JPS5916832A - Composite zeolite and preparation of hydrocarbon using said zeolite as catalyst - Google Patents

Abstract

PURPOSE:To improve the selectivity in the preparation of a lower olefin from methanol, etc., by using a composite zeolite prepared by crystallizing zeolites having different chemical compositions or skeleton structure in layers, and making the outermost layer to an Al-containing crystalline layer. CONSTITUTION:In the preparation of a lower olefin by the reaction of methanol and/or dimethyl ether at 250-450 deg.C and 0.5-10atm in the presence of a zeolite catalyst, a particular composite zeolite is used as the catalyst. The composite zeolite is composed of zeolite crystal forming nucleus, and at least one zeolite crystal layer formed around the nucleus by the hydrothermal synthesis. At least two of the above crystal layers have different chemical compositions and/or skeleton structures from each other, and the outermost layer is a zeolite crystal layer containing Al (the ratio of SiO2/Al2O3 is <300). The skeleton structure of the outermost layer is preferably ZSM-5-type, ZSM-11-type or their mixed crystal, and its thickness is usually about 0.1-50mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel composite zeolite and a method for producing hydrocarbons using the same as a catalyst.

Due to its chemical composition and skeletal structure, zeolite is an oxide of S+02 and other metals, especially "203+1".
"It is determined by the form in which trivalent metal oxides such as e203 and/or 0a201 covalently bond with oxygen. When these trivalent metals are contained, the electronegativity of the tetrahedron is usually electrically neutralized by alkali metal ions. 5in2.
A method is employed in which trivalent metal oxides, alkali metal ion sources, and water are mixed in desired proportions and hydrothermal synthesis is carried out under basic conditions at normal pressure or autogenous pressure. Among these, there is a method of hydrothermal synthesis using organic nitrogen compounds or organic phosphorous compounds as a base, and by this method various types of zeolites with various adsorption capacities and catalytic actions have been synthesized, and in recent years this divine zeolite has been synthesized. Zeolite research is very active. Especially ZSM-5, Z by Mopil Oil
SM-H, ZSM-5 and ZSSi211 mixed-crystalline zeolites, or similar zeolites, have 5 to 6 medium-sized, unique (14-dimensional) pores, and also contain SiO□ and trivalent metals. It is unique in that the ratio to the oxide can be set arbitrarily, and even extremely high 8102 particles can be prepared.This property shows shape selectivity in adsorption of hydrocarbons,
It exhibits an unusual catalytic effect on reactions such as Z8, contact membrane waxing, decomposition, Z1 (1), alkylation, etc. Among them, Z8
M-5 is too old to be used as a catalyst for producing hydrocarbons, mainly gasoline fractions, having up to 10 carbon atoms from methanol.

"Also, this reaction changed the chemical composition of ZSM-5 to 1% S
It is also described in Italian Patent No. 2,935,363 filed by Mopil Oil Co. that the selectivity to lower olefins is dramatically improved by using 102-polymers. A zeolite with the same effect as this
, 120. Instead, a ZSM-5-like zeolite containing Fe2O3 was proposed by BASF, and its details are described in International Patent No. 2,909,929.

Even if only the methanol conversion reaction is used, differences in the chemical composition and skeletal structure of the zeolite used as a catalyst can have a large effect on its activity and selectivity.

As the molecules enter and pass through the pores of the zeolite, they react while being controlled by the chemical composition and skeletal structure of the zeolite. Therefore, it is possible to overlap two or three layers of zeolite with different chemical compositions and skeleton structures in the path through which reactive molecules diffuse within a single crystal, and the thickness of the layers can be reduced. If it is possible to control the activity and selectivity of the catalyst, it would be possible to arbitrarily control the activity and selectivity of the catalyst by overlapping active sites with different functions in one crystal.

From this point of view, the present inventors have conducted various studies regarding the composite of at least two zeolite crystals having mutually different chemical compositions and/or skeleton structures, and as a result, they have completed the present invention. It has arrived.

That is, according to the present invention, the zeolite crystal layer is composed of a zeolite crystal forming a core and one or an imaginary number of zeolite crystal layers formed around it by a hydrothermal synthesis method, and at least two of the zeolite crystals are d, phase 11. A composite zeolite is provided which is characterized by having different chemical compositions and/or skeletal structures.

If the zeolite crystal in the present invention falls under the concept of zeolite, the chemical composition and skeleton of the gods 1':')
It can be something that improves the structure. The chemical composition and skeletal structure of this zeolite crystal are as follows:
Something like the following.

(]) Chemical composition Zeolite crystals are generally crystalline alumino/licade zeolites.In the case of the present invention, the present invention is not limited to such aluminosilicate zeolite VC.
It also includes those in which at least a portion of the aluminum element is replaced with another element, and in extreme cases, those without the aluminum element (for example, noricalide).

Generally, those represented by the following compositional formula may be mentioned.

aM-0・b)′203・cS102・111120 In the formula, M is a cation, and is a monovalent cation such as an alkali metal ion or a hydrogen atom, and/or a divalent cation such as an alkaline earth metal, or more. polyvalent cations, etc. are included.

Y is a trivalent metal, such as one or more metals selected from aluminum, iron, gallium, chromium, rhodium, and scandium.

X is a number corresponding to the valence of the cation M.

a is 0.9±0.3, b is 1, C is a number from 0 to 400.

Incidentally, in the above compositional formula, when an organic compound such as one used as an auxiliary additive in a hydrothermal synthesis reaction is present, that organic compound is excluded.

