JPH0672009B2 - Large crystalline mordenite and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a large crystal mordenite and a method for producing the same, and more specifically to a large crystal having a novel structure that can be effectively used as a catalyst, a catalyst carrier, an adsorbent, a separating agent, and the like. It relates to mordenite and an efficient production method thereof.

[Problems to be Solved by Prior Art and Invention]

Mordenite existing in natural minerals has been conventionally synthesized by various methods (Japanese Patent Laid-Open No. 55-95612).
56-160316, 58-88118, 58-88119, 58-91032, 58-217425, 59-39.
715, 59-39717, 59-64520, 5
9-73424, etc.).

However, all of the mordenites produced by these conventional methods have small crystals and have various restrictions in use or performance.

The present inventors have conducted extensive research to develop a large crystalline mordenite.

[Means for solving problems]

As a result, an intended large crystal mordenite having a new crystal structure is obtained by hydrothermally reacting an aqueous mixture containing at least two kinds of a sodium source, a potassium source, and an amino alcohol together with a silicon source and an aluminum source. I found that The present invention has been completed based on these findings.

That is, in the present invention, the composition represented by the molar ratio after firing is represented by the general formula xNa ₂ O · yK ₂ O · Al ₂ O ₃ · zSiO ₂ (I) [wherein x, y, and z have the following relationships: It is a real number to satisfy.

x ≧ 0, y ≧ 0, x + y = 1, 5 <z <30], and X
The line diffraction pattern provides the large crystalline mordenite shown in Table 1. The present invention also provides at least two compounds selected from the group consisting of (A) silicon source, (B) aluminum source and (C) (i) sodium source, (ii) potassium source and (iii) amino alcohol. And the molar ratio of each component is silica / alumina ≧ 20 sodium / silica = 0 to 3.0 potassium / silica = 0 to 3.0 amino alcohol / silica = 0 to 10 hydroxide ion / silica = 0.05 to 0.50 (however, The amount of hydroxide ion is the amount of the added inorganic base minus the amount of the inorganic acid.) An aqueous mixture is reacted at 150 to 300 ° C. until mordenite is formed. The present invention provides a method for producing large crystal mordenite, the composition of which is represented by the molar ratio of the above-mentioned general formula (I) and the X-ray diffraction pattern of which is shown in Table 1.

The relative strength in Table 1 above is "very strong" from 80 to
When set to 100%, the range of 50-80% is "strong", 10-50
The range of% was defined as "medium", and the range of 0 to 10% was defined as "weak".

According to the method of the present invention, (A) a silicon source, (B) an aluminum source, (C) (i) a sodium source, (i)
At least two of i) a potassium source and (iii) an amino alcohol are added to prepare an aqueous mixture, which is reacted under heating. Here, as the (A) silicon source,
There is no particular limitation, and silica powder, silicic acid, colloidal silica, dissolved silica and the like can be used arbitrarily. As this fused silica, Na ₂ O or K ₂ O is added to SiO ₂ 1 to 1 mol.
Examples thereof include water glass silicate and alkali metal silicate containing 5 mol.

As the aluminum source (B), various sources can be used, and examples thereof include aluminum sulfate, sodium aluminate, colloidal alumina, and alumina.

In the method of the present invention, the ratio of the (A) silicon source to the (B) aluminum source in the aqueous mixture may be appropriately determined, but usually, the silica (SiO ₂ ) / alumina (Al ₂ O ₃ ) molar ratio is 20. Above, preferably selected in the range of 20-100.

Further, in the method of the present invention, an aqueous mixture obtained by adding the component (C) together with the components (A) and (B) is used as a raw material. Here, the component (C) includes (i) a sodium source, ( ii) At least two of potassium source and (iii) amino alcohol, that is, any combination of sodium source and potassium source, sodium source and amino alcohol, potassium source and amino alcohol, or sodium source, potassium source and amino alcohol. It is necessary to use in. When (i) sodium source, (ii) potassium source or (iii) amino alcohol is used alone as the component (C), the intended large crystalline mordenite cannot be obtained.

As the (i) sodium source in the component (C), sodium hydroxide, sodium carbonate, sodium chloride, sodium nitrate, sodium sulfate or the like is used, and (A) a silicon source or sodium silicate or sodium aluminate is used. (B) It can also serve as an aluminum source. On the other hand, examples of the (ii) potassium source include potassium hydroxide, potassium carbonate, potassium chloride, potassium nitrate, potassium sulfate and the like. Further, (iii) amino alcohols include piperazine ethanol, pyridine ethanol, monoethanolamine, monopropanolamine,
Examples include diethanolamine. This (iii) amino alcohol is not contained as a constituent component of the large crystal mordenite to be produced, but plays an important role as a crystallization regulator in forming a crystal structure in the production process. However, when both a sodium source and a potassium source are present in the starting aqueous mixture, this aminoalcohol is not always necessary, and the desired large crystalline mordenite can be produced even in the absence of aminoalcohol.

