JPS58120513A - Modified crystalline aluminosilicate zeolite and isomerizing method for xylenes - Google Patents

Abstract

PURPOSE:To isomerize xylenes while maintaining the activity of a novel zeolite catalyst modified with a prescribed metal or its oxide over a long time by bringing a vapor phase mixture of starting materials into contact with the catalyst. CONSTITUTION:Modified crystalline aluminosilicate zeolite having a composition represented by a formula xM2/nO.Al2O3.ySiO2 (where M is an n-valent cation, x is 0.5-4 and y is >=10) in the form of oxide in an anhydrous state and showing prescribed X-ray interplanar spacing is obtd. by modification with >=1 kind of VIII group metal in the periodic table or its oxide. A vapor phase mixture of starting materials at least one of which contains a xylene isomer at the thermodynamic equilibrium concn. or below is brought into contact with a catalyst contg. said zeolite. Thus, the activity of the catalyst is maintained over a long time, a side reaction is inhibited, and xylenes are isomerized advantageously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel modified crystalline alkinosilicate iolite and a method for isomerizing xylenes using the same as a catalyst. More specifically, it is a crystalline arunosilicate F zeolite which has a crystalline structure different from any of the conventionally known crystalline arunosilicate iolites and is modified with a metal, and xylene using it as a catalyst. Regarding the isomerization method of .

In this specification, the crystalline alkanosicate zeolite will be abbreviated and simply referred to as "1 zeolite" unless otherwise specified.

Zeolites are both natural and synthetic - Na.

Contains cations such as K or hydrogen ions.

It is characterized by having a three-dimensional network structure mainly composed of SiQ and AI, and a highly ordered tetrahedral structure in which 8% atoms and AI atoms are cross-linked through oxygen atoms. be. This zeolite has many pores of uniform size.

It is used as a molecule and is widely used as a catalyst or carrier in various fields of chemical synthesis.

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

For example, so-called silica-rich zeolites with a Sl/A4Q molar ratio of at least 10 have poor stability,
*1 with different acidity, e.g. selective characteristics Ml cracking, hydrocracking.

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

Zeolite with a high silica content is usually produced by reacting an alkali metal cation and other cations used in combination with a silica source and an alumina source, but it can also be obtained by seed noodles and combinations of other cations. The structure and properties of zeolites are different.

Conventionally, specific 4M anthonium has been used as the other cation used in combination with the alkali metal cation (for example, Publications Tl84m-10064, Kaimei 65-6C298).

%@@Refer to newsletter No. 51-47299), carbon number 3 to 10
(411 Kaisho s o
(Refer to Publication No. 54sss), using 1 no.
(Refer to Bulletin No. 9) are known.

As a result of research into a new zeolite, the present inventors discovered that when a specific 4th JR ammonium ion is used in combination with an alkali metal cation, a zeolite with a different crystal structure than the conventional zeolite can be obtained. It was previously proposed that the compound is thermally stable and highly pure, and has excellent catalytic activity for the conversion of various types of carbon and hydrogen.

Therefore, the present inventors improved the new zeolite previously proposed and developed it as a catalyst for the isomerization of xylenes.

The present invention was developed as a result of repeated research to find a modified zeolite that exhibits excellent activity as an isomerization catalyst for xylenes containing two-handed rubenzene, and that maintains its activity at a high level even after long periods of use. #I - that is, one shot - is at least 4. A crystalline aluminosilicate zeolite modified with a seed metal or its oxide, which is a crystalline aluminosilicate zeolite, has the following formula +1)
・-(11 lattice spacing d(A) Relative strong electric ILZ±06 Moderate to strong is±OS Moderate to strong 4-1 ± Ori Moderate 433±α
凰 Very strong Table 02 Sat α05 Strong ~ Very KIfIi 1113
± α 05 Medium L12 soil (LO5
@I~Medium 144±a04 Weak~Strong &lS*(LQ4 11~Strong 龜28 ± α 03 It is a crystalline aluminosilicate zeolite with a lattice spacing substantially represented by a medium value, and is also a ferrous zeolite. This is a method for isomerizing xylenes in which a heated raw material mixture containing xylene isomers, at least one of which has a concentration below the thermodynamic equilibrium concentration, is brought into contact with a catalyst containing the above in the gas phase.

The zeolite used in the method of the present invention and its manufacturing method were discovered by the present inventors as described above, and are ) and the specification of the patent application filed on December 21, 1932, but first, li! I will clarify.

The zeolite in the present invention is a zeolite with a high silica content as described in e above, that is, a zeolite with a hemolar ratio of 81 to A4 of 10 or more.
M-51ZBM-tt, ZBM-IL ZBM-a
Zeolite TPZ- is a zeolite with a new crystal structure that exhibits an It is called 3J.

The zeolite TPZ-3 of the present invention contains water 8, alkali metal compound, N, N, N, N', and methyl L6.
-Hexanedi7ammonium and metal compound, compound C which gives silica under reaction conditions (hydrothermal reaction conditions described below) 5) 1. Reaction conditions (hydrothermal reaction conditions described later) k
A mixture containing an alumina-providing compound (hereinafter referred to as a zeolite source) and water is maintained at a temperature of at least 80°C for a period sufficient to form crystals, and the resulting zeolite must be collected at a temperature of at least 80°C. KG can be produced by a method comprising further subjecting it to an ion exchange reaction with other cations.

Therefore, in this method, in addition to an aqueous alkali metal compound as a cation source constituting the cation portion of the zeolite, samethyl-1, The essential feature lies in the use of a 6-hexanediammonium compound.

