JP6797045B2 - MWF type zeolite - Google Patents

Description

The present invention relates to MWF-type zeolite.

Zeolites can be used as adsorbents, desiccants, separators, catalysts, catalyst carriers, detergent aids, ion exchangers, wastewater treatment agents, fertilizers, food additives, cosmetic additives, etc., among others for gas separation applications. It is useful as.
Patent Document 1 discloses ZSM-25, which is a kind of MWF-type zeolite. Here, the MWF type zeolite is a code having a MWF structure, which is a code that defines the structure of the zeolite defined by the International Zeolite Association (IZA).

Further, as described in Patent Document 2 and Non-Patent Document 1, the structure of ZSM-25, which is a kind of MWF-type zeolite, has been clarified in recent years. It is reported that the structure is a zeolite having a space group of Im3 m of a regular hexahedral crystal system and having pores composed of an oxygen 8-membered ring. In addition, it has been reported that it is used for the separation of carbon dioxide and methane and the separation of carbon dioxide and nitrogen by selectively adsorbing carbon dioxide.

When zeolite is used as an adsorbent, separator, catalyst, or catalyst carrier, its performance deteriorates depending on the difference in pore size and the amount of impurities, so that the crystal lattice is less distorted and defective, and the crystal structure is clearly formed. Being done is an important factor. Especially when adsorbing gas, distortion and defects of the crystal lattice cause a decrease in gas adsorption rate, which is extremely important.

U.S. Patent 4,247,416 Korean patent 10155514

Peng Guo, Jiho Shin, Alex G. Greenaway, Jung Gi Min, Jie Su, Hyun June Choi, Greenaway Liu, Paul A. Cox, Suk Bong Hong, Paul A. Wright, Xiaodong Zou. "A zeolite family with expending strategic complete completeness and embedded isoretical structures" Nature. 2015, 524, 74-78.

X-ray diffraction spectra of each zeolite are shown in Patent Documents 1 and 2 and Non-Patent Document 1, and the crystal structure and crystallinity can be evaluated, but the crystallinity is suitable for quickly adsorbing adsorbable gas molecules. Not enough. That is, it cannot be said that the adsorption rate of the conventional MWF-type zeolite is sufficiently high.

The present invention has been made in view of the above circumstances, and has less distortion and defects in the crystal lattice as compared with the conventional MWF-type zeolite, a crystal structure is clearly formed, and the rate of carbon dioxide (CO ₂ ) adsorption is high. It is an object of the present invention to provide a large MWF type zeolite.

As a result of diligent studies to solve the above problems, the present inventors have determined that the intensity ratio of a specific diffraction peak is within a predetermined value in the diffraction pattern obtained by subjecting MWF type zeolite to X-ray diffraction measurement. We have found that the problems of the present application can be solved, and have come to the present invention.

That is, the present invention is as follows.
[1]
An MWF-type zeolite that satisfies 0.84 <B / A when the peak heights near 2θ = 11.1 and 13.8 ° are A and B, respectively, in the peak obtained by X-ray diffraction.
[2]
The MWF-type zeolite according to [1], which satisfies 0.52 <C / A when the peak height near 2θ = 51.6 ° is C in the peak obtained by X-ray diffraction.

According to the present invention, it is possible to provide an MWF-type zeolite having less distortion and defects in the crystal lattice, a clearly formed crystal structure, and a high rate of carbon dioxide (CO ₂ ) adsorption.

FIG. 3 is an X-ray diffraction (XRD) diagram of the MWF-type zeolite obtained in Example 1.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following description, and can be implemented with various modifications within the scope of the gist thereof.

(X-ray diffraction peak)
The MWF-type zeolite of the present embodiment has 0.84 <B / A at the peaks obtained by X-ray diffraction, where A and B are the peak heights around 2θ = 11.1 and 13.8 °, respectively. Fulfill.

Of the X-ray diffraction peaks of the MWF-type zeolite of the present embodiment at 25 ° C., the peaks near 2θ = 11.1 and 13.8 ° are the diffraction peaks of (440) and (550), respectively. .. That is, these are diffractions by parallel crystal lattice planes, and when the heights of the diffraction peaks of (440) and (550) are A and B, respectively, the larger the B / A, the finer the diffraction. It shows that the structure is clearly formed. That is, it is considered that the adsorption rate of CO ₂ can be maximized because there are few defects in the Si—O or Al—O bond, the bond distance and the angle are uniform, and the defect of the CO ₂ adsorption site is unlikely to occur. From this viewpoint, the B / A is larger than 0.84, preferably 0.85 or more, and more preferably 0.86 or more. Further, the peak near 2θ = 51.6 ° is the diffraction peak of (1880), and when this peak height is C, the C / A is larger than 0.52 from the same viewpoint as above. Is preferable, 0.53 or more is more preferable, and 0.54 or more is further preferable.
The B / A and C / A values can be measured by the methods described in Examples described later, and both have a composition ratio of the mixed gel and conditions for hydrothermal synthesis (heating temperature and heating time). ) Etc. can be adjusted to the above range by a method of adjusting the above range to a preferable range described later.

