CS271488B2 - Method of xylene raw material's catalytic isomerization - Google Patents

Abstract

The method of catalytic isomerization of xylene raw material consists of the fact that the xylene raw material is put into polymerisation conditions into contact with crystalline borosilicate as a catalyser with a composition expressed by the molar ratio of oxides<IMAGE>where:M means at least one kation with valency n from group comprising tetraalkylammonium kation with 8 to 12 atoms of carbon, alkaline metal kation or mixture of these kations,Y's value is 4 to 500 andZ's value is 0 to 160,while this crystalline borosilicate is characterized by a defined x-ray pattern and assigned intensities. Isomerization conditions include temperatures of 121 to 482 degrees C, overpressure 0 to 7.03 MPa, a molar ratio of hydrogen to carbon within the range of 0 to 20 and a weight hour flow rate 1 to 20.

Description

The invention relates to a process for the catalytic isomerization of a xylene feedstock.

The catalytic isomerization of the xylene feedstock by the process of the invention is characterized in that the feedstock is contacted with crystalline borosilicate as a catalyst having a molar ratio of (0.9 + 0.2) M _{2 / n} O: B ₂ O under isomerization conditions. ₃ ; Y SiO ₂ : ZH ₂ O, where

M is at least one cation of the group consisting of a tetraalkylammonium cation of 8 to 12 carbon atoms, an ammonium cation, a hydrogen cation, an alkali metal cation or mixtures of these cations with one another,

Y has a value of 4 to 500 and

Z has a value of 0 to 160, wherein the crystalline borosilicate exhibits interplanar distances and associated intensities, as shown in Table I below.

The isomerization conditions of the process of the invention include a temperature in the range of 121 to 482 ° C, an overpressure in the range of 0 to 7 MPa, a molar ratio of hydrogen to hydrocarbon in the range of 0 to 20 and a mass hourly flow rate in the range of 1 to 20

The crystalline borosilicate used in the process of the invention for the isomerization of the xylene feedstock can also be used as a catalyst for cracking and hydrocracking of hydrocarbons as well as molecular sieves. The prior art is described in U.S. Patents Nos. 423-326, 252-458, and 260-668.

. It has previously been known that zeolite materials, both natural and synthetic, have catalytic properties in numerous hydrocarbon conversion processes. Zeolithic materials are arranged porous crystalline aluminosilicates with a defined structure with large and small, interconnected cavities. The shapes of the cavities and channels are generally the same throughout the crystalline material in terms of size, thereby allowing selective hydrocarbon separation. Therefore, these materials have been described in various cases in the prior art as molecular sieves and are used in addition to selective adsorption also for their certain catalytic properties. The catalytic properties of these materials are to some extent influenced by the size of the molecules that are selectively permeated by the crystal structure, probably to be brought into contact with the catalytically active sites within the ordered structure of the materials.

The designation of a molecular sieve generally includes a large number of crystalline materials containing positive ions, both natural and synthetic. They are generally characterized as crystalline aluminosilicates, although this broad definition includes other crystalline materials. Crystalline aluminosilicates are formed by a network of tetrahedra of SiO4 and AlO4 groups in which the silicon and aluminum atoms are crosslinked by oxygen atom bridges. The electrovalence of the aluminum atom is saturated using a positive ion, for example an alkali metal or alkaline earth metal ion.

Further development of the state of the art has led to the formation of numerous synthetic crystalline materials. Among them, crystalline aluminosilicates predominate, which in the patent and journal literature are designated by letters or other suitable symbols. Examples of such materials are zeolites A (U.S. Pat. No. 2,882,243), zeolites X (U.S. Pat. No. 2,882,244), zeolites Y (U.S. Pat. No. 3,130,007), zeolites ZSM-5 (U.S. Pat. No. 3,702,886), zeolites ZSM-11 (U.S. Patent No. 3,709,979), zeolites ZSM-12 (U.S. Patent No. 3,832,449), and others.

