JPS59336A - Catalyst composition and isomerization of xylenes - Google Patents

Abstract

PURPOSE:To availably isomerize xylenes in a state suppressing side-reaction, by using a catalyst composition containing at least both components of crystalline aluminosilicate zeolite having a specific X-ray lattice plane interval and alumina supporting platinum. CONSTITUTION:Crystalline zeolite having a composition shown by formula shown by an oxide form in an anhydrous state [wherein M is one kind or more (n) valent cation, x is 0.5-4 and y is 10 or more] and a X-ray lattice plane interval d(Angstrom ) shown by the table is a component A while alumina supporting at least platinum is a component B. A stock mixture containing xylene isomers among which at least one kind is equal to or less than thermodynamical equilibrium concn. is brought into contact with the catalyst composition containing at least said components A, B in a gaseous phase to isomerize xylenes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst composition containing a novel crystalline aluminum/silicate zeolite and a method for isomerizing xylenes using the same as a catalyst. The present invention relates to a catalyst composition containing a novel crystalline aluminosilicate zeolite having a crystal structure different from that of any aluminosilicate zeolite, and to the use of the foam as a catalyst in the isomerization of xylenes.

In this specification, unless otherwise specified, crystalline aluminosilicate zeolite will be abbreviated and simply referred to as "zeolite."

Both natural and synthetic zeolites contain Na.

It contains cations such as K or hydrogen ions, has a three-dimensional network structure mainly composed of 8s04 and l'o4, and has a regular tetrahedral structure in which St atoms and Aj atoms are cross-linked via oxygen atoms. It is characterized by having a highly arranged structure. This zeolite has a large number of pores of uniform size, and is used as a molecular node, and is also used as a catalyst or collateral in various chemical synthesis fields.

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, when the SiO□/AJ208 molar ratio is at least 10, the silica-rich zeolite has poor stability, unique acidity, and is suitable for selective adsorption, cracking, and hydrocracking.

It has high activity as a catalyst for hydrocarbon conversion such as isomerization and fullkylation. Many such zeolites with a high silica content have been proposed, mainly 28M zeolites.

Zeolites with a high silica content are usually produced by reacting a silica source and an alumina source with K, alkali metal cations, and other cations used in combination.
However, the structure and properties of the zeolite obtained depending on the types and combinations of other cations differ.

Conventionally, 4) those used in combination with alkali metal cations and those using specific quaternary ammonium as other cations (for example, Japanese Patent Publication No. 46-10064, Japanese Patent Application Laid-Open No. 51-67298).

% (see Japanese Patent Publication No. 51-67299), return prime number 2~! 0
(Japanese Patent Application Laid-Open No. 50-5459)
8), charcoal! ? Those using 2 to 20 furkyl diamines (see JP-A-53-134799)
etc. are known.

As a result of research into new zeolites and their production methods, the present inventors have discovered that when a specific quaternary ammonium ion is used in combination with an alkali metal cation, a zeolite with a completely different crystal structure than conventional zeolites can be obtained. i
[We have already proposed that this zeolite is thermally stable and highly pure, and has excellent catalytic activity for the conversion of various types of hydrocarbons (patent application filed on December 21st). ).

The present inventors conducted further research in order to improve the zeolite proposed earlier as a catalyst with better activity and stability. As a result, a mixture of this zeolite and alumina supporting platinum was developed. The catalyst composition formed therefrom has an excellent activity of isomerizing ethylbenzene into xylenes, and therefore can be used as an isomerization catalyst for xylenes containing ethylbenzene by utilizing this unique activity. The present invention was achieved by discovering that it is possible to do so, and that its activity is maintained at a high level even after long-term use.

That is, the first invention of the present invention has (A) a composition represented by the following formula (1) % formula % (11), and the following 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 Medium 3.72±0.05 Weak to medium 3.44±0.04 Weak to strong 3.33±0.04 Stinging to strong 3.28±0.03 Medium value, real A catalyst composition comprising at least a crystalline aluminosilicate zeolite having the lattice spacing shown above (component A) and (component B) at least platinum-supported alumina (component B). Another invention of the present invention is a method for isomerizing xylenes, which comprises contacting the catalyst composition with a raw material mixture containing at least one xylene isomer having a thermodynamic equilibrium concentration or less in a gas phase. be.

CI) Crystalline aluminosilicate zeolite) (component A)
Preparation of the zeolite in the present invention is a zeolite with a high silica content, that is, a 8102/Al2O8 molar ratio of 10 or more, as described above, and conventionally known zeolites such as 28M-5, Z8M-11, and 78M-12.

X is completely different from high silica-containing zeolites such as zsy-38fI 28M zeolite and Zeta 3 zeolite.
Zeolite is a zeolite with a novel crystal structure exhibiting a line diffraction pattern, hereinafter referred to as [zeolite] TPZ-
It is called 3J.

Zeolite of the present invention) TPZ-9 is a water-soluble alkali metal compound, N,N,N,N',N',N'-hexamethyl-1,6-hexanediammonium compound, under reaction conditions (hydrothermal a compound that gives silica (under reaction conditions) (
A mixture containing a silica source (hereinafter referred to as silica source), a compound that provides alumina (hereinafter referred to as alumina source) under reaction conditions (hydrothermal reaction conditions described below), and water at a temperature of at least 80°C is sufficient to form crystals. It can be produced by a method comprising maintaining the zeolite for a certain period of time and subjecting the resulting zeolite to an ion exchange reaction with other cations as necessary.

Therefore, this method uses N, N, N, N' in addition to a water-soluble alkali metal compound as a cation source constituting the cation portion of the zeolite.

The essential feature lies in the use of N',N'-hexamethyl-1,6-hegisandiammonium compound.

