life hydrocarbon production catalyst, and 0.05 ml/g≦pv≦0.70 ml/g. Preferably, 0.10 ml/g≦pv≦0.70 ml/g, more preferably 0.20 ml/g≦pv≦0.50 ml/g. Here, when pv<0.05 ml/g, the pores tend to be clogged due to the accumulation of coke or the like produced as a by-product during the reaction, resulting in poor catalyst life when used as a catalyst for producing hydrocarbons.

In addition, the MFI-type zeolite of the present invention preferably satisfies 30% ≤ pvr ≤ 100%, more preferably 40% ≤ It is preferred that pvr≦100%.

The MFI zeolite of the present invention has (iv) no peak in the range of 0.1 to 3 degrees in powder X-ray diffraction measurement with a diffraction angle of 2θ. This indicates that there is no regularity in the arrangement of the mesopores and that there are no walls separating the mesopores. Since mass transfer becomes easy, it becomes a catalyst for hydrocarbon production with excellent reaction efficiency.

Further, the MFI-type zeolite of the present invention has (v) PD≦100 nm. Since the thermal stability is particularly excellent, it is desirable that 3 nm≦PD≦100 nm, and more preferably 5 nm≦PD≦100 nm. Here, if the PD exceeds 100 nm, the resulting MFI-type zeolite will be inferior in reaction efficiency when used in conversion reactions and isomerization reactions of aliphatic hydrocarbons.

The PD can be obtained by calculating from the outer 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 indicates the outer surface area (m ² /g).)
Further, the external surface area (S (m ² /g)) in formula (1) can be obtained from a t-plot method using a general nitrogen adsorption method at liquid nitrogen temperature. For example, when t is the thickness of the adsorption amount, linear approximation is applied to the measurement points in the range of 0.6 to 1 nm with respect to t, and the outer surface area of the zeolite is obtained from the slope of the obtained regression line.

The MFI-type zeolite of the present invention has (vi) an outer surface acidity of 0.01 mmol/g or less. Here, the outer surface acid sites of zeolite are, as the term implies, acid sites present on the outer surface of zeolite. Generally, zeolite has acid sites on its outer surface and in (micro)pores, and having no acid sites on its outer surface means having acid sites only in (micro)pores. It can be said. And, since it is particularly excellent in heat resistance, hot water resistance, and durability, it is preferable to use a metal-containing MFI zeolite having an unmodified surface that is not coated with a silicate, a dialkylamine reagent, or the like. Here, when the outer surface acid amount exceeds 0.01 mmol/g, the life of the catalyst becomes inferior when used as a catalyst for producing hydrocarbons.

Any method can be used to confirm the acid sites on the outer surface of the zeolite as long as it can be confirmed. It can be confirmed by adsorption (see Characterization of acid sites on the external surface of zeolites, Reaction Kinetics and Catalysis Letters, vol. 67, p. 281 (1999)).

The MFI-type zeolite of the present invention has (vii) an acid amount of 0.02 to 0.85 mmol/g. The amount of acid can be measured using a method generally known as a method for measuring the amount of acid. , vol.42, p.218 (2000)). Here, when the acid amount is less than 0.02 mmol/g, the catalytic activity of the catalyst for producing hydrocarbons is inferior. On the other hand, if it exceeds 0.85 mmol/g, deterioration of the catalyst due to coking when used as a catalyst for producing hydrocarbons becomes remarkable.

As a method for producing an MFI zeolite that satisfies the above (vi) and (vii), for example, the aluminum in the framework of the MFI zeolite, which is a raw material that satisfies the above characteristics (iii) to (v), is steamed. It can be produced by dealumination by The temperature of the steam treatment at that time is, for example, preferably 400 to 900.degree. C., particularly 450 to 800.degree. C., and more preferably 500 to 700.degree. The partial pressure of steam is preferably 0.001 to 5 MPa, more preferably 0.01 to 0.5 MPa, more preferably 0.05 to 0.2 MPa. The steam concentration is preferably 0.01 to 100 vol % steam/diluent gas, for example. 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.

The MFI-type zeolite of the present invention may have any SiO ₂ /Al ₂ O ₃ ratio as long as it belongs to the category called MFI-type zeolite. Since the efficiency of the isomerization reaction is excellent, the SiO ₂ /Al ₂ O ₃ ratio is preferably 20 to 300, and particularly excellent in heat resistance, reaction selectivity and productivity. Therefore, it is preferable that SiO ₂ /Al ₂ O ₃ =30 to 200.

