JPS5954620A - Preparation of zeolite - Google Patents

Abstract

PURPOSE:To prepare a zeolite resembling ZSM-5, stably without using a harmful organic mineralizing agent, by crystallizing a uniform phase compound of granular amophous aluminosilicate containing a specific amount of Al in an alkaline aqueous solution. CONSTITUTION:The above uniform-phase compound containing 0.5-10wt% (in terms of anhydride) of Al as Al2O3 (abbreviated as uniform compound) is crystallized in an aqueous solution of an alkali metal hydroxide and/or an aqueous solution of an alkali metal silicate. A zeolite having a lattice spacings (d-value) or the table (by powder X-ray diffraction) can be prepared by this process. The above uniform compound can be obtained by the simultaneous and continuous reaction of an aqueous solution of an alkali metal silicate with an Al-containing aqueous solution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing zeolite, particularly 5to2
/A/, 64 molar ratio (hereinafter simply 5iO7'/A/2
03. The present invention provides a novel method for synthesizing a zeolite having a pentaoxygen ring, which is expressed as -f) and is highly pure.

Zeolite, which comes from the Greek word for "boiling stone," is a crystalline aluminone licade containing zeolite water.

Its basic structure consists of four parts formed mainly of silicon.
The 8 104 tetrahedron in which the element is arranged at the top and the A704 tetrahedron in which aluminum is directly substituted for silicon are,
0/(At+S) They are regularly arranged three-dimensionally while sharing oxygen so that the number of atoms in the tile is 2.

The AlO4 tetrahedral charge is balanced by the inclusion of alkali metal and alkaline earth cations. Also, depending on how the tetrahedrons are arranged, 8 (
(One pore is formed and one molecule of water or an exchangeable cation is present in the pore.) Zeolite.

Items in which the cations inside are exchanged with other appropriate cations are 71! It can be used as a so-called molecular sieve that has the function of trapping certain molecules in the pores, or as a catalyst that reacts only in the pores, or as an ion exchanger.

Historically, it has been used in various fields, such as as a catalytic compound.

Zeolites are known to have the following crystal structures and chemical compositions, and depending on their properties: properties such as adsorption properties, catalytic properties, ion exchange/i4 properties, etc. Moderately, each A7. ．． F, C and Zeo 241 names are given.

Among these, mordenite aqueous solution offretite, nanite clinophtilolite, and chabazite exist naturally, and can also be synthesized by hydrothermal synthesis. Zeolite) A', X, and Y do not exist in nature and can only be obtained by hydrothermal synthesis.

One example is the Z 8 M-5. ZSM-! J
A mineralizing agent such as tetrapropyl ammonium
It is hydrothermally synthesized using the father ion as an essential raw material, case proposal: number a = 20.1χ, 'b = 19.9X, c = 1
It is an orthorhombic crystalline alumino hepta-silicate of 3.4χ, and the lattice spacing (
d-value). In addition, tetracylobylammonium ions are present in the crystal as part of the cations that grow the zeolite σ) crystal.

There is ~1 as an improved synthesis method for ZSM-5! ,'Z
The Gods σ method was disclosed as a method for synthesizing zeolite similar to 5M-5. For example, a method using an organic sulfur compound as an organic mineralizing agent is described in JP-A-54-16-S 500, a method using a cyclic ether [U.
140.023, a method using alcohol amines is disclosed in JP-A-56-17-920, and a method using amino acids is disclosed in JP-A-57-817, respectively. G and others all require organic mineralization 1
11V, pertains to the law. However, recently, attempts have been made to synthesize a zeolite similar to 28M-5 without using an organic mineralizing agent, and traglobylammonium bromide is reported in JP-A-57-7.81'9. A synthesis method is disclosed in which the crystals are added as crystals.

Table - Table.