In the above method for synthesizing zeolite, each of the above-mentioned starting materials is used in a proportion that gives the molar ratio of the following components in the reaction mixture after mixing these stage materials to give the molar ratio of the following components. mixed in.

5lo2/12o, = 1o~2000. Preferably lO~500, more preferably 20~250; R/(Si+i) = IX10'~l, preferably 5X10'~0.5, more preferably IX10'~3~1 ×1O-1;OH7/
(Si+1 = I x 10-' ~ 1.5, preferably 1xlO-3 ~ 1, more preferably 5x1O-3 ~ 0.4; H2o/(st-Hl) = s ~ 100, preferably 10 ~50, more preferably 15-40 + OH/H20 = I X t o-5 ~ t x lo
1, preferably I x 10-' to I x 10-''
More preferably lXl0' to lXl0.

Furthermore, OH- in the above formula quantitatively represents the degree of alkalinity in the above mixture, and its value is calculated from the total number of moles of hydroxyl groups brought into the mixture by the starting materials outside the water plate. This is a value calculated by subtracting the number of moles of water consumed by the neutralization reaction with the acid radical. (Next, each starting material will be described in more detail.)

(^) As the silica source, any commonly used for 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, the silica powder is Aerosil silica.

Precipitated silica produced by a precipitation method from an alkali metal silicate such as fuming silica or silica gel is suitable; as colloidal silica, those of various particle sizes, e.g.
Particle sizes of ~50 μm can be used.

In addition, as a water-soluble silicon compound, Na20 or Ni20
Examples include water glass and alkali metal silicates containing 1 to 5 moles, especially 2 to 4 moles of 5IO2' per mole, and colloidal silica or water glass is particularly preferred as the silica source.

1B) As an alumina source, any of those commonly used in the production of zeolites can be used, such as aluminum salts such as chlorides, nitrates, and salts;
For example, colloidal alumina, pseudoboehmite, boehmite, γ-alumina, α-alumina.

Hydrated or hydrated j-state alumina such as β-alumina trihydrate; examples include sodium aluminate, among which sodium aluminate or aluminum salt is preferred. be.

It is also possible to use aluminosilicate compounds, such as naturally occurring feldspar kaolin, acid clay, bentonite, and montmorillonite, as sources of both sulfur and alumina; Salt may be substituted for some or all of the alumina and/or silica sources mentioned above.

Comparing the blending ratios of the silica source and alumina source in the raw material mixture, Sio, A/403 and 1. [7] S l 02 / ATO3 (molar ratio) is 10
It is preferable to set it within the range of ~500, more preferably within the range of 20-250.

(C) On the other hand, as the water-soluble alkali metal compound 2, water-bathable alkali metal bases and alkali metal hydroxides are suitable. , sodium carbonate, potassium carbonate, and alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.

In addition, as a material that also serves as a glue power source or an alumina source,
For silicon, alkali metal silicates such as sodium and potassium silicate, and alkali metal aluminates such as sodium aluminate and potassium aluminate can also be used.

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

■) N , N , N , N', N', N'-hexamethyl- used with the above water-bathable alkali metal compound
The 1,6-hexivundiammonium compound is a compound which can be represented by the formula % and which can be mixed in this form with other starting materials or can be prepared in situ in a mixture, for example with N, N, N'.

It may also be formed by reacting N'-tetramethyl-1,6-hexamethylene diamine with a methyl halide, such as methyl iodide.

Such a diammonium compound has an amount of 1 x 10 to 1 mol, preferably 5 x 10 to 1 mol, per 1 mol of Si and At in total, in terms of the total number of moles of Si and At in the silica source and alumina source. .5 mol, more preferably 1×10”~
It can be used within the range of 1 x 10 mol.

Furthermore, in the raw material mixture used in the synthesis of the above-mentioned zeolite, it is necessary that at least OH- ions of more than 100% ion are present, and therefore, at least one of the starting materials other than the water plate used is must be able to dissociate the OH- ions, which are usually supplied into the mixture by the alkali compounds and/or diammorum compounds mentioned above.

Therefore, OH-ion is converted into 81 moles of silica source and alumina source and At in the mixture.
lXl0' to 1.5 mol, preferably 1xlo-3 to 1 mol, more preferably 5 x 10
-3 to 0.4 moles can be present.

Moreover, the nuclear OH− ion is based on the amount of water in the mixture If
C, lXl0' to IX,10' per mole of water
mol, preferably tL<Htxto' to 1×10 mol, more preferably 1×10 to 1×10 mol.

(g) Furthermore, in the raw material mixture, water is (8 + 10A
t) in a molar ratio of 5 to 100, preferably 1.2 to 10 to 50, particularly 15 to 4
A range of .

In the synthesis of the zeolite (TPZ-3) of the present invention, an alkali metal compound as described above is used.

Mix N, N, N, N', N', N'-hexamethyl-1,6-hexanediammonium compound, silica source, aluminum and water in the proportions described above,
The desired zeolite can be produced by heating and maintaining the resulting mixture at a temperature and for a time sufficient to produce zeolite (that is, subjecting it to a hydrothermal reaction), but the reaction temperature at that time must be 80°C or higher. Yes, especially 100
Advantageously, the temperature is within the range from 200°C to 200°C. The reaction 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 the reaction is carried out under autogenous pressure in an autoclave. However, if necessary, it may be carried out under an inert gas atmosphere such as nitrogen gas.

The zeolite formation reaction is continued by heating the raw mixture to the desired temperature and, if used, under stirring until the zeolite is formed. After crystals have thus formed, the reaction mixture is cooled to room temperature and filtered, preferably so that the ionic conductivity of the washing solution is generally less than 50 gU/cm, preferably less than 25 gU/cm, and more preferably less than 15 gU/cm. Rinse thoroughly with water and dry if necessary. Drying of the crystals can be carried out at room temperature or under heating up to about 150°C, and may also be carried out at normal pressure or reduced pressure; for example, drying at normal pressure of 50-130°C for about 5 to 24 hours preferable.

