Crystalline aluminosilicate and method for producing zeolite using the same

Abstract

To provide at least one of a crystalline aluminosilicate obtained by an inexpensive production method and suitable as a starting material for an AEI-type zeolite, a production method thereof, and a production method for an AEI-type zeolite using the same as a starting material, and to provide a simple production method for FAU-type zeolites having high silica composition.SOLUTION: A crystalline aluminosilicate, which has a peak top at 2θ=6.0-7.5° in the powder X-ray diffraction pattern, and an XRD peak showing the maximum diffraction intensity in the X-ray diffraction pattern, in which the number of XRD peaks having relative intensity between 30% and 50% to the intensity of the XRD peak is 2 or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a crystalline aluminosilicate suitable as a raw material for zeolites such as AEI-type zeolite and a method for producing a zeolite using the same as a starting material.

Background Art

[0002] AEI-type zeolite is an artificially synthesized crystalline aluminosilicate (Patent Document 1), and zeolite having an FAU structure is mainly used as its starting material.

[0003] As a conventional method for producing AEI-type zeolite using zeolite having an FAU structure as a starting material, a method using USY zeolite as a starting material (Non-Patent Document 1), a method using a mixture of sodium silicate or colloidal silica and Y zeolite as a starting material (Patent Document 1, Non-Patent Documents 2 and 3), have been reported.

[0004] The USY zeolite used as a starting material is an FAU-type zeolite having a high silica composition, which is usually produced by post-treating (ultra-stabilization treatment) the Y zeolite after crystallization, such as steaming. On the other hand, as a method for producing USY zeolite from only amorphous raw materials, a production method by a radical reaction using hydrogen peroxide has been studied (Non-Patent Document 4).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Non-Patent Document 2

[0007] USY zeolite is a zeolite obtained by subjecting Y zeolite to a dealumination treatment and is very expensive to use as a starting material. In addition, the production method of Non-Patent Document 4 requires expensive reaction equipment, and as a result, the USY zeolite obtained thereby is also expensive. Further, a mixture of Y zeolite and a silica source (for example, sodium silicate or colloidal silica) is likely to have a non-uniform composition in industrial-scale production, and when this is used as a starting material for crystallization, by-products of impurities are likely to occur.

[0008] An object of the present disclosure is to provide at least one of a crystalline aluminosilicate obtained by an inexpensive production method and suitable as a starting material for AEI-type zeolite, a production method thereof, and a production method of AEI-type zeolite using this as a starting material. Another object is to provide a simple production method capable of producing FAU-type zeolite having a high silica composition. [Means for Solving the Problems]

[0009] In the present disclosure, a novel crystalline aluminosilicate has been found to be suitable as a starting material for producing AEI-type zeolite and also as a starting material for FAU-type zeolite having a high silica composition.

[0010] That is, the present invention is as defined in the claims, and the gist of the present disclosure is as follows. [1] In the powder X-ray diffraction pattern, it has a peak top at 2θ = 6.0 to 7.5°, and has an XRD peak showing the maximum diffraction intensity in the X-ray diffraction pattern, and further, the number of XRD peaks with a relative intensity to the intensity of the XRD peak of 30% or more and 50% or less is 2 or less. A crystalline aluminosilicate characterized by this. [2] The crystalline aluminosilicate according to [1] above, which has an oxygen ring structure of 6-membered rings or more. [3] The crystalline aluminosilicate according to [1] or [2] above, wherein the molar ratio of silica to alumina is 12 or more and 100 or less. [4] A process for treating a crystalline aluminosilicate having a FAU structure with an acid. A method for producing a crystalline aluminosilicate according to any one of [1] to [3] above, which has this. [5] The production method according to [4] above, wherein the crystalline aluminosilicate having the FAU structure is Y zeolite. [6] The production method according to [4] or [5] above, wherein the molar ratio of silica to alumina of the crystalline aluminosilicate having the FAU structure is less than 10. [7] The production method according to any one of [4] to [6] above, wherein the crystalline aluminosilicate having the FAU structure has not undergone ultrastabilization treatment. [8] The production method according to any one of [4] to [7] above, wherein the acid is one or more selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid. [9] The production method according to any one of [4] to [8] above, wherein the acid concentration of the acid is 0.8 N or more.

[10] A method for producing AEI-type zeolite using the crystalline aluminosilicate according to any one of [1] to [3] above.

[11] A method for producing FAU-type zeolite using the crystalline aluminosilicate according to any one of [1] to [3] above. [Effects of the Invention]

[0011] In the present disclosure, it is possible to provide at least any one of a crystalline aluminosilicate obtained by an inexpensive production method and suitable as a starting material for AEI-type zeolite, a production method thereof, and a production method of AEI-type zeolite using this as a starting material. Furthermore, it is possible to provide a simple production method capable of producing FAU-type zeolite having a high silica composition.

Brief Description of the Drawings

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Modes for Carrying Out the Invention

[0013] Hereinafter, an example of an embodiment of the present disclosure will be shown and described. 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] The XRD pattern in this embodiment is measured using CuKα rays as the radiation source, and the following conditions can be cited as the measurement conditions. Radiation source: CuKα rays (λ = 1.5406 Å) Measurement mode: Step scan Scan speed: 4.0° per minute Measurement range: 2θ = 3.0° to 50.0°

[0016] The crystalline XRD peak is a peak whose 2θ at the peak top is specified and detected in the analysis of the XRD pattern using general analysis software (for example, SmartLab StudioII, manufactured by Rigaku Corporation). Although not particularly limited, examples of the half-width (full width at half maximum) of the XRD peak include 2θ = 0.50° or less.

[0017] "Zeolite" is a compound in which the framework atoms (hereinafter also referred to as "T atoms") have a regular structure via oxygen (O), and the T atoms are composed of metal atoms. Zeolites may contain two or more types of metal atoms as T atoms. Note that the metal atom is a concept including both atoms composed of metal elements and atoms composed of metalloid elements.