The ratio of the component (C) in the aqueous mixture is 0 to 3.
0, preferably 0.05-1.0, (ii) potassium source as potassium / silica molar ratio 0-3.0, preferably 0.05-
1.0, (iii) As amino alcohol, the amino alcohol / silica molar ratio should be 0-10, preferably 0-0.6.

In the method of the present invention, these (A), (B) and (C)
The ingredients are added to water in the proportions described above to form an aqueous mixture which is reacted. Here, the molar ratio of hydroxide ion / silica in the aqueous mixture which is the reaction system is 0.05 to 0.50, preferably 0.1.
Should be between 15 and 0.45. However, this hydroxide ion
It is the amount of inorganic acid removed from the amount of inorganic base added.

Further, in reacting the aqueous mixture, it may be heated at a temperature and for a time necessary for producing crystalline mordenite, specifically, a reaction temperature of 150 to 300 ° C., preferably 17
5 hours to 30 days at 0 to 200 ° C, preferably 1 to 7 days,
The reaction may be performed under self-pressure or under pressure.
The reaction system is usually left under stirring, and the atmosphere may be replaced with an inert gas if necessary. The pH is preferably adjusted to neutral to alkaline.

The crystallization reaction described above proceeds in the presence of a sodium source and a potassium source, or in the presence of at least one of a sodium source and a potassium source and an amino alcohol, and when these conditions are not satisfied, large crystals are obtained. However, the desired large crystalline mordenite cannot be obtained. In this reaction, the order of mixing the components (A), (B), and (C) is not particularly limited, but in a preferred embodiment, first, (A) an aqueous solution containing a silicon source and (B) an aluminum source. Is mixed with an aqueous solution containing (C) (i) a sodium source and / or (ii) an aqueous solution containing a potassium source, and (iii) amino alcohol ((i ) It is not essential when both of the sodium source and (ii) potassium source are added) and mixed.

After the above crystallization reaction, it is washed with water, dried at 80 to 150 ° C., and further calcined at 300 to 800 ° C., and the composition is represented by the general formula (I), and the X-ray diffraction pattern is shown in Table 1. A large crystalline mordenite represented by The X-ray diffraction pattern of this large crystal mordenite is basically unchanged before and after firing, and therefore the X-ray diffraction pattern of the large crystal mordenite after drying and before firing is also shown in Table 1.

Further, the large crystalline mordenite of the present invention thus obtained has a size of 30 to 50 μm and is grown in the direction of the pores, and this X-ray diffraction pattern has a diffraction intensity ratio higher than that of conventional mordenite. Is very different.

〔The invention's effect〕

The large crystalline mordenite of the present invention having the above-mentioned composition and crystal structure is a new crystal having a larger crystal than the conventional mordenite and also having a difference in the crystal structure itself, and is a completely new catalyst, or as a catalyst or a catalyst carrier. It can be effectively used for various reactions. Further, it is also effective as an adsorbent and a separating agent, and since it is particularly excellent in shape selectivity, its utility value is remarkably large when it is used as an adsorbent or the like.

〔Example〕

 Next, the present invention will be described in more detail with reference to Examples.

Example 1 A mixture of 21.1 g of aluminum sulfate (18-hydrate) and 200 ml of water was used as liquid a, and colloidal silica (30% by weight of SiO _{2 was used} ).
And 70% by weight of water) 253 g as liquid b, sodium hydroxide
A mixture of 15.2 g, 21.3 g of potassium hydroxide and 500 ml of water was used as liquid C, and 91 ml of piperazine ethanol was used as liquid d.

Solution a and solution b were gradually added dropwise to solution C at the same time.
Next, the liquid d was added to the obtained mixed liquid and thoroughly mixed until homogeneous to prepare an aqueous mixture. The ratio of each component in this aqueous mixture is SiO ₂ / Al ₂ O ₃ = 40 (molar ratio), OH ⁻ /
SiO ₂ = 0.45 (molar ratio) (however, OH ⁻ is the amount of added inorganic base minus the amount of inorganic acid), piperazine ethanol / SiO ₂ = 0.6 (molar ratio), sodium / SiO ₂ = 0.3
(Molar ratio) and potassium / SiO ₂ = 0.3 (molar ratio).

Next, this aqueous mixture was transferred to a 1-volume autoclave, and a reaction was carried out at 190 ° C. under self-pressure for 4 days while stirring. The reaction mixture was then cooled and the product obtained was washed 5 times with 1.5 l of water.

Then, the solid content was separated by filtration and dried at 120 ° C. for 15 hours to obtain large crystalline mordenite. The X-ray diffraction pattern of this product is shown in FIG. Moreover, when this product was fired at 550 ° C., the composition was 0.1Na ₂ O / 0.9K ₂ O / Al ₂ O ₃ / 21.1SiO ₂
Met. An electron micrograph of this large crystal mordenite is shown in FIG. In addition, commercially available mordenite 10
The X-ray diffraction pattern of (SiO ₂ / Al ₂ O ₃ molar ratio 10) is shown in FIG. 2, the electron micrograph is shown in FIG. 4, and the commercially available mordenite 20 (SiO ₂ / Al ₂ O ₃ molar ratio 20) is used. An electron micrograph of is shown in FIG. 5 for reference.