As the method for producing the MFI-type zeolite of the present invention, any method can be used as long as it is possible to produce zeolite that satisfies the properties described in (i) to (vii) above. Then, as a zeolite having an outer surface acid amount of 0.01 mmol/g or less, that is, as a method for selectively reducing or removing acid sites on the zeolite surface, a zeolite that satisfies the characteristics (i) to (ii) is produced. For example, a part or all of the calcination (heat treatment) step may be a hydrothermal (steam) treatment step, and an ion exchange step may be added before or after the calcination step.

The MFI-type zeolite of the present invention can be produced by adding Zn and M, for example, to MFI-type zeolite by impregnation, ion exchange, physical mixing, or the like.

When the novel MFI zeolite of the present invention is used as a catalyst for producing hydrocarbons, the form is not particularly limited. It is also possible to use it in any form, such as using it as a product, mixing it with a binder or the like and molding it to use it as a specific shape.

By using the MFI type zeolite of the present invention as a catalyst for hydrocarbon production, it becomes a catalyst excellent in efficiency such as reaction selectivity and productivity. By contacting with hydrogen and further with aliphatic hydrocarbons having 4 to 6 carbon atoms, it is possible to efficiently produce light hydrocarbon compounds and aromatic compounds at the same time. The aliphatic hydrocarbons in this case include, for example, paraffinic, olefinic, acetylenic, and alicyclic hydrocarbons. Specifically, paraffins such as butane, isobutane, pentane, and hexane olefinic systems such as butene, isobutene, pentene, and hexene; alicyclic systems such as cyclohexane, and mixtures thereof. These aliphatic hydrocarbons are not only derived from petroleum such as naphtha, but are also derived from plants such as bioethanol and bionaphtha, polyolefin, polyvinyl chloride, acrylic, and polystyrene. It may be derived from chemical recycling of resin.

In the reaction that is an 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. A temperature in the range of 400 to 800° C. is desirable because the light hydrocarbon compound and the aromatic compound react efficiently without requiring a heat-resistant reactor more than necessary. Moreover, there is no restriction on the reaction pressure, and operation is possible within a pressure range of, for example, about 0.05 MPa to 5 MPa. In this case, the supply of aliphatic hydrocarbons as reaction raw materials to the catalyst for simultaneous production of light hydrocarbon compounds and aromatic compounds is not particularly limited as a ratio of the volume of the raw material gas to the volume of the catalyst. For example, space velocities of about 1 h ^-1 to 50000 h ^-1 can be mentioned. When supplying an aliphatic hydrocarbon as a raw material gas, a single gas, a mixed gas, and a single or mixed gas selected from inert gases such as nitrogen, hydrogen, carbon monoxide, and carbon dioxide. It can also be used as a thing.

The reaction mode is not limited, and for example, fixed bed, transport bed, fluidized bed, moving bed, multi-tubular reactors as well as continuous-flow, intermittent-flow and swing-type reactors can be used.

The light hydrocarbon compounds to be produced include hydrocarbon compounds having 2 to 3 carbon atoms, specifically ethane, ethylene, propane, propylene and the like, with ethane being particularly preferred. In addition, the aromatic compound is not particularly limited as long as it belongs to the category of aromatic compounds, such as benzene, toluene, xylene, trimethylbenzene, ethylbenzene, propylbenzene, butylbenzene, naphthalene, methylnaphthalene, and the like. can be mentioned, and benzene is particularly preferred.

The present invention relates to an MFI-type zeolite containing Zn and M, and in particular, when simultaneously producing light hydrocarbon compounds and aromatic compounds from aliphatic hydrocarbons, In addition, it is possible to obtain a catalyst for producing hydrocarbons with a long catalyst life, and it is industrially very useful.

Specific examples of the present invention will be described below as examples, but the present invention is not limited to these examples.

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

～Measurement of metal content～
The metal content was measured using an ICP device ((trade name) Optima 8300, manufactured by PerkinElmer Co., Ltd.). After the sample was accurately weighed in a 100 ml polymer volumetric flask, hydrofluoric acid, nitric acid and ultrapure water were added and allowed to stand overnight for dissolution. After measuring up, the sample was separated, ICP-AES was measured, and the metal content was calculated from the calibration curve.