[0018] "Zeolite-like substance" refers to a compound in which T atoms have a regular structure via oxygen, and is a compound containing at least atoms other than metals (hereinafter also referred to as "non-metal atoms") as T atoms. As an example, zeolite-like substances contain metal atoms and non-metal atoms as T atoms. Specific zeolite-like substances include composite phosphorus compounds containing phosphorus (P) as T atoms, such as aluminophosphate (AlPO) and silicoaluminophosphate (SAPO).

[0019] The "regular structure (hereinafter also referred to as the "zeolite structure")" in zeolites and zeolite-like substances is the framework structure specified by the structure code (hereinafter also simply referred to as the "structure code") defined by the Structure Commission of the International Zeolite Association. For example, the AEI structure is the framework structure specified as the structure code "AEI", and the FAU structure is the framework structure specified as the structure code "FAU". The zeolite structure can be identified by comparing with the XRD pattern (hereinafter also referred to as the "reference pattern") of each structure described in Collection of simulated XRD powder patterns for zeolites, Fifth revised edition, p.483 (2007). Regarding the zeolite structure, the framework structure, crystal structure, or crystal phase are used synonymously.

[0020] The "related structure" is a structure formed by connecting the structural units (Building Unit) contained in the zeolite structure and is not identified as a zeolite structure in comparison with the reference pattern.

[0021] In this embodiment, "~ type zeolite" such as "AEI type zeolite" and "FAU type zeolite" means a zeolite having the zeolite structure of the structure code, and preferably means a crystalline aluminosilicate having the zeolite structure of the structure code.

[0022] Hereinafter, an example of an embodiment of the crystalline aluminosilicate of the present disclosure will be shown and described.

[0023] The crystalline aluminosilicate of the present embodiment has a peak top at 2θ = 6.0 to 7.5° in the powder X-ray diffraction pattern, and has an XRD peak (hereinafter, also referred to as the "main peak") showing the maximum diffraction intensity in the powder X-ray diffraction pattern. Moreover, it is a crystalline aluminosilicate characterized in that the number of XRD peaks (hereinafter, also referred to as "sub-peaks") having a relative intensity of 30% or more and 50% or less with respect to the intensity of the XRD peak is 2 or less.

[0024] The crystalline aluminosilicate having such characteristics is considered to be an aluminosilicate having a structure analogous to the FAU structure, and is a crystalline aluminosilicate having a structure formed by connecting the structural units contained in the FAU structure. That is, the crystalline aluminosilicate having the above-described characteristics is considered to be a crystalline aluminosilicate having a structure analogous to the FAU structure. Such an aluminosilicate is a crystalline aluminosilicate different from an aluminosilicate existing as a single structural unit or a crystalline aluminosilicate having a zeolite structure.

[0025] The crystalline aluminosilicate of the present embodiment having the above-described characteristics is a crystalline aluminosilicate, but has high solubility and can serve as a starting material that can promote crystallization even in the crystallization of zeolite in a weak base atmosphere.

[0026] Examples of the structural units contained in the FAU structure include d6r, s4r, and s6r as the structural units defined by the International Zeolite Association. The crystalline aluminosilicate of the present embodiment preferably contains at least one of d6r, s4r, and s6r, and further d6r, as the structural unit.

[0027] In the crystalline aluminosilicate of the present embodiment, the relative intensity of an XRD peak (sub-peak) having a peak top at 2θ = 6.0 to 7.5° with respect to the maximum intensity of the XRD peak (main peak) is 30% or more and 50% or less, and the number of such sub-peaks is 2 or less, and further 1 or less. When the number of sub-peaks exceeds 2 (that is, when there are more than 2 sub-peaks), it becomes a crystalline aluminosilicate having a regular structure almost equivalent to the FAU structure, and when used as a starting material for AEI-type zeolite, it tends to exhibit behavior equivalent to that of Y zeolite or USY zeolite.

[0028] The crystalline aluminosilicate of the present embodiment has a structure in which the T atoms (aluminum and silicon) constituting it are composed of a repeating network via oxygen (O). From the viewpoint of making it a more suitable aluminosilicate as a starting material for AEI-type zeolite, it preferably has an oxygen ring structure of 6-membered ring or more. Here, the PDF function G(r) obtained by pair distribution function (hereinafter also referred to as "PDF") analysis corresponds to a function indicating the frequency of existence of the distance between T atoms (Si, Al), between O atoms, or between a T atom and an O atom. Further, the peak at r = 4.0 or more and 4.5 or less in the PDF function G(r) corresponds to the distance between the second-nearest T atoms and O atoms of an oxygen 6-membered ring structure or more. Therefore, as an example, by having a peak at r = 4.0 or more and 4.5 or less in the PDF function G(r), it can be determined that the crystalline aluminosilicate of the present embodiment has an oxygen ring structure of 6-membered ring or more.

[0029] The PDF function G(r) is obtained by performing PDF analysis using data (scattering spectrum) obtained by high-energy X-ray diffraction measurement. The measurement conditions for high-energy X-ray diffraction are shown below. Energy source: Si(220) 61.4 keV Energy resolution: △E / E = 10 -3 Measurement range: 25 Å-1 Measurement temperature: room temperature

[0030] Such high-energy X-ray diffraction measurements can be carried out, for example, using the BL04B2 beamline at the large synchrotron radiation facility Spring-8. In PDF analysis, after standardizing the obtained data to obtain the Faber-Ziman type structure factor S(Q), the PDF function G(r) can be obtained by the following formula.

[0031] [Number] In the above formula, G(r) is the PDF function, r is the interatomic distance [Å], ρ(r) is the local atomic number density at distance r [1 / Å], ρ0 is the average atomic number density of the entire sample (measurement target) [1 / Å], Q is the scattering (wave number) vector [1 / Å], and S(Q) is the Faber-Ziman type structure factor.