In addition, before carrying out the above-mentioned zeolite formation reaction, the target product zeolite (TPZ-) is added to the raw material mixture.
The presence of powder particles of No. 3 may increase the zeolite formation reaction rate.

Therefore, the desired zeolite (TPZ) is present in the raw material mixture.
Incorporation of a small amount as the type F of powder particles of -3 often brings about favorable results.

1 hole, in the raw material mixture, a quaternary ammonium compound whose molecule is smaller than that of the diammonium compound and/or
Alternatively, water-soluble amines may be added, thereby increasing the zeolite formation reaction rate. Examples of quaternary ammonium compounds that can be used for this purpose include tetramethylammonium and tetramethylammonium.

The amine or ammonium compound is N.

N, N, N', N', N'-hecamethyl-1,
per mole of 6-hegysandiammonium compound [7
．． It can be added in a proportion of 1 to 10 mol, preferably 0.1 to 5 mol.

The thus obtained zeolite TPZ-3 has cations of alkaline ions, N, and N.

N, N', N', N'-hexamethyl-1,6-
It contains hexanediammonium io/, and for example, an aqueous KNH4CA solution can be ion-exchanged to replace the cation sites with ammonium ions.

The crystals thus obtained are heated at about 100 to about 600°C, preferably 1
Calcination at a temperature of about 300 to about 500° C. for about 8 to about 24 hours, preferably about 8 to about 16 hours, results in 11 cations of one -C1 cation site and/or Alternatively, ammonium ions can be removed, and as a result, zeolite TPZ-3 in which cation sites are substantially composed of alkali metal ions and/or hydrogen ions can be obtained.

Further, according to the present invention, by subjecting the cation sites of the zeolite TPZ-3 formed as described above to an ion exchange reaction with other cations, at least a portion of the cations present in the cation sites are exchanged with the other cations. It is also possible to exchange with the cation of

The ion exchange reaction can be carried out by a method known per se, and the ion exchangeable cation can be any cation that can be used for the ion exchange reaction or can exist as a cation in the body. Any metal cation commonly used in ion exchange of zeolites is included. Specifically, for example, lithium and sodium.

Potassium, rubidium, cesium, copper, silver.

Beryllium, magnesium, calcium.

Strontium, barium, zinc, cadmium, mercury,
Scandium, Yztrium.

Lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium.

Disubium, holmium, erbium, thulium, ytterbium, lutetium A, iron, copper nickel, ruthenium.

Examples include rhodium, palladium, osmium, iridium, and platinum.

Among these, cations belonging to the group jJ%mb (rare earth metals) including alkali metals, alkali metal complexes, and lanthanides are particularly preferred.

Exchange with these cations can be carried out by methods known per se, for example by bringing the zeolite into contact with an aqueous solution containing the desired cations. Contact treatment is a patch
Alternatively, the activity may be improved by carrying out the ion exchange described above, which can be achieved by any of the continuous methods.

The zeolite TPZ-3 as component A of the present invention produced as described above has a characteristic X-ray diffraction pattern, and has at least the following characteristic peaks, which makes it difficult to compare with conventional high-silica-containing zeolites. It is clearly distinguished from zeolite. For example, as mentioned above, 4.33
±o, IXyc very strong peak is the zeolite of the present invention)
Although recognized in TPZ-3, the known zeolite ZSM
No such peak is observed in -5.

In addition, the above-mentioned zeolite) 4.02±0.0 for TPZ-3
5 A strong peak is observed in A, but zeolite ZSM
-12, only a relatively weak peak of 4.02±0.05 AK is observed.

The characteristic peak of the X-ray lattice spacing of component A zeolite) TPZ-3 is due to the slight shift in the lattice spacing depending on the type of cation M in the formula (+) indicating the chemical composition of zeolite TPZ-3. It should be understood that this is common to virtually all zeolites (TPZ-3), although some variations in strength and/or relative strength may occur.

Note that the value of the lattice spacing a(X) in the X-ray diffraction pattern described in this specification was determined by standard techniques. That is, the irradiation beam was an alpha twin beam on copper, and a self-recording scintillation argument spectroscopic optical bottom drawing was used.

The peak height (+) and 2θ (θ is the Bragg angle) were read from the spectrophotometer chart.

From this the relative intensity 100 x I/Io (Io is the height of the strongest line or peak) and d, the lattice spacing in Angstrom phase corresponding to the recorded line, were calculated.

In addition, the relative strength here is Zoo~60 is very strong, 60
-40 is strong, 40-20 is medium, and 20-10 is weak.

It should be understood that the zeolite TPZ-3K of the present invention is included in all zeolites as long as they exhibit the characteristic peaks of the above-mentioned X-ray lattice spacing, regardless of whether peaks exist elsewhere. be. However, in the X-ray diffraction pattern of the zeolite (TPZ-3) of the present invention, in addition to the above-mentioned characteristic peaks, a strong peak near 20X may be observed in some cases, but the presence or absence of this peak has no negative effect on the present invention. Zeolite (component A) does not affect the identification of TPZ-3.

The zeolite of the present invention) TPZ-:II has the following general formula (
Summer) x M2/n, 06 A1403・y 5102・River・
・・・(+)non [has 1 composition and is -.

In the above formula (1), X is an indicator of the amount of cations bonded to the zeolite, and ze#? () TPZ-
In case of 3, i40.5-4, fRl mechanism 0.9-3
can be within the range of

Zeolite, that is, crystal + l'l aluminone ricade, is basically made up of a combination of alumina tetrahedron and alumina tetrahedron, and the charge of this alumina tetrahedron is due to the presence of cations in the crystal. It has a structure that is neutralized by Sukomori. Therefore, in the above formula (1) representing zeolite, 1 Usually contains cation precursors that cannot be removed by normal washing, and X is 1 according to actual analytical data of synthesized zeolite. is rather rare. Thus, X'' in the above formula (+) K is the amount (in moles) of total cations in the purified synthetic zeolite, including the cations of the encapsulated cation precursors that cannot be removed by normal washing. shall represent.