(2) Skeletal structure Although the skeleton structure of the zeolite crystal in the present invention is arbitrary, To, (1" is an element incorporated in the old zeolite such as silicon, aluminum, iron, or galiut) The tetrahedron connected to U, the 5-membered ring and 1
It consists of four tetrahedrons (Com I)l +, Me5-1).

Jolm WrLI (Y
Published by St 5ONS, I) ONALD W-BR
, written by ECK “Zl et al. 01. ITE to 1OL E C
It LAR8■tHa1IC8-1 46th to 47th group 6, ComplcJ 5-1)
Preferably, for example, zs-containing +-s (including y Ricalite) type, ZSM-11 (including Noricalite l--It) L
~S, mixed crystal type of ZSM-5 and ZSM-11 (including mixed crystal type of Noricalide and /Ricalite-11), ferrierite type, ZSM-35 type, mordenite type, etc.
fji construction is listed, but 1-5 type to ZS, ZSM-1
1'='l! ! , ZSM 5 and ZSIX-11
The mixed crystal type is particularly suitable.

The composite zeolite of the present invention has a core of zeolite crystals having various chemical compositions and skeletal grooves as described above, and around the core, one or more zeolite crystals are layered. In this case, among the zeolite crystals forming the core and the zeolite crystals forming the coating layer, at least two glazed zeolite crystals have different chemical compositions and/or skeletal structures. has. The zeolite crystals forming the nucleus may have any shape such as granules or needles, and their dimensions are not particularly limited, but generally range from o, i to 501 layers m. On the other hand, regarding the zeolite crystal that forms a coating layer on the zeolite crystal that forms the nucleus, the total thickness of the coating layer is arbitrary, but is usually about 0.01 to 20 μm. ′!
! However, the weight ratio of the entire coating layer to the zeolite crystals forming the nucleus is 0.01 to IO parts by weight, preferably 0.05 to 5 parts by weight, per 1 part by weight of the zeolite crystals forming the nucleus. be.

The composite zeolite of the present invention can be produced using conventionally known methods. For example, in order to coat a core zeolite crystal with a zeolite crystal that has the same skeletal structure but a different chemical composition, first, the core zeolite is hydrothermally synthesized so that there is almost no unreacted raw material. After confirming this, a method is adopted in which the components necessary to form the next coating layer are further added and a hydrothermal synthesis reaction is subsequently performed. On the other hand, to coat the core zeolite crystals with a + olide layer having a different extraction structure, an aqueous gel mixture whose component composition is adjusted so as to obtain zeolite crystals of the first coating layer having a desired (1- structure) is added. , and add another zeolite crystal (made in A), which was separately hydrothermally synthesized and isolated, to this water 1 (1. In the gel mixture), and carry out a hydrothermal synthesis reaction. By repeating the same operation using the obtained composite zeolite as a core, it is possible to form second and third zeolite crystal layers that do not have the desired skeletal structure.Furthermore,
Commercially available zeolite crystals can also be used to form the nucleus. According to the present invention, by combining the above methods, P) is added around the core zeolite crystal.
[One or more coating layers consisting of zeolite crystals having a desired chemical composition and/or skeleton structure are formed, and a ζ composite zeolite can be obtained.

When zeolite crystals having a desired chemical composition and/or skeleton structure are grown in a layered manner on the surface of a core zeolite crystal or a composite zeolite crystal as described in 1j IS, conventionally known methods can be applied.

That is, an aqueous gel mixture is prepared by mixing a 5102 source, a Y2O3 source (Y is a trivalent metal), an alkali metal ion source, water, and auxiliary additive reagents necessary to obtain a desired skeletal structure in desired proportions; This can be used as a raw material for the desired layer to be annealed.

As the 5I02 source, it is desirable to use water glass or Noriyoku sol. Water-soluble salts are usually used as sources of metal oxides such as Aluminum A, iron, gallium, chromium, ronium, and scandium. For example, sodium aluminate, aluminum sulfate, aluminum nitrate, alumina sol, etc. are used as the Al2O3 source. Water-soluble ferric salts can be used as the Fe2O source, and preferred examples include ferric nitrate and ferric ammonium sulfate. G
As the a2O3 source, gallium nitrate, gallium chloride, gallium hydroxide, etc. can be used, but gallium nitrate is preferred.

Alkali gold 1, (as an ion source, thorium oxide in water glass, sodium hydroxide, potassium hydroxide, sodium aluminate, etc. are used).

- Indispensable reagents for regulating the 11-case structure include, for example:
ZSN・1-5 type (I) (tetra n-probyl ammonium, salt or its i′l ■ precursor, tetra-n-probylphosphonium ↓ 1 (1°) herbal tylamine, each type Junior high school grade] 'Lecole et al.) r. Gera I'
+ru. "ZSM-111", Detler n-butylamonium J1, size/kol'J, Tetra-11
-Butylphosphonium salt 1-11, a mixture of 1,000 of these and tetramethylammonium salt 1) is used. -Ma-/j, ZSl'tl-5 and ZSM-11? To obtain the quartz type, use 1, a mixture of tetra-η-butylammonium salt and tetramethylammonium salt, a mixture of tetra-T-butylammonium salt, de]raedilua/monidenum salt and tetramethylammonium salt. , a mixture of tetra-n-propylammonium salt and tetramethylammonium salt is preferably used. Such skeleton J177 structure regulating reagents are conventionally known, and in the present invention, conventionally known ones can be applied.

A typical composition of the aqueous gel mixture used in the present invention, expressed on an oxide basis, is as follows.

S 102/y20. , (molar ratio): 7
Above 011-/SiO (molar ratio): o,
o3~(1,7IIT20/S 102 (molar upper h) 220~70R,,,(')(or +t
'-x)/5lo2 (molar ratio): 0.02-1 However,)
' is a trivalent metal, for example, Al, F+, Qa-
.