[0032] The PDF function G(r) can be obtained by a known method. For example, it can be obtained according to the method described in Physical Chemistry Chemical Physics, 8, 224-227 (2006). By having an extreme value (maximum) when r is 4.0 or more and 4.5 or less in the obtained PDF function G(r), it can be confirmed that there is a peak when r is 4.0 or more and 4.5 or less.

[0033] The crystalline aluminosilicate of this embodiment is not particularly limited, but the molar ratio of silica to alumina (hereinafter, also referred to as "SiO2 / Al2O3 ratio") is 5 or more, 10 or more, 12 or more, 20 or more, or 23 or more, and 100 or less, 80 or less, or 60 or less.

[0034] The BET specific surface area is not particularly limited, but is 500 m 2 / g or more, 520 m 2 / g or more, or 540 m 2 / g or more, and 800 m 2 / g or less, 780 m 2 / g or less, or 760 m 2 / g or less.

[0035] The micropore volume is not particularly limited, but may be 0.20 mL / g or more, 0.22 mL / g or more, or 0.24 mL / g or more, and 0.36 mL / g or less, 0.34 mL / g or less, or 0.32 mL / g or less.

[0036] Next, a method for producing the crystalline aluminosilicate of the present embodiment will be described.

[0037] As a method for producing the crystalline aluminosilicate of the present embodiment, there is a production method having a step of treating a crystalline aluminosilicate having a FAU structure so as to have a related structure of the FAU structure. Specifically, for example, the crystalline aluminosilicate of the present embodiment can be produced by a production method having a step of treating a crystalline aluminosilicate having a FAU structure with an acid.

[0038] The FAU-type zeolite used in the step of treating a crystalline aluminosilicate having a FAU structure (hereinafter also referred to as the "acid treatment step") with an acid is arbitrary. As the FAU-type zeolite, USY zeolite (that is, a FAU-type zeolite having a SiO2 / Al2O3 ratio of 10 or more) can be used, or Y zeolite can be used. From the viewpoint of reducing production costs, the FAU-type zeolite is preferably Y zeolite. The SiO2 / Al2O3 ratio of Y zeolite may be less than 10, further less than 8, or even less than 6, and may be 4 or more, further 5 or more. Also, the cation type is arbitrary, but it may be one or more selected from the group consisting of proton (H + ) type, ammonium (NH4 + ) type, sodium (Na) type, and potassium (K) type, and further preferably at least one of proton type and sodium type.

[0039] The FAU-type zeolite is preferably an FAU-type zeolite that has not undergone a dealumination treatment. The dealumination treatment is a treatment that prevents the collapse of the FAU structure in the acid treatment. Examples of the dealumination treatment include exposing the zeolite to a high-temperature and high-humidity atmosphere such as a steaming treatment (for example, an atmosphere with a H2O concentration of 70% or more and a temperature of 600°C or more and 900°C or less). FAU-type zeolites that have undergone a dealumination treatment, such as USY zeolites, may maintain the FAU structure even after the acid treatment, depending on the treatment conditions and the like.

[0040] The acid used in the acid treatment step is preferably an inorganic acid, and is more preferably at least one selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid, still more preferably at least one of sulfuric acid and hydrochloric acid, and even more preferably sulfuric acid.

[0041] The acid concentration may be a concentration at which the desorption of aluminum from the FAU structure proceeds appropriately, that is, a concentration at which the desorption of aluminum proceeds while partially maintaining the FAU structure, and examples thereof include 0.8 N ([H + mol / L) or more, preferably 1.0 N or more, and further 4.0 N or less, still further 3.0 N or less. The unit N refers to the molar concentration ([H + mol / L) in terms of hydrogen ion conversion.

[0042] For the acid treatment, an acid and a crystalline aluminosilicate having an FAU structure (FAU-type zeolite) may be mixed, and the following conditions can be exemplified as the mixing conditions. Treatment temperature: 65°C or more or 70°C or more, and 100°C or less or 90°C or less Treatment time: 1 hour or more or 2 hours or more, and 10 hours or less or 5 hours or less

[0043] After the acid treatment step, the obtained crystalline aluminosilicate may be recovered by any method, and may be washed and dried as necessary. For example, filtration can be used as the recovery method, water washing can be used as the washing method, and drying in the air at 90 to 150°C can be used as the drying method.

[0044] Next, a method for producing an AEI-type zeolite using the crystalline aluminosilicate of the present embodiment will be described.

[0045] In the method for producing an AEI-type zeolite of the present embodiment, the crystalline aluminosilicate of the present embodiment may be used as a silica source and an alumina source, and a composition containing the crystalline aluminosilicate of the present embodiment, a structure-directing agent source, an alkali source, and water (hereinafter, also referred to as "raw material composition") is crystallized (hereinafter, also referred to as "crystallization step"). It is preferably a production method having a step.

[0046] Since the crystalline aluminosilicate contains aluminum (Al) and silicon (Si), it functions as an alumina source and a silica source. The alumina source and silica source contained in the raw material composition are preferably only the crystalline aluminosilicate of the present embodiment, but may contain at least one of other alumina sources and silica sources as necessary.

[0047] The alumina source 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, pseudoboehmite, alumina sol, and aluminosilicate gel.

[0048] The silica source 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.

[0049] The structure-directing agent source (hereinafter also referred to as "SDA") may be a compound containing a cation known as an SDA for directing AEI-type zeolite. Examples of the SDA for directing AEI-type zeolite include one or more selected from the group consisting of 1,1,3,5-tetramethylpiperidinium cation, 1,1-diethyl-2,6-dimethylpiperidinium cation, 1,1,2,6-tetramethylpiperidinium cation, 1-ethyl-1,2,6-trimethylpiperidinium cation, and 1,1,2-triethylpiperidinium cation. Preferably, at least one of 1,1,3,5-tetramethylpiperidinium cation and 1,1-diethyl-2,6-dimethylpiperidinium cation, and more preferably 1,1,3,5-tetramethylpiperidinium cation.