In the above method for synthesizing zeolite, each of the above starting materials is mixed at a ratio that gives the following molar ratio when converted to the molar ratio of the following components in the reaction mixture after mixing these raw materials. be done.

810, / to kim=10~λ000. Preferably 10 to $00. More preferably 20~zsoH R/(EJj+^j);txso~1. Preferably 5xso ~am, 8 and more preferably IX10-''~txso'':oH7/(
S1+Aj) -t x t o ~Ll, preferably lXl0 -1. More preferably 5×1・−1 to a4: Lock/(Sl+AJ) −! I~10@, preferably 1.
~SO, more preferably 1s~40: More preferably txt・-4 ~I This value is calculated by subtracting the number of moles of hydroxyl groups consumed by the neutralization reaction with acid groups in one reaction mixture from the total number of moles of hydroxyl groups brought into the mixture by starting materials other than water.

Next, each starting material will be described in more detail.

As a silica source, any of those commonly used in zeolite production can be used.

Examples include silica powder, colloidal silica, water-soluble silicon compounds, and silicic acid.

To explain these specific examples in detail, as the silica powder, precipitated silica produced by a precipitation method from an alkali metal silicate such as Ni9sil silica and fuming silica gel is suitable, and as the colloidal silica, there are various types of colloidal silica. For example, those with a diameter of 10 to 80 I can be used. In addition, as an aqueous silicon compound, N~0
Or to Bi for Il, O* moles! Examples include water glass and alkali metal silicates containing 1 to S mol, especially 2 to 4 mol, and cosidial silica or water glass is particularly preferred as the silica source.

As the alumina source, any of those commonly used in the production of zeolites can be used; for example, aluminum salts such as chlorides, nitrates, and ilates;
For example, colloidal F-type alumina, pseudoboehmite, boehmite-T-alumina, α-alumina, l-alumina,
Aluminum in a hydrated or hydrateable state such as a trihydrate is exemplified, and among these, almonate or aluminum salts are preferred.

Al-1 is also a source of both silica and alumina.
It is also possible to use naturally occurring feldspathic kaolin, acid clay, bentonite, montmorillonite, etc., and these full dinosilicates can be used in combination with the above-mentioned aluminum and/or silica sources. It may be replaced in part or in whole.

The blending ratio of the silica source and the alumina source in the raw material mixture is 8 inI and A4, respectively.
10. /A40. (molar ratio) is preferably in the range of 10 to 600, more preferably in the range of 20 to ZSO.

On the other hand, as a water-soluble alkali metal metal.

Water-soluble alkali metal rings and alkali metal hydroxides are suitable, in particular alkali metal chlorides, carbonates, such as sodium chloride, sodium carbonate, potassium carbonate, etc., or sodium hydroxide, water Examples include alkali metal hydroxides such as potassium oxide.

In addition, as a source of silica or algina,
Alkali metal silicates such as sodium silicate and potassium silicate, and alkali metal aluminates such as sodium aluminate and aluminic acid salts can also be used; however, particularly suitable alkali metal compounds include Examples include sodium fluoride hydroxide, sodium silicate, and sodium flunoate.

0 N used with the above water-soluble alkali metal compound
, N, N, N', and N'-hexamethyl-16-, and the compound can be mixed in this form with other starting materials, or it can be mixed in situ in the mixture with 1 For example, it may be formed by reacting N,N,N',N'-tetramethyl-L6-hexamethylenecyanine with a halogen methyl halide, such as methyl haiodide.

Such a diammonium compound is calculated by calculating the total of 81 and ml of the silica source and the alkali source to 1 cm,
IXIQ ~ 1 mol per 1 mol of total of 91 and AI,
Preferably, it can be used in the form of IX1 (1''''~asmol, more preferably IXIQ=~XIO solu).

In addition, it is necessary that the raw material mixture used in the synthesis of the above-mentioned zeolite contains at least an amount of OH- ions, and therefore, at least one of the starting materials used in the water-flooding process should contain O' ions. Such OH- ions are usually supplied into the mixture by the alkali metal compounds and/or diammonium compounds mentioned above.

Therefore, OH- ions are present in the mixture as St and An in terms of 81 of the silica source and alumina source and the molar aK of An.
I x 10-' to LI mol per total mole of, preferably t x t o-'' to 1 mol.

More preferably, it can be present in a range of 1X10 to 04 moles.

In addition, the acid OH- ion is 1 x 10 to 1 x 16 mol, preferably 1 x 10 to 1 x 1 1Q mol, more preferably I 10-'~I
X 10=That's llI! It can exist within II.

(g) Furthermore, in the raw material mixture [, water is (SF+A
I) S in a molar ratio of 2 to 10 G relative to K, preferably 1
It is best to use the range from 0 to SO (.

4I and 15 to 40f) J range gives preferable results.

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

N, N', N', N'-hexamethyl-L6-hexanediammonium compound, silica source, aluminum source, and water are mixed in the proportions described above, and the resulting mixture is heated at a temperature sufficient to form zeolite. The desired zeolite can be produced by heating and maintaining it for a period of time (i.e., subjecting it to a hydrothermal reaction), but the 5th reaction temperature at that time is 8.
0°C or above, preferably within the range of 10°C to 100°C. Pressure is applied at autogenous pressure or higher, and it is common to carry out under autogenous pressure in an autoclave.
This may be carried out under an inert gas atmosphere such as nitrogen gas, if necessary.