Cr + One or more metals selected from Isen and Sc, and Ol [means hydroxyl ion in the aqueous gel mixture. I(, represents the total amount of tetraalkylammonium ions and/or tetraalkylphosphonium ions used, and 11.'-X (X is a hydroxyl group or an amino group) represents the total amount of alcohols and/or amines used.

According to the present invention, in order to complex other zeolite crystals on the surface of the core zeolite crystal or on the surface of the composite zeolite, the aqueous gel mixture is mixed with the uncomplexed or composite zeolite at 80 to 200°C. ~200 hours,
The hydrothermal synthesis reaction is carried out while heating under normal pressure and stirring under reflux, or in a sealed container while heating and stirring under self-pressure. When attempting to grow further crystals with the same skeletal structure but different chemical composition, a portion of the reaction mixture is recycled, and most of the unreacted raw wood I is consumed, resulting in 91 crystals. After confirming that the target crystal is growing, supply a source that is essential for the growth of the desired crystal, and perform hydrothermal synthesis in the same manner as above. By separating the solid components from the reaction mixture subjected to hydrothermal synthesis in this way using a V-mouth filter or centrifugal separation 11, removing excess ionic substances by washing with water, and then drying,
A zeolite crystal powder containing/containing an organic compound is obtained. 2) This powder is heated at a temperature of 300 to 700°C in 5 atmospheres,
By treating for 1 to 50 hours, the contained organic compounds are incinerated and the zeolite is obtained from which the batter compounds have been removed. Any of the zeolite d1, which is charged into the aqueous gel mixture to form the core, a washed product, a dried product, or a calcined product after the zeolite synthesis may be used.

Next, 7 Licalite-11 was prepared, and using it as a core, ZSM-5 was crystallized on the surface layer to obtain the composite zeolite of Example 12 described later, abbreviated as +-Ccz-n(-)-5(AJ). ] will be explained.

Xm of silicalite-H prepared by applying a known method
, diffraction diagram, and scanning electron micrograph, respectively.
As shown in FIG. The X-ray diffraction pattern and scanning electron micrograph of composite zeolite CZ-11(-)-5(A/) obtained by further crystallizing ZSM-5 using Noricalide-11 as a core are shown below. Shown in FIGS. 3 and 4. 5i02 Ryo and to/',,03 source a
Except that there are no dimensions,
X-rays of the solid part after the noricalide-■ was placed in an aqueous solution 1 with the same composition as when crystallizing ZSM-5, and the surface layer was subjected to hydrothermal treatment in the same manner as when crystallizing ZSM-5. The diffractogram and scanning electron micrograph are shown in FIGS. 5 and 6, respectively. Also, under the same conditions as when crystallizing the surface layer ZSM-5, The X-ray diffraction pattern and scanning electron micrograph of Nida ZSM-5 are shown in FIGS. 7 and 8.

The X-ray diffraction patterns shown in the drawings were all obtained by conventional X-ray techniques using I(-alpha) irradiation of copper.

Silicalite l--It and composite zeolite cz of the present invention
By comparing the X-ray diffraction patterns for -11(-) -s(A,z), the following can be found.

(1) Junctioned zeolite 1~(8/7-ro(-)-5
(8) X-ray drawing 1 No. 1 / Ricalite-11 and ZS
It is a combination of the respective X-ray diffraction patterns of M-5 ((Fig. 1, Fig. 3, Fig. 7)).

(2) 7 ri Tsuno rai l--I+, Si fJ self 1i knee "" yo O'ノ＼
e 20 :Hd'j.

Hydrothermally treated with an aqueous solution having exactly the same composition as in the case of ZSM crystallization, except that it does not contain -C, /Ricalite-11 remains and no conversion to rA S 1-5 occurs ( Figures 1 and 5).

1/This, the running of both! The following can be found from the i-type single-lens microscope 'θ.

IC! Akira Itoyoshi of Z-11(-)-5(Al) is/
It's hotter than Ritz Light ■ (21st SjX
Figure 4).

The crystals of 2Cz-1+(-)-s(Az) roughly maintain the shape of noricalide-○, and no crystals of ZSM-5 alone are observed (FIGS. 2, 4, and 8).

No change in crystal shape or size was observed (Fig. 2, Fig. 6).

Therefore, from the above, CZ-11(-) -5(A
j? ) is not a mechanical mixture of 7 Likarai)-n and Z SM -5, nor is it a part of ZSM-5 441 crystallized from Jade/Likarai l---11, but an intentional bend, 1--, Z SM- on the surface layer of n
7 indicates that 5 is crystallized.

The multiplexed theolite of the present invention has an adsorbent or catalyst and 17
It can be used conveniently, especially as a catalyst for many reactions such as isomerization, decomposition, polymerization, and alkylation.

Composite zeolite, which has been calcined after synthesis to remove organic compounds, contains alkali metal ions as cations, but when used as a catalyst, all or part of this is converted into protons, other alkali metal ions, alkaline earth ions, etc. Preferably, the material is ion-exchanged with metal ions and/or transition metal ions. This exchange can be easily performed using known ion exchange techniques. For example, to exchange alkali metal ions with ammonium chloride, treat with ammonium salt solution such as ammonium chloride.
This is achieved by converting E into A/ and then ejecting ammonia by calcination. It is also converted to proto/4- by treatment with an aqueous hydrogen chloride solution.
This is also rjj noh. Ammonium salt aqueous solution-4,
or No. 1 treated with an aqueous solution of hydrogen chloride, 4. The temporary zeolite l-ic was dried and fired.
Upper methanol and 0./I'i can serve as catalysts for the methyl needle conversion reaction.