The prior art is described in the above-mentioned U.S. Pat. No. 3,702,886, which protects crystalline aluminosilicate zeolite ZSM-5 and a process for its preparation. This patent is limited to the formation of zeolite in which the crystalline structure contains oxides of aluminum or gallium together with oxides of silicon or germanium. The latter are allowed to react with the former

CS 271 483 B2 in a certain ratio to each other to form a class of zeolites, referred to as ZSM-5, limited to crystalline aluminosilicates, silicates or germanicates, and characterized by a special X-ray diffractogram. Said patents relating to ZSM-11 and ZSM-12 zeolites are similarly limited to crystalline aluminosilicates, galosilicates or germanicates and are also characterized by a specific X-ray diffractogram.

In the production of ZSM materials, a mixed alkaline system is used in which sodium aluminate and silicon-containing material are contacted with sodium hydroxide and an organic base such as tetrapropylammonium hydroxide or tetrapropylammonium bromide under certain reaction conditions to form the desired crystalline aluminosilicate.

U.S. Pat. No. 3,941,871 discloses organosilicate 9 with a very small amount of aluminum in the crystal structure, which is characterized by an X-ray diffraction act per gram similar to the diffractogram of zeolite ZSM-5. This patent belongs to the prior art, closely related to the 3 catalysts used in the process according to the invention.

The prior art relating to the catalyst used in the process according to the invention also includes US patents describing zirconosilicates or titanium silicates, namely, 3,329,480 and 3,329,481.

However, the catalyst used in the process of the invention is a new group of stable synthetic crystalline materials, which are characterized as borosilicates and referred to as AMS-1B with a special X-ray diffractogram. These crystalline AMS-1B borosilicates are formed by the reaction of a borate salt with a silicon-containing substance in an alkaline medium.

The catalyst of the present invention for the catalytic isomerization of the xylene feedstock may also use a crystalline borosilicate catalyst having a molar ratio of oxides (0.9 + 0.2) (W 1 ^ 0 (1-W) M _{2 / n} 0): B ₂ O ₃ : Y SiO ₂ : · ZH ₂ 0, where

R represents a C 8 -C 12 tetraalkylammonium group, preferably a tetrapropylammonium group,

M is an alkali metal ion,

W is greater than 0 and less than or equal to 1,

Y has a value of 4 to 500 and

Z is 0 to 160.

This borosilicate is characterized by interplanar distances and associated intensities as shown in Table II below.

In a preferred embodiment, W has a value of 0.6 to 0.9, Y a value of 20 to 500 and Z a value of 0 to 40.

The original cation M in the above formulas can be at least partially replaced by ion exchange with other cations by methods known in the art. Preferred exchange cations include tetraalkylammonium cations, metal ions, ammonium ions, protons and mixtures thereof. Particularly preferred cations are those which make crystalline AMS-1B borosilicate catalytically active, particularly for the conversion of hydrocarbons. These include hydrogen, rare earth metals, aluminum, Group IB, IIB and VIII metals of the Periodic Table of the Elements, rare metals, manganese, etc. and other catalytically active substances and metals known in the art. The catalytically active ingredients may be present in an amount of about 0.05 to about 25% by weight based on crystalline AMS-1B borosilicate.

Representatives of the group of crystalline AMS-1B borosilicates have a specified and unambiguous crystalline structure. The X-ray diffractograms of these substances were obtained by standard procedures using 8 powdered substances. The X-ray diffraction pattern used was a Phillips apparatus operating with K K copper radiation along with an AMR-focusing monochrometer and an O-compensating slit * in which its aperture varied at an angle Θ.

The X-ray diffractograph output was processed by a computer with a Cahberr data acquisition system and associated programs and captured using a paper strip and tabular expression. The compensation slot and the Canberra data acquisition system tend to increase the ratio of the useful maxima to the disturbing base * while the maximum intensities at low θ-angles [high d (R)] decrease and the maximum intensities at high angles nízká [low d (R)] increase. All of the above X-ray diffractograms were obtained using this analytical technique.

These relative intensities were calculated as the (100 I / I, _Q), where I * is the intensity _of the captured thereon a stronger peak а I denotes the real value, the corresponding specific interplanáraí distance.

