Zeolite

Abstract

In the production of xylene by the reforming of alcohol, to provide at least any one of a zeolite having an oxygen 10-membered ring structure that can increase the p-xylene selectivity and can be applied to an industrial process at low cost, an alcohol reforming catalyst containing the same, and a method for producing xylene using the same. A zeolite having an oxygen 10-membered ring structure, containing one or more elements selected from the group consisting of magnesium, calcium, titanium, boron, and phosphorus, and having a total pore volume of 0.21 cm 3 / g or less.

Description

Technical Field

[0001] The present disclosure relates to zeolites containing a predetermined element.

Background Art

[0002] As one of the methods for producing p-xylene, which is a raw material for terephthalic acid, there is a production method by reforming methanol using a specific metal-containing zeolite having an oxygen 10-membered ring structure as a catalyst.

[0003] For example, Non-Patent Document 1 discloses that aromatic hydrocarbons containing p-xylene can be obtained by reforming methanol using zinc-containing ZSM-5 (MFI-type zeolite) as a catalyst.

[0004] Further, Patent Document 1 discloses a method for co-producing p-xylene and ethylene propylene from toluene and methanol using an MFI-type zeolite modified with silicon using an organosilicon precursor as a catalyst.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the method for reforming alcohol as described in Patent Document 1 and Non-Patent Document 1, not only p-xylene but also aromatic hydrocarbons other than p-xylene are simultaneously produced. Although it is easy to separate xylene from aromatic hydrocarbons, the separated xylene is a mixture of xylene isomers of p-xylene, o-xylene, and m-xylene. To separate and purify only the target p-xylene from such a mixture of xylene isomers, a large amount of energy is required. Therefore, in the production of xylene by reforming alcohol as well, it is desired that the ratio of p-xylene to the produced xylene is high. However, in the method of Non-Patent Document 1, the ratio of p-xylene to the produced xylene (hereinafter also referred to as "p-xylene selectivity") was low.

[0008] On the other hand, in Patent Document 1, although the p-xylene selectivity is higher than that in Non-Patent Document 1, a large amount of expensive organosilicon precursor is required for the silicon modification of MFI-type zeolite. In addition to this, it is inevitable to generate waste liquid containing organosilicon, and facilities for detoxifying the waste liquid containing organosilicon are required. Therefore, the production method of Patent Document 1 has a high production cost and is difficult to apply to industrial processes.

[0009] An object of the present disclosure is to provide at least one of a zeolite having an oxygen 10-membered ring structure that can increase the p-xylene selectivity in the production of xylene by reforming alcohol, an alcohol reforming catalyst containing the same, and a method for producing xylene using the same, which can be adapted to an industrial process at low cost.

Means for Solving the Problems

[0010] The present inventors focused on zeolite catalysts and examined their structures and compositions in order to improve the p-xylene selectivity in the production of xylene by reforming alcohol. As a result, it was found that by incorporating a predetermined element into a zeolite having an oxygen 10-membered ring structure and setting its total pore volume to a predetermined value or less, the ratio of p-xylene to the produced xylene (p-xylene selectivity) increases.

[0011] That is, the present invention is as described in the claims, and the gist of the present disclosure is as follows. [1] A zeolite having an oxygen 10-membered ring structure, containing one or more predetermined elements selected from the group consisting of magnesium, calcium, titanium, boron, and phosphorus, and having a total pore volume of 0.21 cm 3 / g or less. [2] The zeolite having the oxygen 10-membered ring structure according to [1], wherein the zeolite is an MFI-type zeolite, an MEL-type zeolite, a TON-type zeolite, an STF-type zeolite, an MTT-type zeolite, an MWW-type zeolite, or a ZSM-48 zeolite. [3] The zeolite according to [1] or [2], characterized in that the molar ratio of silica to alumina is 10 or more and 250 or less. [4] The zeolite according to any one of [1] to [3], further containing one or more other elements selected from the group consisting of silver, zinc, gallium, and iron. [5] The zeolite according to any one of [1] to [4], wherein the predetermined element is supported at least on the outer surface. [6] In the difference spectrum obtained by subtracting the IR spectrum of the zeolite before adsorption of 2,6-di-tert-butylpyridine from the IR spectrum of the zeolite adsorbed with 2,6-di-tert-butylpyridine, the ratio of the maximum intensity of the peak having a peak top in the range of 1600 cm -1 or more and 1620 cm -1 or less to the maximum intensity of the peak having a peak top in the range of 1630 cm -1 or more and 1650 cm -1 or less is more than 1.5. The zeolite according to any one of [1] to [5]. [7] When a treatment is performed by bringing a mixed gas of nitrogen and methanol into contact under the conditions of a treatment temperature of 420 ° C, a treatment pressure (gauge pressure) of 0.2 MPa, a treatment time of 6 hours, and a methanol weight space velocity of 1.0 Hr -1 The p-xylene selectivity is 40% or more. The zeolite according to any one of [1] to [6]. A catalyst for alcohol reforming, comprising the zeolite according to any one of [1] to [7]. [9] A method for producing xylene, comprising contacting the zeolite according to any one of [1] to [7] with a fluid containing alcohol.

[10] A method for co-producing benzene, xylene, and toluene, comprising contacting the zeolite according to any one of [1] to [7] with a fluid containing alcohol. 3

[11] Use of a zeolite having an oxygen 10-membered ring structure for producing xylene from alcohol, wherein the zeolite contains one or more predetermined elements selected from the group consisting of magnesium, calcium, titanium, boron, and phosphorus, and the total pore volume is 0.21 cm 3 / g or less. 3

[12] Use of a zeolite having an oxygen 10-membered ring structure for co-producing benzene, xylene, and toluene from alcohol, wherein the zeolite contains one or more predetermined elements selected from the group consisting of magnesium, calcium, titanium, boron, and phosphorus, and the total pore volume is 0.21 cm 3 / g or less.

Advantages of the Invention

[0012] According to the present disclosure, at least one of a zeolite capable of increasing the p-xylene selectivity in the production of xylene by reforming alcohol, a catalyst for alcohol reforming containing the same, and a method for producing xylene using the same can be provided.

Embodiments for Carrying Out the Invention

[0013] The terms in this embodiment are as follows.

[0014] "Aluminosilicate" is a composite oxide having a structure composed of a repeating network of aluminum (Al) and silicon (Si) via oxygen (O). Among aluminosilicates, those having crystalline XRD peaks in their powder X-ray diffraction (hereinafter also referred to as "XRD") patterns are "crystalline aluminosilicates", and those having no crystalline XRD peaks are "amorphous aluminosilicates".

[0015] In this embodiment, examples of the XRD pattern include those obtained from XRD measurements under the following conditions. Accelerating current and voltage: 10 mA·30 kV X-ray source: CuKα ray (λ = 1.54178 Å) Measurement mode: Continuous scan Scan condition: 2° / min Measurement range: 2θ = 10~70° Scattering slit: 1 / 3° Divergence slit: 1 / 3° Receiving slit: 0.3 mm Filter: Ni filter

[0016] The XRD pattern can be measured using a general powder X-ray diffractometer (for example, Ultima IV Protectus, manufactured by Rigaku Corporation). Also, the crystalline XRD peak is a peak in which the 2θ of the peak top is specified and detected in the analysis of the XRD pattern using general analysis software (for example, IGOR Pro 8, manufactured by WaveMetrics), and an XRD peak having a half-value width of 2θ = 0.50° or less can be exemplified.

[0017] "Zeolite" is a compound in which the framework atoms (hereinafter also referred to as "T atoms") have a regular structure through oxygen (O), and the T atoms are composed of at least one of metal atoms and metalloid atoms. Examples of the metal atoms include one or more selected from the group consisting of aluminum (Al), titanium (Ti), iron (Fe), zinc (Zn), gallium (Ga), and tin (Sn), and aluminum is preferred. Examples of the metalloid atoms include one or more selected from the group consisting of boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te), and silicon is preferred. Note that zeolites in which the T atoms consist essentially of aluminum (Al) and silicon (Si) correspond to crystalline aluminosilicates. Here, the fact that the T atoms consist essentially of aluminum (Al) and silicon (Si) means not only that the T atoms consist only of aluminum (Al) and silicon (Si), but also that the inclusion of T atoms other than aluminum (Al) and silicon (Si) is allowed within the scope where the effects of the present invention are achieved.

[0018] "Zeolite-like substance" is a compound in which the T atoms have a regular structure through oxygen, and the compound contains at least atoms other than metals and metalloids in the T atoms. Examples of zeolite-like substances include composite phosphorus compounds containing phosphorus (P) as the T atom, such as aluminophosphate (AlPO) and silicoaluminophosphate (SAPO).

[0019] The "regular structure (hereinafter also referred to as the 'framework structure')" in zeolites and zeolite-like substances refers to the framework structure specified by the framework structure code (hereinafter also simply referred to as the 'framework code') defined by the Structure Commission of the International Zeolite Association, and the framework structure having crystal polymorphs (polymorphs) described on the homepage of the International Zeolite Association at "http: / / www.iza-structure.org / databases / " (hereinafter also referred to as the 'twinning structure'). For example, "MFI-type zeolite" is a zeolite having a framework structure specified by the framework code "MFI". Also, for example, "ZSM-48 zeolite" is a zeolite having a twinning structure composed of a twin crystal consisting of polymorph ZSM-48_A and polymorph ZSM-48_B. The twinning structure in this embodiment is not particularly limited with respect to the ratio of polymorphs (hereinafter also referred to as the 'twinning ratio'), and includes twinning structures with any twinning ratio.

[0020] The framework structure (twinning structure) of zeolite can be identified by comparison with the XRD pattern (hereinafter also referred to as the'reference pattern') of each framework structure described in Zeolite Framework on the homepage of the Structure Commission of IZA at http: / / www.iza-structure.org / databases / . Regarding the structure of zeolite, the terms framework structure (twinning structure), crystal structure, or crystal phase are used interchangeably.

[0021] The "zeolite having an oxygen 10-membered ring structure" refers to a zeolite that includes a ring (pore) formed by T atoms and oxygen atoms constituting the framework structure and having 10 oxygen atoms (hereinafter also referred to as an 'oxygen 10-membered ring'). The "zeolite having an oxygen 10-membered ring structure" may be a zeolite in which the rings formed in the framework structure consist only of oxygen 10-membered rings, or may be a zeolite that includes rings other than oxygen 10-membered rings in addition to oxygen 10-membered rings. Hereinafter, the zeolite having an oxygen 10-membered ring structure is also referred to as an oxygen 10-membered ring zeolite.

[0022] "Xylene" is a general term for p-xylene, o-xylene, and m-xylene, and unless otherwise specified, it means one or more selected from the group of p-xylene, o-xylene, and m-xylene.

[0023] The compositions in this embodiment such as the SiO2 / Al2O3 ratio, predetermined element content, and other element content described below can be determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a general inductively coupled plasma optical emission spectrometer (ICP device) (for example, OPTIMA5300DV, manufactured by PerkinElmer). In addition, for the composition analysis, a sample solution in which the sample is dissolved in a mixed aqueous solution of hydrofluoric acid and nitric acid can be used.

[0024] Hereinafter, an example of an embodiment of the zeolite according to the present disclosure will be shown and described. The present disclosure includes any combination of each configuration and parameter disclosed in this specification, and the upper and lower limits of the values disclosed in this specification include any combination.

[0025] The zeolite of this embodiment is an oxygen 10-membered ring zeolite, contains one or more elements selected from the group of magnesium, calcium, titanium, boron, and phosphorus, and moreover, the total pore volume is 0.21 cm 3 / g or less.

[0026] The zeolite of this embodiment only needs to be an oxygen 10-membered ring zeolite, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably an MFI-type zeolite, a MEL-type zeolite, a TON-type zeolite, an STF-type zeolite, an MTT-type zeolite, an MWW-type zeolite, or a ZSM-48 zeolite, more preferably an MFI-type zeolite or a MEL-type zeolite, and even more preferably an MFI-type zeolite.