[0050] The SDA source may be a salt of the SDA. For example, one or more selected from the group consisting of hydroxide, chloride, bromide, and iodide of the SDA can be mentioned, and further, hydroxide of the SDA can be mentioned.

[0051] The alkali source is a compound containing an alkali metal element, and examples thereof include a compound containing one or more selected from the group consisting of sodium, potassium, cesium, and rubidium, a compound containing at least one of sodium and potassium, or a compound containing sodium. Also, the alkali source can be, for example, one or more selected from the group consisting of hydroxide, carbonate, chloride, bromide, iodide, and sulfate containing an alkali metal element, and further, hydroxide containing an alkali metal element. Particularly preferred alkali sources include at least one of the group consisting of sodium hydroxide, sodium carbonate, sodium chloride, sodium bromide, sodium iodide, and sodium sulfate, and further, sodium hydroxide. Also, the alkali source is not limited to salts, and other raw materials (starting materials) such as sodium silicate, which are other than salts containing an alkali metal element, can also be regarded as the alkali source.

[0052] The water contained in the raw material composition may be distilled water, deionized water, or pure water. Also, water contained in other raw materials such as hydrates, structural water, and solvents can be regarded as the water contained in the raw material composition.

[0053] The following molar compositions can be cited as the composition of the preferred raw material composition. Note that each ratio in the following composition is a molar (mol) ratio, SiO2 is silica (mol), Al2O3 is alumina (mol), H2O is water (mol), M is an alkali metal element (mol), SDA is an organic structure-directing agent (mol), and OH - is the total amount (mol) of hydroxide ions in the raw material composition. SiO2 / Al2O3 ratio = 5 or more, preferably 20 or more, and 100 or less, preferably less than 60 SDA / SiO2 ratio = 0.05 or more, preferably 0.1 or more, and 0.40 or less, preferably 0.30 or less M / SiO2 ratio = 0.01 or more, preferably 0.1 or more, and 1.0 or less, preferably less than 0.35 H2O / SiO2 ratio = 2 or more, preferably 5 or more, and 30 or less, preferably 20 or less OH - / SiO2 ratio = 0.1 or more, preferably 0.2 or more, and 1.0 or less, preferably 0.8 or less

[0054] The raw material composition preferably does not substantially contain elements that require wastewater treatment after crystallization. Such elements can include fluorine (F) and phosphorus (P). The raw material composition may have fluorine and phosphorus each below the detection limit (for example, 0 mass ppm or more and 100 mass ppm or less, and further 0 mass% or more and 10 mass ppm or less).

[0055] In the crystallization process, the raw material composition may be crystallized so as to obtain AEI-type zeolite, and the crystallization method can be appropriately selected. Preferred crystallization methods include hydrothermal treatment of the raw material composition. For hydrothermal treatment, the raw material composition may be placed in a sealed pressure-resistant container and heated. In addition, hydrothermal treatment may be performed after adding seed crystals (AEI-type zeolite) to the raw material composition. The seed crystals can be added, for example, in an amount of 0.2% by mass or more and 5% by mass or less based on the total mass of Si and Al in the raw material composition (excluding seed crystals) converted to SiO2 and Al2O3, respectively, and the total mass of Si and Al in the seed crystals converted to SiO2 and Al2O3, respectively. Examples of the hydrothermal treatment conditions include the following. Treatment temperature: 110 °C or higher, 130 °C or higher, or 150 °C or higher, and 210 °C or lower, 200 °C or lower, or 190 °C or lower Treatment time: 8 hours or longer, 10 hours or longer, or 15 hours or longer, and 500 hours or shorter or 300 hours or shorter Treatment pressure: autogenous pressure

[0056] The crystallization of the raw material composition in the crystallization process may be carried out either in a static state or in a stirred state. Since the composition of the obtained AEI-type zeolite becomes more uniform, it is preferable to carry out the crystallization in a state where the raw material composition is stirred.

[0057] By the production method of this embodiment including the above-described crystallization process, AEI-type zeolite can be obtained. It can be exemplified that the AEI-type zeolite obtained by the production method of this embodiment is a crystalline aluminosilicate having an AEI structure. Examples of the SiO2 / Al2O3 ratio of the AEI-type zeolite include 15 or more or 20 or more, and 100 or less, 50 or less, or 30 or less.

[0058] The method for producing AEI-type zeolite of this embodiment may include one or more of a washing step, a drying step, an SDA removal step, an ammonium treatment step, or a heat treatment step after the crystallization step.

[0059] The washing step is a step of washing the AEI zeolite after the crystallization step. For example, in the washing step, the AEI zeolite after crystallization and the liquid phase are separated by a known method, and the AEI zeolite obtained as the solid phase may be washed with pure water.

[0060] The drying step is a step of removing moisture from the AEI zeolite after the crystallization step or after the washing step. The conditions of the drying step are arbitrary, but examples include allowing the AEI zeolite after the crystallization step or after the washing step to stand or drying it with a spray dryer in the atmosphere at 100°C or higher and 150°C or lower for 2 hours or more.

[0061] The SDA removal step is a step of removing SDA that may be contained in the AEI zeolite. Usually, the AEI zeolite that has undergone the crystallization step contains SDA in its pores. Therefore, it can be removed if necessary.

[0062] The SDA removal step can be carried out by any method as long as the SDA is removed. Examples of these removal methods include at least one kind selected from the group consisting of liquid phase treatment using an acidic aqueous solution, exchange treatment using a resin or the like, thermal decomposition treatment, and calcination treatment. From the viewpoint of production efficiency, the SDA removal step is preferably either thermal decomposition treatment or calcination treatment.

[0063] The ammonium treatment step is a step of treating the AEI zeolite with ammonium and is carried out to remove the alkali metal contained in the AEI zeolite. The ammonium treatment step can be carried out by a known method. For example, it can be carried out by bringing an aqueous solution containing ammonium ions into contact with the AEI zeolite.