~ Measurement of pore distribution, pore diameter, and external surface area ~
The zeolite pore distribution and pore diameter were measured by nitrogen adsorption measurement.

For nitrogen adsorption measurement, a general nitrogen adsorption device ((trade name) BELSOAP-max, manufactured by Bel Japan Co., Ltd.) was used, and the relative pressure (P/P ₀ ) on the adsorption side was measured at intervals of 0.025. The desorption side was measured at relative pressure intervals of 0.05. The outer surface area was obtained by linearly approximating the range of the adsorption layer thickness (t=0.6 to 1.0 nm) by the t-plot method. BELMaster (ver.2.3.1) manufactured by Bell Japan was used for the analysis of the pore distribution curve.

The adsorption process of nitrogen adsorption measurement was analyzed by the Saito-Foley method (AIChE Journal, 1991, Vol. 37, pp. 429-436). The pore distribution curves of micropores with values were obtained.

Then, the desorption process of the nitrogen adsorption measurement was analyzed by the Barrett-Joyner-Halenda method (Journal of the American Chemical Society, 1951, pp. 373-380), the horizontal axis is the constant of the pore diameter, and the vertical axis is the nitrogen gas. A pore distribution curve of mesopores, which is the differential value of the desorption amount of , was obtained. The total pore volume of mesopores was obtained by integrating the amount of nitrogen gas desorption in the range of 2 nm or more and 50 nm or less.

Then, among the peaks of the differential value (d (V / m) / d (D)) of the amount of nitrogen gas desorbed from the mesopores with the mesopore diameter value, the maximum peak is analyzed by the intensity approximation of the Gaussian function. Mesopores having a diameter within the range of twice the standard deviation (2σ) (=μ±2σ) from the central value (μ) of the Gaussian function were defined as uniform mesopores. The pore volume of uniform mesopores was obtained by integrating the amount of nitrogen gas desorption within a range of ±2σ based on the central value (μ).

～Measurement of powder X-ray diffraction～
Using an X-ray diffraction measurement device ((trade name) X'pert PRO MPD, manufactured by Spectris), the measurement was performed in the atmosphere using CuKα1 at a tube voltage of 45 kV and a tube current of 40 mA. A range of 0.04 to 5 degrees was analyzed at 0.08 degrees/step and 200 seconds/step. In addition, the background is removed by correcting the direct beam absorptance.

The presence or absence of a peak can be confirmed visually, or a peak search program may be used. A general program can be used for the peak search program. For example, the horizontal axis is 2θ (degrees) and the vertical axis is intensity (a.u.). After smoothing the measurement results with the SAVITSKY & GOLAY formula and the sliding polynomial filter, when performing the second derivative, three or more continuous points A peak was determined to be present if there was a negative value for

～Measurement of average particle size～
The average particle size was calculated from the outer surface area using the above formula (1). In formula (1), S is the outer surface area (m ² /g) and PD is the average particle diameter (m). The outer 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.

~ Measurement of SiO ₂ /Al ₂ O ₃ molar ratio ~
The SiO ₂ /Al ₂ O ₃ molar ratio of zeolite was determined by dissolving zeolite in a mixed aqueous solution of hydrofluoric acid and nitric acid, and subjecting this to inductively coupled plasma emission spectroscopy using a general ICP device ((trade name) OPTIMA3300DV, manufactured by PerkinElmer). Measured and determined by analysis (ICP-AES).

～2,4-Dimethylquinoline Adsorption Infrared Spectroscopy～
Measurement of infrared absorption spectroscopy is carried out using a general FT-IR measurement device ((trade name) Varian 660-IR, manufactured by Agilent Technologies) under vacuum with parts for IR measurement devices ((trade name) multi-mode cell , manufactured by S.T. Japan) were used in combination. After the sample was disk-molded, it was placed in a cell, heated to 400° C. at a rate of 10° C./min under vacuum evacuation, and held for 2 hours. After cooling to 150° C., an infrared absorption spectrum was measured before adsorption of 2,4-dimethylquinoline. A 2,4-dimethylquinoline gas was introduced and adsorbed for 10 minutes, and after evacuating at 150° C. for 1 hour, the infrared absorption spectrum after adsorption of 2,4-dimethylquinoline was measured. By taking the difference between the infrared absorption spectrum after adsorption of 2,4-dimethylquinoline and the spectrum before adsorption, the change in infrared absorption due to adsorption was measured.