[0027] In the zeolite of the present embodiment, the T atom constituting the framework structure may be composed of at least one of a metal atom and a metalloid atom, and is not particularly limited. However, from the viewpoint of further increasing the p-xylene selectivity, it is preferably substantially composed of aluminum (Al) and silicon (Si). In other words, the zeolite of the present embodiment is preferably a crystalline aluminosilicate having an oxygen 10-membered ring structure.

[0028] The zeolite of the present embodiment contains one or more elements selected from the group consisting of magnesium, calcium, titanium, boron, and phosphorus (hereinafter, also referred to as "predetermined elements"). Among magnesium, calcium, titanium, boron, and phosphorus, the predetermined elements contained in the zeolite of the present embodiment are preferably at least one of magnesium, calcium, and phosphorus from the viewpoint of further increasing the p-xylene selectivity, more preferably at least one of magnesium and calcium, and even more preferably magnesium.

[0029] The state of the predetermined element contained in the zeolite of the present embodiment is not particularly limited, and examples thereof include a compound (for example, an oxide), a metal (or a simple substance), an ion, an alloy, or a state of two or more of them.

[0030] In the zeolite of the present embodiment, the content of a predetermined element (hereinafter also referred to as "predetermined element content") relative to 100% by mass of the dry mass of the zeolite of the present embodiment is not particularly limited, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more. Further, the predetermined element content in the zeolite of the present embodiment is preferably 12% by mass or less, and more preferably 10% by mass or less from the viewpoint of further increasing the p-xylene selectivity. The upper limit value and the lower limit value of the predetermined element content may be any combination of the above-described upper limit value and lower limit value, but are preferably 2% by mass or more and 12% by mass or less, more preferably 4% by mass or more and 12% by mass or less, and even more preferably 6% by mass or more and 10% by mass or less. In the present embodiment, the dry mass is the mass of the zeolite after heat treatment at 600°C for 60 minutes in an air atmosphere.

[0031] Note that the above-described predetermined element content refers to the total content of two or more elements when the predetermined element is two or more elements, and refers to the content of the element alone when the predetermined element is one element.

[0032] The form of the predetermined element contained in the zeolite of the present embodiment is not particularly limited, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably a form in which the predetermined element is supported on the zeolite. In the present embodiment, the inclusion of the predetermined element means that the zeolite contains the predetermined element, and the predetermined element may be contained in any state and at any site. On the other hand, the support of the predetermined element means that the predetermined element is contained as a component other than the T atom of the zeolite. Examples of the supported form of the predetermined element include a form in which it is supported on at least one of the outer surface of the zeolite (the surface of the zeolite excluding the inner surface of the pores) and the inner surface of the pores. From the viewpoint of further increasing the p-xylene selectivity, the supported form of the predetermined element is preferably a form in which it is supported on at least the outer surface of the zeolite, and more preferably a form in which it is supported on both the outer surface of the zeolite and the inner surface of the pores.

[0033] The reason why the p-xylene selectivity is further increased by the loading of a predetermined element on at least the outer surface of the zeolite is not clear, but the predetermined element loaded on the outer surface of the zeolite interacts with the acid sites on the outer surface of the zeolite, making it difficult for the reforming reaction of alcohol by the acid sites on the outer surface of the zeolite to proceed. As a result, it is considered that the proportion of xylene generated at the acid sites on the outer surface of the zeolite is decreased, and the proportion of xylene generated at the acid sites inside the zeolite is increased. The xylene generated at the acid sites inside the zeolite is discharged through the pores (rings) formed in the zeolite. However, as will be described later, it is presumed that the zeolite of the present embodiment is such that o-xylene and m-xylene are difficult to be discharged from the pores, while p-xylene is easily discharged from the pores. Therefore, when the proportion of xylene generated at the acid sites inside the zeolite is increased, the proportion of xylene discharged through the pores (rings) that preferentially discharge p-xylene is increased, and it is considered that the p-xylene selectivity is further improved.

[0034] The zeolite of the present embodiment has a total pore volume of 0.21 cm 3 / g or less. The total pore volume is the volume of pores per unit mass of the zeolite. The total pore volume of the zeolite of the present embodiment can be calculated by obtaining the adsorption amount V (cm 3 ) when the equilibrium relative pressure (hereinafter also referred to as "p / p0") is 0.990 from the nitrogen adsorption / desorption isotherm of the zeolite and substituting the obtained adsorption amount V into the following formula (1). Total pore volume (cm 3 / g) = V × 1.547 × 10 -3 ···(1)

[0035] In addition, the nitrogen adsorption / desorption isotherm for obtaining the adsorption amount V in the above formula (1) can be obtained by the constant volume method in which nitrogen gas is adsorbed on the zeolite while changing the pressure and the amount is measured. For the measurement by the constant volume method, a general nitrogen adsorption apparatus (for example, BELSORP-miniII, manufactured by MicrotracBEL Corp.) can be used, and the following conditions can be used as the measurement conditions. Measured temperature: -196 °C Pretreatment of zeolite: Vacuum drying at 350 °C for 2 hours

[0036] In the zeolite of this embodiment, the lower limit value of the total pore volume may be more than 0 cm 3 / g, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably 0.05 cm 3 / g or more, more preferably 0.09 cm 3 / g or more. That is, from the viewpoint of further increasing the p-xylene selectivity, the total pore volume of the zeolite of this embodiment is 0.05 cm 3 / g or more and 0.21 cm 3 / g or less, preferably 0.09 cm 3 / g or more and 0.21 cm 3 / g or less is more preferable.

[0037] In the zeolite of this embodiment, the molar ratio of silica to alumina (hereinafter also referred to as "SiO2 / Al2O3 ratio") is not particularly limited, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably 250 or less, more preferably 200 or less, and even more preferably 100 or less. Further, in the zeolite of this embodiment, the SiO2 / Al2O3 ratio is preferably 10 or more, more preferably 20 or more, and even more preferably 30 or more from the viewpoint of further increasing the p-xylene selectivity. The upper limit value and the lower limit value of the SiO2 / Al2O3 ratio may be any combination of the above-mentioned upper limit value and lower limit value, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably 10 or more and 250 or less, more preferably 10 or more and 200 or less, even more preferably 10 or more and 100 or less, particularly preferably 20 or more and 100 or less, and most preferably 30 or more and 100 or less.

[0038] In addition to the predetermined elements described above, the zeolite of this embodiment may further contain other elements different from the predetermined elements (hereinafter also simply referred to as "other elements"). The other elements that can be contained in the zeolite of this embodiment are preferably one or more elements selected from the group consisting of silver, zinc, gallium, and iron. In addition to the predetermined elements, the inclusion of these other elements enables the zeolite of this embodiment to not only increase the p-xylene selectivity but also increase the total yield of benzene, xylene, and toluene (hereinafter also referred to as "BTX yield") useful as chemical raw materials. The BTX yield can be obtained by multiplying the ratio of the total number of moles (mol) of carbon atoms contained in benzene, xylene, and toluene in the reaction product to the total number of moles (mol) of carbon atoms contained in the reaction product (all components contained in the reaction product) obtained by reforming alcohol by the alcohol conversion rate (%).

[0039] When the zeolite of this embodiment contains other elements, the combination of the predetermined elements and other elements contained is arbitrary. However, from the viewpoint of increasing the p-xylene selectivity while further increasing the BTX yield, it is preferably a combination of one or more predetermined elements selected from the group consisting of magnesium, calcium, and phosphorus and one or more other elements selected from the group consisting of zinc and gallium, more preferably a combination of one or more predetermined elements selected from the group consisting of magnesium and calcium and one or more other elements selected from the group consisting of zinc and gallium, even more preferably a combination of one or more predetermined elements selected from the group consisting of magnesium and calcium and zinc (other element), and particularly preferably a combination of magnesium (predetermined element) and zinc (other element).

[0040] The state of the other elements that can be contained in the zeolite of this embodiment is not particularly limited, and examples thereof include, for example, compounds (such as oxides), metals (or simple substances), ions, alloys, or two or more of these states.

[0041] In the zeolite of the present embodiment, the content of other elements (hereinafter also referred to as "content of other elements") with respect to 100% by mass of the dry mass of the zeolite of the present embodiment is not particularly limited. However, from the viewpoint of increasing the p-xylene selectivity while further increasing the BTX yield, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. Further, from the viewpoint of increasing the p-xylene selectivity while further increasing the BTX yield, the content of other elements in the zeolite of the present embodiment is preferably 12% by mass or less, more preferably 10% by mass or less, and even more preferably 3% by mass or less. The upper limit value and the lower limit value of the content of other elements may be any combination of the above-described upper limit value and lower limit value. However, from the viewpoint of increasing the p-xylene selectivity while further increasing the BTX yield, it is preferably 0.1% by mass or more and 12% by mass or less, more preferably 0.3% by mass or more and 10% by mass or less, even more preferably 0.3% by mass or more and 3% by mass or less, and particularly preferably 0.5% by mass or more and 3% by mass or less.

[0042] Note that the above-described content of other elements refers to the total content of two or more elements when the other elements are two or more elements, and refers to the content of that element alone when the other element is one element.

[0043] The form of the content of other elements that can be contained in the zeolite of the present embodiment is not particularly limited. However, from the viewpoint of increasing the p-xylene selectivity while further increasing the BTX yield, it is preferable that the other elements are in a form supported on the zeolite. Examples of the supported form of other elements include a form supported on at least one of the outer surface and the inner surface of the pores of the zeolite. It is preferably a form supported on both the outer surface and the inner surface of the pores of the zeolite, and more preferably a form supported on the inner surface of the pores of the zeolite.

[0044] Although the reason why the BTX yield is further increased by supporting other elements on at least the inner surface of the pores of the zeolite is not clear, the other elements supported on the inner surface of the pores of the zeolite interact with the acid sites on the inner surface of the pores of the zeolite, promoting the reforming reaction of alcohol to aromatic compounds by the acid sites on the inner surface of the pores of the zeolite. As a result, it is considered that the proportion of BTX generated at the acid sites on the inner surface of the pores of the zeolite increases and the BTX yield is further improved.

[0045] As described above, it is preferable that the zeolite of the present embodiment has a predetermined element or other elements supported on its outer surface. However, the fact that a metal element (a metal element as a predetermined element and a metal element as other elements) is supported on the outer surface of the zeolite can be determined from the IR spectrum of the zeolite adsorbed with 2,6-di-tert-butylpyridine (hereinafter also referred to as the "adsorption spectrum") by subtracting the IR spectrum of the zeolite before the adsorption of 2,6-di-tert-butylpyridine (hereinafter also referred to as the "background spectrum").) from the difference spectrum (hereinafter also referred to as the "difference spectrum").) obtained by subtracting the IR spectrum of the zeolite before the adsorption of 2,6-di-tert-butylpyridine (hereinafter also referred to as the "background spectrum").) from the IR spectrum of the zeolite adsorbed with 2,6-di-tert-butylpyridine (hereinafter also referred to as the "adsorption spectrum").) In the difference spectrum, 1630 cm -1 Above 1650 cm -1 The peak having a peak top in the following range (hereinafter also referred to as "p(1630 cm -1 ~1650 cm -1 )") can be confirmed by its presence.

[0046] Incidentally, p(1630 cm -1 ~1650 cm -1 ) is a peak attributed to 2,6-di-tert-butylpyridine adsorbed on the metal element supported on the zeolite. Since 2,6-di-tert-butylpyridine cannot enter the inside of the 10-membered oxygen ring zeolite due to its molecular size, p(1630 cm -1 ~1650 cm -1 ) in the difference spectrum can be said to be a peak attributed to 2,6-di-tert-butylpyridine adsorbed on the metal element supported on the outer surface of the zeolite. p(1630 cm -1 ~1650 cm -1) preferably has a peak top in the range of 1635 cm -1 or more and 1645 cm -1 or less.