For simplicity, relative intensities have been assigned to the following values:

^ 0 assigned intensity below 10 = VW 10 to 19 = IN 20 to 39 = M 40 to 70 = MS over 70 = vs

A typical X-ray diffraction pattern in which significant lines with reactive intensities of 11 or greater for crystalline AMS-1B borosilicate after calcination at 535 ° C is captured is shown in Table I below.

Table I

Interplanar Relative Assigned distance d (R) intensity intensity

3 + 0.2 38 M o » ¹ and 0.2 30 M 6.01 + 0.07 14 , w 4.35 and 0.05 1 1 w 4.26 + 0.05 14 w 3.84 + 0.05 100 ALIGN! vs 3,72 i 0,05 52 MS 3.65 and 0.05 31 M 3.44 0.05 14 w 3.33 + 0.05 16 w 3.04 + 0.05 16 w 2.97 and 0.02 22nd M 2.48 + 0.02 1 1 w 1.99 i 0.02 20 May M 1.66 + 0.02 . 12 w

AMS-1B borosilicate, which has only been subjected to mild drying at 165 ° C (as formed material), is characterized by an X-ray diffractogram with the following significant lines: <

Table II

Interplanar distance d (R)

11.4 + 0.2

10.1 + 0.2

Relative intensity

Assigned intensity

W

W

CS 271 488 B2 3.84 + 0.05 100 ALIGN! vs 3.73 + 0.05 43 MS 3.66 + 0.05 26 M 3.45 + 0.05 1 1 w 3.32 0.05 13 w 3.05 + 0.05 12 w 2.98 + 0.02 16 w '99 + 0.02 10 w 1, 66 + 0.02 ^{20 May} M

The entries on the paper strips given in Table I above for calcined borosilicate show that this material is characterized by the following X-ray diffraction lines:

»Table III

Interplanar distance d (s)

handle 1 handle 2 , З 11.2 10.2 10.0 7.49 7.37 6.70 6.70 6.41 6.36 6.02 5.98 5.71 5.67 5.60 5,57 5.01 5.34 4.62 5.01 4.37 4.62 4.27 4.35 4.00 4.25 3.85 4.00 3.72 3.85 3.64 3.70 3.48 3.64 3.44 3.46 3.30 3.42 3.14 3.30 3.04 3.25 2.98 3.12 2.86 3.04 2.71 2.97 2.60 2.86 2.48 2.71 2.39 2.32 2.22 2.00 1, 99 1, 95 1.9 ’ 1, 86 1.75 1, 66

Handle 2 ended at 2.7 ’d

CS 271 468 B2

The crystalline AMS-1B borosilicate catalysts used in the process of the invention for the isomerization of xylene feedstock can also be used in catalytic cracking, in the presence of hydrogen or hydrocracking, in the isomerization of normal paraffins and naphthenes, in the reforming of certain feedstocks, in disproportionation of aromatics , such as toluene, to form mixtures of other valuable products including benzene, xylene and other methyl substituted benzenes; hydrodealkylation or dealkylation in the presence of hydrogen. When used according to the invention for the isomerization of the xylene feedstock, where cations at the ion exchange sites are suitable within the crystalline AMS-1B borosilicate, remarkably high selectivities in the formation of the desired isomers are achieved.

The ability of these materials to remain stable at high temperatures or in the presence of other, usually inactivating agents, makes this group of crystalline materials valuable for high temperature processes including cyclic types of fluidized cracking or other methods.

Crystalline KAMS-1B borosilicates can be used as catalysts or as adsorbents, whether in the form of compounds with alkali metals, ammonium, hydrogen or some other monovalent or polyvalent cation, or with a mixture of cations. They may also be used in close combination with a hydrogenation component such as tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese or a noble metal such as platinum or palladium, or a rare earth metal, where it is desired hydrogenation-dehydrogenation effect. Such components may be exchanged, impregnated or physically blended in the composition at the cationic sites depicted in the above formulas by the symbol ^M M * '. For example, platinum may be deposited on borosilicate with a platinum-containing ion.