In addition, y, which is an index of silica content, is at least 1O1
Preferably lO~2000, more preferably lO~5
A value within the range of 00 is advantageous, and a value within the range of 20 to 250 is particularly preferred since a zeolite with excellent properties can be obtained.

On the other hand, M in K in formula (1), which occupies the kanaon site of the zeonite of the present invention, is an n-valent cation, and specifically includes hydrogen ions, ammonium ions, organic kanaones, and metal cations. Examples of organic cations include those added during TPZ-3 synthesis, N and N.
, N , N', N', N'-hegizamethyl-1,6-
Examples include hexanediammonium cation, tetraethylammonium cation, and tetramethylammonium cation.

On the other hand, as metal ions, those mentioned above in connection with the ion exchange reaction of the zeolite of the present invention can be used.

However, as M in the above formula (1), hydrogen ions and metal ions are preferable, and the metal ions include alkali metal ions, alkaline earth metal ions, and lanthanide-containing periodic ions. Preferably, the cation is at least one type of cation selected from the group consisting of metal ions of Group 11b of the Table of Contents.

In particular, zeolite 'rPZ-3 as component A and [,te,
A catalyst in which at least 10% of the total cation sites are occupied by sodium ions is preferred because it is very suitable for use as a catalyst for isomerization of ginnones as described below.

Here, the total cation site refers to the number of all cations present in the crystal of zeolite TPZ-3 (theoretically, it almost corresponds to the number of aluminum atoms) in the t-meaning (7,
At least 10%, preferably 20% of the cations are sodium ions. A particularly preferred proportion of sodium ions is at least 25%.

On the other hand, it is not preferable for the purpose of the present invention that all cation sites be occupied by sodium ions, and the upper limit of the proportion of sodium ions is 99% or less, preferably 95% or less.
A rating of excellent or below is appropriate.

The zeolite TPZ-3 of the present invention has shape selectivity as one of its properties, and this property is similar to that of cyclohexyl
/n-hexane adsorption ratio.

This adsorption ratio t indicates the size of the pores existing in the zeolite, and is defined as the ratio of 1 weight of cyclohexane and 1 weight of n-hexane adsorbed per unit weight of zeolite at a constant temperature and pressure. Ru. The fact that this ratio is small means that molecules with a large cross-sectional area, such as cyclohexane, are difficult to diffuse into the pores of the zeolite, which leads to improved selectivity from the perspective of catalytic reactions. unit) cyclohexane or n- per INR
The adsorption of cyclohexane/re- The punched zemerite was kept in a saturated gas atmosphere of Hegilin for 6 hours, and then heated with chlorhekilene or n-hexane (T'kc7onite at 25°C to 12θ±20 nw). After holding at 1g for 2 hours, the cyclohegiza/father is n--", the zeolite rod on which xane is adsorbed iiji'L,'A, the zeolite ii before and after the adhesion operation: Qj's me, 6. Determine by calculating Or ten.

The zeolite TPZ-3 of the invention generally does not exceed 0.95,! ! It has a cyclohexane/re-hexane at ratio preferably in the range of 0.1 to 0.95.

Zeolite provided by the present invention) TPZ-3
is also unique in that it has a cracking activity that is an order of magnitude better than commercially available highly active liquor alumina cranking catalysts.

This cracking activity can be expressed by the "Clara Kink Index" (hereinafter referred to as C and I). This cracking index is expressed as a temperature that gives a constant reaction rate constant in the cracking reaction of hexane, and is specifically measured as follows.

10-20 mesh pressure molded zeolite or silica
After calcining the alumina catalyst for 8 hours at 450°C in the air, it was packed into a quartz glass reactor, and then nitrogen gas saturated with hexane was fed into the reaction tube at 25°C. The conversion rate of hexane is measured, the reaction rate constant at each reaction temperature is determined, and the reaction temperature at which the reaction rate constant is 0.5 is determined.

The cracking index of the zeolite TPZ-3 of the present invention varies depending on the type and amount of cations present in the cation site, and examples thereof are as follows.

In the case of hydrogen ion type, it is less than aOO; in the case of beryllium ion type (B e O / A! 40. molar ratio = o, 97), it is about 300; in the case of strontium ion type (S rO / A40
i molar ratio = 0.95) is 400, and
The cracking index differs slightly depending on the storm of cations introduced into the cation site, for example, in the case of sodium ion type, the Na20/A403 molar ratio is about 300 when the molar ratio is 0.12, and about 400 when it is 0.55.
Met.

Furthermore, the zeolite TI) Z- of the A component in the present invention
3 has excellent thermal stability, for example, 1 at 800℃.
Even after heat treatment for 2 hours or more,
It can be seen that this in itself is extremely thermally stable, since the diffraction pattern of is substantially unchanged.

[u] Catalyst composition of the present invention and manufacturing method thereof Catalyst composition of the present invention tit, iIC [1] N! It is a zeolite containing TPZ-3 (component A) and alumina containing at least platinum (component B), and specifically, components A and B are finely and uniformly mixed with each other. It is in the same condition as before.

Therefore, the adhesive composition of the present invention contains at least component A and component B, both of which are mixed as described above, and platinum may be supported at least on alumina, which is component B. There is no restriction in any way depending on the type of preparation method or conditions.

In other words, the catalyst composition of the present invention is a zeolite TPZ.
-3, it can also be expressed as containing at least alumina and platinum, with platinum supported on the alumina.