[0047] Here, a peak (hereinafter also referred to as "p(1600 cm -1 or more and 1620 cm -1 or less)") having a peak top in the range of has a peak attributed to 2,6-di-tert-butylpyridine adsorbed on acid sites (proton acid sites) present on the outer surface of the zeolite. Therefore, the ratio of the maximum intensity (height intensity) of p(1630 cm -1 ~1620 cm -1 ) to the maximum intensity (height intensity) of p(1630 cm -1 ~1620 cm -1 ) in the difference spectrum (hereinafter also referred to as the "IR peak ratio") is an index representing the ratio of the amount of metal elements to the amount of acid sites on the outer surface of the zeolite. Note that p(1600 cm -1 ~1620 cm -1 ) preferably has a peak top at 1605 cm -1 or more and 1615 cm -1 or less. Also, the maximum intensity (height intensity) means the intensity of the peak top. -1 or more and 1615 cm -1 or less.

[0048] In the zeolite of the present embodiment, the IR peak ratio may be 0 or more and is not particularly limited. However, from the viewpoint of further increasing the p-xylene selectivity, it is preferably 1.4 or more, more preferably more than 1.5, and even more preferably 1.6 or more. In the zeolite of the present embodiment, the IR peak ratio may be 0 or more and is not particularly limited. However, from the viewpoint of further increasing the p-xylene selectivity, it is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.6 or less. The upper limit value and the lower limit value of the IR peak ratio may be any combination of the upper limit value and the lower limit value described above. However, from the viewpoint of further increasing the p-xylene selectivity, it is preferably 1.4 or more and 5.0 or less, more preferably more than 1.5 and 5.0 or less, even more preferably more than 1.5 and 4.0 or less, particularly preferably 1.6 or more and 4.0 or less, and most preferably 1.6 or more and 3.6 or less.

[0049] Although the reason why the p-xylene selectivity is further increased when the IR peak ratio is within the above-described range has not been clarified, when the IR peak ratio is within the above-described range, the metal element and the acid site on the outer surface of the zeolite are more likely to interact with each other, and it is presumed that the ratio of xylene generated at the acid site inside the zeolite further increases, resulting in a further increase in the p-xylene selectivity.

[0050] The background spectrum and the adsorption spectrum can be measured by an FT-IR device (for example, FT / IR-6600, manufactured by JASCO Corporation). In the measurement of the background spectrum, the measurement sample (zeolite) is formed into a disk shape (about 10 mg / cm 2) Press-mold it into (0), fill it into a heat transmission cell, and pretreat it at 450 °C for 2 hours under vacuum. After the pretreatment, cool it down to 200 °C under vacuum conditions, and measure the background spectrum under the following measurement conditions. In the measurement of the adsorption spectrum, for example, after measuring the background spectrum, introduce 2,6-di-tert-butylpyridine into the heat transmission cell, and bring 2,6-di-tert-butylpyridine into contact with the measurement sample under the conditions of 200 °C, 30 minutes, and 100 Pa. Then, treat the heat transmission cell at 200 °C for 30 minutes under vacuum to remove the excess 2,6-di-tert-butylpyridine, and then measure the adsorption spectrum under the following measurement conditions. Measurement method: Heat transmission method Measurement temperature: 200 °C Measurement wavelength range: 800~4000 cm-1 Resolution: 2 cm-1 Number of integrations: 128 times Measurement atmosphere: Vacuum

[0051] The zeolite of the present embodiment preferably does not contain a structure-directing agent (hereinafter also referred to as "SDA") derived from its production raw material in terms of being more likely to improve the p-xylene selectivity (that is, the SDA content in the zeolite of the present embodiment is 0% by mass). However, the zeolite of the present embodiment may contain SDA as long as the object of the present invention can be achieved. The SDA content in the zeolite of the present embodiment may be 0% by mass or more and 10% by mass or less, more than 0% by mass and 5% by mass or less, and further 1% by mass or more and 0.5% by mass or less with respect to 100% by mass of the zeolite of the present embodiment. In the present embodiment, the content being 0% by mass or 0 mol% means that the component is substantially not contained, and the component being substantially not contained means that the component is not detected (below the measurement limit).

[0052] The zeolite of the present embodiment described above can be used for the production of xylene by the reforming of alcohol, and can be used as a catalyst for alcohol reforming for reforming alcohol into xylene. The catalyst for alcohol reforming contains at least the zeolite of the present embodiment. In the production of xylene by the reforming of alcohol, by using the zeolite of the present embodiment, the ratio of p-xylene to the produced xylene (p-xylene selectivity) can be increased. In the method for producing xylene by the reforming of alcohol, in addition to xylene, aromatic hydrocarbons other than xylene (for example, benzene and toluene) may be co-produced.

[0053] The method for producing xylene by the reforming of alcohol includes a step of bringing the zeolite of the present embodiment into contact with a fluid containing the zeolite and alcohol (hereinafter also referred to as "alcohol-containing fluid") (hereinafter also referred to as "contact step"). As a specific method of bringing the zeolite of the present embodiment into contact with the alcohol-containing fluid, for example, a method of filling a fixed-bed flow-type reaction tube with the zeolite of the present embodiment to form a packed bed and flowing the alcohol-containing fluid through this packed bed can be exemplified.

[0054] In the method for producing xylene by the reforming of alcohol, since the reforming reaction of alcohol proceeds by bringing the zeolite of the present embodiment into contact with the alcohol-containing fluid, the contact conditions for bringing the zeolite of the present embodiment into contact with the alcohol-containing fluid are not particularly limited. Preferred contact conditions can include the following conditions.

[0055] From the viewpoint of further increasing the p-xylene selectivity, the contact temperature between the zeolite of the present embodiment and the alcohol-containing fluid is preferably 300 °C or higher, more preferably 350 °C or higher. Also, from the viewpoint of further increasing the p-xylene selectivity, the contact temperature between the zeolite of the present embodiment and the alcohol-containing fluid is preferably 550 °C or lower, more preferably 500 °C or lower. The upper and lower limit values of the contact temperature may be any combination of the upper and lower limit values described above, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably 300 °C or higher and 550 °C or lower, more preferably 350 °C or higher and 550 °C or lower, and even more preferably 350 °C or higher and 500 °C or lower.

[0056] From the viewpoint of further increasing the p-xylene selectivity, the pressure (gauge pressure) for bringing the zeolite of the present embodiment into contact with the alcohol-containing fluid is preferably 0.05 Mpa or higher, more preferably 0.1 Mpa or higher. Also, from the viewpoint of further increasing the p-xylene selectivity, the pressure (gauge pressure) for bringing the zeolite of the present embodiment into contact with the alcohol-containing fluid is preferably 1 Mpa or lower, more preferably 0.5 Mpa or lower. The upper and lower limit values of the contact pressure (gauge pressure) may be any combination of the upper and lower limit values described above, but from the viewpoint of further increasing the p-xylene selectivity, it is preferably 0.05 Mpa or higher and 1 Mpa or lower, more preferably 0.05 Mpa or higher and 0.5 Mpa or lower, and even more preferably 0.1 Mpa or higher and 0.5 Mpa or lower. Note that the gauge pressure is the pressure with the atmospheric pressure taken as 0 MPa.

[0057] From the viewpoint of further increasing the p-xylene selectivity, the weight hourly space velocity (WHSV) of the alcohol in the alcohol-containing fluid brought into contact with the zeolite of the present embodiment is preferably 0.05 h -1 or higher, more preferably 0.5 h -1 or higher. Also, from the viewpoint of further increasing the p-xylene selectivity, the weight hourly space velocity (WHSV) of the alcohol in the alcohol-containing fluid brought into contact with the zeolite of the present embodiment is preferably 10 h -1It is preferably as follows, 5 hr -1 It is more preferably as follows. The upper limit value and the lower limit value of the weight hourly space velocity (WHSV) of the alcohol may be any combination of the upper limit value and the lower limit value described above. From the viewpoint of further increasing the p-xylene selectivity, it is 0.05 hr -1 or more and 10 hr -1 It is preferably as follows, 0.05 hr -1 or more and 5 hr -1 It is more preferably as follows, 0.5 hr -1 or more and 5 hr -1 It is even more preferably as follows. Note that WHSV is a parameter representing the supply amount of alcohol per unit mass of zeolite per hour (supply amount of alcohol in terms of liquid) ([g (zeolite)] / [g (alcohol) / h] (= [hr -1 ))

[0058] Regarding the contact time between the zeolite of the present embodiment and the alcohol-containing fluid, it can be appropriately set according to the amount of p-xylene to be obtained

[0059] The alcohol-containing fluid used in the contact step may be a fluid consisting only of alcohol, or may be a fluid containing components other than alcohol in addition to alcohol. Examples of the components other than alcohol include one or more components selected from the group consisting of nitrogen, helium, argon, and hydrogen

[0060] Examples of the alcohol contained in the alcohol-containing fluid include one or more selected from the group consisting of methanol, ethanol, butanol, and isobutanol. From the viewpoint of further increasing the p-xylene selectivity, methanol is preferable

[0061] The alcohol-containing fluid brought into contact with the zeolite of the present embodiment may be one or more selected from the group consisting of a liquid, a gas, and a mixed fluid of a liquid and a gas. From the viewpoint of further increasing the p-xylene selectivity, a gas is preferable

[0062] In the contacting step, as the zeolite of the present embodiment to be contacted with the alcohol-containing fluid, the activated zeolite of the present embodiment may be used. For the activation treatment of the zeolite of the present embodiment, conventionally known activation treatments can be used, and the method is not limited thereto. As an example of a specific activation treatment, an activation treatment in which nitrogen gas is passed through the zeolite of the present embodiment under the following conditions can be mentioned. Flow rate of nitrogen gas: 5 mL / min or more and 100 mL / min or less Treatment temperature: 400°C or more and 600°C or less Treatment pressure: 0.05 Mpa or more and 1 Mpa or less (gauge pressure) Treatment time: 0.5 hours or more and 50 hours or less

[0063] The zeolite of the present embodiment in the contacting step may be formed into a predetermined shape. Examples of the method for forming the zeolite of the present embodiment include rolling granulation molding, press molding, extrusion molding, injection molding, casting molding, and sheet molding. Examples of the shape of the formed zeolite include spherical, substantially spherical, elliptical, disk-shaped, columnar, polyhedral, irregular, and petal-shaped. Note that the zeolite of the present embodiment may be formed together with a binder and may be a molded body containing the binder and the zeolite. By passing the alcohol-containing fluid through such a molded body, the zeolite of the present embodiment contained in the molded body and the alcohol-containing fluid may be brought into contact with each other. Examples of the binder include at least one selected from the group consisting of silica, alumina other than γ-alumina, kaolin, attapulgite, montmorillonite, bentonite, and sepiolite.

[0064] The zeolite of the present embodiment is not particularly limited, but the treatment temperature is 420°C, the treatment pressure (gauge pressure) is 0.2 MPa, the treatment time is 6 hours, and the methanol weight space velocity is 1.0 Hr -1Under the conditions, when a mixed gas of nitrogen and methanol is brought into contact (hereinafter also referred to as "methanol contact treatment (420 °C)"), the p-xylene selectivity (hereinafter also referred to as "p-xylene selectivity (420 °C)") is preferably 35% or more, more preferably 40% or more, and even more preferably 60% or more. The upper limit value of the p-xylene selectivity (420 °C) is not particularly limited, but may be 100% or less or 99.9% or less. The upper limit value and the lower limit value of the p-xylene selectivity (420 °C) may be any combination of the above-mentioned upper limit value and lower limit value. However, the p-xylene selectivity (420 °C) is preferably 35% or more and 100% or less, more preferably 40% or more and 100% or less, even more preferably 40% or more and 99.9% or less, and particularly preferably 60% or more and 99.9% or less.

