JPS61238344A - Catalyst composition and isomerization of xylenes - Google Patents

Abstract

PURPOSE:To keep high catalytic activity for a long period of time, by containing two kinds of crystalline aluminosilicate zeolites, each having a specific X-ray lattice distance and alumina having supported at least platinum. CONSTITUTION:Crystalline aluminosilicate zeolite (A) having a silica/alumina mol. ratio of 10 or more and a specific X-ray lattice distance, crystalline aluminosilicate zeolite (B) having a silica/alumina mol. ratio of 12.5 or more and a specific X-ray lattice distance and a powder having preliminarily supported platinum are mixed in arbitrary order to obtain a catalyst. In use, the obtained catalyst can be treated at about 200-600 deg.C, pref., about 250-550 deg.C under a reductive atmosphere, for example, hydrogen gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst composition containing crystalline aluminosilicate zeolite having two specific X-ray lattice spacings, and a method for isomerizing xylenes using the composition as a catalyst. It is.

In this specification, the crystalline aluminum/silicate zeolite may be simply referred to as 1 zeolite' unless otherwise specified.

Zeolites, both natural and synthetic, contain Na + K.
or containing cations such as hydrogen ions, mainly S
It has a three-dimensional network structure composed of in, and AIO, and has a regular tetrahedral brightness arrangement structure in which St atoms and Al atoms are cross-linked via oxygen atoms. It is. This zeolite has many pores of uniform size, which can be used as a molecular sieve.
It is also widely used as a catalyst or carrier in various fields of synthetic chemistry.

In particular, synthetic zeolites are extremely homogeneous, highly pure, and have excellent properties. Therefore, many synthetic zeolites and methods for producing the same have been proposed.

For example, so-called silica-rich zeolites with a molar ratio of 5iOt/1403 of at least 10 have high stability, specific acidity, and are useful for example in selective adsorption, cracking,
/・Has high activity as a catalyst for hydrocarbon conversion such as cracking, isomerization, and alkylation. Many such zeolites with high silica content have been proposed.

Some of the present inventors previously described 1 zeolite T in the specification of JP-A-59-336 as part of such zeolite.
We proposed PZ-3', and this zeolite TPZ-3 is
It can be used as a catalyst in the isomerization of xylenes.

In addition, the present inventors further researched the isomerization of xylenes and found that the zeolite T
PZ-3 and 'ZS proposed in the specifications of JP-A-55-149119 and JP-A-56-22922.
The catalyst composition formed from the mixture containing M-48' and platinum-supported alumina has a particularly excellent activity K for isomerizing xylenes, and therefore, this unique activity can be utilized. The present invention was achieved by discovering that it can be used as an isomerization catalyst for xylenes, and that its activity is maintained at a high level even after long-term use.

That is, the first invention of the present invention is a crystalline aluminosilicate zeolite whose (A, -1) silica/alumina (molar ratio) is at least ]O, and which has the following 11.2 or strong9.
9 ±0.5 Moderate to strong 4°67
10.1 Medium 4.33±0
．． 1 Strong against non-shielding 4.02±0.05
Strong to very strong 3.83±0.05
Medium 3.72±θ, 05
Weak to medium 3.44±0.04 Weak to strong 3.33±0.04 Weak to strong 3.2S±0.03 Crystalline alumino with an X-ray lattice spacing substantially represented by the medium value Silicate zeolite (A-1 component), (A-2) Silica/alumina (molar ratio) is at least 1
2.5, and the following: 11.8±0.2 Weak to very strong 10.2±0.2 Weak to moderate 7.2
±0.15 Weak 4.2±0.0
8 Very strong 3.9±00 (18 Very strong 3.6±0.06 Weak 3.1±
A crystalline aluminosilicate zeolite (component A-2) having an X-ray lattice spacing substantially represented by a value of 2.85±0.05 weak and tB) Alumina supporting at least platinum (B product)
A catalyst composition comprising at least A-1 component, A-2 component, and B component, and another invention of the present invention is a catalyst composition containing at least component A-1, component A-2, and component B, wherein at least one component is added to the catalyst composition in a gas phase. This is a method for isomerizing xylenes, which is characterized by bringing into contact a raw material mixture containing the silene isomer at a concentration below the equilibrium concentration.

Regarding the A-1 component, the A-1 component in the present invention is a zeolite' proposed by the present inventors in the specification of JP-A-59-336.
It is TPZ-3'.