The half-value width at half maximum obtained by X-ray diffraction indicates the crystallinity of the crystal lattice plane where the diffraction occurs, and it is preferable that the peak width is narrow. The range of peak half widths around 2θ = 11.1, 13.8 and 51.6 ° is preferably 0.40 deg or less, 0.45 deg or less, and 0.50 deg or less, respectively, and more preferably. It is 0.30 deg or less, 0.35 deg or less, and 0.40 deg or less, and more preferably 0.25 deg or less, 0.29 deg or less, and 0.30 deg or less. According to the structure of the MWF-type zeolite suggested by having such a peak half-value width, the loss of the adsorption site of CO ₂ is eliminated and the adsorption can proceed rapidly, so that the adsorption rate of CO ₂ is maximized. The inventor presumes that it can be.
The value of the peak half width is adjusted to the above range by a method of adjusting the composition ratio of the mixed gel, the conditions at the time of hydrothermal synthesis (heating temperature and heating time), etc. to a preferable range described later. be able to.

(Synthesis method)
The method for producing an MWF-type zeolite according to the present embodiment is, for example, an alkali metal containing at least one selected from a silica source containing silicon, an aluminum source containing aluminum, an alkali metal (M1) and an alkaline earth metal (M2). It can include a step of preparing a mixed gel containing a source and water. Hereinafter, the mixed gel and each component contained therein will be described.

[Mixed gel]
The mixed gel in the present embodiment is a mixture containing a silica source, an aluminum source, an alkali metal source, and water as essential components, preferably containing an organic structure defining agent.
The silica source refers to a component in the mixed gel that is a raw material for silicon contained in the zeolite produced from the mixed gel, and an aluminum source refers to a raw material for aluminum contained in the zeolite produced from the mixed gel. The alkali metal source refers to a component in the mixed gel which is a raw material of an alkali metal and / or an alkaline earth metal contained in a zeolite produced from the mixed gel.

[Silica source]
The silica source is not particularly limited as long as it is generally used, but specific examples thereof include amorphous silica, colloidal silica, wet silica, dry silica, silica gel, sodium silicate, and amorphous aluminosilicate. Examples include gel, tetraethoxysilane (TEOS), trimethylethoxysilane and the like. These compounds may be used alone or in combination of two or more. Here, the amorphous aluminosilicate gel is both a silica source and an aluminum source.
Among these, amorphous silica, colloidal silica, wet silica, dry silica, and silica gel are preferable because zeolite having a high degree of crystallinity tends to be obtained. From the same viewpoint, colloidal silica, wet method silica, and dry method silica are more preferable.
Colloidal silica includes, but is not limited to, Ludox (registered trademark), Syon (registered trademark), Nalco (registered trademark), and Snowtex (registered trademark).
The wet method silica is not limited to, for example, Hi-Sil (registered trademark), Ultrasil (registered trademark), Vulcasil (registered trademark), Santocel (registered trademark), Valron-Estersil (registered trademark), Tokusil (registered trademark) Registered Trademarks), Zeosil®, Carplex®, Mizukasil®, Cylysia®, Cycloid®, Gasil®, Silkron®, Nipgel® ), Nippon (registered trademark).
Examples of dry silica include HDK (registered trademark), Aerosil (registered trademark), Reolosil (registered trademark), Cab-O-Sil (registered trademark), Francil (registered trademark), and ArcSilica (registered trademark).

[Aluminum source]
The aluminum source is not particularly limited as long as it is generally used, but specific examples thereof include sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum hydroxide, aluminum oxide, aluminum chloride, and aluminum alkoxide. , Metallic aluminum, amorphous aluminum silicate gel and the like. These compounds may be used alone or in combination of two or more.
Among these, since zeolite having a high degree of crystallization tends to be obtained, sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum hydroxide, aluminum chloride, and aluminum alkoxide are preferable. From the same viewpoint, sodium aluminate and aluminum hydroxide are more preferable, and sodium aluminate is further preferable.

[Alkali metal source]
The type of alkali in the alkali metal source is not particularly limited, and any alkali metal and / or any alkaline earth metal compound can be used.
The alkali metal source is not limited to the following, and examples thereof include hydroxides, hydrogen carbonates, carbonates, acetates, sulfates, and nitrates of alkali metals or alkaline earth metals. These compounds may be used alone or in combination of two or more.
As the alkali metal and alkaline earth metal used as the alkali metal source, Li, Na, K, Rb, Cs, Ca, Mg, Sr, Ba and the like can be usually used. From the viewpoint of facilitating crystal formation of the MWF-type skeleton, Na and K are preferable, and Na is more preferable. Further, the alkali metal and the alkaline earth metal used as the alkali metal source may be used alone or in combination of two or more.
Specifically, the alkali metal source is not limited to the following, but for example, sodium hydroxide, sodium acetate, sodium sulfate, sodium nitrate, sodium carbonate, sodium hydrogencarbonate, potassium hydroxide, potassium acetate, potassium sulfate, potassium nitrate. , Potassium carbonate, potassium hydrogen carbonate, lithium hydroxide, lithium acetate, lithium sulfate, lithium nitrate, lithium carbonate, lithium hydrogen carbonate, rubidium hydroxide, rubidium acetate, rubidium sulfate, rubidium nitrate, rubidium carbonate, rubidium hydrogen carbonate, hydroxide Cesium, cesium acetate, cesium sulfate, cesium nitrate, cesium carbonate, cesium hydrogen carbonate, calcium hydroxide, calcium acetate, calcium sulfate, calcium nitrate, calcium carbonate, calcium hydrogen carbonate, magnesium hydroxide, magnesium acetate, magnesium sulfate, magnesium nitrate , Magnesium carbonate, magnesium hydrogen carbonate, strontium hydroxide, strontium acetate, strontium sulfate, strontium nitrate, strontium carbonate, strontium hydrogen carbonate, barium hydroxide, barium acetate, barium sulfate, barium nitrate, barium carbonate, barium hydrogen carbonate, etc. Be done.
Among these, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, magnesium hydroxide, strontium hydroxide, barium hydroxide are preferable, and sodium hydroxide, potassium hydroxide, etc. Lithium hydroxide, rubidium hydroxide and cesium hydroxide are more preferable, and sodium hydroxide is even more preferable.