[0065] The p-xylene selectivity (420 °C) can be obtained by dividing the mass of p-xylene in the product generated by the methanol contact treatment (420 °C) by the total mass of xylenes (p-xylene, o-xylene, and m-xylene) in the product and expressing this as a percentage. Further, for the zeolite of the present embodiment used in the methanol contact treatment (420 °C), zeolite that has been subjected to a treatment (activation treatment) of flowing nitrogen gas at 50 mL / min for 1 hour under the conditions of a temperature of 450 °C and a pressure of 0.2 MPa (gauge pressure) may be used.

[0066] The zeolite of the present embodiment is not particularly limited. However, when the methanol contact treatment (420 °C) is performed, the BTX yield (hereinafter also referred to as "BTX yield (420 °C)") is preferably 3% or more, more preferably 15% or more, and even more preferably 25% or more. The upper limit value of the BTX yield (420 °C) is not particularly limited, but may be 100% or less or 70% or less. The upper limit value and the lower limit value of the BTX yield (420 °C) may be any combination of the above-mentioned upper limit value and lower limit value. However, it is preferably 3% or more and 100% or less, more preferably 15% or more and 70% or less, and even more preferably 25% or more and 70% or less.

[0067] The BTX yield (420 °C) can be obtained by dividing the total mass of benzene, xylene (p-xylene, o-xylene, and m-xylene), and toluene in the product generated by methanol contact treatment (420 °C) by the mass of the product (total mass of all components in the product) and expressing this as a percentage.

[0068] Note that the zeolite of this embodiment that reforms alcohol into benzene, xylene, and toluene can also be used for co-producing benzene, xylene, and toluene by reforming alcohol. The method for co-producing benzene, xylene, and toluene using the zeolite of this embodiment includes a step of bringing the zeolite of this embodiment into contact with an alcohol-containing fluid (contact step), similar to the method for producing xylene using the zeolite of this embodiment. Since the contact step in the method for co-producing benzene, xylene, and toluene is the same as the contact step in the method for producing xylene, a detailed description thereof will be omitted.

[0069] Next, the method for manufacturing the zeolite of this embodiment will be described.

[0070] The method for manufacturing the zeolite of this embodiment includes a step of incorporating a predetermined element into an oxygen 10-membered ring zeolite (hereinafter also referred to as the "predetermined element incorporation step").

[0071] In the predetermined element incorporation step, the method of incorporating a predetermined element into the oxygen 10-membered ring zeolite is not particularly limited, but it is preferable to use a contact treatment (hereinafter also referred to as the "predetermined element contact treatment") of bringing a solution containing the predetermined element (hereinafter also referred to as the "predetermined element solution") into contact with the oxygen 10-membered ring zeolite.

[0072] When a predetermined element is incorporated into a 10-membered oxygen ring zeolite by a predetermined element contact treatment, depending on the treatment conditions, the total pore volume of the 10-membered oxygen ring zeolite decreases. Therefore, if a predetermined element is incorporated into a 10-membered oxygen ring zeolite by a predetermined element contact treatment, depending on the treatment conditions, even if the total pore volume of the 10-membered oxygen ring zeolite before contact with the predetermined element solution exceeds 0.21 cm 3 / g, a zeolite having a total pore volume of 0.21 cm 3 / g or less (that is, the zeolite of the present embodiment) can be obtained. The reason why the total pore volume of the 10-membered oxygen ring zeolite decreases by the predetermined element contact treatment is not clear, but it is presumed that when the predetermined element contact treatment is performed under predetermined conditions, the predetermined element easily reaches not only the surface (outer surface) but also the inside of the 10-membered oxygen ring zeolite, resulting in a decrease in the total pore volume.

[0073] In the predetermined element contact treatment, the 10-membered oxygen ring zeolite to be contacted with the predetermined element solution preferably has a total pore volume of 0.35 cm 3 / g or less, more preferably 0.28 cm 3 / g or less, even more preferably 0.21 cm 3 / g or less, and particularly preferably 0.19 cm 3 / g or less. The total pore volume of the 10-membered oxygen ring zeolite to be contacted with the predetermined element solution is not particularly limited as long as it exceeds 0 cm 3 / g. For example, it may be 0.05 cm 3 / g or more, 0.07 cm 3 / g or more, or 0.15 cm 3 / g or more. The upper limit and lower limit values of the total pore volume of the 10-membered oxygen ring zeolite to be contacted with the predetermined element solution may be any combination of the above-mentioned upper limit and lower limit values. However, since the zeolite of the present embodiment is easily obtained, it is preferably 0.05 cm 3 / g or more and 0.35 cm 3 / g or less, more preferably 0.05 cm 3 / g or more and 0.28 cm 3 / g or less, and even more preferably 0.07 cm3 0.28 cm or more per g 3 More preferably, it is 0.15 cm or less per g, 3 0.28 cm or more per g 3 Particularly preferably, it is 0.15 cm or less per g.

[0074] As the oxygen 10-membered ring zeolite to be brought into contact with the predetermined element solution, it is preferable to use an oxygen 10-membered ring zeolite that has been subjected to the SDA removal treatment described later, and more preferably to use an oxygen 10-membered ring zeolite that substantially does not contain SDA. Since the total pore volume of the oxygen 10-membered ring zeolite subjected to the SDA removal treatment is likely to decrease by the predetermined element contact treatment as compared with the oxygen 10-membered ring zeolite not subjected to the SDA removal treatment, a zeolite having a total pore volume of 0.21 cm 3 / g or less (that is, the zeolite of the present embodiment) is easily obtained.

[0075] In the oxygen 10-membered ring zeolite to be brought into contact with the predetermined element solution, the framework structure, the type of T atoms constituting the framework structure, and the SiO2 / Al2O3 ratio may be appropriately set according to the framework structure of the zeolite of the present embodiment to be produced, the type of T atoms constituting the framework structure, and the SiO2 / Al2O3 ratio, respectively, and are not particularly limited.

[0076] The predetermined element solution to be brought into contact with the oxygen 10-membered ring zeolite is a solution containing a predetermined element and a solvent. The predetermined element contained in the predetermined element solution may be contained in the form of a compound containing the predetermined element. Examples of the compound containing the predetermined element include at least one compound selected from the group consisting of acetates, nitrates, ammonium salts, sulfates, hydroxides, and chlorides of the predetermined element. Among these, it is preferably at least any one of the acetate, nitrate, and ammonium salt of the predetermined element. Specific examples of the compound containing the predetermined element include at least one compound selected from the group consisting of magnesium acetate, magnesium nitrate, magnesium chloride, magnesium sulfate, calcium nitrate, calcium chloride, calcium sulfate, phosphoric acid, ammonium hydrogen phosphate, diammonium hydrogen phosphate, titanium chloride, titanium sulfate, titanyl sulfate, boric acid, and ammonium tetraborate. It is preferably at least any one of magnesium acetate, calcium nitrate, and diammonium hydrogen phosphate. Examples of the solvent contained in the predetermined element solution include at least one of water and alcohol, and water is preferred.

[0077] The concentration of the predetermined element in the predetermined element solution and the amount of the predetermined element solution brought into contact with the oxygen 10-membered ring zeolite may be appropriately adjusted so that the total pore volume of the oxygen 10-membered ring zeolite obtained by contacting with the predetermined element solution is 0.21 cm 3 / g or less, and although not particularly limited, the lower the concentration of the predetermined element in the predetermined element solution, the less likely the total pore volume of the oxygen 10-membered ring zeolite subjected to the predetermined element contact treatment is to decrease. Therefore, when the total pore volume of the oxygen 10-membered ring zeolite before contacting with the predetermined element solution exceeds 0.21 cm 3 / g, the concentration of the predetermined element in the predetermined element solution is preferably adjusted appropriately in consideration of the above-mentioned tendency, and it is more preferable to adjust it to a concentration such that the predetermined element content in the oxygen 10-membered ring zeolite contacted with the predetermined element solution is 3% by mass or more.

[0078] The contact conditions between the oxygen 10-membered ring zeolite and the predetermined element solution may be appropriately adjusted so that the total pore volume of the oxygen 10-membered ring zeolite obtained by contacting with the predetermined element solution is 0.21 cm 3 / g or less, and it is not particularly limited. For example, the contact time between the oxygen 10-membered ring zeolite and the predetermined element solution may be 0.1 minutes or more and 48 hours or less. Also, for example, the contact temperature between the oxygen 10-membered ring zeolite and the predetermined element solution may be 5°C or more and 100°C or less. Also, for example, the contact pressure between the oxygen 10-membered ring zeolite and the predetermined element solution can be exemplified as 0 Mpa or more and 1 Mpa or less (gauge pressure).

[0079] By bringing the oxygen 10-membered ring zeolite into contact with the predetermined element solution, the oxygen 10-membered ring zeolite contains the predetermined element. Thereby, the zeolite of the present embodiment can be produced. Note that the oxygen 10-membered ring zeolite contacted with the predetermined element solution may be used as the zeolite of the present embodiment as it is, or may be used as the zeolite of the present embodiment after at least one of a drying treatment and a firing treatment.

[0080] The drying treatment is a treatment for removing moisture from the oxygen 10-membered ring zeolite contacted with the predetermined element solution. The drying conditions are not particularly limited as long as moisture can be removed from the oxygen 10-membered ring zeolite. For example, conditions such as drying in an air atmosphere at 60°C or more and 180°C or less for 0.5 hours or more and 48 hours or less can be mentioned.

[0081] The firing treatment is a treatment for firing the oxygen 10-membered ring zeolite contacted with the predetermined element solution or the dried oxygen 10-membered ring zeolite. Examples of the firing conditions can be, for example, the following conditions. Firing temperature: 350°C or more, or 450°C or more, and 700°C or less, or 600°C or less Firing time: 0.5 hours or more, or 1 hour or more, and 24 hours or less, or 12 hours or less Firing atmosphere: Air atmosphere

[0082] As described above, the zeolite of the present embodiment may contain, in addition to the predetermined element, other elements different from the predetermined element. The zeolite of the present embodiment further containing other elements in addition to the predetermined element can be produced by a production method including the above-described predetermined element-containing step and a step of incorporating other elements into the oxygen 10-membered ring zeolite (hereinafter, also referred to as "other element-containing step").

[0083] In the other element-containing step, the method of incorporating other elements into the oxygen 10-membered ring zeolite is not particularly limited. For example, a contact treatment (hereinafter, also referred to as "other element contact treatment") of bringing a solution containing other elements (hereinafter, also referred to as "other element solution") into contact with the oxygen 10-membered ring zeolite can be used.

[0084] The other element solution used in the other element contact treatment is a solution containing other elements and a solvent. The other elements contained in the other element solution may be contained in the form of a compound containing other elements. Examples of the compound containing other elements include at least one compound selected from the group consisting of nitrates, acetates, sulfates, and chlorides of other elements, and nitrates are preferred. Specific examples of the compound containing other elements include at least one compound selected from the group consisting of gallium nitrate, gallium chloride, zinc nitrate, zinc sulfate, zinc chloride, silver nitrate, iron(II) sulfate, iron(III) sulfate, iron chloride, iron oxalate, iron citrate, and iron nitrate, and at least one of gallium nitrate and zinc nitrate is preferred. Examples of the solvent contained in the other element solution include at least one of water and alcohol, and water is preferred.

[0085] The other element contact treatment is the same as the above-described predetermined element contact treatment except that the other element solution is used instead of the predetermined element solution, and thus detailed description thereof is omitted.

[0086] In the method for producing a zeolite of the present embodiment further containing other elements, the order of the predetermined element-containing step and the other element-containing step is not particularly limited, and the predetermined element-containing step may be performed after the other element-containing step, or the other element-containing step may be performed after the predetermined element-containing step.

