JPS6177620A - Zeolite composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to zeolite compositions. Specifically, the present invention relates to a novel crystalline aluminophosphosilicate porous material.

[Conventional technology]

As is well known, zeolites have a wide range of uses, including as catalysts, adsorbents, and ion exchange agents. As a catalyst, it is used in large quantities, for example, for cooking petroleum. This is because zeolite has strong solid acid sites and K
This is because it is excellent in practical aspects such as ITP properties. Zeolite catalysts also have good reaction selectivity. Zeolite is generally an aluminosilicate, and its crystals have a strong and uniform pore structure, so the size of molecules can be distinguished to a certain extent and has selectivity for one reaction.

Therefore, in reactions where reaction selectivity is important.

Zeolite catalysts occupy a large position.

Zeolite is a crystal, and if you observe its powder x&l pattern, zeolites with different structures will have different powder X-ray diffraction patterns that reflect their structures. The number of zeolites identified in this way is approximately <
It is said that there are more than 100 types of synthetic zeolites.

This is because although zeolites are crystals resulting from a combination of relatively simple compounds, the product is not necessarily the thermodynamically most stable phase but a metastable phase.

Zeolites are primarily characterized by their skeletal structure, but other properties are also important.

Especially when used as a catalyst, even if zeolites have the same skeleton structure, differences in other properties have a large effect on the reaction activity. For example, the silica/alumina ratio of zeolite is related to the number and strength of solid acid sites, and the crystal size is related to reaction selectivity. In addition, the distribution position of catalytic active sites also determines the reaction activity.

Product distribution may be affected.

Synthetic zeolite, 4? Crystalline aluminosilicate zeolites are generally synthesized by heating a mixture consisting of at least an alumina source, a silica source, a hydroxide source, and water.

Heating is practically carried out at temperatures from about /θ°C to about 300°C under autogenous water vapor pressure, and this reaction is usually carried out.

It is called a hydrothermal reaction. The manufacturing method of zeolite is
Since the pioneering research of RoM and Barrer et al., numerous studies have been conducted due to its practical importance.

In recent years, by adding organic template agents such as organic ammonium ions and organic amines to a mixture consisting of an alumina source, a silica source, a hydroxide source, and water,
It has been reported that zeolites with crystal structures different from conventional ones are produced. A typical example of such zeolite is a so-called pentasil type zeolite such as ZSM-j or ZSM-//. Pentasil type zeolite exhibits effective shape selectivity because it has pores consisting of 10-membered oxygen rings. This zeolite is an excellent catalyst especially for gasoline synthesis from methanol, selective synthesis of aromatic compounds, etc. In addition to its unique structure, pentasil-type zeolite can be modified to an almost infinite extent compared to natural zeolites and the previously known synthetic zeolites.

The above pentasil type zeolites, especially ZSM-! So-called high-silica zeolites, represented by type zeolites, are often superior in terms of reaction selectivity and catalyst life compared to conventional zeolites, so their synthesis methods have been studied from various angles, and a variety of methods have been proposed. A manufacturing method has been proposed.

A brief summary of some of the research on ZSH-tazeolite.

■ Synthesis method using cheaper organic template agent (
% Kaishoj j -7j4t, 7ri? 1% Kaisho! ! −≦7
, 622, etc.) ■ Methods for synthesizing crystals with well-defined shapes, methods for producing crystals with large crystal sizes (JP-A Show! 6-gyo, //?, JP-A Show!≦-//4t, ? /7, etc.) ■ Control of the distribution position of aluminum (USPa, O♂l, Otsu 0 or composite zeolite (JP-A-Show JJR-Cohe 3!3)) ■ Control of part or most of the aluminum in the lattice Other elements 1, such as boron, iron, gallium, etc., may be substituted with zeotite (Japanese Patent Application Laid-Open No. 2003-120012, J-j3'', jθθ).

[Problem that the invention seeks to solve]

By the way, zeolites are usually chemically rigorous.

Since it is synthesized from a gel that cannot be uniformly defined, the zeolite produced may differ depending on the composition ratio of the preparation, hydrothermal reaction conditions, aging time at room temperature, and raw material sources6. In other words, the zeolite production process is very complicated;
Although it is possible to some extent to carry out inductive zeolite design based on existing data, it is difficult to iteratively consider what synthesis conditions are required to obtain a new crystal structure. . Therefore.