For ease of understanding, the preparation method of the W and fl compositions of the present invention can be roughly classified into the following (
Obtained by methods i) to 61D. Of course, the catalyst composition of the present invention may be applied to any of these methods or to partial modifications thereof.

■ A method in which platinum is added to alumina in advance, and the resulting powder and zeolite TPZ-3 powder are mixed and molded.

(ii) A composition f containing Flumip and Zeolite TPZ-3 was prepared, and this
A method of holding for one hour and then molding.

An AH composition containing alumina and TPZ-3 was prepared, and platinum was supported on the molded product.

Which 1I41'V method? However, the method itself for making platinum compatible is usually Z# in the solid catalyst preparation method.
) Platinum support method f can be adopted.

For example, chloroplatinic acid OfaPtC4), platinum chloride (pt
c4), platinum amine complex [e.g. Pt(NHs)4C1
An aqueous solution of a water-soluble platinum compound such as 4) may be impregnated with alumina or a mixture containing alumina and zeolite TPZ-3, and then water may be removed by evaporation.

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

The alumina in component B in the catalyst composition of the present invention may be any alumina commonly referred to as alumina, and preferred ones have a surface area of i) 150 to 400 rr? /l
, especially in the range of K100 to 3502.

The method for producing alumina is not particularly limited, but it is generally obtained by heat-treating hydrated alumina at a temperature of 1,000 to 1,000°C. Crystal form of alumina and 1. Then χ
Shapes such as γ shape, η shape, θ shape, δ shape, etc. can be used, and the particle size (average) is 1 to 500μ, and the preferred size is 2 to 1.
A range of 00μ is advantageous.

The catalyst composition of the present invention has a composition in which the weight ratio of component A (zeolite TPZ-3) to alumina in component B is 1.
Range of 0:90 to 90:10.

Preferably, a range of 75:25 to 25:5 is appropriate. If the A component is less than this range, zeolite TPZ-
The concentration of K in the catalyst of No. 3 is reduced, and in order to produce xylenes on an industrial scale, K requires a large-capacity reactor, which is economically disadvantageous. Furthermore, if the weight ratio of alumina in component B is lower than the above range, the isomerization activity of ethylpenze/to xylenes tends to decrease, which is undesirable.

The concentration of platinum in the deposited catalyst composition is 0.0% relative to the sum of components A and B. O1 to 5 deep holes, preferably 0.
It is desirable that the concentration of platinum is in the range of 05 to 311. If the concentration of platinum is lower than this range, the efficacy due to the inclusion of platinum and the isomerization activity of marethylbenzene to xylenes will be reduced; However, if the proportion of platinum increases, the effect of platinum will not increase any further, but it will be economically disadvantageous, which is undesirable.

The catalyst composition in 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 amount of the A component and the B component should be 50 or more as an lr amount. It is desirable that the content is preferably 70% or more,
In addition to component A and component B, other components may be contained in an amount of 50% by weight or less, preferably 30% to 11% by weight. Other components include metals from group II of the periodic table other than platinum (
For example, rhodium.

Preferred examples include rhenium and iridium. Also commonly used as binders for zeolite catalysts are metallic or natural refractory anoxides, such as
Silica-alumina, kaolin, silica-magnesia can also be used.

The catalyst composition of the present invention is prepared by uniformly mixing 1 fr fine powder of component A, component B, and other components as necessary, molding it into a desired shape of yuzu, for example, a pellet shape, a tablet shape, and reacting. It can be provided to

When used, the catalyst prepared as described above is heated at 200-600°C under a reducing atmosphere such as in hydrogen gas.
Preferably, the treatment can also be carried out at a temperature of 250 to 550°C.

(11 Isomerization of xylenes The catalyst composition of the present invention described above is extremely excellent as a catalyst for the isomerization of xylenes.The aromatic hydrocarbon raw material used in this case has a thermodynamic equilibrium concentration of at least tm. It is a raw material mixture having the following xylene isomers.As is well known, xylene has three types of isomers: ortho-, meta-, and para-isomers, and a mixture of these 38 isomers in any ratio. When subjected to an isomerization reaction, the isomerization reaction reaches an unbalanced state when the ratio of these three isomers reaches a certain value, and isomerization apparently does not proceed any further.1/ It is known that C.

The composition of the xylene isomer mixture in this equilibrium state is E
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.

[■] In the case of a mixed part of only the 381 isomer of xylene [427°C]; p-xylene 23.4% by weight rn-*/shi7 52.1% by weight 0-xylene 24.5% by weight [ ■〕 In the case of a mixture of xylene isomers containing ethylbenzene [427°C]; Ethylbenzene 8.3% by weight p-xylene 21.5 weights*S m-xylene 4718 xylene 0-xylene 22.4 weight % , in this specification, "a mixture containing at least one xylene isomer having a thermodynamic equilibrium concentration or less" means at least 1 m of the 381 isomers of xylene/
A mixture of xylene isomers in which the concentration of the isomer deviates from the concentration in the thermodynamic equilibrium phase.

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 contain a mixture of xylene isomers and other aromatic hydrocarbons such as ethylbenzene, benzene, It may also be a mixture of toluene, ethyltoluene, trimethylbenzene, diethylbenzene, ethylxylene, dimethylbenzene, and the like. In the latter case, it is desirable that the xylene isomer mixture generally accounts for 30% by weight, 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.

There is a Ca aromatic hydrocarbon fraction obtained from pyrolysis and hydrotacking, which in addition to the xylene isomer mixture also contains ethylbenzene with the same number of carbon atoms. In the present invention, among others, these xylene isomer mixtures and ethylbenzene together account for at least 80% by weight, preferably Qθ%, of the aromatic hydrocarbon fraction, based on the weight of the fraction. Very advantageous results are obtained when using minutes.