～Measurement method of acid content～
The acid content was measured using a general NH ₃ -TPD device ((trade name) BELCATII, manufactured by Microtrac Bell Co., Ltd.) and a gas analyzer ((trade name) BELMass, manufactured by Microtrac Bell Co., Ltd.). . The sample was granulated, placed in a cell, heated to 500° C. at 10° C./min in a helium atmosphere, and held for 1 hour. After that, 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 desorbed ammonia was analyzed with a gas analyzer. The amount of acid in the sample was calculated from the remaining amount of desorption excluding the amount of desorption derived from weak acid.

～Hydrocarbon production equipment and durability test method～
The MFI-type zeolites obtained in the examples and the hydrocarbon-producing catalysts containing the same were subjected to durability tests in which hydrocarbon production and catalyst regeneration were repeated by the following method, and were evaluated.

A fixed-bed gas-phase flow reactor using a stainless steel reaction tube (inner diameter: 16 mm, length: 500 mm) was used. A catalyst for hydrocarbon production was filled in the middle stage of each of the stainless steel reaction tubes, subjected to heating pretreatment under dry air circulation, and then the raw material gas was fed. The apparatus conditions and operating conditions of the reactor are not limited to the conditions described in this example, and can be selected as appropriate. A ceramic tubular furnace was used for heating to control the temperature of the catalyst layer. The reaction outlet gas was analyzed using a gas chromatograph.

The reaction conditions were set as follows.

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

Further, 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.

(Catalyst regeneration conditions)
Catalyst temperature: 600°C.
Flowing gas: dry air 40 ml/min.
Regeneration pressure: 0.1 MPa.

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.

Preparation Example 1 (Preparation of Raw Zeolite)
MFI-type zeolite was manufactured with reference to JP-A-2013-227203.

An amorphous aluminosilicate gel was added to and suspended in an aqueous solution of tetrapropylammonium (hereinafter sometimes abbreviated as TPA) hydroxide and sodium hydroxide. MFI-type zeolite was added as seed crystals to the resulting suspension to prepare a raw material composition. The amount of seed crystals added at that time was 0.7% by weight with respect to the weight of Al ₂ O ₃ and SiO ₂ in the raw material composition. Moreover, by-produced ethanol was removed by evaporation.

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.

The resulting raw material composition was sealed in a stainless steel autoclave and crystallized at 115° C. for 4 days with stirring to obtain a slurry mixture. After solid-liquid separation of the slurry mixed liquid after crystallization by 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. The obtained dry powder was dispersed in 1 mol/l hydrochloric acid, filtered and dried. After calcining in air at 550° C. for 1 hour, a calcining treatment was performed which included steaming at 600° C. and 50% water vapor for 2 hours. The resulting powder was dispersed in 1 mol/l hydrochloric acid, filtered and washed to obtain MFI zeolite.

The obtained MFI-type zeolite had an average particle diameter of 38 nm, a SiO ₂ /Al ₂ O ₃ 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. The half width of the peak of uniform mesopores in the mesopore distribution curve was 16 nm, and the center value was 15 nm. 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%. In addition, 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. Moreover, the acid amount of the obtained MFI type zeolite was 0.20 mmol/g.

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 are added. added and kneaded. Then, the kneaded material was formed into a columnar compact having a diameter of 3 mm. After drying this at 100° C. overnight, it was formed into a columnar compact having a length of 4.5 to 7.5 mm (average length of 6.0 mm). This was calcined at 550° C. for 1 hour under air. The obtained MFI-type zeolite had an average particle size of 34 nm, an outer surface acid amount of 0.003 mmol/g, and an acid amount of 0.14 mmol/g.

Example 1
100 g of the MFI-type zeolite compact obtained in 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 deionized water for 30 minutes. After the compact was separated by filtration, it was heated to 110°C at a heating rate of 10°C/min, dried overnight, and then calcined at 550°C for 5 hours under air flow to obtain a zinc-copper-containing MFI zeolite. rice field. The resulting zinc-copper-containing MFI zeolite had a zinc content of 3.0% by weight, a copper content of 0.5% by weight, an outer surface acid amount of 0.003 mmol/g, and an acid amount of 0.08 mmol. /g.