In the current zeolite synthesis, there are many elements of trial and error.This point is also the same for the z8M-j type zeolite in the research report. Furthermore, it is difficult to control catalytic activity 1 selectivity in a redundant manner from the zeolite synthesis stage.

[Means for solving problems]

In view of the above background, the present inventors have conducted extensive studies on a more effective zeolite synthesis method, and as a result, they have developed a method that uses an alumina source, which has rarely been used in conventional zeolite synthesis or pentasil-type zeolite synthesis. At the same time, by coexisting a phosphoric acid source, a new zeolite composition having several characteristics was discovered.

Furthermore, when these are applied as catalysts, conventional ZS
The present invention was completed based on the result that the selectivity of M-j type zeolite was also very good.

That is, an object of the present invention is to provide a new and useful zeolite composition, the gist of which is to provide a new and useful zeolite composition.
A crystalline aluminophosphosilicate obtained by hydrothermally reacting an aqueous mixture containing am7nium ions, whose main powder X-ray diffraction peaks are shown in the table below.
Or Table-2: Table-7 Table-1//, /±0.3 Medium to Strong //, Ko±0.2
Medium π, θ±0.3 Medium to strong /Q, /±00.2
Medium 7.9t ± θ, Ko Leopard ≦, 23 ± Q, Ko Weak 2.7
±0. - Weak! , 7j±0. / Weak 6.3±0.2 Weak! ,6/±o,i
Weak 6.0g ±0.2 weak! ,03
Shi O07 weak! ,! To ±θ, / Weak Ta, to ±0. / Weak! ,0/±0. /
Weak Ta, 3ri±o, or
Weak, 6θ±o, or weak 3. /6
Shi0.07 Strong, Ko! ±Q, θ♂ @
s, 73rd grade 0.07 junior high school student, ♂! ±θ, 07
Strong JjtY±0.07 Weak 3.7
700, or strong 3.07±0.0
j Weak 3, θ ±θ, 03 Weak 3.0
0shi0.0j weak-, wata ±0.02 dog
Ko, 0/shiO0θko Weak -69ri ±0,0.2
There is a zeolite composition 1c characterized in that it has a weak zeolite composition.

The present invention will be explained in detail below, but first, the characteristics of the zeolite composition and its synthesis method according to the present invention will be explained.

The first feature is that in producing the zeolite composition according to the present invention, a solid alumina source that is substantially insoluble in water is used as the alumina source. Conventionally, silica/
When synthesizing zeolite having an alumina ratio of 70 or more, it is common to use an alumina source that is easily soluble in water.

Typical examples of such alumina sources include aluminum sulfate and sodium aluminate. The reason for this is presumed to be that when a gel is prepared using a water-soluble alumina source, a high-reactivity gel is produced, which in turn facilitates the growth of zeolite crystals. Against this.

An example of using a water-insoluble alumina source is for the synthesis of zeolite with a low silica/alumina molar ratio, such as 0BZ-/type zeolite (JP-A-2-7.123).
J is relatively common, but even if it is overwhelmingly used in the examples of 28M-j type zeolite synthesis, under conditions where phosphoric acid etc. are present, alumina, which is easily soluble in water, which has been commonly used in the past, Sources of water-insoluble alumina that have been found to yield zeolite compositions with better properties than the zeolite sources include hydroxylated aluminum, hydric alumina, and various amorphous or crystalline aluminas.

Aluminum phosphate and the like can be mentioned, and any of them can be used without the invention, but among these, pseudo-boehmite phase alumina is more suitable.

The first feature of the present invention is that for i#l silica zeolite, especially ZSM-j type zeolite, the silica/alumina molar ratio at the time of charging is significantly lowered to 1q, so that the silica/alumina molar ratio of the product is The ratio is similarly low. ZSM-j, a high silica zeolite developed by Mobil Oil, has been synthesized over a wide range of products with a silica/alumina molar ratio of usually 20 or more to almost no alumina. As mentioned above, 1M3M-j type zeolite is characterized by a high silica/alumina molar ratio, and in fact, examples of its production and use show that the ratio is often about 30 or more. In the synthesis of high-silica zeolite, the silica/
The alumina molar ratio is 1 with the silica/alumina molar ratio of the product.
Since the ratio corresponds to -1, this ratio at the time of preparation is often about 30 or more. When this ratio is low, especially below coθ, other crystalline phases such as mordenite or α-cristobalite may replace ZSM-type zeolite as the main crystalline phase, or amorphous zeolite may become the main crystalline phase. Only product is obtained.