The zeolite formation reaction is continued by heating the raw material mixture to the desired temperature and, if used, under stirring until the zeolite is formed. After the crystals have thus formed, the reaction mixture is cooled to room temperature and allowed to pass, preferably until the ionic conductivity of the washing solution is generally less than or equal to 5 Q, preferably less than or equal to 25 JijJ.
Wash thoroughly with water until the Mv is 24 or less, more preferably 15a (Mv or less), and dry if necessary.

Drying of the crystals can be carried out at room temperature or under heating to about tSO°C, and may be carried out at normal pressure or reduced pressure. For example, drying at atmospheric SO to 130°C for about 24 hours is preferred. preferable.

In addition, prior to the above-mentioned zeolite formation reaction in step 5, the desired product (zeolite) TPZ-1 is added to the raw material 1 compound.
The presence of powder particles may increase the reaction rate of (/olide formation).

Therefore, the target zeolite) TPZ-
Infiltration of small amounts of powder particles of s as seeds often has favorable results.

In addition, a quaternary ammocam compound and/or a water-soluble compound having a smaller molecular weight than the diammonium compound may be added to the raw material mixture, thereby increasing the reaction rate of zeolite formation. . Examples of quaternary ammonium compounds that can be used for this purpose include tetramethylammonium and tetraethylammonium. The amine or ammonium compound may be N,N.

N, N', W, N'-hexamethyl-L--hexanediammonium metal compound can be added at a ratio of α1 to 10 mol, preferably 11 to 1 mol, (zeolite thus obtained) TPZ -1, the cations are alkali metal ions and N, N, N, N'
.

N',N'-hexamethyl-L6-hexanediammonium ion.For example, 1@I(J
Ion exchange is performed using an aqueous solution.

Cation sites can also be replaced with ammonium ions.

The thus obtained worms may be calcined in a greenhouse at a temperature of about 100 to about 60°C, preferably about 100 to about 500°C, for about 8 to about 24 hours, preferably about 20 to about 16 hours, whereby , organic cations and/or ammonium ions at cation sites can be removed.

As a result, the zeolite TPZ-8 whose cation sites essentially consist of alkali metal ions and/or water bulk ions
can be obtained.

In addition, according to #4, by subjecting the cation sites of the zeolite TPZ-3 formed as described above to an ion exchange reaction with other cations, at least one of the cations present in the zeolite TPZ-3 is It is also possible to replace III with other cations.

The ion exchange reaction can be carried out by a method known per se, and the ion exchangeable cation can be any cation that exists as a cation in the medium in which the ion exchange reaction is carried out. Any metal cation commonly used as an ion exchange KII is included. Specifically, for example.

Lithium, sodium, potassium, rubidium, cesium, steel, silver, beryllium, magnesium, strontium, barium, zinc.

Cadium, water pot, scandium, yttrium, lanthanum, cerium, praseodymium.

Neodymium, pumetium, samanuum, aeropium, gadolinium, terbium? Dysphrodium, holmium, erbium.

Thulium, itterbiu^, rhudetium, iron.

cobalt, nickel, ruthenium, a-dium.

Examples include palladium-osium, iridium, and platinum.

Of these five, cations of metals belonging to group 1b (rare earth metals) K, including alkali metals, alkaline earth metals, and lanthanides, are particularly preferred.

The exchange reaction with these cations can be carried out by a method known per se. For example, it can be carried out by bringing the zeolite into contact with an aqueous solution containing the desired cation. Fragile contact treatment can be accomplished in either a patch or continuous manner. The activity may be improved by performing the ion exchange described above.

Zeolite T of the present invention produced as described above
PZ-3 is a distinctive X! 1 diffraction pattern, and is clearly distinguished from conventional high-silica-containing zeolites by having at least the following characteristic peaks. The zeolite TPZ-3 of the present invention has a peak of 1.5 mm, but the known zeolite ZBM-5K does not have such a peak.

In addition, the zeolite of the present invention) TPZ-sK has a table OR±405
A strong AK peak is observed, but Zeo-j) 28
M-12K+t, tO2f a OS AKG! Comparatively, only @- peak is observed.

The characteristic peak of the X@ lattice spacing of the zeolite (zeolite of the present invention) TPZ-s is 1. Formula (1) showing the chemical composition of the zeolite of the present invention (PZ-3) It should be understood that although there may be some shifts and/or some f-shifts in relative strength, this is essentially common to all zeolites TPZ-3K.

In addition, one IIPKf! The values of interplanar spacing d (A) in the ribbed X-diffraction pattern were determined by standard techniques. That is, the m-ray was an alpha twin ray of steel, and a self-recording sickle-type shisothyresin counting spectroscopic needle was used. The beater heights Il and 2a (# is the Pradder angle) were read from the chart of the spectrophotometric needle. From now on the relative side 1too
xI/l5 (Is is the height of the strongest line or bee) and d, which is the lattice spacing in ondastroms, were calculated to correspond to the loosely recorded.

In addition, the relative strength here is 100~6G is very strong, 60~
40 is strong, 40-20 is medium.

It was expressed as 20-10 weak.

It is understood that the zeolite of the present invention) TPZ-sK includes all zeolites that exhibit the characteristic peak of the above-mentioned X-shaped lattice spacing, regardless of whether beaters are present elsewhere. Should. However, the X-ray diffraction pattern of the zeolite (TPZ-s) of the present invention is as follows.

In some cases, a strong peak near 20 may be observed in addition to the characteristic peak.