This firing is carried out at -300 to 70 degrees (1 to 1 degrees at a temperature of 1℃).
This is achieved by processing in air for 100 hours.

Conversion reaction of methanol and/or molten powder 1. What type of reaction can be achieved by supplying these raw materials as a gas and bringing them into sufficient contact with a solid catalyst?
The fixed bed reaction method and the flowing/supported bed reaction method are excellent.

1 sentence ratio, (1 can be carried out under the conditions of 71110+il. For example, reaction temperature 250-450℃, soil 1i time-space velocity 0, 1-201+r', favorable -! L <
(r, J1~] 01+r-', total pressure (), 1~10
It can be carried out under conditions of 0 atm, preferably 0.5 to 10 atm. The raw material can also be supplied onto the catalyst in the form of steam or an inert gas such as nitrogen or argon. 9 of the raw IJk products that reacted on the catalyst!
The e-filter consists of water vapor, hydrocarbons, and unreacted raw ore, and known methods can be applied to make these separation shields.

As is clear from the above description, the composite zeolite of the present invention has a wide range of uses as a catalyst or adsorbent for many reactions such as isomerization, decomposition, alkylation, and polymerization. In particular, in the production of hydrocarbons through the conversion reaction of methanol and/or dimethyl ether, the activity and selectivity of the composite zeolite can be controlled by varying the structure, chemical composition, order, etc. of the zeolite to be combined. It is possible to prepare any catalyst for lower olefin production, ganolite/distillation production, etc.

The present invention will be specifically explained and explained below by way of Examples.

In addition, the composite zeolite according to the present invention is indicated (dl, CZ is attached to the prefix, and the outline of each skeleton structure 1, y, O, and chemical composition is shown in order from the core to the surface layer, and the hyphen is used to indicate each other. We will tie the skeleton ((7, 8 for 4 structures)
4-5] 1 Suha 5, ZSM-11 type (
d, 11
S lvl -: (type 5 is indicated by 35, mordenite is indicated by M.) Regarding the chemical composition, it is a metal element of a trivalent metal oxide impregnated in the zeolite by a method other than ion exchange. symbol)' It will be written in the parentheses following the symbol indicating all 11 case structures. For example, the cz
-11(-)-s()~7? ) is 7. in the nucleus. 1-11 to S
A zeolite that has a type skeleton structure and does not contain 13 valent metals, i.e. / Ricalite - 11.-1, and the surface layer (
The first layer) shows that it is a composite zeolite obtained by consolidating normal strength ZSM-5-1~lyzeolite containing aluminum as a trivalent metal.

Examples 1 to 12 The preparation of CZ-11(-)-5(A7?) of Example 12 will be explained in detail.

Colloidal silica Cataloid manufactured by Catalysts Kasei Co., Ltd.
S I -; U060, thorium hydroxide 1.2! P
,,'j,! Tetra-n-butylammonium 6.
07 and 4.0 g of tetramethylammonium bromide were homogeneously mixed with 2:309 of water to obtain an aqueous gel mixture;
This was heated under reflux and stirred for 21 days under normal pressure. The solid component in the reaction mixture obtained here was extracted in an amount necessary for analysis, thoroughly washed with water, then dried at 100°C, and calcined at 500°C for 15 hours. The XKM diffractogram and scanning electron micrograph of this product are shown in Figures 1 and 2, which are already known (Nature V (Il, 2).
80, 664 (1979)]. Solid components were repeatedly separated from the reaction mixture to separate 11 pieces, which were then treated with Cataloid 3I-3030.
An aqueous gel mixture obtained by mixing f, aluminum nitrate nonahydrate 1.14 fF, potassium 1.34 ii', tetra-n-propylammonium bromide 3.91 S' and water 30 Of. In addition, the mixture was sufficiently stirred and mixed, and the second hydrothermal synthesis was carried out by heating and refluxing and stirring under normal pressure for 6 days.

A solid component was separated from the reaction mixture, thoroughly washed with water, then dried at 100°C, and further calcined at 500°C for 15 hours to obtain zeolite C7-11(-)=s (Az).

X-ray 191 diagram of this and )'', +, 4X111
The truth ;! G, II Figures 3 and 4 are shown.

Next, use the same method as above (>)
r, - A trowel from which 11 parts of the aqueous solution had been removed, to which was added horny potash I, 07 f/, enriched Tetler 11-zorobiyl anomoniol, 3,911, and water 30 o.
An aqueous solution consisting of y was added, and the mixture was stirred under normal pressure and heated under reflux for 61R]4). Separating solid components from the reaction mixture,
1. Washing with water and firing were carried out in the same manner as described above.The X and ray diffraction diagrams are shown in Figs. Seen in Figure 2/X-ray drawing of Rikarai l--II JR-ξCuno, 1
...There is no difference from the Yohiyuihin shape. A/ξ, an aqueous gel mixture with the same composition as that prepared for condensing the first layer was subjected to 4ν synthesis under normal pressure (7 Jll heat reduction γ + ij + · II water with stirring for 511 minutes), After washing with water and drying, the X-ray drawing of C-1 and the mountain of ZSM-5 were completed.
The photographic unit 1 is shown in FIGS. 24'-7 to 8.

By comparing and parsimoniously these figures, we have already clarified that
) is / Lipfry-11 VCZ S IVl
” 5 is a;, it can be seen that it is a composite zeolite made up of 11 items.

Other composite zeolites and methods for producing them are shown in Table 1.