[Organic structure regulator]
When zeolite is produced by hydrothermal synthesis of a mixed gel, the organic structure defining agent is a compound that promotes crystallization into the zeolite structure. In the crystallization of zeolite, an organic structure defining agent can be used if necessary. It is preferable to synthesize using a mixed gel containing an organic structure defining agent because the crystal formation of the MWF type skeleton becomes easier and / or the synthesis time becomes shorter and the zeolite is excellent in economic efficiency. ..
The organic structure defining agent may be of any kind as long as it can form a desired MWF-type zeolite. Further, the organic structure defining agent may be used alone or in combination of two or more.
Organic structure defining agents include, but are not limited to, amines, quaternary ammonium salts, alcohols, ethers, amides, alkylureas, alkylthioureas, cyanoalkans, and nitrogen as a heteroatom. Alicyclic heterocyclic compounds can be used, preferably a quaternary ammonium salt, more preferably a tetraalkylammonium salt, and even more preferably a tetraethylammonium salt.
Such salts are accompanied by anions. Representatives of such anions include, but are not limited to, ^{e.g., Cl -, Br -, I} - halogen ions and hydroxide ions, such as, acetate ion, sulfate ion, nitrate ion, carbonate ion and carbonate Contains hydrogen ions. Among these, halogen ions and hydroxide ions are preferable, and halogen ions are more preferable, from the viewpoint of facilitating crystal formation of the MWF type skeleton.

[Composition ratio of mixed gel]
The ratio of the aluminum source to the alkali metal source in the mixed gel is expressed as the added molar ratio of M1 ₂ O and M ₂ O to Al ₂ O ₃ , that is, (M1 ₂ O + M ₂ O) / Al ₂ O ₃ (where M1 is an alkali metal). , And M2 indicates an alkaline earth metal). In order to synthesize an MWF-type zeolite having an ideal structure, the formation of an ideal precursor oligomer is important. In order not to generate Si—O or Al—O deficiency or bond distortion, it is preferable that the precursor is small, and in order to reduce the precursor, it is preferable that there are many core alkali metal sources. On the other hand, if the amount of the alkali metal source is too large, the core of the produced zeolite is redissolved and the crystal structure is destroyed, resulting in a decrease in crystallinity. In view of the above, the amount of the alkali metal source present in the synthesis solution is preferably to Al ₂ O _3, is _{1.3 ≦ (M1 2 O + M2O} ) / Al 2 O 3 ≦ 3.0. Within this range, precursors and nuclei are formed, sufficiently small precursors are formed, and small-particle MWF-type zeolites tend to be synthesized.
Within the above range, (M1 ₂ O + M2O) / Al ₂ O ₃ is more preferably 1.4 or more, and further preferably 1.5 or more.
Within the above range, (M1 ₂ O + M2O) / Al ₂ O ₃ is more preferably 2.5 or less, and further preferably 2.2 or less.

The ratio of the silica source to the aluminum source in the mixed gel is expressed as the molar ratio of oxides of each element, that is, SiO ₂ / Al ₂ O ₃ .
The SiO ₂ / Al ₂ O ₃ is not particularly limited as long as it can form a zeolite, but 5.0 or more is preferable because the formation of a zeolite having a skeleton different from that of the MWF type skeleton tends to be suppressed. , 6.0 or more is more preferable. From the same viewpoint, it is more preferably 6.8 or more.
Since SiO ₂ / Al ₂ O ₃ tends to suppress the formation of zeolite having a skeleton different from that of the MWF type skeleton, it is preferably 12 or less, and more preferably 10 or less. From the same viewpoint, it is more preferably 7.8 or less.

The ratio of aluminum source to water in the mixed gel is expressed as the molar ratio of water to Al ₂ O ₃ , that is, H ₂ O / Al ₂ O ₃ . Since the components in the mixed gel tend to be dispersed more uniformly, it is preferably 100 or more, and more preferably 200 or more. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, it is more preferably 300 or more.
H ₂ O / Al ₂ O ₃ is preferably 3000 or less, and more preferably 1000 or less, from the viewpoint of shortening the synthesis time and being excellent in economic efficiency in producing zeolite. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, it is more preferably 500 or less.