A hydrocarbon-producing catalyst containing the obtained zinc-copper-containing zeolite was prepared, and the hydrocarbons were produced according to the above method, and the durability test of the catalyst was carried out. Table 1 shows the average yields of each product between the first and twelfth reactions of the durability test. The average yield of ethane in the first cycle was 15.6% by weight, the average yield of benzene was 13.8% by weight, and the average yield of ethane in the 12th cycle was 11.2% by weight, maintaining high yields. , and the average yield of benzene was 14.7% by weight. After the endurance test, the zinc content was 1.3% by weight and the copper content was 0.5% by weight. The zinc residual ratio was 43%, and the zinc volatilization was suppressed, and it was a catalyst that maintained high catalytic activity and excellent selectivity in balance between light hydrocarbon compounds and aromatic compounds over a long period of time. Each result is shown in Table 1. In addition, Table 2 shows a graph relatively showing the balance between catalyst life, catalyst activity and produced compounds according to the results of the 1st and 12th endurance tests.

Example 2
100 g of the MFI-type zeolite compact obtained in Preparation Example 2 was immersed in an aqueous solution of 15.9 g of zinc acetate, 2.3 g of cobalt nitrate hexahydrate, and 100 ml of deionized water for 30 minutes. After the compact was separated by filtration, it was heated to 110°C at a rate of 10°C/min, dried overnight, and then calcined at 550°C for 5 hours under air circulation to obtain a zinc-cobalt-containing MFI zeolite. rice field. The resulting zinc-cobalt-containing MFI zeolite had a zinc content of 3.0% by weight, a cobalt content of 0.5% by weight, an outer surface acid amount of 0.003 mmol/g, and an acid amount of 0.09 mmol. /g.

A hydrocarbon-producing catalyst containing the obtained zinc-cobalt-containing zeolite was prepared, and a durability test was conducted while producing hydrocarbons according to the above. Table 1 shows the average yields of each product between the first and twelfth reactions of the durability test. The average yield of ethane in the first cycle was 14.7% by weight, the average yield of benzene was 12.3% by weight, and the average yield of ethane in the 12th cycle was 10.4% by weight, maintaining high yields. and the average yield of benzene was 13.7% by weight. After the endurance test, the zinc content was 1.2% by weight and the cobalt content was 0.5% by weight. The zinc residual rate was 40%, and the zinc volatilization was suppressed, and the catalyst had selectivity that maintained high catalytic activity and excellent selectivity in balance between light hydrocarbon compounds and aromatic compounds over a long period of time. Each result is shown in Table 1. In addition, Table 2 shows a graph relatively showing the balance between catalyst life, catalyst activity and produced compounds according to the results of the 1st and 12th endurance tests.

Example 3
100 g of the MFI-type zeolite compact obtained in Preparation Example 2 was immersed in an aqueous solution of 15.9 g of zinc acetate, 2.3 g of nickel nitrate hexahydrate and 100 ml of deionized water for 30 minutes. After the compact was separated by filtration, the temperature was raised to 110°C at a rate of 10°C/min, dried overnight, and then calcined at 550°C for 5 hours under air flow to obtain a zinc-nickel-containing MFI zeolite. rice field. The resulting zinc-nickel-containing MFI zeolite had a zinc content of 3.0% by weight, a nickel content of 0.4% by weight, an outer surface acid amount of 0.003 mmol/g, and an acid amount of 0.09 mmol. /g.

A hydrocarbon-producing catalyst containing the obtained zinc-nickel-containing zeolite was prepared, and a durability test was conducted while producing hydrocarbons according to the above. Table 1 shows the average yields of each product between the first and twelfth reactions of the durability test. The average yield of ethane in the first cycle was 14.6% by weight, the average yield of benzene was 13.2% by weight, and the average yield of ethane in the 12th cycle was 9.5% by weight, maintaining high yields. and the average yield of benzene was 14.3% by weight. After the endurance test, the zinc content was 1.2% by weight and the nickel content was 0.4% by weight. The zinc residual rate was 40%, and the zinc volatilization was suppressed, and the catalyst had selectivity that maintained high catalytic activity and excellent selectivity in balance between light hydrocarbon compounds and aromatic compounds over a long period of time. Each result is shown in Table 1. In addition, Table 2 shows a graph relatively showing the balance between catalyst life, catalyst activity and produced compounds according to the results of the 1st and 12th endurance tests.