For Example 5, Kozu CZ-5(Af)-5(-)
And to y, S which was used as a nucleus to prepare this +
-5 lln! Yuken(1ν・′)r, 4! j; as the 0th
07. -5(Al)zu(
-), it is a composite structure; L is 1'l.

Below are blank spaces Example 1 3-20 Dego zeolite 1y VC7''L, (1, f
i JJJ, constant hydrogen chloride water activity 2 (repeat the operation of mixing both in the ratio of l d and stirring for 8 hours in chamber 7Al'l?/, L,,)) as a boom. 7) Replace the alkali gold containing 4 (n7 with 1) and then heat at room temperature. 4) After washing with water, 120
Dry at 500°C, then dry at 500°C.
'J between'1'Kichu TesuJ''(',+J'y,
Proto7) 111]'s 1-on fl., 4I
Geko.

``11.7 chapters of Harai zeolite powder is moon-power-I.
(l II I(ri/L'l) I7te4"J' A6
+'-1~, then crush the stiffness】O~20 horns e crushed 2 mI! , is the inner diameter 10 + m + anti-1
f+' to heart i′i, JIIT i jt=o7HM-like methanol 4 In1′/ II rsu′) mountain 1.0
-C to the vaporizer, where □+ 51n/ / m i
The mixture was mixed with irrigated gas and introduced into the reaction layer, and the reaction was carried out at 3°C. Analysis of the product was performed using a gas chromatograph.

Table 2 shows the catalytic activity of Akutamoro Biolite.

≧meat; jjfj' of Example 12, for the sake of clarity, i・rl,'
j L7.8＼l-5; used in place of zeolite
20 and the same 11* (l to r-1.

♂(~2 *1 methyl ether is considered as unreacted 1.!10-1.

Carbon base conversion rate (%) *2 Carbon base selectivity (%) of (ethylene 10%) in all products

[Brief explanation of drawings]