Silica source and OH in the mixed gel ^- ratio of, OH for SiO ₂ ^- molar ratio, i.e., OH ^- / expressed in SiO ₂ (OH ^- hydroxide contained in the alkali metal source, and / or an organic structure directing agent It is a substance ion). Since the components in the mixed gel tend to be dispersed more uniformly, it is preferably 0.10 or more, and more preferably 0.13 or more. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, it is more preferably 0.15 or more.
OH ⁻ / SiO ₂ is preferably less than 0.30, more preferably 0.29 or less, from the viewpoint of high solid content yield and excellent economic efficiency in producing zeolite. From the viewpoint of facilitating crystal formation of the MWF type skeleton, it is more preferably 0.28 or less. In the present embodiment, from the viewpoint of purity and selectivity of carbon dioxide adsorption, it is particularly preferable that the value of OH ⁻ / SiO ₂ satisfies the above range when sodium aluminate is used as the aluminum source.

If the mixed gel comprising an organic structure directing agent, the ratio of aluminum source and an organic structure directing agent in the mixed gel, the molar ratio of the organic structure-directing agent for Al ₂ O _3, i.e. expressed as R / Al ₂ O ₃ (Here, R indicates an organic structure defining agent). It is preferably 2.0 or more, more preferably 3.0 or more, from the viewpoint of facilitating crystal formation of the MWF-type skeleton and / or shortening the synthesis time and being excellent in economic efficiency when producing zeolite. preferable. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, it is more preferably 4.0 or more.
R / Al ₂ O ₃ is preferably 50 or less, and more preferably 30 or less, from the viewpoint of shortening the synthesis time and being excellent in economic efficiency in producing zeolite. It is more preferably 20 or less from the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton.

As described above, the method for producing the MWF type zeolite according to the present embodiment is at least one selected from a silica source containing silicon, an aluminum source containing aluminum, an alkali metal (M1) and an alkaline earth metal (M2). A step of preparing a mixed gel containing an alkali metal source containing water and water is included, and the molar ratio of each component in the mixed gel is set to the silicon, aluminum, alkali metal (M1) and alkaline earth metal (M2). When calculated as an oxide of each element, the molar ratios α, β, γ, and δ represented by the following formulas (1), (2), (3), and (4) are 5.0 ≦ α ≦. It is particularly preferable to satisfy 12, 1.3 ≦ β ≦ 3.0, 100 ≦ γ ≦ 3000 and 0.10 ≦ δ <0.30. It is particularly preferable that the MWF-type zeolite according to the present embodiment is obtained by the above-mentioned method for producing the MWF-type zeolite according to the present embodiment.
α = SiO ₂ / Al ₂ O ₃ (1)
β = (M1 ₂ O + M2O) / Al ₂ O ₃ (2)
γ = H ₂ O / Al ₂ O ₃ (3)
_{^{δ = OH - / SiO 2 (}} 4)

Further, in the method for producing MWF type zeolite according to the present embodiment, the molar ratios α, β, γ, and δ satisfy the above range, and the mixed gel further contains the organic structure defining agent R, and the following formula ( It is more preferable that the molar ratio ε represented by 5) satisfies 2.0 ≦ ε ≦ 50.
ε ＝ R / Al ₂ O ₃ (5)
It is not always necessary for the seed crystal to be present in the mixed gel, but the MWF-type zeolite of the present embodiment can also be obtained by adding the MWF-type zeolite produced in advance as a seed crystal to the mixed gel.

[Preparation process of mixed gel]
The step of preparing the mixed gel is not particularly limited, and for example, a mixing step of mixing a silica source, an aluminum source, an alkali metal source, water, and an organic structure defining agent as needed at one time or in multiple steps, and this mixing. It may include the aging step of the mixture obtained in the step.
The mixing step can mix these components, including a silica source, an aluminum source, an alkali metal source, water, and optionally an organic structure defining agent, at one time or in multiple steps.
The order of mixing in multiple stages is not limited, and may be appropriately selected depending on the conditions to be used. When mixing in multiple stages, either stirring or no stirring may be performed.
The stirring method is not particularly limited as long as it is a generally used stirring method, and specific examples thereof include a method using blade stirring, vibration stirring, shaking stirring, centrifugal stirring and the like.
The rotation speed of stirring is not particularly limited as long as it is a generally used stirring speed, and examples thereof include 1 rpm and more and less than 2000 rpm.
The temperature of the mixing step is not particularly limited as long as it is a generally used temperature, and examples thereof include −20 ° C. or higher and lower than 90 ° C.
The time of the mixing step is not particularly limited and may be appropriately selected depending on the temperature of the mixing step, and examples thereof include more than 0 minutes and 1000 hours or less.