The original cation associated with crystalline AMS-1B borosilicate can, as mentioned above, be replaced by a number of other cations by methods known in the art. The prior art ion exchange processes are described in numerous patents, including U.S. Pat. Nos. 3,140,249, 3,140,251 and 3,140,253.

After ion exchange, impregnation, or contact with other material to incorporate or apply catalytically ambitious materials into the borosilicate structure, the treated material may be washed and then dried at temperatures from about 66 to about 316 ° C. It can then be annealed in air or under a nitrogen atmosphere or in a mixture of the two at a precisely controlled temperature of from about 260 to about 816 ° C.

The ion exchange at cationic sites within the crystalline materials usually has a relatively insignificant effect on the overall X-ray diffraction pattern that characterizes the crystalline borosilicate material. There may be small variations at different distances in the diffractogram, but the overall diffractogram remains essentially the same. Small changes in the X-ray diffraction pattern may also result from differences in borosilicate preparation; however, the material still falls within the general group of crystalline AMS-1B borosilicates, which are defined on the basis of their X-ray diffractograms as shown in Tables I, II and III or in the examples below.

The crystalline borosilicate used as catalyst in the process of the invention may be used as pure borosilicate or may be mixed with various binders or carriers according to the intended use. In many cases, crystalline borosilicate can be pelletized or extruded. Crystalline borosilicate can be combined with active or inactive materials, synthetic or natural zeolites, as well as inorganic or organic materials that are useful for binding the silicate. Other well known materials include mixtures of silica, silica-alumina, alumina salts, clays such as bentonite or kaolin, or other binders known in the art. Crystalline borosilicate may also be intimately mixed with porous matrix materials such as silica - zirconia, silica - magnesium oxide, silica - alumina, silica - thorium dioxide, silica - liner oxide, silica - titanium dioxide, as well as three component mixtures which include, without limited, silica - alumina - thorium dioxide, and many others ma

CS 271 488 B2 materials known from the prior art. The content of crystalline borosilicate in the compositions may vary as desired from a few to 100% of the total product.

Crystalline AMS-1B borosilicate can generally be prepared by mixing oxides of boron, sodium or some other alkali metal and silicon 3 with a tetraalkylammonium compound in an aqueous medium. The molar ratios of the individual reactants may vary considerably to obtain the desired crystalline AMS-1B borosilicates. In particular, for the preparation of said borosilicate, the molar ratios of the reactants, expressed by the respective oxides, may be in the ranges as indicated in Table IV below:

Table IV sieve ₂ / b ₂ o ₃

R ^ N ⁺ / (R 'n ⁺ + Na ⁺ )

OHT / SiO ₂ molar ratios

- 600 (or higher)

0.1

0.01 - Ю where

R * represents an alkyl group having 2 or 3 carbon atoms, preferably a propyl group.

The amounts may vary in their concentration in the aqueous medium. Generally, it is preferred that the molar ratio of water to hydroxyl ion be arbitrarily in the range of about Ю to about 500 or above.

By simply varying the amount of point (as the boron oxide B ₂ op in the reaction mixture, the molar ratio of silica to boron oxide SiO ₂ / B ₂ O ₃ in the resulting product can be varied from about 40 to about 500 or above. By deliberate efforts to remove aluminum from the borosilicate crystal structure due to its adverse effect on certain conversions, the molar ratios of silica to SiO 2 / Al 2 O 4 can easily exceed 2000-3000. This ratio is generally limited only by the availability of aluminum-free raw materials.

The molar ratios of silica to boron trioxide SiO ₂ / B ₂ O ₃ in the crystalline final product may range from about 4 to about 500 or greater. Current laboratory products under the general conditions described above provide molar ratios of silica to boron trioxide SiO ₂ / B ₂ O ₃ starting at about 40 or below. Lower ratios can generally be achieved using the manufacturing processes described above.