Figures 1 and 2 are the X-ray diffraction diagram and scanning electron micrograph (magnification 7500) of Noricalide-H.
Figures 3, 0, and 4 are X-ray images of cz-+1(-)-5(Az), Figures 4 and 1, and traveling type electron micrographs (magnification: 7500). Figures 5 and 6 d. :Nrikarai l-,
X-ray diffraction diagram and chemotactic fr-type electrons of -I+ treated with an alkali 171 water bath solution containing Taylor I/Lah II-norobylammonium bromide! 171'J microphotograph (magnification 750
0) Figures 7 and 8 are the X-ray drawings of ZSM-5, and Hashimori Kataichi, Konuma J Weiyoku Katsada (magnification 7500)
) According to Figure C), Figure 10 shows cz-5 (A, g)-5.
(-) and how to read the polarized light microscope of Z S M -5 which is its core ↓'1, (magnification 4 (1 + 1). Revision applicant Makoto Ishizaka, Director of the Agency of Industrial Science and Technology - No. 9
Amendment to Figure Procedure (Voluntary) Translation of No. 58 Hi 4 I 1 No. 839 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of the case 1988 1-! l Permission No. 12
7133 No. 3, Patent applicant address related to the case of the person making the amendment Kasumigaseki, Chiyoda-ku, Tokyo] 'l'+43
Number 1 Shigeru:”f+ (11,4) Director of the Agency of Industrial Science and Technology
Makoto Ishizaka - Explanation column, brief explanation column and drawings, g,) Contents of sleeve correction (4) In the column of the title of the invention of application v+, "Production of composite zeolite and hydrocarbons using it as a catalyst" method” (2
) Details 1 attached] Main gate +! I will correct the sleeves as per Book II. (3) Delete the drawing. Amended Description 1, Name of the Invention Process for Producing Lower Olefins 2, Claim 3, Detailed Description of the Invention The present invention is a method for crystallizing zeolites with different chemical compositions or skeletal structures in layers, in double or triple layers. The present invention relates to a method for selectively producing lower olefins such as metal, tri dimethyl ether, caraethylene, and fluoropylene using a composite zeolite prepared by the above method as a catalyst. In recent years, zeolites with various adsorption abilities and catalytic activities have been synthesized. Among these, ZSM-5, ZSM-11, and ZS proposed by Mopil Oil Co., Ltd.
M-5 and ZSM-11 mixed crystal zeolites, or similar zeolites, have a unique structure of medium-sized pores of 5 to 6 holes, and are composed of SiO□ and trivalent metal oxides. It is unique in that the ratio of SiOz can be set arbitrarily, and products with extremely high SiOz can be prepared. Due to this property, these zeolites exhibit shape selectivity in the adsorption of hydrocarbons,
It also exhibits a unique catalytic effect on reactions such as catalytic dewaxing, decomposition, isomerization, and alkylation. Among them, ZSM-5 is famous for being a catalyst for producing hydrocarbons, mainly gasoline fractions, having up to 10 carbon atoms from methanol. still,
By changing the chemical composition of ZSM-5 to a high 5iOz property through this reaction, the selectivity to lower olefins can be dramatically improved. , No. 863. At2 is a zeolite with the same effect.
On the other hand, Mopil Oil Co. has proposed a new composite zeolite consisting of a core and an outer shell, in which the core is a crystalline aluminosilicate and the outer shell is a crystalline silicate consisting only of SiO2 without an aluminum component. Both have substantially the same skeletal structure (Japanese Unexamined Patent Application Publication No. 1989-1999)
3-39999). Exxon Research and Engineering Co., Ltd. is a crystalline silicate whose core is 5i02 and whose outer shell is a crystalline metallosilicate containing metals such as aluminum, with the core and outer shell having substantially the same skeletal structure. A certain composite zeolite has been proposed (European Patent Publication No. 0055044). However, this patent application only discloses that this composite zeolite is effective as a catalyst for hydrocarbon conversion reactions. As a result of various studies, it was discovered that a certain type of composite zeolite in which a zeolite crystal layer containing an aluminum component is arranged in the outermost layer has selectivity as a catalyst for producing lower olefins, and the present invention was completed. Ta. That is, the present invention provides a method for producing lower olefins by reacting methanol and/or dimethyl ether in the presence of a zeolite catalyst, in which as the zeolite catalyst,
It consists of a zeolite crystal forming a nucleus and one or more zeolite crystal layers formed around it by a hydrothermal synthesis method, and at least two of these zeolite crystal layers including nucleate are mutually bonded. The present invention provides a method for producing lower olefins, which is a composite zeolite having different chemical compositions and/or skeleton structures, and which is characterized by using a composite zeolite whose outermost layer is a zeolite crystal layer containing an aluminum component. . According to the present invention, not only ZSM-5 type zeolite but a wider range of zeolites can be composited, and by using various composite zeolites with a zeolite crystal layer containing an aluminum component in the outermost layer as a catalyst, methanol can be produced. It becomes possible to selectively produce lower olefins by reacting dimethyl ether and/or dimethyl ether. Zeolite crystals constituting the composite zeolite used in the present invention can have various chemical compositions and skeleton structures. The chemical composition and skeleton structure of this zeolite crystal are as follows, for example. (1) Chemical Composition Zeolite crystals generally mean crystalline aluminosilicate zeolites, but in the case of the present invention, they are not limited to this, and in this crystalline aluminosilicate zeolite, the aluminum element In extreme cases,
Items without aluminum element (for example, silicalite, etc.)
etc. are also included. Generally, those represented by the following compositional formula can be mentioned. aM-0・bY203・cSio2・nH2゜In the formula, M
is an X-valent cation, a monovalent cation such as an alkali metal ion or proton, and/or a divalent cation such as an alkaline earth metal.
Included are valent cations and higher valence cations. Y is a trivalent metal, for example, one or more metals selected from aluminum, iron, gallium, chromium, rhodium, and scandium. a is 0.9±03, b is 1, C is 10 or more, n is O~4
It is a number of 00. In addition, in the present invention, when the zeolite crystal layer serving as the outermost layer contains an aluminum component, it means that Si0 in the above composition formula.
2 and Y2o3 middle No At2o3. Note that in the above compositional formula, even if an organic compound is present as a skeletal structure adjusting reagent in the hydrothermal synthesis reaction for synthesizing zeolite crystals, that organic compound is excluded. (2) Skeletal structure The skeletal structure of the zeolite crystal is arbitrary, but TO4 (T
is an element incorporated into the zeolite skeleton, such as silicon, aluminum, iron, or gallium), and five tetrahedrons are connected to each other to form a five-membered ring, to which one tetrahedron is bonded. Next frame structure (JOHN WILEY
& 5ONS published, DONALD W, BRECK
Author1”-ZEOLITEMOLECULAR5IEVE
Group 6, Com described on pages 46-47 of SJ
plex 5-1), such as ZSM-5 (including silicalite) type,