This TPZ-3 is a crystalline aluminosilicate zeolite with a silica/alumina (mole ratio) of at least 10 and the following 11.2 ± (1,5 moderate to strong 9.9 ±0.5 moderate or strong 4.
67±0.1 Medium 4.3
3±0.1 Very strong 4.02±0.
05 Strong to very strong 3.83±0.
05 Medium゛3,72±0.05
Weak to moderate 3.44±0.04
Weak to strong 3.33±0.04 Weak to strong 3.28±0.03 Medium
It is a crystalline aluminosilicate zeolite having an xm lattice spacing substantially expressed in terms of lattice spacing.

As detailed in the above-mentioned publication IIaI4I, this TPZ-3 contains a water-soluble alkali metal compound, N2, N2, N2, N', N', N'-hexamethyl-1,6- as an organic template. hexanediammonium compound,
A compound that provides silica under reaction conditions (hydrothermal reaction conditions described below) (hereinafter referred to as silica source), a compound that provides alumina under reaction conditions (hereinafter referred to as hydrothermal reaction conditions) (hereinafter referred to as alumina source), and water. a mixture containing at least 8
By a method consisting of subjecting the heptaolide, which forms crystals at a temperature of 0°C, to an ion exchange reaction with other cations if necessary! ! ! ! can be built.

Therefore, this method uses N + N + N t as an organic template in addition to a water-soluble alkali metal compound as a cation source constituting the cation part of the zeolite.
The essential feature lies in the use of N',N',N'-hexamethyl-1,6-hexanediammonium compound.

Regarding the A-2 component, the A-2 component in the present invention is a zeolite with a silica/alumina (molar ratio) of 12.5 or more, and its manufacturing method is basically disclosed in JP-A-55-149119 and JP-A-55-149119. Zeolite ZSM-48 can be synthesized according to the method described in JP-A-56-22922.The zeolite zSM-48 used in the present invention has a silica/alumina (molar ratio) of at least 12. 5 and below: 11.8±0.2 Weak to very strong 10.2±0.2 Weak to moderate 7.2
±0.15 Weak 4.2±0.08
Very strong 3.9±0.08 Very strong 3.6±0.06 Weak 3.1±
It has an X-ray lattice spacing substantially represented by a value of 2.85±0.05 weak. The crystalline heptaolide is produced from a raw material mixture containing a silica-producing compound, an alumina-producing compound and water under reaction conditions, and the crystalline zeolite ZSM-
48 is applied to each of the above starting materials as a bearing pressure template,
Preferably H2N(CHt)nNHt (n=4-12)
, an alkylamine having 2 to 12 carbon atoms, a quaternary ammonium compound, or a mixture thereof as raw materials.

Next, each starting material for synthesizing component A-1 or component A-2 will be described in more detail.

(4) As the silica source, any of those commonly used in zeolite production can be used, such as silica powder and colloidal silica.

Examples include water-soluble silicon compounds and silicic acid. To explain these specific examples in detail, there are many types of silica powder.
Losirshiri force.

Precipitated silica prepared by a precipitation method from an alkali metal silicate such as fuming silica or silica gel is suitable, and colloidal silica of various particle sizes, e.g.
Particle sizes of ~50 microns are available.

In addition, water-soluble silicon compounds include Na, O, 0,
Examples include water glass, alkali metal silicates, etc. containing 1 to 5 mol, especially 2 to 4 mol of SlO per 1 mol, and colloidal silica or water glass is particularly preferred as the silica source.

(81 As an alumina source, any of those commonly used in the production of heptaolides can be used, such as salts of aluminum such as chlorides, nitrates, and sulfates; for example, colloidal alumina, pseudoboehmite, boehmite) , r-alumina, α-alumina.

Hydrated materials such as β-alumina trihydrate.

Or alumina in a state that can be converted into an aqueous phase; examples include sodium aluminate, among which sodium aluminate or aluminum salts are preferred.

It is also possible to use aluminosilicate compounds as sources of both silica and alumina, such as naturally occurring feldspars, kaolin, acid clay, bethonite, heptato/soraite, etc. These aluminum/silicates may be substituted for part or all of the alumina source and/or silica source. salts and alkali metal hydroxides, specifically alkali metal chlorides such as sodium chloride, sodium carbonate, potassium carbonate, etc.