Lattice spacing (d- value) Relative strength 11.1
Warrior 03 Strong 10.0 +03 Strong Z4 +02
Weak 7,1 -t 0.2 Weak 6.3
+0.2 weak 6.04±0.2
Weak 5.56 0.1
Weak・501±0.1 Weak
stomach .

4.60±008 Weak 4.25±0.08 Weak 68510
．． 07 Very strong.

&71±0.05 Strong 3.04±0.
03 Weak: 2.99±0.02
Weak 2.94±002 Weak Moreover, in Japanese Patent Publication No. 56-49.851, ZSM-5-like zeolite synthesis can be achieved by using a silica source and soo silica sol without destroying the organic mineralizing agent. A method is disclosed.

According to the research results of the present inventors, it is extremely difficult to synthesize a zeolite similar to ZSM-5 without using an organic mineralizing agent, and even if the methods disclosed so far are strictly followed and implemented, Sushi does not always have to be synthesized efficiently. The silica raw material, the mixing of the raw materials +111', and the reaction issues such as the presence of stirring and the degree of crystallization were introduced in a complicated manner, and it was not possible to perform a detailed synthesis. For example, when using silica sol, which has conventionally been used as a silica source, if stirring is performed during crystallization, it is difficult to obtain a zeolite similar to ZSM75, even if the raw material composition and crystallization temperature are deliberately changed. Hadedani was forced. In addition, when heating was performed without searching or stirring except when preparing raw materials, in most of the numerous experiments, the products were amorphous or mainly composed of mordenite. However, even if a zeolite similar to ZSM-5 was occasionally observed, impurities such as mordenite were always present.

Aqueous sodium silicate solution is used as a silica source.
sM-s was added with a seed crystal and crystallized by heating while stirring.
・was defeated. However, both mordenite and kenyite were present as impurities. Various attempts were made using an aqueous sodium silicate solution/liquid source without using seed crystals, but all ended in failure.

As a result of extensive research into zeolite synthesis methods, Nagisa et al. discovered the following important 11 results, which are described in detail below.
The present inventors have developed an extremely economical and stable synthesis method using silica soda water lava η? as a silica source. However, for example, by reacting an aqueous solution of sodium hyalate and an aqueous solution of aluminium oxide simultaneously and in a similar manner, 71i, granular aluminosilicate Jj1
11. A homogeneous phase compound (hereinafter simply referred to as a homogeneous compound) is prepared, and then the homogeneous compound is crystallized in a fresh alkaline water bath. We have discovered that it is possible to efficiently produce 2s' ya-54 of 2s' ya-54 of a similar product without any problems. The present invention was completed as a result of extensive research □ based on this knowledge, and it is a highly pure ZS'M-5 that does not use harmful organic mineralizing agents and uses inexpensive raw materials.
This method provides a method for easily producing similar zeolites, and considering that although conventional methods are possible in the laboratory, they have many disadvantages in terms of economics, quality, operation, etc. industrially. , the industrial significance of the present invention is extremely large.

The present invention will now be described in greater detail.

The present invention uses aluminum as A/203 of 0.5 to 1
By crystallizing a homogeneous compound containing 0 wt% (on anhydrous basis) in an alkali metal hydroxide aqueous solution and/or an alkali metal silicate aqueous solution (hereinafter simply referred to as alkali aqueous solution), no organic mineralizing agent is used. Zeolite similar to ZSM-5 J1. ! It is something that I build.