That is, the ZS is substantially uncontaminated by impurity phases in the pond.
It has been difficult to synthesize M-j type zeolite. Therefore, when these were used as catalysts, reaction selectivity etc. were naturally not good. However, the present inventors have found that by using a water wash-insoluble alumina source, especially a pseudo-boehmite phase, and coexisting a phosphoric acid source, it is possible to easily form the desired zeolite phase even when the silica/alumina molar ratio is lower than 10. It has been found that it can be produced while suppressing the contamination of other crystal phases. For the first time according to the present invention, silica/
The alumina molar ratio is lower than 20, and more! It has become clear that the ability of 28M-j type zeolite as a pure crystal phase can be obtained as an almost pure crystal composition containing only trace amounts of other crystal phases. Note that even when some other crystal phases are observed in the powder X-ray pattern, the selectivity for one reaction is good.

A third feature of the present invention is that the zeolite composition according to the present invention contains phosphorus.

For zeolites, such as ZI3M-type zeolites, 1K is usually used after the zeolite has been synthesized once.

Methods of modifying the zeolite with various phosphorus compounds are known (J, 0ata1., 74゜ltt
/r ('?2)), by carrying phosphorus.

Improvements in reaction selectivity as catalysts are being pursued. On the other hand, there are also known techniques for producing zeolite by adding a phosphoric acid source during synthesis; for example, JP-A-Sho! Tar/3,6
Ko/ discloses a method using phosphate as a buffering agent. This patent publication describes a method for producing a zeolite with a defined crystalline form by adding a phosphate when synthesizing a high-silica zeolite with a silica/alumina molar ratio greater than 70, preferably greater than or equal to roθ.

The content of phosphorus in the product 1tFiθ, θ/
It is about Wtchi or less.

Moreover, even when looking at other conventional known techniques, the content of phosphorus contained in ZSM-j type zeolite is small. On the other hand, in some cases, the inventors completed the
It reaches more than wt%. That is, in the zeolite composition for body washing of the present invention.

Before modifying it, there is a considerable amount of phosphorus.

The second feature of the present invention is when the zeolite composition according to the present invention is used as a catalyst.

The reaction selectivity may be good. That is, the Z 19 M-j i zeolide produced according to the present invention is as clear from the Examples shown below.

It has been found that the reaction selectivity is superior to that of the conventional ZSM-J' type zeolite, and the shape selectivity held by the conventional ZSM-j type zeolite is further improved.

Next, a method for producing a zeolite composition according to the present invention will be explained.

The zeolite composition of the present invention is prepared by forming one reaction mixture in the same way as in conventional aluminosilicate zeolite synthesis, heating it until crystallization proceeds, and mixing organic amine or tertiary ammonium ions. . Phosphoric acid is preferably used as the phosphoric acid source, and alumina substantially insoluble in water, especially pseudo-boehmite phase, is preferably used as the alumina source. It is also possible to use an alumina source or aluminum phosphate that can form insoluble alumina in an aqueous solution and a combination of a phosphoric acid source and an aluminum source that can form it in an aqueous solution.As the silica source, Water glass, colloidal silica, silica hydrogel, silicic anhydride, orthoethylsilicate, etc. used in conventional zeolite production techniques can be used;
A preferred silica source is colloidal silica. As the organic amine, an amine having a 7- to tertiary-carbon alkyl group is suitable, and as a Z-class ammonium ion source, a quaternary ammonium salt, an alkyl ammonium hydroxide, etc. are suitable. . It is also possible to use combinations of compounds that are expected to form these in aqueous solution, such as amines and alkyl halides. In the case of adding alkylantane7ium hydroxide or organic amine, the addition of the hydroxide source can be omitted.

The hydroxide source can be omitted when water glass is used as the silica source, but when using a combination of silica sol and ZR ammonium salt, hydroxide is added. It is necessary to add an appropriate amount of an alkali hydroxide such as potassium oxide, an alkaline earth hydroxide, etc.

The composition range of the slurry mixture prepared before the hydrothermal reaction is as follows.