Alternatively, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide may be used.

In addition, as a source of silica or alumina,
Alkali metal silicates such as sodium silicate and potassium silicate, and alkali metal aluminates such as sodium aluminate and potassium aluminate can also be used.

Particularly suitable alkali metal compounds, therefore, include sodium hydroxide, sodium silicate, sodium aluminate and the like.

0 N, N, N as an organic template used with the above water bathable alkali metal compound in component A-1
, N', N', N'-hexamethyl-1,6-hexanediammonium compound is a compound that can be represented by the following formula %, and this compound can be mixed with other starting materials in this form. , or formed in situ in a mixture, e.g. by reacting N,N,N',N'-tetramethyl-1,6-hexamethylenediamine with methyl acetate, e.g. methyl iodide. You can also do this.

In addition, as a template for the A-2 component, HtN
(OH,)nNHt (n = 4-12), carbon a2
~12 alkylamines, quaternary ammonium compounds or mixtures thereof, especially H,N (cH2)6
NH, is preferably used.

In the synthesis of A-1 component and A-2 component, an alkali metal compound as described in @.

The organic template, silica source, alumina source, and water are mixed in the proportions described above, and the resulting mixture is heated and maintained at a temperature and for a time sufficient to form zeolite (i.e., subjected to a hydrothermal reaction). Zeolite can be produced, but the reaction temperature at that time is so'
c or higher, particularly preferably within the range of 100 to 200°C.

The limestone time is usually 5 hours to 100 days, preferably 10 hours to 50 days, particularly preferably 1 day to 7 days, and the pressure is autogenous pressure or higher, and autogenous pressure is applied in an autocrane. Although this is generally carried out under an atmosphere of an inert gas such as nitrogen gas, if necessary.

The silica/alumina (molar ratio) of component A-1 obtained as described in 1 is at least 10, preferably 10 to 15.
0, more preferably 30-110.

On the other hand, it is advantageous for component A-2 to have a silica/alumina molar ratio of at least 2.5, preferably in the range of 70 to 250.

If the silica/alumina (molar ratio) of both components A-1 and A-2 is larger than this, the number of acid sites (active sites) in the zeolite decreases, and the activity for isomerizing xylene decreases.

Conversely, if the value is small, the loss will be large.

In the catalyst composition of the present invention, the ratio of the A-1 component to the A-2 component described in CI) is 1=9 to 9:1, preferably 3 to 7:3. It contains a mixed mixture and at least platinum-supported alumina (component B). Specifically, it is a mixture in which component A and component B are mixed finely and uniformly with each other. DeA
The component refers to the combination of A-1 component and A-2 component.

Therefore, the catalyst composition of the present invention only needs to contain at least component A and component B, both of which are mixed as described above, and platinum supported at least on alumina, which is component B. The type of subpoena law is not subject to the same restriction based on the JP conditions.

The catalyst composition of the present invention consists of component A-1 and component A.
- A mixture containing at least flurus and platinum mixed in a ratio of 1:9 to 981 by weight with two components,
It can also be expressed that platinum is supported on alumina. Moreover, if the A-1 component is large, the isomerization ability of xylenes is high, and if the A-2 component is large, the isomerization ability of xylenes is low, but the loss of xylenes is reduced. In addition, when the A-1 component and the A-2 component are mixed together, the reaction of converting ethylbense into xylene is more efficient and there is less loss than when using each of the A-1 and A-2 components individually. To make it easier to understand, the preparation method can be roughly divided into the following (1).
~+1+1). Of course, the catalyst composition of the present invention may be produced by methods other than these methods, or even if they are partially modified.

Mix the U+ A-X component, the A-2 component, and a powder obtained by supporting platinum on alumina in an arbitrary order,
How to mold.

11i) A composition containing a mixture of A-1 component and A-2 component and alumina is v! 4. A method in which platinum is deposited on a preheated product, and then heated.

A method in which a composition containing a mixture of LIIDA-1 and A-2 components and alumina is made into a molded product, and platinum is supported on the molded product.

Among the preparation methods (1) to (110) above, the method (1) is the most preferred, but whichever p4 cleavage method is used, the method itself for supporting platinum is usually law may be adopted.

For example, chloroplatinic acid (H, P tC4), platinum chloride (
PtCl, ), platinum amine complexes [e.g. p t (NH
3) Impregnate alumina or a mixture containing alumina and a mixture of components A-1 and A-2 with an aqueous solution of a water-bathable platinum compound such as < clt ), and then remove the water by evaporation. .