The homogeneous compound used in the method of the present invention can be obtained, for example, by intermittent and continuous reaction with an aqueous alkali metal silicate solution and an aqueous aluminum-containing solution. In the method of the present invention, the simultaneous and continuous reaction refers to a mode in which an aqueous alkali metal silicate solution and an aqueous aluminum-containing solution are supplied to the reaction zone simultaneously and while maintaining a substantially constant ratio. do. As the aqueous alkali metal silicate solution, an aqueous solution of sodium silicate, potassium silicate, lithium silicate, etc., or an aqueous alkali solution containing silicic acid can be suitably used. In addition, aluminum-containing aqueous solutions include sodium aluminate, potassium aluminate, aqueous solutions such as ``Hardened Aluminum+'' (lfij r5 aluminum, aluminum nitrate, etc.), aluminum hydroxide, aluminum 11P dissolved in alkaline solution in water or mineral acid. A water bath solution can be suitably used.When preparing a homogeneous compound, the pH of the slurry in which the granular homogeneous compound produced by the reaction is suspended is
A mineral acid or alkali is added to the reaction system and/or the raw material aqueous solution to adjust the pH so as to maintain the pH between 5 and 9, and the rainwater solution is reacted continuously. The most preferred pH of the reaction slurry is 6-8.

An example of the most preferred embodiment for preparing a homogeneous compound is a method in which a rainwater solution is simultaneously and continuously fed into an overflow type reaction tank equipped with a stirrer and reacted under stirring. . In this case, the apparent residence time of the reaction slurry in the reaction tank is preferably calculated by the residence time (actual volume of the reaction tank (3)/reaction slurry volume per unit time discharged from the reaction tank [: l/min]). Set it to 3 minutes or more.

If the residence time □ is less than 3 minutes, the particles of the homogeneous compound will be fine and fragile, which is not preferable for carrying out the method of the present invention.

As another example, it is of course possible to apply a so-called batch-continuous preparation method in which the rainwater solution is continuously supplied at a fixed ratio to the reaction tank under stirring conditions without discharging the reaction slurry. It is essential to feed the mixture over at least 5 minutes, preferably over 30 minutes, without adding it rapidly.

Homogeneous compounds of various compositions can be prepared by these methods, but in order to carry out the method of the present invention, aluminum tg Al, O, must be 05 to 10% (without any complications including anhydrous conversion). In order to obtain the !+j,02/A/203 ratio of 4-tone zemerite, it is necessary to have a homogeneous compound with a low At, 03 content. .t/A4゜3Ji3,9ke9
．． -, i′1. ．． Iyuro meba 11'? At, O
A homogeneous compound with a s content of 91+: Yes. The homogeneous compound Al2O content is 05 wt% (anhydrous EA-).
If it is lower than 10wt%, or conversely if it is higher than 10wt%, the target ZSM-5 similar zeolite is not produced.
) is not a problem.

to 120. A homogeneous compound with a content of 0.5 to 10 wt% (anhydrous conversion 11) is, for example, each S' of the raw material aqueous solution.
This can be obtained by adjusting the flow rate ratio of both aqueous solutions in consideration of the concentrations of L 02 and At, ○. By increasing the Al2O3P degree of the aluminum-containing aqueous solution and its flow rate ratio, a homogeneous compound with a high Al2O content can be obtained.

The granular amorphous compound used in the method of the present invention has a homogeneous phase and 11.
P extrusion is as follows.

For example, the precipitate obtained by adding an aluminum oxide aqueous solution to a sodium silicate aqueous solution is separated and combined with a new zitorium hydroxide solution to crystallize the desired Z. , S￥-5 class zeolite was not rejected.In addition, the chemical compound obtained by adding silicic acid and a soda solution to an aqueous aluminum sulfate solution was separated, and a new sodium aqueous solution was obtained. When heated and crystallized in an aqueous solution, 28
It would be great if we could get a zeolite similar to M75! Umordenite and Ke-Yaito coexisted together. However, in a preferred embodiment of the method of the present invention, the raw material prepared by continuously reacting the two aqueous solutions always has a constant composition. Since the compound is precipitated in a uniform state, there are no non-uniform parts in the precipitate, and it is thought that this facilitates the regular arrangement of atoms necessary for crystallization of 5'F'. In this sense, the amorphous aluminosilicate used in the Kyokumei method is a homogeneous phase 4.
It can be called 1 compound.