The isomerization of the aromatic hydrocarbon raw material described above in VC can be carried out under xylene isomerization reaction conditions known per se, except for the use of the above-mentioned specific catalyst. Therefore, the reaction temperature is generally 280-500°C, preferably 30°C.
The reaction pressure can be freely selected within the range of generally normal pressure to 30 Kg/cd, preferably normal pressure to 25 KV/cd.

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 generally about 0.1 to about 200,
It is advantageous to supply at a weight hourly space velocity IW, preferably in the range from 0.1 to 50.

In this specification, "weight unit time space velocity" (WH8V
) is a value calculated from the weight of component A in the following formula, where "weight of component A" means the weight ffjr of crystalline aluminosilicate, that is, zeolite TPZ-3, which is the pace of the catalyst.

Further, it is more preferable that the isomerization of the present invention is carried out in the presence of limescale. The supply ratio of hydrogen at that time can be varied over a wide range VC depending on the type of raw material mixture and/or catalyst composition used, but it is generally 1 to 30, preferably 1 to 30, 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 the isomerization reaction of the present invention, prior to the reaction or when the activity falls below a certain level after performing the isomerization reaction, the zeolite may be subjected to the commonly known chlorination treatment. , increase the initial activity of the catalyst,
Alternatively, the activity after regeneration, especially the ethylbenzene isomerization activity, can be returned to a high level.

Such a chlorination treatment can be carried out on the catalyst composition of the present invention at the time of catalyst preparation, by introducing chlorine into the catalyst17, or sometimes during the isomerization reaction. It is also possible to mix a chlorine compound into the raw material mixture as a component of the raw material mixture.

According to the method of the present invention described above, xylene isomerization activity can be maintained for a longer time than when a composition containing alumina and zeolite TPZ-3 that do not support platinum is used as a catalyst. Also, disproportionation reactions and trans-
Since undesirable side reactions such as alkylation can be suppressed, xylenes can be isomerized industrially and efficiently.

Furthermore, in comparison with the case where only 1 zeolite TPZ-3 is modified with platinum (no platinum is mixed with alumina 7), the catalyst #L composition of the present invention has a high isomerization selectivity of ethylbenzene to xylenes. Industrial benefits can be obtained from dramatic improvements in performance.

Example 1 Water glass (5i0136.2 manufactured by Wako Junkei Co., Ltd.) was used as a silica source.
4 wt%, Na2O17.30 wt%, 8046.46 wt%) 3315F, aluminum sulfate 18 water field 2661. as an alumina source. As a neutralizing agent,
668F sulfuric acid, 5oo of sodium chloride as mineralizing agent
r, Mausoleum 77 Monium Ryo, N, N, N'.

N'-tetramethyl-1,6-hexanediamine 339
f, a gel was prepared from methioiodide A = 5679 and 10 t of pure water.

The composition of this substance is expressed in molar ratio, SiO2/A4oJ=s.

Ammonium salt/81+At= 0.0 9 60H
-/SI+At=0.1080/5t4kl=30.90H-/food0=3.3X10''.

This gel was placed in a 201-volume stainless steel autoclave, and reacted for 1 a at 160° C. autogenous pressure while being gently stirred.

After depositing the reaction products and distributing them from house to house, wash the cleaning solution with pure water for 50 minutes.
It was washed until the size was 0.7657 cm or less and dried at 60° C. overnight.

The TPZ-3 thus obtained had a weight of 1.2)4
The X# diffraction sound diagram is shown in Table 1 of 11.

The composition of this TPZ-3, expressed in molar ratio of oxides, is: 1.26 RO; 0.21 Na2O,'; 42.
Oa 8i02; 4.75 0, and the detected elongation ratio of carbon and nitrogen is o, 1a 7
(Theoretical value 0.194).

Note that this TPZ-:11 will be referred to as ff1Z-1 hereinafter.

Table-1 Example 2 As a silica source, Nrikasol (Kafloid S manufactured by Catalyst Kasei Co., Ltd.) was used as a silica source.
30L 5i0230 wt%) 4 to 9. Aluminum sulfate 18 hydrate 266' as alumina source + caustic soda 222f as neutralizing agent, N as organic ammonium
, N, N', N'-tetramethyl-1,6-hexanediamine (358 F), 590 vol of methyl iodide, and 8.5 t of pure water to prepare a gel.

Its composition, expressed in moles, is SIO, /A/, 0. == 50 ammonium salt/St+At= 0.1 0 00H
/SI+At= 0.1 0 08078i+At
= 30.20H/8l-1-At=3.3X10-3.

This gel was placed in a 201-volume stainless steel autoclave, and reacted for one week at 160° C. under autogenous pressure while being gently stirred.

After taking out the reaction product and distributing it from house to house, wash the washing solution with pure water for 5 minutes.
It was washed to below 0 pT5/rrn Jl and dried at 60°C overnight. TPZ-3 obtained in this way is heavy @
1.4 Kf, and its X-ray diffraction diagram is shown in Figure 2゜Table.
Shown in 2.

The composition of this TPZ-3, expressed in molar ratio of oxides, is: 1.2 3 RO; 0.1 7 Na, 0;
A/4()3; 4 0.5 6SiO,: 6.8
2 H,,0, and the detected atomization of carbon and nitrogen was 0.159.

Note that this TPZ-3 will be referred to as Z-2. ! : I will call you.

Table-2 Example 3 After baking Z-1 and z-215f at 500°C for 6 hours,
The ammonium chloride solution was ion-exchanged under reflux with 100 ml of an aqueous solution of 1 Owt% to obtain an ammonium form, and this ion-exchange operation was repeated three times. After sipping this, pure water'
Wash thoroughly until the cleaning solution becomes less than 50 μm, dry again, and bake at 500°C for 6 hours in an electric Matsufuru furnace to produce hydrogen type TP.
Z-3f. Hereinafter, these will be referred to as kHz-1 and H2-2.