The catalyst composition in which platinum is supported on alumina in this way has a temperature of 100 to 700°C, preferably 200 to 600°C.
The heat treatment can be carried out at a temperature of about 1 to about 20 hours in an oxygen-containing atmosphere such as air, or an inert gas atmosphere such as 90%, and is preferred.

The alumina in component B in the catalyst composition of the present invention may be of any type generally referred to as alumina, and preferably has a surface area of 50 to 400 m1/! 9, especially 1
It is in the range of 00 to 350 rrl/jl.

Although the productivity of alumina is not particularly limited, it is generally obtained by heat treating alumina hydrate at a temperature of 2 (1 to 10 + l O'C).

The crystal forms of alumina are Z-type, R-type, and η-type.

θ type, δ type, LC type etc. can be used, and particle shape (average)
A range of 1 to 500μ, preferably 2 to 100μ is advantageous.

The catalyst composition of the present invention has a composition in which the weight ratio of alumina in component A to component B is in the range of 10:90 to 9, preferably in the range of 75:25 to 25,875.

If the amount of component A is less than this range, the concentration of zeolite in the catalyst will be low9, and in order to produce xylenes on an industrial scale, a large-capacity reactor will be required, which will be economically disadvantageous.

Also, from the above range, 4. If the it ratio of alumina in component B becomes small, the isomerization activity of ethylbenzene to xylenes tends to decrease, which is undesirable.

Also, what is the concentration of platinum in the catalyst composition?

OjJ 1 to 5 times t for the sum of A and B components fftK
H, preferably 0605-3]! If the platinum concentration is lower than this range, the effect of containing platinum, that is, the isomerization activity of nitylpenze/xylenes to xylenes, will be reduced. If the proportion of platinum increases more than that, the effect of platinum will not increase any further, but rather it will be disadvantageous in terms of efficiency, which is not preferable.

The catalyst composition of the present invention basically only needs to contain both the A component and the B component, but in order to be used as a catalyst, the total of the A component and the B component must be 50% or more by weight.
Preferably, the content of is preferably 70% or more, and other components other than component A and component B may be contained in an amount of 503 or less, preferably 30 or less.

Other components include metals from Group 1 of the periodic table other than platinum (for example, a-dium).

, dirim, iridium) are mentioned as preferred examples. Also, synthetic or natural refractory anoxides commonly used as binders for zeolite catalysts, such as silica, silica-alumina, kaolino, silica-magnesia, may be used.

The catalyst composition of the present invention is produced by uniformly mixing component A, component B, and other components as necessary in the form of fine powder, molding the mixture into a desired shape, such as a pellet shape or a taglet shape, and reacting the mixture. It can be served to

The M medium thus prepared in step 5 is used under a reducing atmosphere such as in hydrogen gas with a concentration of 200 to 60+1''.
c, preferably at a temperature of 25° to 550°C.

(III) Isomerization of xylenes The above-mentioned catalyst composition of the present invention is highly effective as an isomerization catalyst for xylenes. The aromatic hydrocarbon raw material used in this case is a raw material mixture having at least one of the isomers and isomers having a concentration below the thermodynamic equilibrium concentration. As is well known, there are 34 isomers of dried silene, including ortho-, meta-, and para-isomers, and when a mixture of these three isomers in any proportion is subjected to an isomerization reaction, the isomerization reaction It is known that an equilibrium state is reached when the proportions of the three isomers reach a certain value, and a situation appears in which disintegration does not proceed any further.

The composition of the xylene isomer mixture in this equilibrium state is V
This thermodynamic equilibrium composition differs slightly depending on the temperature. For example, the equilibrium composition of a xylene isomer mixture at the following temperature is as follows.

CI) In the case of a mixture of only three isomers of xin/
427°C]; p-xylene 23.4% by weight m-xylene 52.1 im% 0-xylene 24.5% by weight (II) In the case of an isomer mixture of xylene containing ethylbenzene 427°C]; Ethylbenzene 8.3 Weight% p-xylene 21.5% m-xylev 47.81[:6i%.

0-xylene 22.4 wt 1% Therefore, in this specification, "a mixture containing at least one xylene isomer having a thermodynamic equilibrium concentration or lower" refers to A mixture of xylene isomers in which the concentration of at least one isomer deviates from the concentration in the thermodynamic equilibrium composition.