The aging step may be carried out by either standing or stirring.
When stirring in the aging step, the stirring method is not particularly limited as long as it is a generally used stirring method, and specific examples thereof include a method using blade stirring, vibration stirring, rocking stirring, centrifugal stirring and the like. ..
The rotation speed of stirring is not particularly limited as long as it is a generally used stirring speed, and examples thereof include 1 rpm and more and less than 2000 rpm.
The temperature of the aging step is not particularly limited as long as it is a generally used temperature, and examples thereof include −20 ° C. and higher and lower than 90 ° C.
The time of the aging step is not particularly limited and can be appropriately selected depending on the temperature of the aging step, and examples thereof include more than 0 minutes and 1000 hours or less.

[Hydrothermal synthesis process]
In the method for producing MWF-type zeolite according to the present embodiment, it is preferable to further include a hydrothermal synthesis step in which the hydrothermal synthesis temperature is 100 ° C. to 170 ° C. That is, preferably, hydrothermal synthesis is performed by holding the mixed gel obtained in the preparation step at a predetermined temperature for a predetermined time in a stirring or standing state.
The temperature of hydrothermal synthesis is not particularly limited as long as it is a generally used temperature, but it is preferably 100 ° C. or higher from the viewpoint of shortening the synthesis time and excellent economic efficiency in zeolite production. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, the temperature is more preferably 110 ° C. or higher, and further preferably 120 ° C. or higher.
The temperature is preferably 170 ° C. or lower because it tends to suppress the decomposition of the organic structure defining agent. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, the temperature is more preferably 155 ° C or lower, further preferably 145 ° C or lower.
The temperature of hydrothermal synthesis may be constant or may be changed stepwise.
The time of hydrothermal synthesis is not particularly limited as long as it is a generally used time, and can be appropriately selected depending on the temperature of hydrothermal synthesis.
The time for hydrothermal synthesis is preferably 3 hours or more, and more preferably 10 hours or more, from the viewpoint of forming the MWF skeleton. From the viewpoint of increasing the yield of the MWF-type zeolite and being excellent in economy, it is more preferably 24 hours or more.
Since the decomposition of the organic structure defining agent tends to be suppressed, it is preferably 30 days or less, and more preferably 20 days or less. From the viewpoint of suppressing the formation of zeolite having a skeleton different from that of the MWF type skeleton, it is more preferably 10 days or less.
In the hydrothermal synthesis step, the container in which the mixed gel is placed is not particularly limited as long as it is a generally used container, but it is used when the pressure inside the container increases at a predetermined temperature or under gas pressure that does not inhibit crystallization. In this case, it is preferable to put it in a pressure-resistant container and hydrothermally synthesize it.
The pressure-resistant container is not particularly limited, and for example, various shapes such as a spherical shape, a vertically long shape, and a horizontally long shape can be used.
When stirring the mixed gel in the pressure-resistant container, the pressure-resistant container is rotated in the vertical direction and / or in the horizontal direction, preferably in the vertical direction.
When the pressure-resistant container is rotated in the vertical direction, the rotation speed is not particularly limited as long as it is in a generally used range, but 1 to 50 rpm is preferable, and 10 to 40 rpm is more preferable.
In the hydrothermal synthesis step, in order to preferably stir the mixed gel, a method of using a vertically long pressure-resistant container and rotating the mixed gel in the vertical direction can be mentioned.

[Separation / drying process]
After the hydrothermal synthesis step, the product solid and the liquid containing water are separated, but the separation method is not particularly limited as long as it is a general method, and filtration, decantation, spray drying method (rotary spraying, rotary spraying). (Nozzle spraying and ultrasonic spraying, etc.), drying method using a rotary evaporator, vacuum drying method, freeze drying method, natural drying method, etc. can be used, and usually separation can be performed by filtration or decantation.
The separated material may be used as it is, or may be washed with water or a predetermined solvent. If necessary, the separated material can be dried.
The temperature at which the separated product is dried is not particularly limited as long as it is a general drying temperature, but is usually from room temperature to 150 ° C. or lower.
The atmosphere for drying is not particularly limited as long as it is a generally used atmosphere, but usually an air atmosphere, an atmosphere to which an inert gas such as nitrogen or argon or oxygen is added is used.

[Baking process]
If necessary, MWF-type zeolite can be calcined and used. The firing temperature is not particularly limited as long as it is a generally used temperature, but when it is desired to remove the organic structure defining agent, the remaining ratio can be reduced, so that it is preferably 300 ° C. or higher, preferably 350 ° C. or higher. Is more preferable. It is more preferably 400 ° C. or higher from the viewpoint that the firing time is shortened and the efficiency of producing zeolite is excellent.
Since the crystallinity of the zeolite tends to be maintained, the temperature is preferably less than 550 ° C, more preferably 530 ° C or lower, and even more preferably 500 ° C or lower.
The firing time is not particularly limited as long as the organic structure defining agent is sufficiently removed, and can be appropriately selected depending on the firing temperature, but the proportion of the organic structure defining agent remaining tends to be reduced. Therefore, it is preferably 0.5 hours or more, more preferably 1 hour or more, and further preferably 3 hours or more.
Since the crystallinity of the zeolite tends to be maintained, it is preferably 20 days or less, more preferably 10 days or less, and further preferably 7 days or less.
The firing atmosphere is not particularly limited as long as it is a generally used atmosphere, but usually an air atmosphere, an atmosphere to which an inert gas such as nitrogen or argon or oxygen is added, is used.