ZSM-11 (including Silicalite-■) type, ZSM-
5 and ZSM, -11 mixed crystal type (including silicalite and silicalite-■ mixed crystal type), ferrierite type, ZSM
Skeletal structures such as -35 type and mordenite type are mentioned. However, the outermost layer is ZSM-5 type, ZSM-11 type, ZS
A mixed crystal type of M-5 and ZSM-11 is particularly preferred. The composite zeolite used in the present invention is one of the zeolite crystals having various chemical compositions and skeleton structures as described above.
It has a structure in which a seed is the core, and one or more types of zeolite are crystallized and coated in layers around it, but in this case, the zeolite crystals that form the core and the coating layer are formed. Among the zeolite crystals, adjacent zeolite crystals have mutually different chemical compositions and/or skeleton structures. The zeolite crystals that form the nucleus are granular,
It has an arbitrary shape such as a needle shape, and its dimensions are not particularly limited, but are generally 01 to 507 Zjl. On the other hand, the thickness of the zeolite crystal layer forming the outermost layer is usually 0.0
It is about 1 to 20 μm. Next, a general method for preparing composite zeolite will be outlined. Composite zeolite can be prepared using conventionally known methods. For example, in order to coat a core zeolite crystal with a zeolite crystal that has the same skeleton structure but a different chemical composition, first hydrothermally synthesize the core zeolite and confirm that there is almost no unreacted raw material. A method is adopted in which the components necessary to form the next coating layer are added and then a hydrothermal synthesis reaction is performed. On the other hand, in order to coat a core zeolite crystal with a zeolite crystal having a different skeleton structure, an aqueous gel with an adjusted component composition is prepared by mixing raw materials so as to obtain a zeolite crystal of the first coating layer having a desired skeleton structure. A mixture is prepared, and a zeolite crystal with a different skeleton structure, which has been separately hydrothermally synthesized and isolated, is added to this aqueous gel mixture, and a hydrothermal synthesis reaction is carried out. Further, by repeating the same operation using the composite zeolite thus obtained as a core, it is possible to form second and third zeolite crystal layers having a desired skeleton structure. Furthermore, commercially available zeolite crystals can also be used to form the nucleus. By combining the above-mentioned methods, a composite superolide is obtained in which one or more coating layers made of zeolite crystals having a desired chemical composition and/or skeleton structure are formed around a core zeolite crystal. I can do it. Conventionally known methods can be applied to the hydrothermal synthesis of the core zeolite and the zeolite crystals surrounding it. That is, an aqueous gel mixture is prepared by mixing a 5i02 source, a Y2O3 source (Y is a trivalent metal), an alkali metal ion source, water, and a skeletal structure adjusting reagent necessary to obtain a desired skeletal structure in the desired proportions. This can then be subjected to hydrothermal synthesis at a temperature, time, and pressure that will produce the desired zeolite crystals. As the 5i02 source, it is desirable to use water glass or silica sol. Metal oxide sources such as aluminum, iron, gallium, chromium, rhodium and scandium typically include
Water-soluble salts are used. For example, sodium aluminate, aluminum sulfate, aluminum nitrate, alumina sol, etc. are used as the At203 source. A water-bathable ferric salt can be used as the Fe 203 source, and preferred examples include ferric nitrate and ferric ammonium sulfate. G
a 203 sources] 4 are gallium nitrate, gallium chloride,
Gallium hydroxide and the like can be used, but gallium nitrate is preferred. As the alkali metal ion source, sodium oxide, sodium hydroxide, potassium hydroxide, sodium aluminate, etc. in water glass and silica sol are used. As a reagent for adjusting the skeleton structure, for example, ZSM-
To obtain Type 5, tetra-n-propylammonium salt or its precursor, tetra-n-propylphosphonium salt, 11-butylamine, lower alcohols, etc. may be used. To obtain the ZSM-11 type, a tetra-n-butylammonium salt or a tetra-n-butylphosphonium salt alone or a mixture of one of these and a tetramethylammonium salt is used. Good luck, ZSM
In order to obtain a mixed crystal form of -5 and ZSM-11, tetra-n-
It is preferable to use a mixture of butylammonium salts and tetramethylammonium salts, a mixture of three types of tetra-n-butylammonium salts, tetraethylammonium salts and tetramethylammonium salts, and a mixture of tetra-n-pum salts. To obtain ZSM-35 types, 1,4-butanediamine, ethylenediamine, pyrrolidine, etc. are used. In the case of ferrierite type and mordenite type, they can be prepared without using a skeleton structure adjusting reagent consisting of a disintegrator compound as described above. Generally, skeletal structure regulating reagents for each skeletal structure are conventionally known, and conventionally known reagents can be applied to the present invention as well. An aqueous gel mixture can be obtained by mixing each raw material compound with water, and its typical composition, expressed on an oxide basis, is as follows. SiO□/Y2O3 (molar ratio): 7 or more OH/5i
O2 (molar ratio): 0.03-0.4H20/5
iOz (molar ratio): 20-70R/5iOz
(Molar ratio): 0.02~, where Y is trivalent metal% jj/lJ, and one or more types of gold selected from aluminum, iron, gallium, chromium, rhodium, and scandium means. R represents the total amount of organic compounds used as skeleton structure adjusting reagents. Note that any mixing method may be used as long as the aqueous gel mixture can be mixed homogeneously so that the composition thereof falls within a predetermined range. To synthesize a core zeolite crystal, use the aqueous gel mixture as it is, or to coat the surface of the core zeolite crystal or composite zeolite with another zeolite crystal, add the aqueous gel mixture to the core zeolite crystal or in the presence of the composite zeolite. 8
The hydrothermal synthesis reaction is carried out at a temperature of 0 to 200° C. for 5 to 500 hours while heating under normal pressure and stirring under reflux, or in a closed container while heating and stirring under autogenous pressure. The reaction mixture that was subjected to hydrothermal synthesis in this way is separated from the solid components by rinsing or centrifugation, washed with water to remove excess ionic substances, and then dried to obtain zeolite powder containing organic compounds. obtain. By treating this powder in air at a temperature of 300 to 700° C. for 1 to 50 hours, the organic compounds contained therein are incinerated, resulting in zeolite from which the organic compounds have been removed. The zeolite to be charged into the aqueous Kel mixture to form the core may be any of the washed, dried, and calcined products after the hydrothermal synthesis. The composite zeolite thus obtained is a layered crystallization of zeolites with different chemical compositions and/or skeletal structures around a core theolite crystal. This can be confirmed using polarized light micrographs. Composite zeolite, which has been incinerated to remove organic compounds after hydrothermal synthesis, contains alkali metal ions as cations, but when used as a catalyst, all 1 / moss is partially protons, other alkali metal ions, alkali Preferably, it is ion-exchanged with earth metal ions and/or transition metal ions. This exchange can be easily performed using known ion exchange techniques. For example, to exchange protons, alkali metal ions are converted to ammonium ions by treatment with an aqueous solution of ammonium salt, such as ammonium chloride, and then the alkali metal ions are converted to ammonium ions. This is achieved by expelling ammonia. It is also possible to convert it into protons by directly treating it with an aqueous hydrogen chloride solution. After treatment with ammonium salt aqueous solution or hydrogen chloride aqueous solution, thoroughly wash with water.