The aromatic hydrocarbon feedstock used as starting material in the process of the invention can consist solely of a mixture of xylene isomers or may consist of a mixture of xylene isomers and other aromatic hydrocarbons such as ethylbenzene, benzene, It may be a mixture of toluene, ethyltoluene, trimethylbenzene, diethylbenzene, ethylxylene, tetramethylbenzene, and the like. In the latter case, it is desirable that the xylene isomer mixture generally accounts for 30% by weight or more, preferably 50% by weight or more, based on the weight of the aromatic hydrocarbon feedstock.

A raw material mixture that can be used particularly advantageously in the method of the invention is petroleum reforming.

A C6 aromatic hydrocarbon fraction obtained from thermal fractionation, Hyde A cranking, which in addition to a mixture of xylene isomers also contains ethylbenzene with the same number of carbon atoms. The VC feed of the present invention contains, inter alia, these xylene isomer mixtures and ethylbenzene in total of 1% by weight of the fraction.
at least 801i%, preferably 90% by weight
Very advantageous results are obtained when C8 aromatic hydrocarbon fractions are used.

The isomerization of the aromatic hydrocarbon raw material described above can be carried out under xylene isomerization reaction conditions known per se, except for the use of the above-mentioned specific catalyst. However,
The reaction temperature is generally 280-500°C, preferably 300°C.
450° C., and the reaction pressure is generally normal pressure to 30 k&/cd, preferably normal pressure to 2
It can be freely selected within the range of 5 kg/d.

In carrying out the isomerization method of the present invention, the feed ratio of the raw material mixture can vary widely depending on the type of hydrocarbon raw material and/or catalyst used, but is generally about 0.1 to about 200, preferably 0. Advantageously, it is fed at an hourly space velocity in the range from .1 to 50.

As used herein, "weight unit time space velocity" (wnsv
The weight is calculated by the following formula, where the "weight of component A" is the weight of crystalline aluminum 7 silicate, which is the base of the catalyst, that is, the weight of zeolite TPZ-3 and the weight of biolite ZSM-4.
It means the total weight of Heron with a weight of 8.

Further, the isomerization of the present invention is more preferably carried out in the presence of hydrogen. The hydrogen supply ratio at that time can be varied widely depending on the type of raw material mixture and/or catalyst composition used, but it is generally 1 to 30, preferably 1, expressed as a molar ratio of hydrogen/raw material mixture. It is appropriate to supply the amount within the range of 20 to 20.

In addition, when carrying out isomerization reaction process 6 of the present invention, prior to the reaction or when the activity falls below a certain level after performing the isomerization reaction, the commonly known chlorination treatment of the heptaolide is carried out. The initial activity of ms can be increased or the activity after regeneration, especially the isomerization activity of ethylbenzene, can be returned to a high level.

In addition, such chlorination treatment is performed using catalyst 11! ll! This can sometimes be carried out on the catalyst composition of the present invention by introducing chlorine into the catalyst, or sometimes by mixing a chlorine compound as a component of the raw material mixture during the isomerization reaction. It can also be done by

According to the method of the present invention described above, alumina that does not support platinum, zeolite TPZ-3, and zeolite Z
Compared to the case where a composition containing SM-48 is used as a catalyst, xylene isomerization activity can be maintained for a long time, and undesirable side reactions such as disproportionation reactions and trans-alkylation can be prevented. Since it can be suppressed, xylenes can be isomerized industrially advantageously.

Furthermore, the catalyst composition of the present invention has a significantly higher isomerization selectivity of ethylbenzene to xylenes than a catalyst in which only zeolite TPZ-3 is modified with platinum (compared to a catalyst in which no platinum is supported on alumina). The industrial benefits of improved development can be obtained.

The method of the present invention will be described in detail below with reference to Examples.

Example 1 (Synthesis of 1″PZ-3) Synthesis was performed according to the specification of JP-A-57-95821. That is, water glass (Sin, 36.93 wt%).

(including Na, 017.62 wt4) 49.9,
NINININ'IN'.

N'-hexamethyl-1,6-hexanediammonium iodide 7,2,9. The reaction mixture was prepared from sulfur ff11O, 0,9, aluminum sulfate 4I and water 180,117.

The composition of this product expressed in molar ratio was as follows.