The presence or absence of this peak essentially determines whether the zeolite of the present invention) TPZ
It does not affect the identification of -3111.

The zeolite of the present invention) TPZ-s is chemically represented by the following general formula (1
) It has the composition of the formula %().

In formula (1),
In the case of Z-3, al~4. Preferably, it can be within the range of α9-3.

Zeolites, or crystalline aluminosilicate, are basically made up of a combination of silica tetrahedra and alumina tetrahedra, and the charge on the alumina tetrahedra is due to the presence of cations within the crystal. It has a structure neutralized by K. Therefore, in the above formula (1) representing zeolite, @X" representing the amount of cation is theoretically equivalent to the amount of alumina, that is, 5, but in reality, zeolite in one synthetic state is ) K usually contains cation precursors that cannot be removed by normal washing, and it is rather rare for X to be 1 in actual analysis data of synthesized zeolites. , f
1x” in the lJ notation (!)k is 1The amount of total cations (in moles) in the purified synthetic zeolite, which also contains cations of encapsulated cation precursors that cannot be removed by normal washing. shall be expressed.

Moreover, y, which is an index of silica content, is at least 410.
Preferably 10~000. More preferably 10-B
It is advantageous to go within the Go range, especially 20~! A value within the range of 50 is particularly preferred since a zeolite with excellent properties can be obtained.

On the other hand, m occupies the cation site of the zeolite of the present invention.
M in the formula ([) is an am cation, and specifically includes a hydrogen ion, ant7nium ion, an organic cation, and a metal cation.The organic cation is 1
For example, N, N, N added during TPZ-3 synthesis.
.

Examples include N', N', N'-hexamethyl-1,6-hexanediammonium cation, tetraethylammonium cation, and tetramethylammonium cation.

On the other hand, examples of metal ions include those mentioned above regarding the ion exchange reaction of the zeolite of the present invention.

Therefore, as M in m notation (1).

Hydrogen ions and metal ions are preferred, and also.

The metal ion °C is the periodic table f, which includes alkali metal ions, alkaline earth metal ions, and lanthanides.
A small number selected from the group consisting of f1b group metal ions.
Preferably, it is a species cation.

The zeolite of the present invention) TPZ-3 has shape selectivity as one of its II# properties, and this property can be expressed by the cyclohexane/n-hexane adsorption ratio. This adsorption ratio indicates the size of the pores present in the zeolite, and is defined as the ratio of the weight of cyclohexane to the weight of n-hexane adsorbed per unit weight of zeolite under constant temperature and pressure. A small ratio means that a molecule with a large molecular discontinuity, such as cyclohexane, is difficult to diffuse into the pores of the zeolite, which leads to increased selectivity from the viewpoint of catalytic reaction. The adsorption amount of cyclohexane or rhohexane per unit weight of zeolite was determined by weighing a certain amount of zeolite dried by firing at 450° C. for 8 hours in an electric furnace.

Then 2II'C, and * 20-th:t 41 ■
The weighed zeolite was kept in a saturated gas atmosphere of Ht cyclohexane or n-hexane for 6 hours.

Further, in the absence of cyclohexane or n-hexane, the zeolite was held at 3 s°C and 120±20 mH for 1 hour, and then the zeolite to which cyclohexane or n-hexane had been added was weighed.

@M It can be determined by determining the difference in weight of the zeolite before and after harvesting. The zeolite TPZ-3 of the present invention generally has a thick adsorption ratio in Ils of not more than 1s, preferably al-α9s. It has a 11-hexane dye deposition ratio.

Zeolite TPZ-3 provided by the present invention is also unique in that it has far superior cracking activity compared to commercially available highly active silica-fluorine cracking catalysts. .

This cracking activity can be expressed by 1 cracking index' (hereinafter referred to as C and I5). This cracking index is in the cracking reaction of hexane.

It is expressed as a temperature that gives a constant reaction rate constant, and specifically, it is measured as follows.

Zeolite or silica formed into 10 to 20 meshes
After calcining the full catalyst in electricity at 410°C for 8 hours,
4 was filled into a quartz glass reactor, and then nitrogen gas saturated with hexane was introduced into the reaction tube at t25°C.

The conversion rate of the hexane was measured.

Then, the reaction rate constant at each reaction temperature is calculated, and the reaction temperature at which the reaction rate constant becomes aS is estimated.

The cracking index of TPZ-s (zeolite of the present invention) is determined by the type and amount of cations present in the cation site, and representative examples of 10 are as follows.

300 or less for hydrogen ion type; beryllium ion i
ll (B@o/A4 hemolar ratio = (L12), approximately 10 nistrontium ion depths (8rO/A4(4-e
In the case of k ratio = aass), it is 40G, and the cracking index also differs slightly depending on the amount of cation introduced into the cough cation site.
In the case of , it was about 300. In the case of 1151, it was about 400.

Furthermore, the zeolite TPZ-1 of the present invention has extremely excellent thermal stability; for example, the X-ray diffraction pattern described above does not substantially change to ice even if it is heat-treated for 12 hours or more at soO°C. It is understood that it is extremely thermally stable.

In the present invention, the zeolite TPZ-4 is modified with at least one metal of Group 1 of the periodic table or its oxide, and the Group 1 metal is 1, for example, platinum (p
t), adium (Rh), palladium (Pd),
Iridium A (Ie) e t sumilum (Oa), iron (IF @) e cobalt (Co) e = y Kel (Nth), ruthenium (Ra), among others, platinum is $IC
preferable.