[0087] Here, when the predetermined element contact treatment is performed after the other element contact treatment, the total pore volume of the oxygen 10-membered ring zeolite is more likely to decrease than when the other element contact treatment is performed after the predetermined element contact treatment. For this reason, in the production method in which the predetermined element contact treatment is performed after the other element contact treatment, even if the total pore volume of the oxygen 10-membered ring zeolite before being subjected to these treatments exceeds 0.21 cm 3 / g, zeolite having a total pore volume of 0.21 cm 3 / g or less (that is, the zeolite of the present embodiment) is more easily produced. For this reason, in the method for producing a zeolite of the present embodiment further containing other elements, after the step of incorporating other elements into the oxygen 10-membered ring zeolite by the other element contact treatment (other element-containing step), the step of incorporating a predetermined element into the oxygen 10-membered ring zeolite containing other elements by the predetermined element contact treatment (predetermined element-containing step) is preferably performed.

[0088] As the oxygen 10-membered ring zeolite used in the predetermined element-containing step and the other element-containing step, commercially available zeolite may be used, or zeolite obtained by crystallizing a composition containing an alumina source, a silica source, an organic structure-directing agent source, an alkali source, and water (hereinafter also referred to as "raw material composition") may be used.

[0089] Hereinafter, the method for producing an oxygen 10-membered ring zeolite for crystallizing the raw material composition will be described.

[0090] The alumina source contained in the raw material composition is a compound containing aluminum (Al), and examples thereof include one or more selected from the group consisting of aluminum isopropoxide, aluminum sulfate, aluminum chloride, aluminum hydroxide, boehmite, alumina sol, and amorphous aluminosilicate, and amorphous aluminosilicate is preferred. Note that substances containing aluminum (Al) and silicon (Si) such as amorphous aluminosilicate can be used not only as the alumina source but also as the silica source described later.

[0091] The silica source contained in the raw material composition is a compound containing silicon (Si), and examples thereof include one or more selected from the group consisting of silica sol, fumed silica, colloidal silica, precipitated silica, sodium silicate, amorphous silicic acid, and amorphous aluminosilicate, and amorphous aluminosilicate is preferred.

[0092] The organic structure-directing agent (hereinafter also referred to as "SDA") source may be a substance containing an SDA that directs a skeletal structure containing a 10-membered oxygen ring, and a known SDA known to direct a 10-membered oxygen ring zeolite can be used. For example, as the SDA that directs MFI-type zeolite, at least one selected from the group consisting of normal butylamine, tetrapropylammonium bromide, diethylenetriamine, and cyclohexylamine can be mentioned. Among these, at least one selected from the group consisting of normal butylamine, diethylenetriamine, and cyclohexylamine is preferably used, and normal butylamine is more preferred. Normal butylamine, diethylenetriamine, and cyclohexylamine can reduce the total pore volume of the produced 10-membered oxygen ring zeolite more than other SDAs.

[0093] The SDA source may be a salt of the SDA, and examples thereof include one or more salts selected from chlorides, bromides, iodides, and hydroxides.

[0094] The alkali source contained in the raw material composition is a compound containing an alkali metal element, and examples of the compound containing one or more alkali metal elements selected from the group consisting of sodium, potassium, cesium, and rubidium can be given. The alkali source may be, for example, in the form of one or more salts selected from the group consisting of hydroxides, carbonates, chlorides, bromides, iodides, and sulfates containing an alkali metal element. Preferred alkali sources include at least one or more of the group consisting of sodium hydroxide, sodium carbonate, sodium chloride, sodium bromide, sodium iodide, and sodium sulfate.

[0095] The water contained in the raw material composition can be, for example, distilled water, deionized water, pure water, or two or more of these. In addition, when the raw materials other than the water contained in the raw material composition contain water such as hydrates, structural water, and solvents, the water contained in the raw materials other than water can be regarded as the water contained in the raw material composition.

[0096] The raw material composition may be composed only of an alumina source, a silica source, an SDA source, an alkali source, and water, but may also contain other raw materials other than these raw materials.

[0097] The composition of the raw material composition can be appropriately selected according to the skeletal structure of the oxygen 10-membered ring zeolite to be produced, etc. An example of a preferred composition can be the following molar composition. Note that each ratio in the following composition is a molar (mol) ratio. SiO2 represents the mol amount of silicon, Al2O3 represents the mol amount of aluminum in terms of alumina, H2O represents the mol amount of water, M represents the mol amount of the alkali metal element (total mol amount of the alkali metal element), SDA represents the mol amount of the organic structure-directing agent, and OH - represents the mol amount of hydroxide ions.

[0098] SiO2 / Al2O3 ratio = 15 or more, preferably 23 or more, and 500 or less, preferably 300 or less SDA / SiO2 ratio = 0.05 or more, preferably 0.10 or more, and 0.50 or less, preferably 0.30 or less The M / SiO2 ratio = 0.05 or more, preferably 0.10 or more, and 0.15 or less, preferably 0.20 or less The H2O / SiO2 ratio = 5 or more, preferably 10 or more, and 40 or less, preferably 20 or less OH - / SiO2 ratio = 0.05 or more, preferably 0.10 or more, and 0.20 or less, preferably 0.15 or less

[0099] The raw material composition can be obtained by mixing the above-described alumina source, silica source, SDA source, alkali source, water, and other raw materials contained as necessary.

[0100] The crystallization treatment of the raw material composition may be any method that can crystallize the raw material composition so as to obtain an oxygen 10-membered ring zeolite, and the treatment method is not particularly limited. Preferred crystallization treatment methods include hydrothermal treatment of the raw material composition. For hydrothermal treatment, for example, the raw material composition may be placed in a sealed pressure-resistant container and heated. Examples of hydrothermal treatment conditions include the following conditions. Treatment temperature: 90°C or higher, or 115°C or higher, and 200°C or lower, or 180°C or lower Treatment time: 10 hours or longer, or 20 hours or longer, and 72 hours or shorter, or 48 hours or shorter Treatment pressure: autogenous pressure

[0101] The crystallization treatment of the raw material composition may be performed after adding seed crystals to the raw material composition. The seed crystals are zeolites having a function of promoting the formation of the framework structure of the oxygen 10-membered ring zeolite to be produced. For example, zeolites having the same framework structure as the zeolite to be produced can be used. The addition amount of the seed crystals can be, for example, 0.1% by mass or more and 10% by mass or less, and can also be 0.5% by mass or more and 3% by mass or less with respect to 100% by mass of the raw material composition (excluding seed crystals).

[0102] In addition, the oxygen 10-membered ring zeolite obtained by the above-described crystallization treatment may be subjected to one or more treatments selected from the group consisting of a washing treatment, a drying treatment, an SDA removal treatment, and an ammonium treatment, and it is preferable that at least the SDA removal treatment is performed. The oxygen 10-membered ring zeolite subjected to the SDA removal treatment is liable to have a decrease in the total pore volume by a predetermined element contact treatment, and the total pore volume tends to be 0.21 cm 3 / g or less through a predetermined element-containing step, so that the zeolite of the present embodiment is easily produced.

[0103] The washing treatment is a step of washing the oxygen 10-membered ring zeolite. For example, in the washing treatment, the oxygen 10-membered ring zeolite may be washed with pure water.

[0104] The drying treatment is a treatment for removing moisture from the oxygen 10-membered ring zeolite. The conditions of the drying treatment are not particularly limited as long as moisture can be removed from the oxygen 10-membered ring zeolite. For example, the drying temperature may be 100°C or higher and 150°C or lower. Also, for example, the drying time may be 2 hours or longer and 20 hours or shorter. Also, for example, the atmosphere during drying may be in the air.

[0105] The SDA removal treatment is a treatment for removing the SDA contained in the oxygen 10-membered ring zeolite. Usually, the zeolite crystallized using SDA contains SDA in its pores. By including the SDA removal step, the SDA contained in the oxygen 10-membered ring zeolite can be removed.

[0106] The SDA removal treatment only needs to remove the SDA and can be carried out by any method. Examples of the SDA removal method include at least one selected from the group consisting of liquid-phase treatment using an acidic aqueous solution, exchange treatment using a resin, etc., and heat treatment (pyrolysis). From the viewpoint of production efficiency, the SDA removal treatment is preferably heat treatment (pyrolysis). The conditions of the heat treatment (pyrolysis) are not particularly limited as long as the SDA is removed. For example, the heat treatment temperature may be 400°C or higher and 800°C or lower. Also, for example, the heat treatment time may be 1 hour or longer and 5 hours or shorter. Also, for example, the atmosphere during the heat treatment may be in the air.

[0107] The ammonium treatment is a treatment for removing the alkali metal contained in the oxygen 10-membered ring zeolite. The ammonium treatment can be carried out by a known method. For example, it can be carried out by contacting an aqueous solution containing ammonium ions with the oxygen 10-membered ring zeolite. By being subjected to the ammonium treatment, the cation type of the oxygen 10-membered ring zeolite becomes the NH4 type. Note that the ammonium-treated oxygen 10-membered ring zeolite can also have its cation type changed to the proton type (H + type) by firing treatment at 400°C or higher and 700°C or lower.

[0108] The zeolite of the present embodiment described above can increase the p-xylene selectivity in the production of xylene by the reforming of alcohol. The reason why the zeolite of the present embodiment increases the p-xylene selectivity has not been clarified, but the total pore volume of the oxygen 10-membered ring zeolite is 0.21 cm 3It is below / g, and when the xylene generated inside the oxygen 10-membered ring zeolite (acid sites inside the zeolite) is discharged through the pores due to the inclusion of a predetermined element in the oxygen 10-membered ring zeolite, it is considered to cause steric hindrance. As a result, among the xylenes generated inside the oxygen 10-membered ring zeolite, o-xylene and m-xylene are less likely to be discharged from the pores, and only p-xylene among the xylenes generated in the pores is likely to be discharged outside the pores, and it is speculated that the p-xylene selectivity increases.

[0109] Moreover, according to the zeolite of the present embodiment, the p-xylene selectivity can be increased without using expensive organosilicon as used in Patent Document 1. Therefore, the zeolite of the present embodiment does not necessarily require a facility for detoxifying waste liquid containing organosilicon, and thus can be applied to an industrial process at low cost.

Examples

[0110] The present disclosure will be described more specifically with reference to the following examples, but the present disclosure is not limited to the following examples at all.

[0111] (Identification of crystal phase) The measurement sample (zeolite) was subjected to XRD measurement of the measurement sample using a general powder X-ray diffractometer (device name: Ultima IV, manufactured by Rigaku Corporation). The measurement conditions are as follows. Accelerating current and voltage: 10 mA·30 kV X-ray source: CuKα ray (λ = 1.54178 Å) Measurement mode: continuous scan Scan condition: 2° / min Measurement range: 2θ = 10~70° Scattering slit: 1 / 3° Divergence slit: 1 / 3° Receiving slit: 0.3 mm Filter: Ni filter

[0112] The obtained XRD patterns were subjected to baseline correction, detection of each XRD peak after correction, and intensity analysis using an analysis program (trade name: IGOR Pro 8, manufactured by WaveMetrics) attached to the measuring device. The crystal phase of the zeolite was identified by comparing the corrected XRD pattern with a reference pattern.

[0113] (Composition analysis) As a pretreatment, the measurement sample was heat-treated at 600 °C for 60 minutes in an air atmosphere. The pretreated measurement sample was dissolved in a mixed aqueous solution of hydrofluoric acid and nitric acid to prepare a sample solution. The sample solution was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) using a general ICP device (device name: OPTIMA5300DV, manufactured by PerkinElmer). From the measured values of aluminum (Al), silicon (Si), a predetermined element, and other elements obtained, the SiO2 / Al2O3 ratio of the measurement sample, the mass ratio of the predetermined element to the measurement sample (predetermined element content), and the mass ratio of other elements to the measurement sample (other element content) were determined. The mass of the pretreated measurement sample was used as the mass of the measurement sample.