[0064] In the heat treatment step, the AEI zeolite is heat treated. For example, the AEI zeolite is heat treated at 400°C or higher and 600°C or lower. The cation type is ammonium type (NH4 +In the case of an AEI-type zeolite of type), by heat treatment at 400 ° C or higher and 600 ° C or lower, the cation type becomes a proton type (H + type) AEI-type zeolite. More specific heat treatment conditions (firing conditions) include 500 ° C for 1 to 2 hours in the atmosphere.

[0065] Next, a method for producing a FAU-type zeolite using the crystalline aluminosilicate of the present embodiment will be described.

[0066] In the method for producing a FAU-type zeolite of the present embodiment, the crystalline aluminosilicate of the present embodiment may be used as the silica source and the alumina source, and a composition containing the crystalline aluminosilicate, the structure-directing agent source, the alkali source, and water of the present embodiment (hereinafter, also referred to as "raw material composition") is crystallized (hereinafter, also referred to as "crystallization step").), is preferably a production method having

[0067] Since the crystalline aluminosilicate contains aluminum (Al) and silicon (Si), it functions as an alumina source and a silica source. The alumina source and the silica source contained in the raw material composition are preferably only the crystalline aluminosilicate of the present embodiment, but may contain at least one of other alumina sources and silica sources as necessary.

[0068] In the method for producing a FAU-type zeolite of the present embodiment, the composition of the crystalline aluminosilicate, the alumina source, the silica source, the structure-directing agent source, the alkali source, water, and the preferred raw material composition may be the same as that of the method for producing the AEI-type zeolite of the above-described present embodiment. By crystallizing a raw material composition containing the crystalline aluminosilicate of the present embodiment and the structure-directing agent source, a FAU-type zeolite, particularly a FAU-type zeolite having a high silica composition (that is, USY zeolite) is crystallized.

[0069] In the crystallization process, the raw material composition may be crystallized so as to obtain an FAU-type zeolite, and the crystallization method can be appropriately selected. Preferred crystallization methods include hydrothermally treating the raw material composition. The hydrothermal treatment may be performed by placing the raw material composition in a sealed pressure-resistant container and heating it. Similar to the method for producing the AEI-type zeolite of the present embodiment described above, the hydrothermal treatment may be performed after adding seed crystals (AEI-type zeolite) to the raw material composition.

[0070] Examples of preferable heat treatment conditions include the following. Treatment temperature: 110 °C or higher, 130 °C or higher, or 150 °C or higher, and 210 °C or lower, 200 °C or lower, or 190 °C or lower Treatment time: 0.5 hour or longer, 1 hour or longer, or 1.5 hours or longer, and Less than 8 hours or 7 hours or less Treatment pressure: autogenous pressure

[0071] The method for producing the FAU-type zeolite of the present embodiment may include one or more of the washing step, drying step, SDA removal step, ammonium treatment step, and heat treatment step similar to those of the method for producing the AEI-type zeolite of the present embodiment described above after the crystallization step.

[0072] The FAU-type zeolite obtained by the production method of the present embodiment (hereinafter, also referred to as "the present FAU-type zeolite") is a crystalline aluminosilicate having an FAU structure. More specifically, according to the production method of the FAU-type zeolite of the present embodiment, a crystalline aluminosilicate having a high silica composition, that is, USY zeolite, can be produced.

[0073] The SiO2 / Al2O3 ratio of the present FAU-type zeolite may be 10 or higher, 13 or higher, 15 or higher, or 20 or higher, and 100 or lower, 50 or lower, or 30 or lower.

[0074] This FAU-type zeolite preferably contains little aluminum other than T atoms (hereinafter also referred to as "extra-framework Al"), and more preferably contains no extra-framework Al. By having little extra-framework Al, aluminum is included as a T atom. As a result, this FAU-type zeolite has a high SiO2 / Al2O3 ratio, yet the FAU structure is stabilized. Note that "containing no extra-framework Al" means 27 in the Al-MAS-NMR spectrum, not having a peak with a peak top at a chemical shift of 0 ± 5 ppm (hereinafter also referred to as "extra-framework Al peak"), and does not necessarily mean that there is no extra-framework Al in this FAU-type zeolite. That is, the FAU-type zeolite containing no extra-framework Al 27 may be allowed to contain extra-framework Al to such an extent that it cannot be detected by the Al-MAS-NMR spectrum.

[0075] 27 The Al-MAS-NMR spectrum can be measured under the following conditions using a general magic angle spinning nuclear magnetic resonance apparatus (for example, JNM-ECA 500, manufactured by JEOL, 130.33 MHz). Rotation speed of the measurement sample: 14 kHz Pulse length: 3.2 microseconds Relaxation time: 5 seconds

[0076] The particle size of this FAU-type zeolite is arbitrary, and the average particle size can be 100 nm or more, or 120 nm or more, and can also be 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, or 200 nm or less. The average particle size is the average value of the particle sizes of 50 ± 20 particles whose entire shape (outline) can be observed in the SEM observation image. The particle size of each particle can be measured by the longest diameter, and the SEM observation image can be observed at any magnification as long as there are 50 ± 20 particles.

[0077] The difference between the adsorption amount and the desorption amount at a relative pressure of 0.5 in the nitrogen adsorption isotherm of this FAU-type zeolite (hereinafter also referred to as "adsorption-desorption hysteresis") is preferably 40 mL / g or less or 30 mL / g or less. The adsorption-desorption hysteresis may be 0 mL / g or more or more than 0 mL / g.

[0078] Here, as described above, the crystalline aluminosilicate of the present embodiment can be produced by subjecting the above-mentioned FAU-type zeolite to an acid treatment. Therefore, the crystalline aluminosilicate of the present embodiment is simpler to produce and can be produced at a lower cost compared to USY zeolite produced by subjecting Y zeolite to a super-stabilization treatment.