[Cation exchange]
If necessary, the MWF-type zeolite can be cation-exchanged to the desired cation-type. Ion exchange is not limited to, but for example, NH ₄ NO ₃ , LiNO ₃ , NaNO ₃ , KNO ₃ , RbNO ₃ , CsNO ₃ , Be (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ , Mg (NO _3). ) ₂ , Sr (NO ₃ ) ₂ , Ba (NO ₃ ) _2, etc. Nitrate, or nitrate ion contained in the nitrate is halide ion, sulfate ion, carbonate ion, hydrogen carbonate ion, acetate ion, phosphate ion, phosphorus Salts that are hydrogen acid ions and acids such as nitric acid and hydrochloric acid can be used.
The temperature of the cation exchange is not particularly limited as long as it is a general cation exchange temperature, but is usually 100 ° C. or lower from room temperature.
When separating zeolite after cation exchange, the separation method is not particularly limited as long as it is a general method, and filtration, decantation, spray drying method (rotary spray, nozzle spray, ultrasonic spray, etc.), rotary evaporator, etc. A drying method, a vacuum drying method, a freeze-drying method, a natural drying method, or the like can be used, and usually the particles can be separated by filtration or decantation.
The separated material may be used as it is, or may be washed with water or a predetermined solvent. If necessary, the separated material can be dried.
The temperature at which the separated product is dried is not particularly limited as long as it is a general drying temperature, but is usually from room temperature to 150 ° C. or lower.
The atmosphere for drying is not particularly limited as long as it is a generally used atmosphere, but usually an air atmosphere, an atmosphere to which an inert gas such as nitrogen or argon or oxygen is added is used.
Further, the ammonium-type zeolite can be converted into a proton-type zeolite by calcining the zeolite.

The application of the MWF-type zeolite of the present embodiment is not particularly limited, and for example, a separating agent such as various gases and liquids, an electrolyte membrane such as a fuel cell, a filler of various resin moldings, a membrane reactor, or hydrocracking. , Catalysts such as alkylation, catalyst carriers for supporting metals, metal oxides, etc., adsorbents, desiccants, detergent aids, ion exchangers, wastewater treatment agents, fertilizers, food additives, cosmetic additives, etc. Can be done.

The present embodiment will be described in more detail with reference to examples and the like, but these are exemplary examples, and the present embodiment is not limited to the following examples. One of ordinary skill in the art can implement the present embodiment by making various modifications to the examples shown below, and such modifications are included in the scope of the present invention as long as the predetermined requirements of the present embodiment are satisfied.

[Crystal structure analysis]
The crystal structure analysis was performed by the following procedure.
(1) The dried products obtained in each Example and Comparative Example were used as samples and pulverized in an agate mortar.
(2) The sample of (1) above was uniformly fixed on a non-reflective sample plate for powder, and crystal structure analysis was performed under the following conditions.
X-ray diffractometer (XRD): Rigaku powder X-ray diffractometer "RINT2500 type" (trade name)
X-ray source: Cu tube (40 kV, 200 mA)
Measurement temperature: 25 ° C
Measuring range: 5 to 60 ° (0.02 ° / step)
Measurement speed: 0.2 ° / min Slit width (scattering, divergence, light reception): 1 °, 1 °, 0.15 mm

[Gas adsorption isotherm measurement]
The gas adsorption isotherm measurement was performed according to the following procedure.
(1) Using the fired products obtained in each Example and Comparative Example as a sample, 0.2 g was placed in a 12 mm cell (manufactured by MicroMetrics).
(2) The sample placed in the cell of (1) above is placed in a gas adsorption measuring device "3-Flex" (trade name) manufactured by Micro Technologies, and heated at 250 ° C. and 0.001 mmHg or less for 12 hours for vacuum degassing treatment. did.
(3) Place the sample in the cell after the treatment of (2) above in constant temperature circulating water at 25 ° C, and after the temperature of the sample reaches 25 ± 0.2 ° C, liquefied carbon dioxide gas (Sumitomo Seika Co., Ltd.) The absolute pressure was measured up to 0.25 to 760 mmHg using a product with a purity of 99.9% by mass or more. During the above measurement, the pressure was measured over time, and it was determined that the saturated adsorption amount was reached when the pressure fluctuation was 0.001% / 10 sec or less.

[Initial gas adsorption rate]
In gas adsorption isotherm measurement, the amount of carbon dioxide adsorbed a (P1) (cm ³ /) of the MWF-type zeolite measured when the MWF-type zeolite and carbon dioxide are placed in a system at 25 ° C. and pressure P1 (mmHg). The value obtained by dividing g) by P1 (mmHg) was taken as the gas adsorption rate (cm ³ / g · mmHg). Here, the gas adsorption rate at P1 = 10 mmHg was defined as the initial gas adsorption rate. That is, the amount of carbon dioxide adsorbed by the MWF-type zeolite measured when the MWF-type zeolite and carbon dioxide are placed in a system at 25 ° C. and 10 mmHg is defined as a (cm ³ / g) and divided by the measured pressure of 10 mmHg. a / 10 (cm ³ / g · mmHg) was calculated as the initial gas adsorption rate.