Comparative example 1
100 g of the MFI-type zeolite compact obtained in Preparation Example 2 was immersed in an aqueous solution of 15.9 g of zinc acetate and 100 ml of deionized water for 30 minutes. After the compact was separated by filtration, the temperature was raised to 110°C at a rate of 10°C/min, dried overnight, and then calcined at 550°C for 5 hours under air flow to obtain a zinc-containing MFI zeolite. The resulting zinc-containing MFI zeolite had a zinc content of 3.1% by weight, an outer surface acid amount of 0.003 mmol/g, and an acid amount of 0.08 mmol/g.

A hydrocarbon-producing catalyst containing the obtained zinc-containing zeolite was prepared, and a durability test was conducted while producing hydrocarbons according to the above. Table 1 shows the average yields of each product between the first and twelfth reactions of the durability test. The average yield of ethane in the first cycle was 15.9% by weight, the average yield of benzene was 13.1% by weight, and the average yield of ethane in the 12th cycle was 7.6% by weight. The average yield of benzene was 14.8% by weight. The zinc content after the durability test was 0.73% by weight. The zinc residual rate was 22%, and the volatilization of zinc proceeded remarkably, making the catalyst inferior in terms of catalyst life. Tables 1 and 2 show the respective results.

Comparative example 2
100 g of the MFI-type zeolite compact obtained in 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 deionized water for 30 minutes. After the compact was separated by filtration, it was heated to 110°C at a heating rate of 10°C/min, dried overnight, and then calcined at 550°C for 5 hours under air flow to obtain a zinc-copper-containing MFI zeolite. rice field. The resulting zinc-copper-containing MFI zeolite had a zinc content of 2.9% by weight, a copper content of 1.8% by weight, an outer surface acid amount of 0.003 mmol/g, and an acid amount of 0.08 mmol. /g.

A hydrocarbon-producing catalyst containing the obtained zinc-copper-containing zeolite was prepared, and a durability test was conducted while producing hydrocarbons according to the above. Table 1 shows the average yields of each product between the first and twelfth reactions of the durability test. The average yield of ethane in the first cycle was as low as 13.0% by weight, the average yield of benzene was 15.7% by weight, and the average yield of ethane in the 12th cycle was further reduced to 8.5% by weight. , and the average yield of benzene was 14.1% by weight. After the endurance 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 the catalyst was inferior in terms of selectivity. Tables 1 and 2 show the respective results.

When the MFI-type zeolite of the present invention is used as a catalyst for hydrocarbon production, for example, when light hydrocarbon compounds and aromatic compounds are produced at the same time, it is possible to achieve excellent productivity and a stable production method for each. , its industrial value is extremely high.

Claims (7)

An MFI-type zeolite characterized by satisfying the following properties (i) to (vii).
(i) Zinc is contained in an amount of 0.05 to 5% by weight based on the zeolite.
(ii) It contains one or more metals belonging to Groups 8 to 11, and the metal/zinc content (weight ratio) is 0.1 to 0.5.
(iii) The mesopore distribution curve has a peak, the half width (hw) of the peak is hw≦20 nm, and the central value (μ) of the peak is 10 nm≦μ≦20 nm, corresponding to the peak It has a mesopore group with a mesopore volume (pv) of 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 a diffraction angle of 2θ.
(v) The average particle diameter (PD) is PD≦100 nm.
(vi) The outer surface acid content is 0.01 mmol/g or less.
(vii) acid amount is 0.02 to 0.85 mmol/g; The MFI-type zeolite according to claim 1, characterized in that the SiO ₂ /Al ₂ O ₃ ratio is 20-300. The MFI-type zeolite according to claim 1 or 2, wherein the metal belonging to Groups 8 to 11 elements is copper, cobalt and/or nickel. A catalyst for the simultaneous production of light hydrocarbon compounds and aromatic compounds, comprising the MFI zeolite according to any one of claims 1 to 3. In the presence of the catalyst for simultaneous production of a light hydrocarbon compound and an aromatic compound according to claim 4, an aliphatic hydrocarbon having 4 to 6 carbon atoms is contacted to obtain a light hydrocarbon compound having 2 to 3 carbon atoms and an aromatic compound. A method for producing a hydrocarbon compound, characterized by forming a compound. 6. The method for producing a hydrocarbon compound according to claim 5, wherein 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 a hydrocarbon compound according to claim 5 or 6, wherein the aliphatic hydrocarbons having 4 to 6 carbon atoms include plant-derived and/or chemically recycled aliphatic hydrocarbons.