[0079] In addition, the crystalline aluminosilicate of the present embodiment can be used as a silica source and an alumina source for producing at least one of AEI-type zeolite and FAU-type zeolite (hereinafter also referred to as "AEI-type zeolite etc."), and AEI-type zeolite etc. can be produced without mixing other silica sources. That is, the crystalline aluminosilicate of the present embodiment is more suitable as a starting material for AEI-type zeolite compared to Y zeolite that requires other silica sources to produce AEI-type zeolite. Furthermore, the crystalline aluminosilicate of the present embodiment is suitable as a starting material that can provide a simpler production method compared to other production methods for producing FAU-type zeolite (USY zeolite) having a high silica composition from amorphous raw materials.

[0080] In addition to being a starting material for producing AEI-type zeolite etc., the crystalline aluminosilicate of the present embodiment can also be used for applications of conventional crystalline aluminosilicates, including adsorbents, catalysts, and carriers thereof. Similarly, in addition to being a starting material for producing AEI-type zeolite, this FAU-type zeolite can also be used for applications of conventional crystalline aluminosilicates, including adsorbents, catalysts, and carriers thereof.

Examples

[0081] Hereinafter, the present disclosure will be described in detail with reference to examples. However, the present disclosure is not limited to these examples.

[0082] (Calculation of XRD Peak Intensity) Using a general X-ray diffractometer (trade name: Ultima-IV, manufactured by Rigaku Corporation), XRD measurement of the product was performed. The measurement conditions are as follows. X-ray source: CuKα ray (λ = 1.5406 Å) Measurement mode: Step scan Scan condition: 4.0° per minute Measurement time: 11.8 minutes Measurement range: 2θ = 3.0° to 50.0°

[0083] The obtained XRD pattern was subjected to baseline correction, and detection and intensity analysis of each XRD peak after correction using an analysis program (trade name: SmartLab StudioII, manufactured by Rigaku Corporation) attached to the measuring device. In the examples and comparative examples shown below, the fact that the aluminosilicate is crystalline was specified by confirming that it has a crystalline XRD peak (a peak whose 2θ at the peak top is specified and detected) in the analysis of the above-described XRD pattern.

[0084] (Composition Analysis) Composition analysis was performed using an ICP emission spectroscopic analyzer (device name: iCAP-6300, manufactured by Thermo Fisher Scientific). The sample was analyzed for a solution obtained by dissolving it in an aqueous potassium hydroxide solution. From the obtained analysis results, the SiO2 / Al2O3 ratio of the product was determined.

[0085] (SEM Observation) Using a general scanning electron microscope (device name: JSM-7000F, manufactured by JEOL Ltd.), an SEM image of the product was taken at an acceleration voltage of 15.

[0086] (PDF Analysis by High-Energy X-rays) The scattering spectrum was measured using the BL04B2 high-energy X-ray diffraction beamline at SPring-8, and PDF analysis was performed on the obtained scattering spectrum. The measurement sample was introduced into a quartz capillary, and the scattering spectrum was measured under the following conditions. Energy source: Si(220) 61.43 keV Energy resolution: ΔE / E = 10 -3 Measurement range: 25 Å -1 Measurement temperature: room temperature In the PDF analysis, the obtained data was normalized to obtain the Faber-Ziman type structure factor S(Q), and then the above-mentioned PDF function G(r) was calculated.

[0087] ( 27 Al-MAS-NMR) Using a general magic angle spinning nuclear magnetic resonance apparatus (apparatus name: JNM-ECA 500, manufactured by JEOL, 130.33 MHz), the spectrum was measured while rotating the zeolite sample at 14 kHz with a pulse length of 3.2 microseconds and a relaxation time of 5 seconds. 27 An Al-MAS-NMR spectrum was obtained to confirm the state of aluminum.

[0088] (Adsorption-desorption hysteresis) A nitrogen adsorption isotherm was measured using a general nitrogen adsorption apparatus (apparatus name: NOVAtouch, manufactured by Anton Paar). The nitrogen adsorption isotherm was obtained by subjecting the measurement sample to a treatment at 150 °C for 20 minutes, followed by heating at 350 °C for 5 hours for pretreatment, and then measuring at liquid nitrogen temperature using nitrogen as the adsorption medium. The adsorption-desorption hysteresis was determined by the difference [mL / g] between the desorption amount and the adsorption amount at a relative pressure of 0.5 of the adsorption isotherm (= desorption amount [mL / g] - adsorption amount [mL / g]).

[0089] (Synthesis of crystalline aluminosilicate) Example 1 Y zeolite as a crystalline aluminosilicate having a FAU structure (cation type: Na +5 g of a type with an SiO2 / Al2O3 ratio of 5.5 was added to 50 g of 1.4 N sulfuric acid, and this was mixed at 75 °C for 4 hours to obtain the crystalline aluminosilicate of this example.

[0090] The obtained crystalline aluminosilicate had an SiO2 / Al2O3 ratio of 55.4, and main peaks with peak tops at 2θ = 6.34° and 6.86° were confirmed. Also, in the obtained crystalline aluminosilicate, the number of sub-peaks with a relative intensity of 30% to 50% with respect to the maximum intensity of the main peak was 0 (zero). The XRD measurement results are shown in Figure 1, and the PDF analysis results by high-energy X-rays (a graph showing the relationship between the PDF function G(r) and the interatomic distance r) are shown in Figure 2. As shown in Figure 2, since the crystalline aluminosilicate of this example has an extreme value (maximum) at r = 4.15 in the PDF function G(r), it was revealed that it has an oxygen ring structure of 6-membered rings or more.