[Evaluation of initial adsorption rate]
When the initial gas adsorption rate was 2 or more, it was judged to be good (“◯”), and when it was not, it was judged to be defective (“x”).

[Example 1]
A mixture of 20.00 g of water, 0.72 g of sodium hydroxide (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) and 11.15 g of tetraethylammonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as an organic structure regulator, and water 40. A mixture of .08 g, sodium aluminate (NaAlO ₂ , manufactured by Wako Pure Chemical Industries, Ltd.) 1.64 g and colloidal silica (Nalco DVSZN002, manufactured by Nalco) 12.74 g was mixed and mixed by stirring for 24 hours. A gel was prepared. The composition of the mixed gel is α = SiO ₂ / Al ₂ O ₃ = 7.2, β = Na ₂ O / Al ₂ O ₃ = 1.9, γ = H ₂ O / Al ₂ O ₃ = 380, δ = OH ⁻ / SiO ₂ = 0.25 and ε = R / Al ₂ O ₃ = 5.3. The mixed gel was placed in a 200 mL stainless steel autoclave containing a fluororesin inner cylinder, hydrothermally synthesized at 120 ° C. for 7 days while holding at a vertical stirring speed of 20 rpm, the product was filtered and dried at 120 ° C., and then dried. A powdery zeolite was obtained.
The XRD spectrum of the obtained zeolite is shown in FIG. From the spectrum, it was confirmed that it was an MWF type zeolite. Furthermore, since no peaks derived from other zeolites, amorphous silica alumina, etc. were observed, it was evaluated as a high-purity MWF-type zeolite. The peak intensity ratio obtained from the XRD pattern was B / A = 0.90 and C / A = 0.55. The peak half width obtained from the XRD pattern was A = 0.15 deg, B = 0.18 deg, and C = 0.22 deg.
When the CO ₂ adsorption isotherm of the obtained MWF-type zeolite was measured, the adsorption amount at 25 ° C. and 10 mmHg was 37.2 cm ³ / g, and the initial gas adsorption rate (a / 10) was 3.72 cm ³ It was / g · mmHg. As a result of evaluating the initial adsorption rate, it was judged as "○".

[Example 2]
A mixture of 20.00 g of water, 0.72 g of sodium hydroxide (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) and 11.15 g of tetraethylammonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as an organic structure regulator, and 39 of water. A mixture of .44 g, sodium aluminate (NaAlO ₂ , manufactured by Wako Pure Chemical Industries, Ltd.) 1.64 g and colloidal silica (Nalco DVSZN002, manufactured by Nalco) 13.62 g is mixed and mixed by stirring for 24 hours. A gel was prepared. The composition of the mixed gel is α = SiO ₂ / Al ₂ O ₃ = 7.7, β = Na ₂ O / Al ₂ O ₃ = 1.9, γ = H ₂ O / Al ₂ O ₃ = 380, δ = OH ⁻ / SiO ₂ = 0.25 and ε = R / Al ₂ O ₃ = 5.3. The mixed gel was placed in a 200 mL stainless steel autoclave containing a fluororesin inner cylinder, hydrothermally synthesized at 120 ° C. for 7 days while holding at a vertical stirring speed of 20 rpm, the product was filtered and dried at 120 ° C., and then dried. A powdery zeolite was obtained.
From the XRD pattern of the obtained MWF-type zeolite, B / A = 0.85 and C / A = 0.54. The peak half width obtained from the XRD pattern was A = 0.17 deg, B = 0.23 deg, and C = 0.25 deg.
When the CO ₂ adsorption isotherm of the obtained MWF-type zeolite was measured, the adsorption amount at 25 ° C. and 10 mmHg was 24.9 cm ³ / g, and the initial gas adsorption rate (a / 10) was 2.49 cm ^3. It was / g · mmHg. As a result of evaluating the initial adsorption rate, it was judged as "○".

[Comparative Example 1]
A mixture of 20.00 g of water, 0.19 g of sodium hydroxide (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) and 11.15 g of tetraethylammonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as an organic structure regulator, and water 40. A mixture of .02 g, sodium aluminate (NaAlO ₂ , manufactured by Wako Pure Chemical Industries, Ltd.) 1.64 g and colloidal silica (Nalco DVSZN002, manufactured by Nalco) 12.74 g was mixed and mixed by stirring for 24 hours. A gel was prepared. The composition of the mixed gel is α = SiO ₂ / Al ₂ O ₃ = 7.2, β = Na ₂ O / Al ₂ O ₃ = 1.2, γ = H ₂ O / Al ₂ O ₃ = 380, δ = OH ⁻ / SiO ₂ = 0.07, ε = R / Al ₂ O ₃ = 5.3. The mixed gel was hydrothermally synthesized at 120 ° C. for 7 days with stirring, and the product was filtered and dried at 120 ° C. to obtain a powdered zeolite.
From the XRD pattern of the obtained MWF-type zeolite, B / A = 0.59 and C / A = 0.35. The peak half width obtained from the XRD pattern was A = 0.18 deg, B = 0.22 deg, and C = 0.32 deg.
When the CO ₂ adsorption isotherm of the obtained MWF-type zeolite was measured, the adsorption amount at 25 ° C. and 10 mmHg was 16.8 cm ³ / g, and the initial gas adsorption rate (a / 10) was 1.68 cm ³ It was / g · mmHg. As a result of evaluating the initial adsorption rate, it was determined to be "x".