In the method of the present invention, the homogeneous compound appears to be spherical or has the shape of a particle aggregate.
Although the particle size can be arbitrarily selected within the range of 00μ, a particle size of 10 to 1.0Qμ is preferable for carrying out the present invention. Solid-liquid separation of the reaction slurry is extremely easy, and a homogeneous compound with a high dehydration rate can be obtained by ordinary filtration operations. Note that one of the economic features of the present invention is that a dilute aqueous solution can be used as a raw material for zeolite synthesis. When a homogeneous compound is subjected to crystallization, the present invention can be carried out regardless of whether it is in a wet state or a dry state. 1. Crystallization is carried out by heating the homogeneous compound in an aqueous alkaline solution. Although it is not an essential condition to perform top stirring during crystallization, stirring is preferable in order to ensure uniform heat transfer throughout the system.

An example of an alkaline aqueous solution is sodium hydroxide.

Aqueous solutions of potassium hydroxide, lithium hydroxide, sodium silicate, potassium silicate, lithium silicate, and the like are suitable. Alternatively, a mixed aqueous solution of two or more of these may be used. Also preferably sodium hydroxide.

These are an aqueous solution of IJium (silicic acid) or an aqueous solution of these iTWs.

The concentration of the alkaline aqueous solution is 05 to 5 wt% as Mol (M is alkali gold 1'α) and 0 to jO as Sin.
Wt% is desirable, most preferably a mol concentration of 0.5 to
It is 5wt%. When the Mol concentration exceeds 5 wt%, impurities, especially mordenite, coexist. 5Si becomes difficult to crystallize when the MOH concentration is less than 0.5 vt%.
If 021t4 degrees exceeds 10 wt%, crystallization will not occur. Note that it is also possible and economically preferable to use the mother liquor recovered by solid-liquid separation after completion of crystallization as an alkaline aqueous solution.

Although the ratio of the homogeneous compound to be subjected to crystallization to the alkaline aqueous solution can be arbitrarily determined, it is preferable to use 20 to 2000 parts by weight of the alkaline aqueous solution per 100 parts by weight (wet basis) of the homogeneous compound.

The temperature for crystallization is preferably 120 to 220°C.

If it is lower than 120°C, it is difficult to crystallize, and if it is higher than 220°C, mordenite and quartz coexist.

The time required for crystallization is 10 to 200 hours, depending on the temperature.

The crystallized slurry lJ, -'Y solid-liquid content *1r, was washed with water and dried to form X1vIII shown in Table 1.
! High purity 78M-5 similar zeolite cutting filter with d-value by powder diffraction.

Table 3 shows the d-values of representative examples obtained based on the method of the present invention. X-ray powder diffraction is limited to the values listed in Table 3, as the d-value and mutual quotient 5-strong dust vary slightly depending on the zeolite manufacturing conditions and measurement conditions. isn't it.

The zeolite obtained by the 11JJ method of this invention has 100λ and 9
8th, 685th and 3.81th, S, 75X and 3.72, 2-9'9 (A and 2. q a It is characteristic.

Its composition is expressed by the following formula: zNa, 0wAl2O3-(15-100nSio2*
yH2'0 (However, X is the degree of water washing of the product, and the difference is usually around 1. Father, y is 0 or a positive number for drying.

The difference is 11 degrees of dehydration. ) S102 /A1203 has a high ratio of 15 to 10o, and after being in powder form or calcined or molded, it can be ion-exchanged with an appropriate cation by a known method and used for divine purposes, such as dehydrating agents, adsorption/separation agents, and catalysts. Be able to use it.

Examples will be explained below.

Table 3 - Preparation of homogeneous and heterogeneous compounds with relative strength (d-value) Into an overflow type reaction tank (actual volume 11) under stirring, a silicon having the composition shown in Table 3 was placed. An acid soda aqueous solution and an aluminum sulfate aqueous solution containing sulfuric acid were mixed at 1.5, (1/hr +'-, o
, 5//hr [e continuous feed. The apparent retention time of the reaction slurry is 30 minutes2.The reaction temperature is 30-30 minutes.
At 2°C, the P)T of the overflowing slurry was 6.3-6.6.