[0091] Example 2 As the crystalline aluminosilicate having the FAU structure, the crystalline aluminosilicate of this example was obtained in the same manner as in Example 1 except that Y zeolite (cation type: H + type, SiO2 / Al2O3 ratio: 5.5) was used and 1.2 N sulfuric acid was used. The obtained crystalline aluminosilicate had an SiO2 / Al2O3 ratio of 25.4, and a main peak with a peak top at 2θ = 6.30° was confirmed. Also, in the obtained crystalline aluminosilicate, the number of sub-peaks with a relative intensity of 30% to 50% with respect to the maximum intensity of the main peak was 0 (zero). The XRD measurement results are shown in Figure 1.

[0092] Example 3 The crystalline aluminosilicate of this example was obtained in the same manner as in Example 1 except that 1.2N sulfuric acid was used. The obtained crystalline aluminosilicate had an SiO2 / Al2O3 ratio of 38.0, and a main peak with a peak top at 2θ = 7.22° was confirmed. Further, in the obtained crystalline aluminosilicate, the number of sub-peaks with a relative intensity of 30% to 50% with respect to the maximum intensity of the main peak was 0 (zero). The XRD measurement results are shown in Figure 1, and the PDF analysis results by high-energy X-rays are shown in Figure 2. As shown in Figure 2, since the crystalline aluminosilicate of this example has an extreme value (maximum) at r = 4.15 in the PDF function G(r), it was revealed that it has an oxygen ring structure of 6-membered rings or more.

[0093] Comparative Example 1 The crystalline aluminosilicate of this comparative example was obtained in the same manner as in Example 1 except that 0.6N sulfuric acid was used. The obtained crystalline aluminosilicate was a FAU-type zeolite with an SiO2 / Al2O3 ratio of 9.4, and the number of sub-peaks with a relative intensity of 30% to 50% with respect to the maximum intensity of the main peak having a peak top at 2θ = 6.28° was 4. The XRD measurement results are shown in Figure 1. The fact that the crystalline aluminosilicate of this comparative example was a FAU-type zeolite was identified by comparing the XRD pattern with the reference pattern of the FAU-type zeolite.

[0094] Comparative Example 2 As the crystalline aluminosilicate having a FAU structure, Y zeolite (cation type: H +A crystalline aluminosilicate of this comparative example was obtained in the same manner as in Example 1, except that a type (SiO2 / Al2O3 ratio: 5.5) was used and 0.4N sulfuric acid was used. The obtained crystalline aluminosilicate was a FAU-type zeolite with an SiO2 / Al2O3 ratio of 11.9, and the number of sub-peaks having a relative intensity of 30% to 50% with respect to the maximum intensity of the main peak having a peak top at 2θ = 6.30° was 4. The XRD measurement results are shown in Figure 1. The fact that the crystalline aluminosilicate of this comparative example was a FAU-type zeolite was identified by comparing the XRD pattern with the reference pattern of the FAU-type zeolite.

[0095] (Synthesis of AEI-type zeolite) Example 4 The crystalline aluminosilicate of Example 1, 35.2 mass% TMPOH (1,1,3,5-tetramethylpiperidinium hydroxide), sodium hydroxide, and pure water were mixed to obtain a raw material composition having the following composition. The TMP cation represents a 1,1,3,5-tetramethylpiperidinium cation. SiO2 / Al2O3 = 55.4 Na / SiO2 = 0.30 H2O / SiO2 = 5.0 TMP cation / SiO2 = 0.20 OH - / SiO2 = 0.50

[0096] After mixing AEI-type zeolite as a seed crystal so as to be 2 mass% with respect to the raw material composition, it was sealed in an autoclave. The autoclave was allowed to stand and treated at 180 °C for 72 hours to crystallize the raw material composition. The above-mentioned addition amount of the seed crystal (2 mass%) is the ratio (mass%) of the total mass of Si and Al in the seed crystal converted to SiO2 and Al2O3, respectively, to the total mass of Si and Al in the raw material composition (excluding the seed crystal) converted to SiO2 and Al2O3, respectively.

[0097] The obtained product was filtered, washed, and dried overnight at 110 °C in air. The obtained product was an AEI-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 ratio of 19.7. The fact that the obtained product was an AEI-type zeolite was identified by comparing the XRD pattern (Figure 3) with the reference pattern of the AEI-type zeolite.

[0098] Example 5 A product was obtained in the same manner as in Example 4, except that the composition of the raw material composition was changed to the following composition. SiO2 / Al2O3 = 55.4 Na / SiO2 = 0.20 H2O / SiO2 = 5.0 TMP cation / SiO2 = 0.20 OH - / SiO2 = 0.40

[0099] The obtained product was an AEI-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 ratio of 23.9. The fact that the obtained product was an AEI-type zeolite was identified by comparing the XRD pattern (Figure 3) with the reference pattern of the AEI-type zeolite.

[0100] Example 6 A product was obtained in the same manner as in Example 4, except that the crystalline aluminosilicate of Example 3 was used as the crystalline aluminosilicate and the composition of the raw material composition was changed to the following composition. SiO2 / Al2O3 = 38.0 Na / SiO2 = 0.30 H2O / SiO2 = 5.0 TMP cation / SiO2 = 0.20 OH - / SiO2 = 0.50

[0101] The obtained product was an AEI-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 ratio of 19.4. The fact that the obtained product was an AEI-type zeolite was identified by comparing the XRD pattern (Figure 3) with the reference pattern of the AEI-type zeolite.

[0102] Comparative Example 3 The FAU-type zeolite of Comparative Example 1, 35.2% by mass of TMPOH, sodium hydroxide, and pure water were mixed to obtain a raw material composition having the following composition. SiO2 / Al2O3 = 9.4 Na / SiO2 = 0.30 H2O / SiO2 = 5.0 TMP cation / SiO2 = 0.20 OH - / SiO2 = 0.50

[0103] A product was obtained in the same manner as in Example 4 except that the above raw material composition was used. The obtained product was a mixture of ANA-type zeolite (crystalline aluminosilicate) and GME-type zeolite (crystalline aluminosilicate), and when only Y zeolite was used as the starting material (alumina source and silica source), AEI-type zeolite could not be obtained. The fact that the obtained product was a mixture of ANA-type zeolite and GME-type zeolite was identified by comparing with the reference patterns of AEI-type zeolite, ANA-type zeolite, and GME-type zeolite.