The gel composition can be led to the desired product by heating it for a necessary period of time at a temperature at which crystallization substantially proceeds.
It is preferable to carry out heating at a reaction temperature of /θ0 to 3θO°C until crystallization progresses. The heating reaction time naturally varies depending on the raw materials used, the composition ratio of the mixture, the temperature of the hydrothermal reactor, etc., but in reality it is from 72 hours to about 3Q.
days is appropriate. In this reaction, the gel composition is usually synthesized in a pressure-resistant container under naturally occurring pressure or in the presence of a gas that does not inhibit crystallization. The product obtained in this way is
Preferably, the powder has a powder X-ray diffraction pattern mainly shown in Table 1, and its composition is preferably as shown in Table 1.

EliO□/Al, 03 molar ratio is /~/θO1, more preferably /~E0, P2O5/A120g
The molar ratio is in the range of θ, θ/ to /θ.

The intermediate washing of the zeolite composition produced as described above incorporates the added organic template agent.1. This can be easily removed, for example, by firing. This operation also removes water in the zeolite, resulting in a so-called activated state in which it can adsorb various molecules such as water and organic compounds.

The zeolite can be converted into H-type by ion exchange with ammonium ions and subsequent calcination, or by direct reaction with acid, as is well known to those skilled in the art.

There are various reactions using the zeolite composition according to the present invention as a catalyst, but it is particularly suitable for reactions where shape selectivity is essential, such as production of dialkylbenzene compounds, hydrocarbon synthesis from methanol, etc. used for

Seven such examples include the alkylation of toluene to produce dialkylbenzenes.

Techniques for producing xylenes by methylating toluene have been known for a long time, and studies have been made using 91 different catalysts. Z
The technique of producing xylenes by alkylating toluene with methanol using SM-Nashi zeolide as a catalyst is well known.

However, in unmodified Z 8 M-f, the selectivity of p-xylene, which is the most useful, is low, and the distribution of xylenes is close to the thermodynamic composition.

By using the product according to the invention as a catalyst,
The selectivity of p-xylene is improved even if it remains unmodified.

The reaction conditions for producing dialkylbenzene by alkylating toluene using the product according to the present invention as a catalyst are normal pressure ~! θkg/G pressure, gA degree 30θ~to
℃.

Toluene/alkylating agent molar ratio/~j, and o-WHE
A range of IV 03-4tOhr-' is suitable.

When hydrogen is used as a reactive gas, a molar ratio of H2/toluene of 10 to 10 is suitable.

Alkylating agents include alcohols such as methanol and ethanol, and ethylene.

Olefins such as propylene can be suitably used. [Example] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited by the following Examples unless it exceeds the gist thereof. do not have.

In the following examples, the pseudo-boehmite used was a product manufactured by Condeia (A120 content?%), and the silica sol used was a product manufactured by Catalysts & Chemicals (Katayaki Kasei 5-jO).
H, 5in2 content 30%) was used.

Example / Sodium hydroxide / j, 2 F is dissolved in 200 - of water, and this is ♂! Tyrinic acid 23. /l of water and an aqueous solution of 20θ- were mixed. Tetrapropylammonium bromide (TPABr)/r, 7f was added to this solution, and pseudoboehmite≦1 was added while stirring. After stirring this mixture until it became homogeneous, 10θ,
Gradually add 2 parts of silica sol, then go! A solution of sodium hydroxide (2) dissolved in water (30) was added, and the mixture was stirred at room temperature for about 3Q minutes. This gel composition was transferred to a stainless steel autoclave and heated at 0° C. for 7 hours to cause a hydrothermal reaction. Collect the product by Fm and add /1 water,
! After washing with θomi hot water and 2 tons of water, 10
It was dried at 0°C. Yield'f/k<t7:zf, the powder X-ray diffraction pattern of this product is.

A diffraction peak showing a ZSM-j type pattern (Table 7 above) and considered to be due to a very small amount of Ginumonden type crystals was detected.

The gel composition in this example is SiO2/Al□03/θ
, P2O,/Si0.0,20. NaOH/5i0
20.96. R/Si0°0, /Z. , and the chemical analysis values of the product are P, O, /A1. O
, molar ratio 0.2/, SiO2/A'120° molar ratio/θ,/.

Example--/θ) Synthesis was carried out in substantially the same manner as in Example/. Table 3 shows these gel compositions and hydrothermal reaction conditions.