The sodium content after the ion exchange is extremely low as shown in Table 3, and #11. indicates that ions are exchanged with light. Moreover, the X-ray diffraction of this H+-TPZ-3 is essentially the same as that before ion exchange, and at 800°C
Further, ion exchange was performed under reflux using 100 ml of a 1 wt % aqueous solution of H2-1 and H2-21s r'1i-jti obtained in this manner.

This ion exchange operation was repeated three times. This was passed through the mouth in the same manner as above, washed thoroughly, dried again, and fired in an electric Matsufuru furnace at 500°C for 6 hours to obtain NaZ-1 and NaZ-2, respectively. The sodium content is shown in Table-3.

As a comparative example, the results of ZSM-5 synthesized according to Japanese Patent Publication No. 46-100f14 are also described.

Using 1fF-fKH2-15ft, NaZ-1- was brought into contact with various alkali IJ 11 by changing the concentration of sodium chloride aqueous solution and the number of ion conversion operations at 70°C.
1 to 3 were adjusted. The results are shown in Table-3.

The above NaZ-1 and NaZ-259 were brought into contact with a 5 wt % aqueous solution of strontium nitrate (100° C.) at 70° C. for 6 hours to perform ion exchange. After passing this through the mouth, strontium type TPZ-3 was obtained by the same operation as above. Thereafter, this was converted into 8r-NaZ-1 and 5r-NaZ-1, respectively.
We will call it 2. Table 3 shows the sodium and strontium contents of 5r-NaZ-1.

Example 4 Various powdered H-TPZ-3Na obtained in Example 3
- TPZ-3 was fired in an electric Matsufuru furnace under 1 atmosphere of rough air for 4501:8 hours to remove adhering moisture, and about 12 pieces were weighed in a weighing bottle VC. Next, the weighed zeonite was placed in a desiccator containing the adsorbed solvent for 25 minutes.
The adsorbed substance was saturated and adsorbed by leaving it for 6 hours under a reduced pressure of 120 ± 20 mI (g) at 25 °C.
The mixture was evacuated under reduced pressure of 20 ++ m)Ig for 2 hours and then weighed. The adsorption amount of zeonite to the adhering substances is determined as follows.

Here, V is defined as the adsorption sound per zeolite weight, and each zeolite represents one zeolite before and after adsorption.

The adsorption coefficients of H2O, EB, PX, OX, n-hexane, and cyclohexane and the adsorption ratio of n-hexane and cyclohexane (V-cyclohexane/V
n-hexane) are summarized in Table 4 together with comparative examples.

Table 4 The above results: By introducing more thorium ion, molecules with larger molecular diameters become difficult to diffuse into the pores, and adsorption selectivity can be greatly improved.

Example 5 H2-159 or NaZ-15ft” each with nitric acid IJ f
Ion exchange was performed by contacting the sample with 100 ml of a 5% aqueous solution of rum, potassium chloride, beryllium nitrate, and lanthanum nitrate at 70° C. for 6 hours three times.

Post-processing was performed in the same manner as in Example 2, and each L++-112
-1゜K H2-1, Ba -NaZ-1 and La
+10+-NaZ-1f was obtained.

10-++ A mixture of these and the various zeolites obtained in Example 3 and an equal weight of alumina gel for chromatography was pelletized, and the catalyst obtained by adjusting the viscosity to a 10×20 mesh was heated in an electric Matsufuru furnace in an air atmosphere. After baking at 450°C for 8 hours, it was filled into a glass reaction tube. A saturated gas stream (P hexane - 0.2 atm) after passing nitrogen gas through hexane at 25 DEG C. in an absorption pin was then fed to the catalyst bed. The reaction temperature is such that the conversion rate of hexane is 5-40%.
Kvj verse 4 [7. Here, the hexane conversion rate is defined as follows. However, the fed hexane contains at least 80% or more of 4In-hexane.
It is possible to modulate the cracking activity by controlling the rosefish.

Example 6 (Catalysts 1 to 7, 11.12) Alumina for chromatography] 5.5 f to 90-print) ll in water! )%PtC/,・6H,,0
A 50-aqueous solution of 10-containing 1,0282 was added.

After contacting for 8 hours at 70°C with occasional shaking, the solvent was distilled off using a rotary evaporator under reduced pressure at about 30°C. Dry in an electric dryer at 100℃ for 6 hours, 7
After c, 0.5 inch of platinum was supported on the alumina by firing in an electric Matsufuru furnace at 450°C for 8 hours in an air atmosphere.

This 0.5% platinum-supported alumina and the same weight of )l-1 were thoroughly mixed and pelletized. ．． Catalyst 2 was obtained by adjusting the particle size to 10 to 20 meshes.

Catalyst 1, 3.41 was obtained in the same manner as Catalyst 8 by changing the amount of platinum supported on alumina and the mixing ratio with zeolite. Furthermore, the gods of zeolite are changed to catalysts 5 and 6.
I got a 7.

In addition, catalysts 11 and 12 were used in the same manner as Catalysts 1 to 7, except that catalytic chemical synthesis (mtJγ alumina (trade name ACP-1) and Sumitomo Chemical @l γ-alumina (trade name A-11) were used as alumina. Obtained.

(Catalyst 13) Gamma-alumina (trade name: ACP-1) and H2PtCl4.611. 3.3% of PTL was supported in the same manner as Catalyst 8 using an aqueous solution of .

1.5 parts by weight of this 3.3% platinum-supported alumina and +12
-1 1. 1.5 parts by weight of γ-alumina manufactured by Catalysts & Chemicals@ (trade name ACP-1) as a molding aid: After thorough mixing, pelletize and adjust the particle size to a 10-2o mesh to obtain catalyst 13. Ta.