5iO1/AA! ,O,=50.18R/(Si
+Al) = 0.050H/ (S i + Al = 0.10HtO/(Sl+Al) = 3 5
．． 80H/H, 0=2. s x 1 o-” This gel was placed in a 300a capacity autoclave and heated at 160°C.
, reacted under autogenous pressure for 7 days.

The reactant was taken out, filtered, thoroughly washed with pure water until the washing solution became less than 50 μA/L, and dried overnight at 70° C. to obtain Zeolite 19,5.9.

The composition of this zeolite, expressed in molar ratio, was as follows.

SiO,/AI! to, = 42 Na, O/ Al, O = (1,95) The X-ray diffraction data of the obtained zeolite was the same as that of TPZ-3.

Practical Example 2 (Synthesis of ZSM-48) Synthesized according to the specification of JP-A-55-149119. That is, water glass (Sin, 36.24 wt.
%, including NayOI 7.30 wVIr) 18
0. li', 37.8 g of 1,6-hexanediamine,
Sulfuric acid 44y.

A reaction mixture was prepared from 1.4 y of sulfurized aluminum and 680 d of water.

The composition of this product expressed in molar ratio was as follows.

SiO,/AA! ,0. = 517 R/ (St +AAi) = 0.300H''/
(Si +AA!) = 0.10H,O/ (S
i + AIt) = 38.90H/H, 0 = 2.5
The 7 x 10-'' gel was placed in a 118 autoclave and reacted at 160'C under autogenous pressure for 2 days.

After taking out the reaction product and filtering it, the washing solution was diluted with 50μ of pure water.
The zeolite 61.6.9 was obtained by photospectrically cleaning the product until it became less than F/crIL and drying at 70°C overnight.

The composition of this heptaolide, expressed in molar ratio, was as follows.

S io, / A40. = 480NatO/A
ltos = 0.91 The X-ray diffraction theta of the obtained heptaolide was that of ZSM-48 and 1σj-.

Silica/alumina (
ZSM-48(C) with different molar ratios were synthesized (
Table 1).

Table 1 Example 3 (14 g of catalyst) 10 parts by weight of a 10 wt% ammonium chloride aqueous solution was added to the zeolite TPZ-31 obtained in Example 1, and ion exchange was carried out under heating under reflux. I went there 3 times.

This ammonium ion-exchanged olide was filtered off, thoroughly washed until the washing solution became less than 50 μ"!'!"/cm, dried overnight at 100°C, and then baked in an air atmosphere at 500°C for 4 hours. It was converted into hydrogen ion-exchanged zeolite.

Similarly, heptaolide ZSM-48 obtained in Example 2 was also converted to hydrogen ion exchange zeolite.

A HW zeolite component was prepared by mixing TPZ-31 (parts by weight) converted into a hydrogen ion form and ZSM-481 (parts by weight) converted into a hydrogen ion form.

H type upper olide a minute 1! [xit part and 2 parts by weight of r-Flumina carrying 1°2 wt% platinum? After mixing,
A catalyst was prepared by compression molding and pulverizing it into 10 to 20 meshes (Catalyst J).

Using H-type zeolite mixtures with different mixing ratios of TPZ-3 and ZSM-48, catalysts G to I were heated in the same manner as above.
R was adjusted to y4 (Table 2).

Table 2 Example 4 (Xylene isomerization reaction) Prior to the reaction, the catalyst obtained in Example 3 was
C. for 8 hours. Fill this into a glass pearstone tube,
Mixed xylene was passed through the oil in a hydrogen stream under normal pressure to perform isomerization and reaction of the xylene.

Here, px average attainment rate (Ku = Xylcl steel = EB disappearance rate (0A = Table 3 Example 5 (Ethylcyclohexane skeletal isomerization reaction)
Prior to the reaction, the catalyst obtained in Example 3 was heated to 450 ml in advance.
This was packed into a glass reaction tube and subjected to an extraction reduction treatment for 2 hours at 450°C in a hydrogen stream under normal pressure.Then, the catalyst bed was set at a desired temperature and a hydrogen stream was added. Medium ethylcyclohexane was passed through the oil to perform skeletal isomerization and dehydrogenation of ethylcyclohexane.