Comparative Example/A mixture having the same composition as in Example ♂ was prepared using sodium aluminate instead of pseudoboehmite as an alumina source, and a hydrothermal reaction was carried out at /J-0°C for /hour.

The powder xi# diffraction pattern of the product was determined to be an amorphous phase.

Example // The hydrothermal reaction product synthesized in Examples 7 to /θ was catalyzed (converted into H type) as follows. First, the hydrothermal reaction product was calcined for 6 hours at r4to°C under air flow. Next, to this fired product, add ammonium chloride per 〇f to 33F in an aqueous solution of water/8/d.

After heating at 700°C for 2 hours, P was passed through it. After repeating this operation three times, wash the product thoroughly with water.

It was dried at 700°C. After compressing into tablets to a particle size of 2 to 7.2 mesh, it is placed under air circulation! It was baked at θ℃ for a certain period of time. Table 3 lists these catalyst numbers and chemical analysis results.

Example 72~/<= Using each of the catalysts prepared in Example //, an alkylation reaction of toluene with methanol was carried out.

Shape selectivity for p-xylene synthesis was evaluated. The reaction was a normal pressure flow reaction using a quartz reaction tube. Reaction conditions are toluene/methanol molar ratio λ, WH8V 70hr
-i was used. The catalyst was heated at 50°C in a nitrogen gas stream before the reaction.
After pretreatment at 0°C for 7 hours, the mixture was subjected to reaction. These results are summarized in Table d.

Comparative Example 2 ZSM-J-type zeolide was synthesized as follows using a water-soluble alumina source without strictly adding a phosphoric acid source.

After adding 3.42 g of sodium aluminate to a water bath solution in which 92 g of sodium hydroxide was dissolved in 100 g of water, 29.9 f of jetanolamine was added. Next, while continuing to stir, add zt4ty silica sol,
The mixture was further stirred at room temperature for 30 minutes. This gel aqueous solution
The hydrothermal reaction was carried out at θ°C for rt hours.

Comparative Example 3 The hydrothermal reaction product of Comparative Example A was catalyzed in the same manner as in Example 5, and the reaction was carried out under the same conditions as in Example 2.

The results are shown in Table y.

Table ★) In each column of reaction results, the upper row shows the reaction temperature (°C), the middle row shows the toluene conversion rate (c%; the theoretical maximum value is 0%), and the lower row shows the p-xylene in the produced xylene. Indicates the percentage of

From the above description, it is recognized that the zeolite composition according to the invention has significantly improved selectivity for p-xylene compared to the conventional ZSM-5' type zeolite. Effects] When the zeolite composition of the present invention is used as a catalyst, it has good shape selectivity, especially shape selectivity.

Patent applicant: Mitsubishi Chemical Industries, Ltd. Representative Patent Attorney Hase - Others/names

Claims (3)

[Claims] (1) A crystalline aluminophosphosilicate obtained by hydrothermally reacting an aqueous mixture containing a poorly water-soluble alumina source, a silica source, a phosphoric acid source, and an organic amine or quaternary ammonium ion, A zeolite composition characterized in that main powder X-ray diffraction peaks are shown in Table 1 or Table 2 below. ￥Table-1￥￥￥Table-2￥￥Plant spacing (Å)￥￥Peak intensity￥￥Plant spacing (Å)￥
￥Peak intensity￥11.1±0.3 Medium to strong
11.2±0.2 Medium 10.0±0.3 Medium to strong 10.1±0.2 Medium 7.4±0.2
Weak 6.73±0.2 Weak 7.
1±0.2 weak 5.75±0.1
Weak 6.3±0.2 Weak 5.61±
0.1 Weak 6.04±0.2 Weak
5.03±0.1 Weak 5.56±0.1
Weak 4.62±0.1 Weak 5.01±0.
1 Weak 4.39±0.08 Weak 4.
60±0.08 weak 3.86±0.07
Strong 4.25±0.08 Weak 3.73±
0.07 medium 3.85±0.07 strong
3.49±0.07 Weak 3.71±0.05
Strong 3.07±0.05 Weak 3.04±0.
03 Weak 3.00±0.05 Weak 2.
99±0.02 weak 2.01±0.02
Weak 2.94±0.02 Weak (2) The zeolite composition according to claim 1, wherein the alumina source is pseudopeumite. (3) In the zeolite composition according to claim 1 or 2, the silica/alumina molar ratio is 1 to 1.
50 range.