Based on the known properties of mordenite and ferririte aluminosilicates, the present crystalline borosilicates contain about 4.5 BO 4,5-tetrahedron per unit particle at a molar ratio of silica to boron trioxide of SiO ₂ / B ₂ O _{3 of} about 80. Consequently, at A ratio of silica to boron oxide of SiO ₂ / B ₂ O _{3 of} about 500 is present in a single BO 4-tetrahedron. Above this ratio, there would be numerous unit particles that contain no B ^ ^-tetrahedron, and the obtained crystalline structure could not be considered borosilicate. There are no fixed criteria by which to determine at which molar ratio of silica to boron oxide SiO 2 / B 2, the crystalline material ceases to be borosilicate. It is sufficient to assume that at high SiO ₂ / B ₂ O ₃ ratios (above 1000 or more), the effect of the BO 4 -stainer in the crystalline structure decreases somewhat and the crystalline material is no longer considered a borosilicate.

Crystalline AMS-1B borosilicate used as a catalyst in the process of the invention is formed under carefully controlled conditions using the above data. Typical reaction conditions include heating the reactants at a temperature of from about 90 to about 250 ° C or higher for any period of time from about a few hours to a few weeks or more. Preferred temperature ranges are from about 150 to about 180 ° C for the time required to precipitate crystalline AMS-1B borosilicate. Particularly preferred conditions include a temperature of about 165 ° C for about 7 days.

CS 271 488 B2

The material thus formed can be separated and isolated by known methods, for example by filtration. It may be slightly dried for a few hours to several days at different temperatures to form a dry cake, which may then be comminuted into powder or small particles and extruded, pelletized or rendered in a form suitable for the intended use. Typically, such a mild drying material contains a tetraalkylammonium ion within the solid mass, and subsequent activation or calcination is required to remove the material from the product.

High temperature calcination is typically conducted at temperatures from about 427 to about 871 ° C or above. Extreme calcination temperatures can have a detrimental effect on the crystal structure or can completely disturb it. In general, calcination at temperatures above 927 ° C does not need to be carried out to remove the tetraalkylammonium cation from the initially formed crystalline material.

When crystalline AMS-1B borosilicate is used as the hydrocracking catalyst, the hydrocracking feedstock can be passed through the catalyst at temperatures of about 260 ° C to about 454 ° C or higher, using known moles of hydrocarbon to hydrogen ratios and various pressures from multiple 0.007 MPa up to a multiple of 7.03 MPa. The hourly liquid flow rate and other operating parameters can be varied as known in the art.

When borosilicate is used as a catalyst in a fluidized catalytic cracking process, generally known operating conditions may be employed, including temperatures from about 260 to about 649 ° C in the reaction zone and temperatures from about 427 to about 704 ° C in the recovery zone. Contact times, raw materials and other operating conditions are known in the art.

The specific crystalline AMS-1B borosilicate is also suitable as a reforming catalyst, which is used together with suitable hydrogenation components under known reforming conditions including temperatures from about 260 to 566 ° C or higher, pressures from a few thousandths of MPa to 2.11 to 7 300 MPa and hourly flow rates of liquid components and molar hydrocarbon to hydrogen ratios in accordance with known prior art parameters for the reforming process.

Crystalline AMS-1B borosilicates can also be used as adsorption agents for the selective adsorption of specific isomers or generally hydrocarbons from a liquid or gaseous stream.

The following examples illustrate the invention.

Example 1

Crystalline AMS-1B borosilicate is prepared by dissolving 0.25 g of boric acid H 2 BO 4 and 1.6 g of NaOH in 60 g of distilled water. 9.4 g of tetra-n-propylammonium bromide are then added and allowed to dissolve. It is then added with vigorous stirring

12.7 g of aqueous colloidal silicic acid sol (30% dry matter). Addition of the silica sol results in a thick, gelatinous solution. This solution is poured into a reaction vessel which is sealed. The reaction vessel was then placed in an oven at 165 ° C for 7 days. After this time, the container is opened and its contents filtered. The crystalline material obtained is washed with a considerable amount of water and then dried in an air pressure oven at 165 ° C. The dried material was identified by X-ray diffraction as a typical AMS-1B structure with 100% crystallinity. The yield is approximately 2 g.

Example 2

This example describes the crystalline AMS-1B borosilicate of Example 1 and its use to form a catalyst with isomerization properties.