[0114] (Total pore volume) A nitrogen adsorption / desorption isotherm for the measurement sample was obtained using a general nitrogen adsorption device (device name: BELSORP-miniII, manufactured by MicrotracBEL). Nitrogen gas adsorption was performed using the constant volume method. The measurement conditions are as follows. Measurement temperature: -196 °C Pretreatment: Vacuum drying at 350 °C for 2 hours

[0115] The adsorption amount V (cm 3 ) of nitrogen gas at p / p0 = 0.990 was determined from the nitrogen adsorption / desorption isotherm, and the total pore volume was calculated by substituting the obtained adsorption amount V into the above equation (1).

[0116] (IR spectrum) The IR spectrum was measured using an FT-IR device (device name: FT / IR-6600, manufactured by JASCO Corporation) equipped with a heated transmission cell (manufactured by Makuhari Glass Co., Ltd.). The measurement sample was in disk form (about 10 mg / cm2 ) It was press-molded and pretreated in a heating permeation cell at 450 °C for 2 hours under vacuum. Then, it was cooled down to 200 °C under vacuum conditions, and the background spectrum was measured under the following measurement conditions. Measurement method: Heating permeation method Measurement temperature: 200 °C Measurement wavelength range: 800~4000 cm-1 Resolution: 2 cm-1 Number of integrations: 128 times Measurement atmosphere: Vacuum

[0117] Subsequently, 2,6-di-tert-butylpyridine was introduced into the heating permeation cell and brought into contact with the measurement sample for 30 minutes at 200 °C and 100 Pa. Then, the heating permeation cell was treated at 200 °C for 30 minutes under vacuum to remove the excess 2,6-di-tert-butylpyridine, and then the adsorption spectrum was measured under the above measurement conditions. The background spectrum was subtracted from the obtained adsorption spectrum to obtain a difference spectrum. In the obtained difference spectrum, the maximum intensity (height intensity) of p(1600 cm -1 ~1620 cm -1 ) and the maximum intensity (height intensity) of p(1630 cm -1 ~1650 cm -1 ) were determined, and the IR peak ratio was determined.

[0118] Synthesis Example 1 (Synthesis of MFI-type zeolite) Normal butylamine (hereinafter also referred to as "NBA"), a 48 mass% aqueous sodium hydroxide solution, pure water, and amorphous aluminosilicate (SiO2 / Al2O3 ratio: 50) were mixed to obtain a raw material composition having the following molar composition. SiO2 / Al2O3 ratio = 50 NBA / SiO2 ratio = 0.10 Na / SiO2 ratio = 0.10 OH - / SiO2 ratio = 0.10 H2O / SiO2 ratio = 11

[0119] The seed crystal (MFI-type zeolite; SiO2 / Al2O3 molar ratio: 2400) was mixed with 55 g of the raw material composition so that the seed crystal content was 1% by mass with respect to 100% by mass of the raw material composition, and then the mixture was filled into a sealed container with a volume of 80 mL. After filling, the container was rotated at 55 rpm and reacted by hydrothermal treatment at 150 °C for 36 hours under autogenous pressure to obtain a crystallized product. The obtained crystallized product was recovered after solid-liquid separation, washing with pure water, and drying in an air atmosphere at 110 °C. The crystallized product (hereinafter, also referred to as "the crystallized product of Synthesis Example 1") consisted of a single phase of MFI-type zeolite, had an SiO2 / Al2O3 molar ratio of 48, and a total pore volume of 0.23 cm 3 / g.

[0120] Next, the obtained crystallized product (MFI-type zeolite) of Synthesis Example 1 was calcined in an air atmosphere at 600 °C for 2 hours (SDA removal treatment). The calcined MFI-type zeolite and an aqueous ammonium chloride solution with an NH4Cl concentration of 20% by mass were mixed at 60 °C so that the mass ratio was 1:1, thereby obtaining an MFI-type zeolite with an NH4 type cation type. The MFI-type zeolite was washed with pure water and dried in an air atmosphere at 110 °C for 12 hours to obtain the MFI-type zeolite of this synthesis example.

[0121] The MFI-type zeolite of this synthesis example was a crystalline aluminosilicate with an SiO2 / Al2O3 molar ratio of 48 and a total pore volume of 0.25 cm 3 / g. Also, the MFI-type zeolite of this synthesis example had an IR peak ratio of 0.1.

[0122] Synthesis Example 2 A raw material composition having the following molar composition was obtained in the same manner as in Synthesis Example 1, except that tetrapropylammonium bromide (hereinafter, also referred to as "TPABr") was used instead of NBA and the following molar composition was used. SiO2 / Al2O3 ratio = 50 TPABr / SiO2 ratio = 0.05 Na / SiO2 ratio = 0.17 OH - / SiO2 ratio = 0.17 H2O / SiO2 ratio = 10

[0123] A seed crystal (MFI-type zeolite; SiO2 / Al2O3 molar ratio: 50) was mixed with 55 g of the raw material composition so that the seed crystal content was 1% by mass with respect to 100% by mass of the raw material composition. After that, the mixture was filled into a sealed container with a volume of 80 mL. After filling, the container was rotated at 55 rpm and reacted by hydrothermal treatment at 115 °C for 84 hours under autogenous pressure to obtain a crystallized product. The obtained crystallized product was recovered after solid-liquid separation, washing with pure water, and drying in an air atmosphere at 110 °C. The crystallized product (hereinafter also referred to as the "crystallized product of Synthesis Example 2") consisted of a single phase of MFI-type zeolite and was an MFI-type zeolite (crystalline aluminosilicate) with a SiO2 / Al2O3 ratio of 48.

[0124] Next, under the same conditions of calcination, ion exchange, washing, and drying as those performed on the crystallized product of Synthesis Example 1, the obtained crystallized product of Synthesis Example 2 (MFI-type zeolite) was calcined, ion-exchanged, washed, and dried to obtain the MFI-type zeolite of this synthesis example.

[0125] The MFI-type zeolite of this synthesis example had a SiO2 / Al2O3 molar ratio of 48 and was a crystalline aluminosilicate with a total pore volume of 0.64 cm 3 / g. Also, the MFI-type zeolite of this synthesis example had an IR peak ratio of 0.0.

[0126] Synthesis Example 3 A raw material composition having the following molar composition was obtained in the same manner as in Synthesis Example 1, except that an amorphous aluminosilicate (SiO2 / Al2O3 ratio: 83) was used instead of the amorphous aluminosilicate (SiO2 / Al2O3 ratio: 50) and the following molar composition was used. SiO2 / Al2O3 ratio = 83 NBA / SiO2 ratio = 0.10 Na / SiO2 ratio = 0.10 OH - / SiO2 ratio = 0.10 H2O / SiO2 ratio = 11

[0127] The seed crystal (MFI-type zeolite; SiO2 / Al2O3 molar ratio: 2400) was mixed with 55 g of the raw material composition so that the seed crystal content was 1% by mass based on 100% by mass of the raw material composition, and then this was filled into a sealed container with a volume of 80 mL. After filling, the container was reacted by hydrothermal treatment at 150 °C for 36 hours under autogenous pressure while rotating at 55 rpm to obtain a crystallized product. The obtained crystallized product was recovered after solid-liquid separation, washing with pure water, and drying in an air atmosphere at 110 °C. The crystallized product (hereinafter also referred to as "the crystallized product of Synthesis Example 3") consisted of a single phase of MFI-type zeolite and was an MFI-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 molar ratio of 80.

[0128] Next, under the same conditions of calcination, ion exchange, washing, and drying as those performed on the crystallized product of Synthesis Example 1, the obtained crystallized product of Synthesis Example 3 (MFI-type zeolite) was calcined, ion-exchanged, washed, and dried to obtain the MFI-type zeolite of this synthesis example.

[0129] The MFI-type zeolite of this synthesis example had an SiO2 / Al2O3 molar ratio of 80 and was a crystalline aluminosilicate with a total pore volume of 0.21 cm 3 / g. Also, the MFI-type zeolite of this synthesis example had an IR peak ratio of 0.1.

[0130] Synthesis Example 4 A raw material composition having the following molar composition was obtained in the same manner as in Synthesis Example 1, except that an amorphous aluminosilicate (SiO2 / Al2O3 ratio: 216) was used instead of the amorphous aluminosilicate (SiO2 / Al2O3 ratio: 50) and the following molar composition was used. SiO2 / Al2O3 ratio = 216 NBA / SiO2 ratio = 0.10 Na / SiO2 ratio = 0.10 OH - / SiO2 ratio = 0.10 H2O / SiO2 ratio = 11

[0131] The seed crystal (MFI-type zeolite; SiO2 / Al2O3 molar ratio: 2400) was mixed with 55 g of the raw material composition so that the seed crystal content was 1% by mass with respect to 100% by mass of the raw material composition. After that, the mixture was filled into a sealed container with a volume of 80 mL. After filling, the container was rotated at 55 rpm and reacted by hydrothermal treatment at 150 °C for 36 hours under autogenous pressure to obtain a crystallized product. The obtained crystallized product was recovered after solid-liquid separation, washing with pure water, and drying in an air atmosphere at 110 °C. The crystallized product (hereinafter also referred to as the "crystallized product of Synthesis Example 4") consisted of a single phase of MFI-type zeolite and was an MFI-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 molar ratio of 197.

[0132] Next, under the same conditions of calcination, ion exchange, washing, and drying as those performed on the crystallized product of Synthesis Example 1, the obtained crystallized product of Synthesis Example 3 (MFI-type zeolite) was calcined, ion-exchanged, washed, and dried to obtain the MFI-type zeolite of this synthesis example.

[0133] The MFI-type zeolite of this synthesis example had an SiO2 / Al2O3 molar ratio of 206 and a total pore volume of 0.21 cm 3 / g and was a crystalline aluminosilicate. Also, the MFI-type zeolite of this synthesis example had an IR peak ratio of 0.1.

[0134] Example 1 An aqueous magnesium acetate solution was obtained by dissolving 5.29 g of magnesium acetate tetrahydrate in 4 g of pure water at 60 °C. 10.0 g of the MFI-type zeolite of Synthesis Example 1 and the aqueous magnesium acetate solution were mixed in a mortar at room temperature and atmospheric pressure for 10 minutes. The obtained mixture was dried in an air atmosphere at 110 °C overnight and then calcined in an air atmosphere at 550 °C for 2 hours to obtain the MFI-type zeolite of this example with magnesium supported (hereinafter also referred to as "magnesium-containing MFI-type zeolite").

[0135] The magnesium-containing MFI-type zeolite of this example was an aluminosilicate with a SiO2 / Al2O3 ratio of 48 and a mass ratio of magnesium element to the MFI-type zeolite of this example (hereinafter, also referred to as "Mg content") of 6.0% by mass. Further, the magnesium-containing MFI-type zeolite of this example had a total pore volume of 0.18 cm 3 / g and an IR peak ratio in the difference spectrum of 1.8.

[0136] Comparative Example 1 The MFI-type zeolite obtained in Synthesis Example 1 was used as the MFI-type zeolite of this comparative example.

[0137] Comparative Example 2 An aqueous zinc nitrate solution was obtained by dissolving 0.49 g of zinc nitrate hexahydrate in 3.8 g of pure water. An MFI-type zeolite of this comparative example (hereinafter, also referred to as "zinc-containing MFI-type zeolite") supported with zinc was obtained in the same manner as in Example 1, except that the aqueous zinc nitrate solution was used instead of the aqueous magnesium acetate solution.