Example 2 Large crystal mordenite was obtained in the same manner as in Example 1 except that piperazine ethanol was not added. The composition of this product after firing was 0.1 Na ₂
It was O · 0.9K ₂ O · Al ₂ O ₃ · 21.0SiO ₂ .

Example 3 In Example 1, 30.4 g of sodium hydroxide as the C liquid
Large crystal mordenite was obtained in the same manner as in Example 1 except that a mixture of water and 500 ml of water was used. The composition of this product after firing is 0.9Na ₂ O ・ Al ₂ O ₃・ 19.7Si
It was O ₂ .

Example 4 Large crystal mordenite was obtained in the same manner as in Example 1 except that 42.2 g of potassium hydroxide and 500 ml of water were used as the C liquid. The composition of this product after firing is 1.0K ₂ O ・ Al ₂ O ₃・ 23.6SiO.
_{Was 2} .

[Brief description of drawings]

1 is an X-ray diffraction pattern of the large crystal mordenite obtained in Example 1, FIG. 2 is an X-ray diffraction pattern of the large crystal mordenite 10, and FIG. 3 is an electron micrograph of the large crystal mordenite obtained in Example 1. 4 is an electron micrograph of mordenite 10 and FIG. 5 is an electron micrograph of mordenite 20. Note that θ in FIGS. 1 and 2 indicates the Bragg angle. The wavelength of the X-ray used at this time is 1.5418Å.

Claims (6)

[Claims] 1. A in the composition, expressed in molar ratio formula after calcination _{xNa 2 O · yK 2 O ·} Al 2 O 3 · zSiO 2 [wherein, x, y, z are is a real number satisfying the relationship: . x ≧ 0, y ≧ 0, x + y = 1, 5 <z <30], and X
Line diffraction pattern has a lattice spacing d (Å) Relative intensity 13.75 ± 0.2 Medium 10.36 ± 0.2 Medium 9.14 ± 0.2 Very strong 6.61 ± 0.15 Medium 6.42 ± 0.15 Medium 6.10 ± 0.15 Weak 5.92 ± 0.15 Medium 4.60 ± 0.15 Medium lattice spacing d (Å) Relative strength 4.01 ± 0.15 Strong 3.84 ± 0.1 Medium 3.80 ± 0.1 Weak 3.48 ± 0.07 Medium 3.40 ± 0.07 Medium 3.23 ± 0.07 Strong 3.21 ± 0.07 Strong 2.90 ± 0.07 Medium 2.50 Large crystalline mordenite characterized by being expressed as ± 0.05 weak. 2. At least two compounds selected from the group consisting of (A) silicon source, (B) aluminum source and (C) (i) sodium source, (ii) potassium source and (iii) amino alcohol. The contained and molar ratio of each component is silica / alumina ≧ 20 sodium / silica = 0 to 3.0 potassium / silica = 0 to 3.0 amino alcohol / silica = 0 to 10 hydroxide ion / silica = 0.05 to 0.50 (however, water The amount of acid ions is the amount of inorganic base added minus the amount of inorganic acid.) An aqueous mixture is reacted at 150-300 ° C until mordenite is formed, which is characterized by the following: composition of the general formula _{xNa 2 O · yK 2 O ·} Al 2 O 3 · zSiO 2 [formula expressed in molar ratio, x, y, z are real numbers satisfying the following relationships. x ≧ 0, y ≧ 0, x + y = 1, 5 <z <30], and X
Line diffraction pattern shows lattice spacing d (Å) relative intensity 13.75 ± 0.2 Medium 10.36 ± 0.2 Medium 9.14 ± 0.2 Very strong 6.61 ± 0.15 Medium lattice spacing d (Å) Relative strength 6.42 ± 0.15 Medium 6.10 ± 0.15 Weak 5.92 ± 0.15 Medium 4.60 ± 0.15 Medium 4.01 ± 0.15 Strong 3.84 ± 0.1 Medium 3.80 ± 0.1 Weak 3.48 ± 0.07 Medium 3.40 ± 0.07 Medium 3.23 ± 0.07 Strong 3.21 ± 0.07 Strong 2.90 ± 0.07 Medium 2.50 Production method for large crystalline mordenite expressed as ± 0.05 weak. 3. The production method according to claim 2, wherein the component (C) is (i) sodium source and (ii) potassium source. 4. The production method according to claim 2, wherein the component (C) is (i) a sodium source and (iii) an amino alcohol. 5. The component (C) is (ii) a potassium source and (ii)
i) The production method according to claim 2, which is amino alcohol. 6. The component (C) is (i) a sodium source, (ii)
The production method according to claim 2, wherein the potassium source and (iii) amino alcohol.