Furthermore, modification with these group metals or their oxides refers to zeolites TPZ-IK in which these metals have been ion-exchanged, those in which these metals or their oxides are supported, or zeolites that have undergone ion exchange. and carrying.

Next, a method of modifying with this group metal or its oxide will be explained.

To simplify the explanation, the first Akebono group metal or its oxide will be collectively referred to as "1 metal a" below.

To modify zeolite TPZ-3 with metal porcelain.

Generally known methods for modification with zeolite metals may be used.

To facilitate understanding, representative methods will be explained in more detail.

As mentioned above, when TPZ-3 is synthesized and obtained by sintering, some of its cation sites are N.
a, etc., so that the alkali metal ions are exchanged with hydrogen or ammonium ions. This exchange may be carried out simultaneously with the modification with the metal (<, # or prior to the modification.

However, one method involves immersing a zeolite in which cation sites are substituted with alkali metals in an aqueous solution containing gold II (II) and ammonium ions.

In this way, zeolite 1 in which at least most of the cation sites are of the ammonium ion type and modified with metal (a) is obtained. The ammonium ion type zeolite modified with metal (a) obtained by
~6o.

If it is calcined at a warm temperature of 0.degree. C., it can be converted into hydrogen ion type zeolite modified with metal (a).

The other one is hydrochloric acid for zeolite whose cation sites are amended with an alkali metal.

Treated with inorganic or organic acids such as sulfuric acid, acetic acid, and oxalic acid,
This is a method in which most of the cation sites are in the hydrogen ion type, and gold 4 (a) is ion-exchanged or supported thereon.

Still another method is to use an aqueous #! water-based ammonium compound for zeolite in which cation sites are substituted with alkali metals. Treat with liquid.

A zeolite in which most of the cation sites are replaced with ammonium ions is obtained, and the metal (a) is ion-exchanged with the metal (a) after being made into H-type zeolite as it is or by pre-calcination at a temperature of, for example, about 250 to 6sO℃. It is a method of carrying or carrying. In this case, the ammonium ion replacement treatment can be easily carried out by contacting zeslite with an aqueous solution of a water-soluble ammonium compound such as ammonium chloride or ammonium nitrate with a concentration of S to 20%.

Still another method is to exchange the cation sites with ions of at least one metal selected from the group consisting of alkali metals, alkaline earth metals, and metals of group NTB of the periodic table, including lanthanides, as described in the above method. Zeolite) TPZ-s
This is a method of preparing and ion-exchanging and/or supporting metal a with metal a.

The ion exchange and/or support of the metal (a) K on the zeolite can be carried out by the method of ion exchange or the method of supporting gold@(a) with respect to the usual zeolite) K.

For example, a compound of metal (1) for which various zeolites are desired to be treated is II! Such gold may be contacted with a water-soluble or non-aqueous medium containing F-Sakai*
As for the compound (a).

Halides, oxides, sulfides, oxyacids.

For example, when platinum is used as the metal (a), a water-soluble platinum compound [for example, 3ptc4] is used.

Zeolite)K is impregnated with water S@ of PtC^].

It may be supported on a platinum zeolite by subsequently removing water by evaporation, or it may be supported on a platinum zeolite by evaporating the water, or in an aqueous phase solution of a platinum compound that enhances ion or conversion ability, such as a platinum complex (for example, Pt(NHa), Cjl). Platinum may be ion-exchanged by soaking zeolite in water and filtering it [by thoroughly washing the zeolite, platinum may be ion-exchanged.
c, pre-ply t' temperature of 100-700°C;
Preferably at a temperature of 100 to 600°C under an acidic atmosphere such as air or an inert gas atmosphere such as nitrogen.
Heat relief for 50 hours can also be used to obtain a superior catalyst which is generally preferred.

Zeolite modified with metal (a) in this way is
The heat treatment can be carried out at a temperature of 100 to 100°C, preferably 200 to 200°C, in an oxygen-containing atmosphere such as air, or in an inert gas atmosphere such as nitrogen, for about 1 to about 20 hours.

And it is preferable.

Note that the present invention is characterized in that the zeolite (TPZ-3) is modified with a metal of group Ⅰ of the periodic table or its oxide as described above.
If! #It has mold, but this does not mean only those modified with Group 1 metals or their saponified products, but rather those modified with other metals or their oxides to the extent that the object of the present invention is not impaired. It should be understood that it also encompasses those that have been modified in a sequestrant manner.

The modified zeolite TPZ-3 obtained by further 5vc is molded into a fine powder or, if necessary, into a desired mk shape, such as pellets or tablets, and then molded into one piece. It can be subjected to the isomerization reaction of the invention. When molding pattern-modified zeolite,
Synthetic or natural refractory inorganic oxides, such as skeleton-modified zeolites, are commonly used as binders for zelite-based catalysts according to conventional methods.

For example, silica, alumina, silica al-Z.

After heating with kaolin, silica-magnesia, etc., it can be shaped into a desired shape and then fired and hardened.

The amount of modified zeolite as a catalytically active component in such a molded product is -1!1lc based on the weight of the plated molded product.
It is advantageous to use from 1 to 119% by weight, preferably from 10 to 119% by weight.

The catalyst consisting of the modified olide prepared in this way is heated at a temperature of 200 DEG to 20 DEG C., preferably 20 DEG C., under a reducing atmosphere such as in hydrogen gas.
This reduction treatment is usually carried out after filling one reactor.