[0138] The zinc-containing MFI-type zeolite of this comparative example was an aluminosilicate with a SiO2 / Al2O3 ratio of 48 and a mass ratio of zinc element to the MFI-type zeolite of this comparative example (hereinafter, also referred to as "Zn content") of 1.1% by mass. Further, the zinc-containing MFI-type zeolite of this comparative example had a total pore volume of 0.25 cm 3 / g and an IR peak ratio in the difference spectrum of 0.0.

[0139] Example 2 An MFI-type zeolite of this example (hereinafter, also referred to as "magnesium / zinc-containing MFI-type zeolite") supported with magnesium and zinc was obtained in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained in Comparative Example 2 was used instead of the MFI-type zeolite of Synthesis Example 1.

[0140] The magnesium / zinc-containing MFI-type zeolite of this example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48, a Mg content of 6.0 mass%, and a Zn content of 1.1 mass%. Also, the magnesium / zinc-containing MFI-type zeolite of this example had a total pore volume of 0.19 cm 3 / g and an IR peak ratio in the difference spectrum of 1.7.

[0141] Example 3 An aqueous calcium nitrate solution was obtained by dissolving 3.54 g of calcium nitrate tetrahydrate in 3 g of pure water. A calcium- and zinc-supported MFI-type zeolite of this example (hereinafter also referred to as "calcium / zinc-containing MFI-type zeolite") was obtained in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained in Comparative Example 2 was used instead of the MFI-type zeolite of Synthesis Example 1, and an aqueous calcium nitrate solution was used instead of the aqueous magnesium acetate solution.

[0142] The calcium / zinc-containing MFI-type zeolite of this example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48, a mass ratio of calcium to the MFI-type zeolite of this example (hereinafter also referred to as "Ca content") of 6.0 mass%, and a Zn content of 1.1 mass%. Also, the calcium / zinc-containing MFI-type zeolite of this example had a total pore volume of 0.20 cm 3 / g and an IR peak ratio in the difference spectrum of 3.6.

[0143] Example 4 An aqueous diammonium hydrogen phosphate solution was obtained by dissolving 2.56 g of diammonium hydrogen phosphate in 4 g of pure water. A phosphorus- and zinc-supported MFI-type zeolite of this example (hereinafter also referred to as "phosphorus / zinc-containing MFI-type zeolite") was obtained in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained in Comparative Example 2 was used instead of the MFI-type zeolite of Synthesis Example 1, and an aqueous diammonium hydrogen phosphate solution was used instead of the aqueous magnesium acetate solution.

[0144] The phosphorus / zinc-containing MFI-type zeolite of this example had a SiO2 / Al2O3 ratio of 48, a mass ratio of phosphorus element to the MFI-type zeolite of this example (hereinafter also referred to as "P content") of 6.0% by mass, and a Zn content of 1.1% by mass, and was an aluminosilicate. Further, the phosphorus / zinc-containing MFI-type zeolite of this example had a total pore volume of 0.14 cm 3 / g.

[0145] Example 5 An aqueous zinc nitrate solution was obtained by dissolving 0.88 g of gallium nitrate n-hydrate (gallium nitrate content: 64.5% by mass) in 2.3 g of pure water. A gallium-supported MFI-type zeolite of this example (hereinafter also referred to as "gallium-containing MFI-type zeolite") was obtained in the same manner as in Comparative Example 2, except that the aqueous gallium nitrate solution was used instead of the aqueous zinc nitrate solution.

[0146] An MFI-type zeolite of this example supporting magnesium and gallium (hereinafter also referred to as "magnesium / gallium-containing MFI-type zeolite") was obtained in the same manner as in Example 1, except that the gallium-containing MFI-type zeolite obtained instead of the MFI-type zeolite of Synthesis Example 1 was used.

[0147] The magnesium / gallium-containing MFI-type zeolite of this example had a SiO2 / Al2O3 ratio of 48, an Mg content of 6.0% by mass, and a mass ratio of gallium element to the MFI-type zeolite of this example (hereinafter also referred to as "Ga content") of 1.7% by mass, and was an aluminosilicate. Further, the magnesium / gallium-containing MFI-type zeolite of this example had a total pore volume of 0.21 cm 3 / g and an IR peak ratio in the difference spectrum of 2.0.

[0148] Example 6 A zinc-containing MFI-type zeolite was obtained in the same manner as in Comparative Example 2, except that the MFI-type zeolite of Synthesis Example 3 was used instead of the MFI-type zeolite of Synthesis Example 1, and the amount of zinc nitrate hexahydrate added was changed from 0.49 g to 0.28 g. A magnesium / zinc-containing MFI-type zeolite of this Example, supporting magnesium and zinc, was obtained in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained was used instead of the MFI-type zeolite of Synthesis Example 1, and the amount of magnesium acetate tetrahydrate added was changed from 5.29 g to 3.53 g.

[0149] The magnesium / zinc-containing MFI-type zeolite of this Example was an aluminosilicate having an SiO2 / Al2O3 ratio of 80, a Mg content of 4.0 mass%, and a Zn content of 0.66 mass%. Further, the magnesium / zinc-containing MFI-type zeolite of this Example had a total pore volume of 0.17 cm 3 / g and an IR peak ratio in the difference spectrum of 3.5.

[0150] Example 7 A magnesium / zinc-containing MFI-type zeolite of this Example, supporting magnesium and zinc, was obtained in the same manner as in Example 6, except that the amount of magnesium acetate tetrahydrate added was changed from 3.53 g to 5.29 g.

[0151] The magnesium / zinc-containing MFI-type zeolite of this Example was an aluminosilicate having an SiO2 / Al2O3 ratio of 80, a Mg content of 6.0 mass%, and a Zn content of 0.66 mass%. Further, the magnesium / zinc-containing MFI-type zeolite of this Example had a total pore volume of 0.15 cm 3 / g and an IR peak ratio in the difference spectrum of 2.2.

[0152] Example 8 The magnesium / zinc-containing MFI-type zeolite of this example carrying magnesium and zinc was obtained in the same manner as in Example 6, except that the addition amount of magnesium acetate tetrahydrate was changed from 3.53 g to 5.29 g and the addition amount of zinc nitrate hexahydrate was changed from 0.28 g to 0.34 g.

[0153] The magnesium / zinc-containing MFI-type zeolite of this example was an aluminosilicate having an SiO2 / Al2O3 ratio of 80, a Mg content of 6.0% by mass, and a Zn content of 0.79% by mass. Also, the magnesium / zinc-containing MFI-type zeolite of this example had a total pore volume of 0.13 cm 3 / g and an IR peak ratio in the difference spectrum of 2.1.

[0154] Example 9 The magnesium / zinc-containing MFI-type zeolite of this example carrying magnesium and zinc was obtained in the same manner as in Example 6, except that the addition amount of magnesium acetate tetrahydrate was changed from 3.53 g to 5.29 g and the addition amount of zinc nitrate hexahydrate was changed from 0.28 g to 0.87 g.

[0155] The magnesium / zinc-containing MFI-type zeolite of this example was an aluminosilicate having an SiO2 / Al2O3 ratio of 80, a Mg content of 6.0% by mass, and a Zn content of 2.0% by mass. Also, the magnesium / zinc-containing MFI-type zeolite of this example had a total pore volume of 0.11 cm 3 / g and an IR peak ratio in the difference spectrum of 4.0.

[0156] Example 10 A zinc-containing MFI-type zeolite was obtained in the same manner as in Comparative Example 2, except that the MFI-type zeolite of Synthesis Example 4 was used instead of the MFI-type zeolite of Synthesis Example 1, and the amount of zinc nitrate hexahydrate added was changed from 0.49 g to 0.28 g. A magnesium / zinc-containing MFI-type zeolite of this Example carrying magnesium and zinc was obtained in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained was used instead of the MFI-type zeolite of Synthesis Example 1, and the amount of magnesium acetate tetrahydrate added was changed from 5.29 g to 3.53 g.

[0157] The magnesium / zinc-containing MFI-type zeolite of this Example was an aluminosilicate having an SiO2 / Al2O3 ratio of 206, a Mg content of 4.0% by mass, and a Zn content of 0.66% by mass. Further, the magnesium / zinc-containing MFI-type zeolite of this Example had a total pore volume of 0.17 cm 3 / g and an IR peak ratio in the difference spectrum of 1.7.

[0158] Example 11 A zinc-containing MFI-type zeolite was obtained in the same manner as in Comparative Example 2, except that a commercially available MEL-type zeolite (ZSM-11 manufactured by ACS Material, SiO2 / Al2O3 ratio: 50) was used instead of the MFI-type zeolite of Synthesis Example 1. A magnesium / zinc-containing MEL-type zeolite of this Example carrying magnesium and zinc was obtained in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained was used instead of the MFI-type zeolite of Synthesis Example 1.

[0159] The magnesium / zinc-containing MEL-type zeolite of this Example was an aluminosilicate having an SiO2 / Al2O3 ratio of 50, a Mg content of 6.0% by mass, and a Zn content of 1.1% by mass. Further, the magnesium / zinc-containing MEL-type zeolite of this Example had a total pore volume of 0.17 cm 3 / g and an IR peak ratio in the difference spectrum of 3.2.

[0160] Example 12 An aqueous calcium nitrate solution was obtained by dissolving 3.54 g of calcium nitrate tetrahydrate in 3 g of pure water. A calcium-supported MFI-type zeolite of this example (hereinafter, also referred to as "calcium-containing MFI-type zeolite") was obtained in the same manner as in Example 1, except that an aqueous calcium nitrate solution was used instead of the aqueous magnesium acetate solution.

[0161] The calcium-containing MFI-type zeolite of this example was an aluminosilicate having an SiO2 / Al2O3 ratio of 48 and a Ca content of 6.0% by mass. Also, the calcium-containing MFI-type zeolite of this example had a total pore volume of 0.21 cm 3 / g and an IR peak ratio in the difference spectrum of 5.0.

[0162] Comparative Example 3 An MFI-type zeolite of this comparative example (magnesium-containing MFI-type zeolite) supporting magnesium was obtained in the same manner as in Example 1, except that the crystallized product of Synthesis Example 1 was used instead of the MFI-type zeolite of Synthesis Example 1.

[0163] The magnesium-containing MFI-type zeolite of this comparative example was an aluminosilicate having an SiO2 / Al2O3 ratio of 48 and an Mg content of 6.0% by mass. Also, the magnesium-containing MFI-type zeolite of this comparative example had a total pore volume of 0.23 cm 3 / g and an IR peak ratio in the difference spectrum of 1.4.

[0164] Comparative Example 4 An MFI-type zeolite of this comparative example (magnesium-containing MFI-type zeolite) supporting magnesium was obtained in the same manner as in Example 1, except that the MFI-type zeolite of Synthesis Example 2 was used instead of the MFI-type zeolite of Synthesis Example 1.

[0165] The magnesium-containing MFI-type zeolite of this comparative example was an aluminosilicate having an SiO2 / Al2O3 ratio of 48 and an Mg content of 6.0% by mass. Also, the magnesium-containing MFI-type zeolite of this comparative example had a total pore volume of 0.62 cm3 It was / g, and the IR peak ratio in the difference spectrum was 1.5.

[0166] Comparative Example 5 The magnesium-containing MFI-type zeolite of this comparative example was prepared in the same manner as Comparative Example 4, except that the addition amount of magnesium acetate tetrahydrate was changed from 5.29 g to 10.59 g.

[0167] The magnesium-containing MFI-type zeolite of this comparative example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48 and a Mg content of 12.0 mass%. Also, the magnesium-containing MFI-type zeolite of this comparative example had a total pore volume of 0.52 cm 3 / g.