The 1:1 discharged slurry was separated into solid and liquid using a centrifugal filter, and after thorough washing with water, a wet cake of a homogeneous compound having the composition shown in Table 3 was obtained.

A-E rQ got it. These homogeneous compounds include SO4
All Xa powder diffraction results were amorphous.

Next, the same silicon from which homogeneous compound C was prepared (fji)
Using a sorter aqueous solution and an aqueous aluminum sulfate solution, add 2 g of an aqueous aluminum sulfate solution to 61 aqueous sodium silicate solutions.
Prepare the average-compound F by adding the father,
Heterogeneous compound G was prepared by adding 61rc of an aqueous solution of sodium silicate to 21 rc of aluminum sulfate.

Solid-liquid separation and water washing of the slurry were performed in the same manner as in the case of a homogeneous compound. Table 3 shows its composition.

The results of X-ray powder and diffraction were both of a regular shape.

Examples 1' to 4 and Comparative Examples 1 to 5 The wet cake of the homogeneous compound or the heterogeneous compound prepared as described above and the alkaline solution were placed in a No. 21 autoclave and heated with stirring. After completion, the first generation of the suspended slurry IJ-' is taken out, solid-liquid separation is completed, and the washing is carried out for a long time.
It was dried at 20°C. Crystallization conditions and results are shown in Table 4.

Example 5' Compound B and NaOHl 60' wt% aqueous sodium hydroxide solution were mixed in 1. ．． 07 autoclave and heated at 165℃ for 72 hours, s], o2/Δt20
．． High purity zSM-5a-like theolite with a ratio of 5a8 was obtained.

The crystallization conditions and results are shown in Table 4.

Figure 1 shows the X-ray powder diffraction pattern 1-0

[Brief explanation of drawings]

Figure 1 is an X-ray powder diffraction pattern of the product obtained in Example 5. Measurements were made using alpha doublet for copper. Patent applicant: Toyo Soen Kogyo Co., Ltd. For procedural amendment October 26, 1981 'I'+, 'i't1'+ Long eyebrows Kazuo Wakasugi 1゛Former 11
Display of Showa, T1157, l14. , i'l request No. 162123
2 Name of the invention; ・]Manufacturer of 4-knob method 6-corrector iT f/1. Relationship with 71” 4J permission 1!iQ Address 〒746t, Lt11 Prefecture Kannanyo City Oaza ff', l
114 et 60 Hinoki E1 track ■ 1 story hanging bow (5R5) Roro 11 'I 1i1ii1 command's 1:1 I゛j white Ikui mountain 1
1' 5=(jli-i8-+-19-41H y-'rN4
Katakuwa-5 Subject of amendment *lli 11 6 Type stamp of detailed statement of contents of amendment) 11 7 Attached document type Printed specification

Claims (1)

[Claims] (1) Aluminum 1iAl, 0.5 to 03
Crystallizing a granular can-shaped aluminosilicate homogeneous phase compound containing 10 wt% (anhydrous test) in an aqueous alkali metal hydroxide solution and/or an aqueous alkali metal silicate solution is lr!
The Xm shown in Table 2 is assumed to be a characteristic of j. A method for producing a zeolite having a lattice spacing (d-value) determined by a powder diffractogram. (21 Particulate amorphous aluminosilicate salt uniform box compound obtained by simultaneously and continuously reacting an alkali metal silicate aqueous solution and an aluminum-containing aqueous solution 7-1 Claim 1
Method in item 4N. (31) The method according to claim 1, wherein the aqueous solution for crystallizing the granular shaped aluminosilicate homogeneous compound contains Na'(J140.'5 to 5 w't%.) (4) Granular The method according to claim 1, wherein the aqueous solution in which the amorphous aluminosilicate homogeneous phase compound is crystallized is NaOHO, 5 to 5 wt%, q to 10 wt%.