The amount of metal (a) consumed in the modified zeolite of the present invention can be varied depending on the type of metal used, etc., but metal (1) is generally ic&001~59@%, preferred L<
Gto, oos ~3% by weight, more preferably a61
Advantageously, it is included in the #crystalline aluminosilicate in a range of ~2% by weight.

The catalyst according to the present invention classified as Ii# as described above is
In the state before reduction before being subjected to the isomerization reaction, the metal (a) is usually contained in a cationic and/or oxide form, and when it is reduced by KII to be subjected to the isomerization reaction, the metal bullet) becomes an element. State, #! chemical or cationic, 1t,
It is converted into a combination of these trends.

The aromatic hydrocarbon raw material to be subjected to the isomerization reaction of xylenes according to the present invention is a raw material mixture containing xylene isomers, at least one of which has a concentration below the thermodynamic equilibrium concentration. As is well known, xylene has three types of isomerization: ortho-, meta-, and baro-isomers, and when a mixture of these three isomers in any ratio is subjected to an isomerization reaction, the isomerization reaction It is known that an equilibrium state is reached when the ratio of the three isomers reaches a certain value, and isomerization apparently does not proceed any further. The composition of the xylene isomer mixture in this equilibrium field is called the "thermodynamic equilibrium composition."

This thermodynamic equilibrium composition differs slightly depending on the temperature.1For example, the composition of a xylene isomer mixture at the following temperature is as follows.

CI) In the case of a compound of only three isomers of xylene [487°C]; p-xylene 214 to 1 m-xylene 1IIL1jli1% O-xylene
1411% by weight (If) In the case of a xylene isomer mixture containing ethylbenzene [427°C]: Ethylbenzene & 3% by weight p-xylene 2LS@@% m-xylene 47.8% by weight O-xylene 22424% by weight and 1 Specification In the book, "a heated mixture containing at least one xylene isomer having a thermodynamic equilibrium concentration or lower" means that at least one of the three isomers of xylene has a thermodynamically A mixture of xylene isomers whose concentrations deviate from their equilibrium composition.

The aromatic hydrocarbon feedstock used as starting material in the process of the invention can consist solely of a xylene isomer mixture or -(a mixture of silene isomers and other aromatic hydrocarbons such as ethylbenzene). , benzene, toluene, ethyltoluene, trimethylbenzene,
It may be a mixture of diethylbenzene, ethylxylene, tetramethylbenzene; in the latter case, the xylene isomer mixture is generally 30% by weight, preferably SO type weight, based on the weight of the aromatic hydrocarbon feedstock. It is desirable that the total number of employees be at least the same.

In the method of the invention, l! A raw material mixture that can be advantageously used for # is 1 part petroleum paste, 7 parts O2 ng.

C, an aromatic hydrocarbon fraction obtained from pyrolysis p-hydrocracking; this fraction is.

In addition to the xylene isomer mixture, it also contains ethylbenzene having the same number of carbon atoms.In the present invention, among others, these xylene isomer mixtures and ethylbenzene
Very advantageous results are obtained if a C6 aromatic hydrocarbon fraction is used which in total accounts for at least % by weight of --SO, preferably 90% by weight or more, based on the weight of the fraction.

The above-mentioned isomerization of aromatic hydrocarbon bulk feedstocks is performed except for the use of the above-mentioned specific catalysts.

It can be carried out under xylene isomerization reaction conditions known per se. Therefore, the reaction temperature is generally 280~so
0°C, preferably within the range of soo to 450°C.

The reaction pressure can be freely selected from normal pressure to 3 Gk#/d, preferably from normal pressure to 25 kl/7.

- When carrying out the isomerization method of the present invention, the feed ratio of the raw material mixture varies depending on the type of hydrocarbon raw material and/or catalyst used, etc.5, but is generally about 0.01 to about 100.0%.
Preferably ゛(Ll-50, weight unit time within the range)
It is advantageous to feed at space velocity.

In this book, "Iris volume unit time air velocity" (WH8V
) is calculated by the following formula, where the "weight of the eyebrow medium" means the weight of the crystalline fluminosilicate which becomes the pace of the catalyst.

Further, it is more preferable that the isomerization of the present invention is carried out in the presence of hydrogen, although the proportion of hydrogen supplied to the hoe can vary widely depending on the raw material mixture and/or the type of catalyst used.

Expressed as a molar ratio of water*/raw material mixture, generally 1 to SO
, preferably in the range of 1 to 20.

According to the method of the present invention described above, TPZ-s
Compared to the case where xylene isomerization is used as a catalyst, the xylene isomerization activity can be maintained for a longer period of time, and undesirable side reactions such as disproportionation reactions and trans-alkylation can be suppressed, so it is industrially advantageous. Xylenes can be isomerized into

In particular, zeolite TPZ-s modified with platinum is
When used as an isomerization catalyst, it promotes not only the isomerization of xylene but also the isomerization of ethylbenzene to xylene.

Extremely excellent as an isomerization catalyst for xylenes containing ethylbenzene.

Furthermore, when the modified zeolite 'rPZ-1 of the present invention is used as a naturalization catalyst, it has the effect of suppressing the formation of coke on the catalyst, and this effect is particularly significant at relatively high temperatures, so xylene It has great industrial value as an isomerization catalyst.