[0168] Comparative Example 6 The gallium-containing MFI-type zeolite of this comparative example was obtained in the same manner as in Example 5. That is, an aqueous zinc nitrate solution was obtained by dissolving 0.88 g of gallium nitrate n-hydrate (gallium nitrate content: 64.5 mass%) in 2.3 g of pure water. The gallium-containing MFI-type zeolite of this comparative example was obtained in the same manner as Comparative Example 2, except that the aqueous gallium nitrate solution was used instead of the aqueous zinc nitrate solution.

[0169] The gallium-containing MFI-type zeolite of this comparative example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48 and a Ga content of 1.7 mass%. Also, the gallium-containing MFI-type zeolite of this comparative example had a total pore volume of 0.24 cm 3 / g.

[0170] Comparative Example 7 The magnesium / zinc-containing MFI-type zeolite of this comparative example was prepared in the same manner as in Example 6, except that the addition amount of magnesium acetate tetrahydrate was changed from 3.53 g to 1.76 g.

[0171] The magnesium / zinc-containing MFI-type zeolite of this comparative example was an aluminosilicate with an SiO2 / Al2O3 ratio of 80, an Mg content of 2.0% by mass, and a Zn content of 0.66% by mass. Also, the total pore volume of the magnesium / zinc-containing MFI-type zeolite of this comparative example was 0.22 cm 3 / g.

[0172] Comparative Example 8 A zinc-containing MFI-type zeolite was obtained in the same manner as in Comparative Example 2, except that the amount of zinc nitrate hexahydrate added was changed from 0.49 g to 0.28 g. The magnesium / zinc-containing MFI-type zeolite of this comparative example was prepared in the same manner as in Example 1, except that the zinc-containing MFI-type zeolite obtained instead of the MFI-type zeolite of Synthesis Example 1 was used, and the amount of magnesium acetate tetrahydrate added was changed from 5.29 g to 3.53 g.

[0173] The magnesium / zinc-containing MFI-type zeolite of this comparative example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48, an Mg content of 4.0% by mass, and a Zn content of 0.66% by mass. Also, the total pore volume of the magnesium / zinc-containing MFI-type zeolite of this comparative example was 0.24 cm 3 / g, and the IR peak ratio in the difference spectrum was 1.2.

[0174] Comparative Example 9 An aqueous zinc nitrate solution was obtained by dissolving 0.49 g of zinc nitrate hexahydrate in 3.8 g of pure water. A magnesium / zinc-containing MFI-type zeolite of this comparative example (hereinafter also referred to as "zinc / magnesium-containing MFI-type zeolite") carrying zinc and magnesium was obtained in the same manner as in Example 1, except that the magnesium-containing MFI-type zeolite of Example 1 was used instead of the MFI-type zeolite of Synthesis Example 1, and the aqueous zinc nitrate solution was used instead of the aqueous magnesium acetate solution.

[0175] The zinc / magnesium-containing MFI-type zeolite of this comparative example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48, a Zn content of 1.1% by mass, and a Mg content of 6.0% by mass. Also, the total pore volume of the zinc / magnesium-containing MFI-type zeolite of this comparative example was 0.22 cm 3 / g.

[0176] Comparative Example 10 An aqueous nickel nitrate solution was obtained by dissolving 0.43 g of nickel(II) nitrate hexahydrate in 2 g of pure water. A nickel-supported MFI-type zeolite of this comparative example (hereinafter also referred to as "nickel-containing MFI-type zeolite") was obtained in the same manner as in Example 1, except that the aqueous nickel nitrate solution was used instead of the aqueous magnesium acetate solution.

[0177] The nickel-containing MFI-type zeolite of this comparative example was an aluminosilicate with an SiO2 / Al2O3 ratio of 48 and a mass ratio of nickel element to the MFI-type zeolite of this comparative example (hereinafter also referred to as "Ni content") of 1.0% by mass. Also, the total pore volume of the nickel-containing MFI-type zeolite of this comparative example was 0.17 cm 3 / g.

[0178] Comparative Example 11 7.06 g of a sodium silicate No. 3 aqueous solution (containing 14.5% by mass of Si in terms of SiO2 and 4.5% by mass of Na in terms of Na2O) and 10.0 g of the MFI-type zeolite of Synthesis Example 1 were mixed in a mortar for 10 minutes, and the resulting mixture was dried overnight at 110°C in an air atmosphere and then calcined at 550°C for 2 hours in an air atmosphere to obtain the MFI-type zeolite of this comparative example supported with silica (hereinafter also referred to as "silica-supported MFI-type zeolite").

[0179] The silica-supported MFI-type zeolite of this comparative example had an SiO2 / Al2O3 ratio of 58, and the mass ratio of the supported silicon element to the MFI-type zeolite of this comparative example (hereinafter also referred to as "Si content") was 8.4% by mass. Further, the silica-supported MFI-type zeolite of this comparative example had a total pore volume of 0.13 cm 3 / g, and the IR peak ratio in the difference spectrum was 0.0.

[0180] The characteristics of the zeolites of each example and each comparative example are shown in Tables 1 and 2 below. For Tables 1 and 2 below, SAR refers to the SiO2 / Al2O3 ratio.

Table 1

Table 2

[0181] As can be understood from the results of Comparative Examples 1, 2, and 6 shown in the above table, simply supporting other elements such as zinc and gallium on the oxygen 10-membered ring zeolite did not show a significant change in the total pore volume. On the other hand, as is clear from the comparison between Comparative Example 2 and Examples 2, 3, and 4, and the comparison between Comparative Example 6 and Example 5, when a predetermined element such as magnesium, calcium, or phosphorus was supported on the oxygen 10-membered ring zeolite, the total pore volume decreased. From this result, it was inferred that in the oxygen 10-membered ring zeolites of Examples 1 to 12, at least a part of the predetermined elements such as magnesium, calcium, and phosphorus was supported on the inner surface of the pores of the zeolite, resulting in a decrease in the total pore volume. On the other hand, in Comparative Example 3 in which magnesium was supported on the non-fired oxygen 10-membered ring zeolite (zeolite without SDA removal treatment), and in Comparative Example 7 in which the Mg content was low compared to other examples and comparative examples, it was understood that the total pore volume was less likely to decrease and magnesium was less likely to be supported on the inner surface of the pores.

[0182] Also, as can be understood from the IR peak ratios of Example 1 and Comparative Example 1 shown in the above table, the IR peak ratio increased by supporting magnesium on the MFI-type zeolite. Further, as can be understood from the IR peak ratios of Examples 2 to 4 and Comparative Example 2 shown in Table 1 above, the IR peak ratio increased by supporting predetermined elements such as calcium, magnesium, and phosphorus on the zinc-containing MFI-type zeolite. From these results, it was understood that predetermined elements such as magnesium, calcium, and phosphorus are likely to be supported on the outer surface of the zeolite. On the other hand, as can be understood from the IR peak ratios of Comparative Example 1 and Comparative Example 2, the IR peak ratio hardly changed even when zinc was supported on the MFI-type zeolite. From this result, it was inferred that in the MFI-type zeolite of Comparative Example 2, zinc was supported on a site other than the outer surface of the MFI-type zeolite (for example, inside the MFI-type zeolite).

[0183] Measurement Example 1 <Methanol reforming reaction> Using a fixed-bed flow-type reactor, a stainless-steel reaction tube with an inner diameter of 8 mm was filled with 2 g of the measurement sample. Nitrogen was passed through the reaction tube at a flow rate of 50 mL / min, a temperature of 450 °C, and a pressure of 0.2 MPa (gauge pressure) for 1 hour, and this was used as a pretreatment (activation treatment). After the pretreatment, nitrogen supplied at a flow rate of 20 mL / min and gaseous methanol vaporized from liquid methanol supplied at 2 g / min at 65 °C were supplied to the reaction tube, and a mixed gas of nitrogen and methanol (nitrogen / methanol mixed gas) was passed through the reaction tube at 420 °C, 0.2 MPa (gauge pressure), and a weight hourly space velocity of methanol of 1.0 Hr -1 The methanol concentration at the inlet and outlet of the fixed-bed flow-type reaction tube was measured 6 hours after the start of the flow of the mixed gas. The products were also analyzed by gas chromatography.

[0184] From the obtained results, the methanol conversion rate (%), p-xylene selectivity (%), and BTX yield were determined using the following formulas (2), (3), and (4), respectively.

[0185] Methanol conversion rate (%) ={(Methanol)in - (Methanol)out) / (Methanol)in}×100 ···(2) In the above formula (2), (Methanol)in is the methanol concentration (v / v%) at the inlet of the fixed-bed flow-through reaction tube, and (Methanol)out is the methanol concentration (v / v%) at the outlet of the fixed-bed flow-through reaction tube.

[0186] p-Xylene selectivity (%) =([p-Xylene]out / [Xylene]out)×100 ···(3) In the above formula (3), [p-Xylene]out is the total number of moles (mol) of carbon atoms contained in p-xylene at the outlet of the fixed-bed flow-through reaction tube, and [Xylene]out is the total number of moles (mol) of carbon atoms contained in xylene (p-xylene, o-xylene, and m-xylene) at the outlet of the fixed-bed flow-through reaction tube.

[0187] BTX yield (%) =([BTX]out / [Product]out)×Methanol conversion rate ···(4) In the above formula (4), [BTX]out is the total number of moles (mol) of carbon atoms contained in benzene, xylene (p-xylene, o-xylene, and m-xylene), and toluene at the outlet of the fixed-bed flow-through reaction tube, [Product]out is the total number of moles (mol) of carbon atoms contained in the product (all components in the product) at the outlet of the fixed-bed flow-through reaction tube, and the methanol conversion rate is the methanol conversion rate (%) obtained from the above formula (2).

[0188]

Table 3

Table 4

[0189] As shown in Tables 3 and 4 above, the zeolite of the example was able to increase the p-xylene selectivity in the production of xylene by alcohol reforming compared to the zeolite of the comparative example.

Claims

1. The zeolite has a total pore volume of more than 0 cm3 / g and less than 0.21 cm3 / g, and the content of the predetermined element is 2 mass% or more and 12 mass% or less relative to 100 mass% of the dry mass of the zeolite. ３ / g or less, and a molar ratio of silica to alumina is 10 or more and 250 or less, and a zeolite having a 10-membered oxygen ring structure (excluding MFI type zeolite containing phosphorus).

2. The zeolite according to claim 1, wherein the zeolite having a 10-membered oxygen ring structure is an MFI type zeolite, an MEL type zeolite, a TON type zeolite, an STF type zeolite, an MTT type zeolite, an MWW type zeolite, or a ZSM-48 zeolite.

3. A zeolite described in claim 1 or 2, wherein the zeolite having a 10-membered oxygen ring structure is a crystalline aluminosilicate.

4. 3. The zeolite of claim 1 or 2, further comprising one or more other elements selected from the group consisting of silver, zinc, gallium and iron.

5. 3. The zeolite according to claim 1, wherein the predetermined element is supported on at least the outer surface.

6. In the difference spectrum obtained by subtracting the IR spectrum of the zeolite before 2,6-di-tert-butylpyridine adsorption from the IR spectrum of the zeolite to which 2,6-di-tert-butylpyridine has been adsorbed, －１ 1620cm or more －１ 1630 cm for the maximum intensity of the peak having a peak top in the range －１ More than 1650cm －１ 3. The zeolite according to claim 1 or 2, wherein the ratio of the maximum intensities of the peaks having peak tops in the following ranges is greater than 1.

5.

7. Treatment temperature: 420° C., treatment pressure (gauge pressure): 0.2 MPa, treatment time: 6 hours, and methanol weight hourly space velocity: 1.0 Hr. －１ 3. The zeolite according to claim 1, wherein the p-xylene selectivity is 40% or more when the zeolite is contacted with a mixed gas of nitrogen and methanol under the above-mentioned conditions.

8. A catalyst for alcohol reforming, comprising the zeolite according to claim 1 or 2.

9. A method for producing xylene, comprising contacting the zeolite according to claim 1 or 2 with a fluid containing an alcohol.

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