A composite zeolite comprising a dried and calcined zeolite crystal layer containing an aluminum component in the outermost layer is used as a catalyst for producing lower olefins by methanol and/or hashimethyl ether conversion reaction. This firing is
For example, this can be achieved by treating in air at a temperature of 300 to 700°C for 1 to 100 hours. For the production of lower olefins through the conversion reaction of methanol and/or dimethyl ether, any reaction format may be used as long as these raw materials are supplied as a gas and can be brought into sufficient contact with a solid catalyst, such as a fixed bed reaction method or a fluidized bed reaction method. Examples include methods. The reaction can be carried out under a wide range of conditions. For example, 1 reaction temperature 250-450℃ 1M amount time fertilization rate 0.1-2
0hr', preferably 1~], Ohr', total pressure 0.
It can be carried out under conditions of 1 to 100 atm, preferably 0.5 to 10 atm. The raw material can also be diluted with water vapor or an inert gas such as nitrogen, argon, etc. and then fed onto the catalyst. The product stream after reaction over the catalyst consists of water vapor, hydrocarbons, and unreacted raw materials, the hydrocarbons being enriched in lower olefins such as ethylene and propylene. Known methods can be applied to these separations and purifications. According to the present invention, an excellent effect is achieved in that lower olefins such as ethylene and propylene can be selectively obtained at a relatively low temperature using methanol or dimethyl ether as a raw material. In addition, Z as a zeolite that constitutes the catalyst.
It has the excellent advantage that not only SM-5 type but also a wider variety of zeolites can be combined and used. The present invention will be specifically explained below using Examples. Note that the composite zeolite used in the present invention is represented by adding CZ to the prefix, and the outline of each skeleton structure and chemical composition is shown in order from the core to the surface layer, and they are connected to each other with a hyphen. Regarding the skeleton structure, ZSM-5 type is 5, ZSM-11 type is 11.28M-5, and ZSM-11 mixed crystal type is 11. Ferrierite type ID: F. The ZSM-35 type is denoted by 35, and the mordenite type is denoted by M. Regarding the chemical composition, the metal element symbol of aluminum and/or trivalent metal oxide contained in the zeolite by a method other than ion exchange will be written in parentheses following the skeleton structure symbol. for example,
CZ-11(-)-5(At) described below contains ZSM-1 in the nucleus.
Sunawati Silicalite-II, a zeolite with a type 1 skeleton structure and containing no trivalent metals, is placed, and the surface layer (first layer) is a normal Z containing aluminum as a trivalent metal.
This shows that it is a composite zeolite obtained by crystallizing SIVI-5 type zeolite. Examples 1 to 3 A) Preparation of composite zeolite The preparation of CZ-11(-)-5(At) (zeolite A3 in Table 1 below) will be described. Colloidal silica Cataloid SI manufactured by Catalyst Kasei
:3060g, sodium hydroxide 1.2g1 tebromide 1
7- 6.0 g of n-butylammonium and tetramethylammonium bromide4. Og was uniformly mixed with 230 g of water to obtain an aqueous gel mixture, which was heated under normal pressure and stirred under reflux for 21 days. The solid components in the reaction mixture obtained here were extracted in an amount necessary for analysis, thoroughly washed with water, then dried at 100°C, and further calcined at 500°C for 15 hours. This substance is already known from X-ray diffraction and scanning electron microscopy [Nature vol, 280.
664 (197'J):] was confirmed to be the same as Silicalite I. The solid component is separated from the reaction mixture by centrifugation/after which it is
id 81-30 30g. Add an aqueous gel mixture obtained by mixing 1.14 g of aluminum nitrate/9 water, 1.34 g of bent casolabe, 3.91 g of tetra-n-propylammonium bromide, and 300 g of water, and stir and mix thoroughly. Then, the mixture was heated under reflux and stirred for 6 days under normal pressure to perform a second hydrothermal synthesis. Solid components were separated from the reaction mixture, thoroughly washed with water, dried at 100°C, and further calcined at 500°C for 15 hours to obtain composite zeolite CZ~11(-)-5(Az). As explained by X-ray diffraction, electron micrograph, and chemical analysis, CZ-11(-)-5(At) is a composite zeolite in which ZSM-5 is crystallized around silicalite-n. It turns out. Other composite zeolites and methods for preparing them are listed in Table 1 as zeolites s1-3. B) Production of lower olefins 1 g of composite zeolite obtained in A) above and subjected to calcination to remove organic compounds is mixed with 20 ml of 0.6N hydrogen chloride aqueous solution, and stirred at room temperature for 8 hours. The treatment operation was repeated twice in total to exchange the alkali metal ions contained as cations with protons. Thereafter, it was thoroughly washed with water at room temperature, dried at 120°C, and then calcined in air at 500°C for 10 hours to obtain a proton type composite zeolite. Composite zeolite powder made into proton type is heated to 400k pressure.
The mixture was compressed into tablets at a rate of 10 g/cd, then crushed into 10 to 20 meshes, and 2 mt of the tablets were filled into a reaction tube with an inner diameter of 10 mm. Liquid methanol was sent to the vaporizer at a rate of 4 mL/hr, where it was mixed with argon gas sent at 45"t/min, and introduced into the reaction tube, where the reaction was carried out at 360°C. Analysis of the product. was carried out using a gas chromatograph. The catalytic activity of each composite zeolite is summarized in Table 2. Carbon-based selectivity (%) of (ethylene + propylene) in the product Example 4

Claims (2)

[Claims] (1) A zeolite crystal forming a nucleus and one or more zeolites 1 formed around it by a hydrothermal synthesis method.
-A zeolite consisting of a crystal layer and a crystal layer! - A composite zeolite l- characterized in that at least two of the crystal glues have mutually different chemical compositions and/or -11 lattice structures. (2) In a method for producing hydrocarbons by reacting methanol and/or trimethyl ether in the presence of a zeolite catalyst, the zeolite catalyst includes zeolite 1 to crystals that form a nucleus, and a hydrothermal synthesis method surrounding the zeolite 1 to crystals that form a nucleus. It is recommended to use a composite zeolite catalyst which is formed and consists of one or more zeolite crystal layers, and at least two of the zeolite crystals have mutually different chemical compositions and/or skeleton structures. Characteristic method for producing hydrocarbons.