Water glass (manufactured by Wako Pure Chemical Industries, Ltd., N L to s1) was used as the silica source.
24 vt%-Na! 017. * Ovt%, H, 0
41L46vt%>ss*sg, aluminum sulfate II hydrate 26·I as an alumina source, iI#g as a neutralizing agent
asIi, sodium chloride 5o as mineralizer.

l, N , N , N', N' as organic ammonia A source
-Tet 5) Thiru L--hexanediamine 5ssII.

A gel was prepared from 5syy of methyl fluoride and 101% of pure water.

The composition of this substance is expressed in molar ratio. 810m/A4Ck = s.

Ammonium, jL'Si+Aj =
o, oesOH-/81+Aj 8e-
as.

to O/81+Aj -λO OH-/H,
O=1sx1o'''''.

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 reactants and separating them, wash the solution with pure water. OB
It was washed until the temperature became 15/am or less and dried overnight at SO°C. This product weighed tz kg, and was found to be TPZ-3 from the X-ray diffraction diagram shown in Figure 1 and Table IK.

The composition of this zeolite is L expressed as a molar ratio of oxides.
26 RO: a 2 i NILIO:mujA:4
103810! :Table 7rt40, detected C
The ratio of and N was αway (iJ theoretical value axsa).

Table-1 11 Tt'Z-s t obtained in Example 1! I ml
After calcining for 6 hours at OO°C, ion exchange was performed under reflux with 100 d of a 10% ammonium chloride aqueous solution to obtain ammonium di, and this ion exchange operation was repeated three times. After filtering, it was stirred for light and dried again, and then heated in an electric Matsufuru furnace.
C. @ hours to obtain hydrogen fpTPZ-3. From now on, this will be considered a curse.

What is the sodium content after the above ion exchange?

It is expressed as Na, O/AltOn (sol ratio).

It is extremely low, indicating that ion exchange is almost complete. Also, this? -The X-ray diffraction of TPZ-3 is essentially the same as that before ion exchange.

There was no change even after heat treatment at SOO°C.

Furthermore, the H21 ml Jll obtained by this 5K reaction was ion-exchanged under reflux using a 10% aqueous solution of sodium chloride. This ion-exchange operation was repeated three times.

After filtering this, wash thoroughly.

After drying again, it was fired in an electric Matsufuru furnace at SOO°C for 6 hours to obtain NaZ. Its sodium content is NafO/A&
(expressed as 4 (molar ratio), it was α74.

Example 3 Powdered H-TPZ-3°Na-T obtained in Example 2
To remove adhering moisture, PZ-3 was calcined in an electric Matsufuru furnace at 450°C for 8 hours in an air atmosphere, and approximately IIi was weighed in a weighing bottle. 2 S ”Q in the skin,
The substance to be adsorbed was saturatedly adsorbed by leaving it under a reduced pressure of 120:1:20 wiH, g for 6 hours.Then, the adsorption solvent in the desiccator was removed, and the mixture was further heated at 25°C.
, 120±20-odor vacuum for 2 hours and reweighed. The adsorption amount of zeolite to the adsorbed substance is determined as follows.

Here, V (%) is defined as the amount of adsorption per unit amount of zeolite, and 傴 and 弌 represent the adsorption N#II and the subsequent zeolite weight, respectively.

)110 e EB + P K e OX + u-
The adsorption amounts obtained for hexane and cyclohexane and the adsorption ratio of n-hexane and cyclohexane (V cyclohexane/vI11-hexane) are summarized in Table 2 together with comparative examples.

Table-2 C3 4 =4 C2 1 311+ I ki ■ From the above results, by introducing sodium ions, it becomes difficult for molecules with a large molecular diameter to diffuse into the pores, and adsorption selectivity can be greatly improved. I can do it.

1 Example 4 Hl l # or NaZ S li of lithium nitrate, potassium chloride, beryllium nitrate, strontium nitrate and lanthanum nitrate, respectively! 6 at 100 m of 1% aqueous solution and 70°C.
Ion exchange was performed by contacting three times for three hours. Post-treatment was carried out in the same manner as in Example 2 to obtain Li''-H2, K1-Hz-B@masu-NmZ and L1+-NaZ.

These and the various zeolites obtained in Example 2 were thoroughly mixed with the same weight of alumina gel for chromatoguts 7, and the resulting catalyst was pelletized and the viscosity was adjusted to 10 to 20 mesh. 8 at 45'O℃
A saturated gas flow (P hexane ≠ a 2 atm) after passing nitrogen gas through the hexane of 2 S'C filled in a 1 m reaction tube with a glass surface baked for 1 hour was applied to the catalyst bed. The supplied reaction temperature is such that the conversion rate of hexane is 5 to 4.
It was adjusted to be in the 0% range@kC. Here, the hexane conversion rate is defined as follows. However, the fed hexane is pseudoparaffin containing at least 10% of n-hexane.

The product was sampled for 1G-20 minutes after the start of FiF and analyzed by gas chromatography.

The reaction rate constant at each reaction temperature was calculated as follows.

Here, 1 ((sec): Rate constant t (W): Contact time [Catalyst capacity (1d) 7mm trace flow moderate (Jaj/5ec)) #: A: Xane conversion rate, above hexane conversion rate is reaction temperature 50°~5sio
℃ and a contact time of 1-20 seconds.

As an indicator of the cranking activity of the catalyst, C6! .

are summarized in Table 3.

Table-3 Synthesized according to Kantokko Sho 46-1001i4, Example 2
Same as 41111C and ion exchanged.

It is possible to adjust the cranking activity by changing the type of cation introduced into the zeolite manufactured by JGC Chemicals.