The material of Example 1 was calcined for 4 hours in air at 535 ° C to remove the organic base. The calcined material was first treated with a solution of 20 g of ammonium nitrate NH 4 NO 2 in 200 ml of water and then with a solution of 20 g of ammonium acetate CH 2 CO 2 NH 4 in 200 ml of water at 87.8 ° C for 2 hours. The resulting borosilicate, obtained by ion exchange,

CS 271 488 B2 is dried, then calcined in air by heating at 482 ° C for 4 hours; then cooled to 37.8 ° C over a further 4 hours. The calcined material was treated for one hour with 100 ml of a 5% nickel nitrate hexahydrate solution of Ni (NO 2) 2. 6 H 2 O at 87 ° C · The molecular sieve obtained is washed with water and the nickel (II) nickel ion is completely removed by washing. The screen is then dried and re-calcined as described above. 2 g of borosilicate are dispersed in 16.9 g of PHF-Al2O4 hydrosol (8.9 g of dry matter) and the dispersion is mixed carefully. To 1 ml of distilled water, 1 ml of concentrated NH4OH is added and the mixture is added to the dispersion with vigorous stirring. The AMS-1B-Al 2 O 4 mixture was then dried in an oven at 165 ° C for 4 hours. The dried material was calcined as described above. The calcined catalyst is milled to a grain size

0.297 to 0.55 mm and soak 2 ml of a 5% solution of nickel nitrate hexahydrate Ni (NO ₃ ) ₂ · 6 H 2 O in distilled water. The catalyst was dried again and activated again by the fourth calcination.

The calcined catalyst contains 65% by weight of silicate and 35% by weight of amorphous alumina and about 0.5% by weight of nickel based on the total solid.

g of the screened and activated catalyst is charged to the microreactor and treated with hydrogen sulfide at room temperature for 20 minutes. The catalyst was then treated with hydrogen under pressure while heating to a temperature of 3-6 ° C. After 1 hour, the microreactor is started to feed under the following conditions:

temperature 427 ° C overpressure 1.05 MPa throughput (WHSV) 6.28 h ¹ molar ratio H / HC 7 (hydrogen / hydrocarbon k)

The liquid raw material and products obtained by this process are listed below. Due to the limitations of the separation apparatus, only liquid product analysis was performed. The formation of a light end product on this catalyst is slight according to gas chromatographic analysis of the off-gas stream. It has been found that the amount of off-gas does not in any way reduce the overall yields of the liquid components obtained using the catalyst.

Folders liquid raw material mass) liquid product (% by weight) paraffins and naphthenes 0.03 0.08 benzene - 5i toluene 0,077 0.26 ethylbenzene 19.71 17.35 p-xylene - 19.43 m-xylene. 79.80 46.40 o-xylene 0.38 14.96 C ₉ ⁺ X) ¹ - 1, 0 X) (x) approximate values only

Even more detailed and comprehensive analyzes of the obtained products have been performed, which are summarized in Table IV (A) below. The term operating time given for each sample represents the total number of hours from the start of the test to the end of the time that the sample was taken. The term PATE represents the percentage approximation to equilibrium calculated for each of the xylene isomers.