Here, Table 4 Example 6 (Ethylbenzene Isomerization Reaction) Prior to the reaction, the catalyst obtained in Example 3 was preliminarily calcined at 450°C for 8 hours.The catalyst was charged into a pressurized fixed bed flow reactor and heated under normal pressure. ,
Reduction treatment was carried out for 2 hours at 430 to 480°C in a leaf air stream.

The catalyst bed was then set at a temperature of 370°C and a pressure of 80 psia to convert ethylbenzene and mixed xylenes containing ethylbenzene into hydrogen/hydrocarbon (mole ratio) of 7 and 'AIH
8V 101 (R-') Oil was passed in the gas phase under the conditions of zeolite heavy smoke pacen to perform an isomerization reaction.

here PX equilibrium reached (%) - KB disappearance rate (@= Xyl　cxsu(%)= C, A + N yield (@= gB conversion rate (@=

Claims (1)

[Claims] 1. (A-1) A crystalline aluminosilicate zeolite having a silica/alumina (molar ratio) of at least 10, and having the following \\lattice spacing d (Å)\\\relative strength\ 11.2±0.5 Moderate to strong 9.9±0.5 Moderate to strong 4.67±0.1 Moderate 4.33±0.1 Very strong 4.02±0.05 Strong to Very strong 3.83±0.05 Moderate 3.72±0.05 Weak to moderate 3.44±0.04 Weak to strong 3.33±0.04 Weak to strong 3.28±0.03 a crystalline aluminosilicate zeolite (component A-1) having an X-ray lattice spacing substantially represented by a medium value; (A-2) a crystalline aluminosilicate zeolite having a silica/alumina (molar ratio) of at least 12.5; Aluminosilicate zeolite with the following lattice spacing d (Å) Relative strength 11.8±0.2 Weak to very strong 10.2±0.2 Weak to medium 7.2±0 .15 Weak 4.2±0.08 Very strong 3.9±0.08 Very strong 3.6±0.06 Weak 3.1±0.05 Weak 2.85±0.05 Weak values A-1 component, A-2 component, and (B) alumina carrying at least platinum (component B), a crystalline aluminosilicate zeolite having an X-ray lattice spacing substantially expressed as A catalyst composition containing at least component B. 2. A first catalyst composition in which the ratio of component A-1 to component A-2 in the catalyst composition is in the range of 90:10 to 10:90 by weight.
Catalyst composition as described in . 3. The proportion of component B in the catalyst composition is 10% by weight.
The catalyst composition of claim 1, wherein the catalyst composition is in the range of 90%. 4. The alumina in the B component has a surface area of 50~
Catalyst composition according to claim 1, in the range of 400 m^2/g. 5. The platinum is 0.01% of the total of A component and B component
The catalyst composition according to item 1, containing ~5% by weight. 6. (A-1) A crystalline aluminosilicate zeolite having a silica/alumina (molar ratio) of at least 10, and having the following lattice spacing d (Å) relative strength 11.2±0. 5 Moderate to strong 9.9±0.5 Moderate to strong 4.67±0.1 Moderate 4.33±0.1 Very strong 4.02±0.05 Strong to very strong 3.83 ±0.05 Moderate 3.72±0.05 Weak to moderate 3.44±0.04 Weak to strong 3.33±0.04 Weak to strong 3.28±0.03 Medium value, real A crystalline aluminosilicate zeolite (component A-1) having the X-ray lattice spacing shown above, (A-2) a crystalline aluminosilicate zeolite having a silica/alumina (molar ratio) of at least 12.5; , and the following ￥ Lattice spacing d (Å) ￥ ￥ Relative intensity ￥ 11.8 ± 0.2 Weak to very strong 10.2 ± 0.2 Weak to moderate 7.2 ± 0.15 Weak 4.2 ±0.08 Very strong 3.9±0.08 Very strong 3.6±0.06 Weak 3.1±0.05 Weak 2.85±0.05 Weak Contains at least A-1 component, A-2 component and B component of crystalline aluminosilicate zeolite having lattice spacing (A-2 component) and (B) alumina supporting at least platinum (B component). 1. A method for isomerizing xylenes, which comprises contacting a catalyst composition comprising a catalyst composition with a raw material mixture containing xylene isomers, at least one of which has a concentration below the thermodynamic equilibrium concentration, in a gas phase. 7. The method for isomerizing xylenes according to item 6, wherein the raw material mixture contains ethylbenzene. 8. The method for isomerizing xylenes according to item 6, wherein the nuclear contact is carried out in the presence of hydrogen.