[0104] The XRD patterns of Examples 4 to 6 are shown in FIG. 3, and the SEM observation images are shown in FIGS. 4 to 6, respectively. In addition, the XRD pattern of Comparative Example 3 is shown in FIG. 7. By using a crystalline aluminosilicate having a related structure of the FAU structure (that is, having an XRD peak having a peak top at 2θ = 6.0 to 7.5°, and the number of XRD peaks having a relative intensity of 30% or more and 50% or less with respect to the maximum intensity of the XRD peak is 2 or less) as the starting material, it was confirmed that AEI-type zeolite can be produced without performing a dealumination treatment on Y zeolite to convert it into USY zeolite and without mixing it with other silica sources.

[0105] Example 7 (Production of FAU-type zeolite) The crystalline aluminosilicate of Example 1, 35.2% by mass of TMPOH (1,1,3,5 - tetramethylpiperidinium hydroxide), sodium hydroxide, and pure water were mixed to obtain a raw material composition having the following composition. The TMP cation represents the 1,1,3,5 - tetramethylpiperidinium cation. SiO2 / Al2O3 = 55.4 Na / SiO2 = 0.20 H2O / SiO2 = 5.0 TMP cation / SiO2 = 0.20 OH - / SiO2 = 0.40

[0106] The raw material composition was sealed in an autoclave, and the autoclave was treated at 180 °C for 2 hours under static conditions to crystallize the raw material composition.

[0107] The obtained product was filtered, washed, and dried overnight at 110 °C in air. The obtained product was a FAU - type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 ratio of 20.6. The fact that the obtained product was a FAU - type zeolite was identified by comparing the XRD pattern (Figure 8) with the reference pattern of the FAU - type zeolite. 27 In the Al - MAS - NMR spectrum (Figure 9), no extra - framework Al peak was confirmed. Therefore, it was considered that all Al was present within the framework. From SEM observation, the average particle size was 293 nm. A representative SEM observation image is shown in Figure 10. Also, mesopores were confirmed within the particles from the cross - sectional SEM observation image of the particles (Figure 12). The adsorption - desorption hysteresis (Figure 13) was 29.9 mL / g.

[0108] Example 8 A product was obtained in the same manner as in Example 7 except that the crystalline aluminosilicate of Example 2 was used as the crystalline aluminosilicate and the composition of the raw material composition was made the following composition. SiO2 / Al2O3 = 25.4 Na / SiO2 = 0.20 H2O / SiO2 = 5.0 TMP cation / SiO2 = 0.20 OH - / SiO2 = 0.40

[0109] The resulting product was a FAU-type zeolite (crystalline aluminosilicate) with an SiO2 / Al2O3 ratio of 17.2. The fact that the resulting product was a FAU-type zeolite was identified by comparing the XRD pattern (Figure 8) with the reference pattern of the FAU-type zeolite. 27 In the Al-MAS-NMR spectrum (Figure 9), an extra-framework Al peak was not confirmed. The average particle size observed by SEM was 166 nm. A representative SEM observation image is shown in Figure 11. The adsorption / desorption hysteresis (Figure 13) was 11.5 mL / g. Note that in Figure 13, in order to display the nitrogen adsorption isotherms of Examples 7 and 8 without overlapping, the nitrogen amount (V) per unit mass of Example 8 is shown as a value increased by 100 mL / g (a value obtained by adding 100 mL / g as an offset value).

[0110] The XRD patterns of Examples 7 and 8 are shown in Figure 8, 27 the Al-MAS-NMR spectrum is shown in Figure 9, and the SEM observation images are shown in Figures 10 and 11, respectively. It was confirmed that a FAU-type zeolite having a high silica composition can be produced from an amorphous raw material by a simple method using a crystalline aluminosilicate having a related structure of the FAU structure (that is, a crystalline aluminosilicate having an XRD peak with a peak top at 2θ = 6.0 to 7.5° and having 2 or less XRD peaks with a relative intensity of 30% or more and 50% or less with respect to the maximum intensity of the XRD peak) as a starting material.

Claims

1. In the powder X-ray diffraction pattern, it has a peak top at 2θ = 6.0 to 7.5°, and has an XRD peak showing the maximum diffraction intensity in the X-ray diffraction pattern, and further, the relative intensity with respect to the intensity of the XRD peak is 30% or more and 50% or less, and the number of XRD peaks is 0. A method for producing a crystalline aluminosilicate (excluding crystalline aluminosilicates containing germanium), comprising a step of treating a crystalline aluminosilicate having a FAU structure with an acid, The method for producing a crystalline aluminosilicate, wherein the acid is one or more selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid.

2. The production method according to Claim 1, wherein the crystalline aluminosilicate to be produced has an oxygen ring structure of 6-membered rings or more.

3. The production method according to Claim 1 or 2, wherein the molar ratio of silica to alumina of the crystalline aluminosilicate to be produced is 12 or more and 100 or less.

4. The production method according to any one of Claims 1 to 3, wherein the crystalline aluminosilicate having the FAU structure is Y zeolite.

5. The production method according to any one of Claims 1 to 4, wherein the molar ratio of silica to alumina of the crystalline aluminosilicate having the FAU structure is less than 10.

6. The production method according to any one of Claims 1 to 5, wherein the crystalline aluminosilicate having the FAU structure has not undergone ultrastabilization treatment.

7. The production method according to any one of Claims 1 to 6, wherein the acid concentration of the acid is 0.8 N or more.

8. A method for producing an AEI-type zeolite using the crystalline aluminosilicate produced by the production method according to any one of Claims 1 to 7.

9. A method for producing a FAU-type zeolite using a crystalline aluminosilicate produced by the production method according to any one of claims 1 to 7.

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