Example 5 (Catalyst C) Liquid K in which Hz gourd OIi was dissolved in 30aj.
Ni (Non) * @@HA s 24 p including #
6 was added to z o *. While shaking this at the appropriate time,
It was left at ℃ overnight. After distilling off the m-solvent using a rotary evaporator under reduced pressure of about 30'C, the
℃ for 4 hours, then heated in an electric Matsufuru furnace at 450℃.
Baked for 8 hours and α against Ken-rpz-sy! IO% of nickel was supported.

o, so%Ni-supported sapon-TPZ-s and the same weight of Full 4 Nagel for chromatography were thoroughly mixed and formed into pellets, and the particle size was adjusted to 10 to 20 mesh to obtain catalyst C.

Catalysts A-L were obtained by supporting various metals in the same manner as in the case of catalyst C except that the type of metal source was changed.

Table 4 Example 6 The catalyst obtained in Example 5 was activated in an electric Matsufuru furnace at 450° C. for 8 hours in an air-enriched atmosphere. This catalyst LOIi was packed into a glass reaction tube with a diameter of 36 mm into which a thermocouple was inserted, and mixed xylene was fed from the surroundings under normal pressure at a temperature that was warmed by a Niku-V wire heater and the electricity was cut off. A chemical reaction was carried out.

The mixed xylene to be fed contains toluene aIIwt%,
It contained ethylbenzene 15vt%, para-xylene 8vi%, I-meta-xylene + ortho-xylene 711wt% - the results are shown in Table-5.

here.

x to.

However, each concentration in the formula represents the percentage of Kl amount.

Table 5 Example 7 Based on Cultivating Zeolite Weight Catalysts E and (1) were packed into a pressurized fixed bed flow reactor, and a gas phase xylene isomerization reaction was carried out under water pressure. As shown in Table 1, the xylene isomerization activity is high even under extremely mild conditions, and its deterioration is not expected over a long MK.

Table 6 Example 8 In the same manner as in Example 7, using Catalyst H, the isomerization reaction to xylene was carried out by passing the oil through Lebenzene. The results are in the table-
In the 6 tables showing 7VC, △ indicates the amount of change, N is naphthene, A
Table 0 indicates aroma -7

[Brief explanation of drawings]

FIG. 1 shows the Xd diffraction pattern of PZ-31 obtained in Example 1 of the present invention. Proceedings Amendment Document February 12, 1980 Director-General of the Tokuken Agency 1. Indication of the incident % Tsumugi Sho 57-278'1 No. 2. Name of the invention J14 modification of modified flocculating aluminosilicate zeolite and xylenes. Method 1 Relationship with the M-correction case Patent applicant representative Tomoo Tokusue (26 years old) Patent attorney 1) Hiroshi Jun contact information (506)
) 4481 5. Column 6 for detailed explanation of the invention subject to amendment, Contents of amendment (1) Page 14 of the specification, lines 3-4, 1゛lO~500
range of 10 to 2000, preferably i'it
The range is from o to 500.” (2) [Magnesium] on page 21, lines 9-10. Correct "strontium" to "magnesium, calcium, strontium". (3) Iridium (re
) 1 is corrected as “iridium (Ir) J. (4) r B e+ ” − in line 1 of 50jjl.
N & Z J to “Bs++-NaZ, Sr”-N
Correct it as aZ J. (5) Correct "P-hexane" in line 61ji1 to "hexane partial pressure." (6) Correct 1 K = , (1/l) ju -J in the 5th line from the bottom of page 51 to -1 Tel Table 3 on page 52 of the same page is corrected as per the queen.

Claims (1)

[Scope of Claims] L A crystalline alkinosicate zeolite F modified with at least one metal of Group Ⅰ of the periodic table or its oxide, the zeolite having the following formula (1 ) Has a relative expressed by the % formula % (1), and the lower lattice box relation 4 (A)
Moderate to strong IL Udomaigun Moderate to strong 4, 1 Dōshi Kame Tsubasa
Moderate table s1±al Very strong table O寞±aos Strong to very strong east83 ±
Ill, Os Medium! L72±αOs
A modified crystalline aluminosilicate zeolite having an X-ray lattice spacing substantially represented by a medium value. *The modified crystalline aluminosilicate zeolite according to item 1, wherein the Group Ⅰ metal is platinum. The first term in which y in the above formula (1) is at least one cation selected from the group consisting of hydrogen ions, alkali metal ions, alkaline earth metal ions, and Group Ⅰb metal ions including lanthanides. 1ellE modified crystalline aluminosilicate zeolite. Table Crystalline alkinosilicate (olide) modified with at least one metal of group ■ of the periodic table or its oxide, #zeolite is represented by the following formula (1) % formula % ( ↑ ILj±am Moderate to Strong 9±aS Moderate to Strong 4.61 ± a 1 Medium Position 33
±a1 Very strong tOW±aOS Strong to very strong LSI5
± aos Medium λ7 ± aSS
@ Medium 144 * & 04 @ Lie 1 13s ± a04 Strong ~ Strong 1 ± aSS A modified crystalline aluminosilicate that has an X-ray lattice spacing substantially represented by a medium value. A method for converting xylenes into a substance, which comprises contacting a catalyst containing zeolite with a raw material mixture containing at least one xylene isomer having a thermodynamic equilibrium temperature of once or less in a gas phase. 5. The method for isomerizing xylenes according to item 4, wherein the xylenes contain ethylbenzene. (The contact is carried out in the presence of hydrogen with xylene as described in line 5, item 4.
isomerization method.