(Catalysts 8 to 10) γ-Alumina manufactured by Catalysts & Chemicals (trade name ACP-1) 10j'
A chloroplatinic acid aqueous solution containing 6.16 mf/tne of platinum was added to a solution made by clouding 30 tnl of pure water with Kl #5.
added. Next, 2.87 g of 100 ml of water-A-4 solution containing Re2O30,905f' was added, and the mixture was allowed to stand overnight while being shaken at appropriate times. After that, the solvent was distilled off at about 30°C under reduced pressure (C rotary evaporator), and after drying at 100°C for 4 hours in an electric dryer, under an air atmosphere,
It was fired in an electric Matsufuru furnace at 450°C for 8 hours.

0.5% platinum and o.s% rhenium supported aluminum 1. After thoroughly mixing the same weight of H2-1, the particle size was adjusted to 10 to 20 mesh to obtain catalyst 8.

Catalyst 9.10 was obtained in the same manner as Catalyst 8 except that the type of supporting metal was changed.

The catalysts obtained above are summarized in Table 6.

Comparative Example H2-15, Of was suspended in 50 mt, )%
3+d of a 50-aqueous solution containing IPtC/4.61% 01.02 Rf was added. While shaking this at the appropriate time7
It was left at 0°C overnight. After distilling off the solvent in a rotary evaporator at about 30°C under reduced pressure,
Dry at 00℃ for 4 hours and then heat at 450℃ in an electric Matsufuru furnace.
After firing for 8 hours, 0.46 inches of platinum was supported on H7-1.

This 0.46% platinum-supported H2-1 and the same weight of alumina for chromatography were thoroughly mixed and pelletized.
The particle size was adjusted to 10 to 20 mesh to obtain catalyst 14.

Table 6 Example 7゜The catalyst obtained in Example 6 was activated at 450°C in an air atmosphere in an electric Matsufuru furnace for 8 hours, and then charged into a pressurized fixed bed flow reactor and treated with normal pressure sewage purplish gas. Reduction treatment was performed at 430 to 480° C. for 4 hours. Next, the catalyst bed was set at a desired temperature and pressure with hydrogen pressurization, and ethylbenzene was passed through oil in the gas phase to perform an isomerization reaction to xylene.

The results are shown in Table 7.
The yield of phlegm) is extremely high, and the selectivity for ferns is also good. The production rate of henaphthenes among the father and nonaromatic components is high, indicating that naphthenes, which are thought to be intermediates in the reaction, are less likely to be lost due to claragging.

In addition, in the table, disappearance EB, generation Xy4 generation CsN ke feed 1. It is expressed in weight relative to fCFBl 00 f.

Further, C and N represent C8 naphthenes, A-)-N represents C8 aroma+C, naphthene, and NA represents a non-aromatic component.

Examples 8-1 to 5 EB was prepared in the same manner as in Example 7 using catalysts 3 and 4.12.
A xylene isomerization reaction was carried out by passing warm xylene containing . (Examples 8-1 to 8-4) Furthermore, after carrying out Example 8-4, the temperature of the coke, which had generated a catalytic soil volume, was gradually raised under normal pressure and air atmosphere to reach a maximum temperature of 480°C. The catalyst was activated by combustion.

Continue to heat at 480℃ under 9 Q d/m air circulation.
250 - of C4 saturated gas was injected to chlorine the catalyst.

Thereafter, Example 8-5 was conducted in the same manner as Examples 1-4.

As shown in Table 8, the isomerization reaction from ethylbenzene to xylene occurred effectively, and the equilibrium attainment rate of xylene was also high.

here, (Feed, number of moles of 9C, A-1-N)

[Brief explanation of drawings]

Figure-1 and Figure-2 are Examples 1 and 2 of the present invention, respectively.
This figure shows an X-ray diffraction diagram of zeolite TPZ-3 obtained in .

Claims (1)

[Claims] IJA) The following formula (Sx M'/nO・Aj203-y S i 02-
-- The composition represented by (1) is below 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±11.05
Medium 3.72±0.05 Weak to medium 3.44±0.04 Weak to strong 3.33±0.04 Weak to strong 3628±0.03 X1lA virtually illuminated at medium value A catalyst composition comprising at least the A component and the B component, which are a crystalline aluminosilicate zeolite (component A) with uniform lattice spacing and alumina (component B) supporting at least platinum. 2. A. Component 2. The catalyst composition according to item 1, wherein the proportion of alumina in component B is in the range of 10:90 to 90:10 in terms of mold needles. 3. The alumina in component B has a surface area of 50 to 90:10.
Catalyst composition according to claim 1, in the range of 4o0m/I/. 4. 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. 5. The catalyst composition according to item 1, wherein M in the core A component is a cation of at least 1 m selected from the group consisting of hydrogen ions, alkali metal ions, alkaline earth metal ions, and NRB group metal ions including lanthanides. thing. 6. The catalyst composition according to item 1, wherein the zeolite as component A has at least 10% of its total cation sites occupied by sodium ions. 7, (A) has a composition expressed by the following formula (1) % formula % (1)
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 Medium 3.72±0.05 Weak to medium 3.44±0.04 Weak to strong 3.33±0.04 Weak to strong 3.28±0.03 Medium value, practically sandbag a crystalline aluminosilicate zeolite (component A) having shoulder spacing between the X-ray lattice planes and (component B) at least platinum-supported alumina (component B); 1. A method for isomerizing xylenes, which comprises contacting a substance in a gas phase with a raw material mixture containing at least one 14-mer xylene having a concentration below the thermodynamic equilibrium concentration. 8. The method for isomerizing xylenes according to the eighth frame, wherein the raw material mixture contains ethylbenzene. 9. The method for isomerizing xylenes according to item 8, wherein the contact is carried out in the presence of hydrogen.