[Comparative Example 2]
A mixture of 20.00 g of water, 1.52 g of sodium hydroxide (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) and 11.15 g of tetraethylammonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as an organic structure regulator, and water 40. A mixture of .00 g, 1.92 g of aluminum hydroxide (Al (OH) ₃ , manufactured by Aldrich) and 12.73 g of colloidal silica (Nalco DVSZN002, manufactured by Nalco) is mixed, and the mixture gel is stirred for 24 hours. Was prepared. The composition of the mixed gel is α = SiO ₂ / Al ₂ O ₃ = 7.2, β = Na ₂ O / Al ₂ O ₃ = 1.9, γ = H ₂ O / Al ₂ O ₃ = 380, δ = OH ⁻ / SiO ₂ = 0.53, ε = R / Al ₂ O ₃ = 5.3. The mixed gel was hydrothermally synthesized at 120 ° C. for 7 days with stirring, and the product was filtered and dried at 120 ° C. to obtain a powdered zeolite.
From the XRD pattern of the obtained MWF-type zeolite, B / A = 0.60 and C / A = 0.33. The peak half width obtained from the XRD pattern was A = 0.21 deg, B = 0.30 deg, and C = 0.42 deg.
When the CO ₂ adsorption isotherm of the obtained MWF-type zeolite was measured, the adsorption amount at 25 ° C. and 10 mmHg was 15.4 cm ³ / g, and the initial gas adsorption rate (a / 10) was 1.54 cm ³ It was / g · mmHg. As a result of evaluating the initial adsorption rate, it was determined to be "x".

[Comparative Example 3]
A mixture of 20.00 g of water, 1.70 g of sodium hydroxide (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) and 27.70 g of tetraethylammonium bromide (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as an organic structure regulator, and water 46 A mixture of .44 g, sodium aluminate (NaAlO ₂ , manufactured by Wako Pure Chemical Industries, Ltd.) 1.64 g and colloidal silica (Nalco DVSZN002, manufactured by Nalco) 15.92 g is mixed and mixed by stirring for 24 hours. A gel was prepared. The composition of the mixed gel is α = SiO ₂ / Al ₂ O ₃ = 9.0, β = Na ₂ O / Al ₂ O ₃ = 3.1, γ = H ₂ O / Al ₂ O ₃ = 427, δ = OH ⁻ / SiO ₂ = 0.47, ε = R / Al ₂ O ₃ = 13.2. The mixed gel was hydrothermally synthesized at 120 ° C. for 7 days with stirring, and the product was filtered and dried at 120 ° C. to obtain a powdered zeolite.
From the XRD pattern of the obtained MWF-type zeolite, B / A = 0.81 and C / A = 0.48. The peak half width obtained from the XRD pattern was A = 0.37 deg, B = 0.42 deg, and C = 0.73 deg.
When the CO ₂ adsorption isotherm of the obtained MWF-type zeolite was measured, the adsorption amount at 25 ° C. and 10 mmHg was 13.8 cm ³ / g, and the initial gas adsorption rate (a / 10) was 1.38 cm ^3. It was / g · mmHg. As a result of evaluating the initial adsorption rate, it was determined to be "x".

Α to ε in Table 1 represent the following molar ratios.
α = SiO ₂ / Al ₂ O ₃ ,
β = (M1 ₂ O + M2O) / Al ₂ O ₃ ,
γ = H ₂ O / Al ₂ O ₃ ,
δ ⁼ OH - / SiO _2,
ε = R / Al ₂ O ₃ (R represents an organic structure regulator)
In addition, B / A and C / A in Table 1 are obtained as follows.
B / A = (Peak intensity near 2θ = 13.8 °) / (Peak intensity near 2θ = 11.1 °)
C / A = (Peak intensity near 2θ = 51.6 °) / (Peak intensity near 2θ = 11.1 °)
Further, the peak half widths A, B, and C in Table 1 are the peak half widths around 2θ = 11.1, 13.8, and 51.6 °, respectively.

The MWF-type zeolite according to the present invention includes a separating agent for various gases and liquids, an electrolyte membrane for a fuel cell, a filler for various resin moldings, a membrane reactor, a catalyst for hydrocracking and alkylation, a metal, and a metal oxide. It has the potential for industrial use as a catalyst carrier for supporting such as, adsorbents, desiccants, detergent aids, ion exchangers, wastewater treatment agents, fertilizers, food additives, cosmetic additives and the like.

Claims (2)

An MWF type zeolite that satisfies 0.84 <B / A when the peak heights near 2θ = 11.1 and 13.8 ° are A and B, respectively, in the peak obtained by X-ray diffraction. The MWF-type zeolite according to claim 1, which satisfies 0.52 <C / A when the peak height near 2θ = 51.6 ° is C in the peak obtained by X-ray diffraction.