Q CS 271 488 B2 Table IV (A) Isomerase of xylene using a catalyst from of Example 2 sample no. supplied 3 4 5 raw material reactor temperature, ° C • 338 360 382 reactor pressure, kPa 1,138 1,138 1,138 the amount of hydrogen supplied, 0.009. 0.009 0.009 quantity of feedstock gh ¹ 7.48 8.53 9.14 Product analysis, wt. paraffins + naphthenes - 0,066 0.33 0.17 benzene - 0,107 0.28 0.58 toluene 0.03 0.154 0.26 0.20 ethylbenzene (EB) 20.97 20.30 19.94 19.58 p-xylene (pX) - 1 38 14.31 18.45 m-xylene (mX) 78.5 62.49 57.60 50.57 o-xylene (oX) - 5.44 7.28 10.46 0.5 - - - Calculated results partial pressure phi _? , kPa (abs.) 968.6 949.3 938.3 H / HC 5.8 5.1 4.8 contact time, sec 3.03 2.87 2.74 WHSV, hr 7.48 8.53 9.14 pX PATE,% 60.5 76.4 98.4 mX PATE,% 44.6 57.4 76.6 oX PATE,% 28.16 37.9 54.4 EB conversion,% 3.2 4.9 6.6 operating hours, hours 6.5 22.5 40.5 sample no. 6 9 10 1 1 reactor temperature, ° C 404 427 427 427 reactor pressure, kPa 1 138 1 13Θ 1 138 1 138 quantity of hydrogen supplied, m \ h ¹ 0.009 0.009 0.009 0.009 amount of feedstock, g.h ^ 8.58 6.28 8.20 5.47 Product analysis, wt. paraffins ♦ naphthenes - 0.09 0.12 - benzene 0.90 1, 79 1.55 1, 64 toluene 0.24 0.31 0.25 0.28 ethylbenzene (EB) 19.1 17.9 8.3 18.1 p-xylene (pX) 19.2 20.8 20.2 20.7 m-xylene (mX) 49.0 44.2 45.9 45.0 o-xylene (oX). 11.5 14.9 ¹ 3,7 14.3 ^C 9 - - - - Calculated results steam, H ₂ pressure, kPa 948.6 992 955.5 1 1 008,6 h / HC 5.1 6.9 5.3 8.0 contact time, sec. 2.68 2.71 2.61 2.76 WHSV, hour “ ¹ 8.58 6.28 8.20 5.47 pX PATE,% 102.5 111.06 108.0 1 10.4 mX PATE,% 80.7 93.3 88.6 91.3 oX PATE,% 59.0 75.9 69.7 72.7

CS 271 4-88 B2 Conversion ЕВ,% Operating Time, Hour Sample_No.

reactor temperature ° C reactor overpressure, kPa hydrogen feed rate, feedstock feed rate, gh ¹ Product analysis, wt.

paraffins + naphthenes benzene toluene ethylbenzene (EB) p-sylene (pX) m-xylene (mX) o-xylene (oX) V

Calculated results of steam, pressure Hg, kPa (ab) H / HC contact time, sec.

WHSV, h " ¹ pX PATE,% mX PATE,% OX PATE,% EB Conversion,% Operating Time, Hours

Sample reactor temperature ° C reactor overpressure, kPa hydrogen feed rate, np.h ~ ¹ feed rate, gh.

paraffins + naphthenes benzene toluene ethylbenzene (EB) (pX) (mX) (oX)

Calculated results of steam, pressure Hg, kPa (abs.)

H / HC contact time, sec.

WHSV, h "’ PX PATE,% tnX PATE,% oX PATE,% EB Conversion,% Operating Hours, Hours

p-xylene m-xylene o-xylene +

С _л

8.9 ’4.6 12.7 '3,7 47.5 '36, 5 '45, 6 '60, 5 12 _____13.- 16 17 427 427 428 428 1 138 1 138 1 138 1 138 0.009 0.009 0.009 0.009 5.53 6.23 6.71 6.19 0.06 0.09 0.06 0.07 3.09 3.00 1, 61 ', 33 0.48 0.46 0.25 0.20 16.4 16.4 17.1 17.6 21.0 21, ’ 19.2 14.5 42.4 42.4 45.5 5 ', 3 16.6 16.5 15.2 '4,2 __

1 007.2 993.4 994.1 994.1 7.9 7.0 7.0 7.0 2.75 2.71 2.72 2.72 5.53 6.23 6.71 6.19 111.6 ”2,5 102.6 76.8 98.2 98.2 89.7 74.4 84.7 84.1 77.2 72.2 21.8 21.8 18.5 16.1 168.5 184.5 223.0 238.5 18 19 Dec 20 May 21 384 383 427 428 1 138 1 138 1 138 1 138 0.009 0.009 0.009 0.009 6.29 4.88 6.63 5.00

0.05 0.07 0.14 0.06 0.52 0.70 1.45 1, 87 0.13 0.16 0.22 0.31 '9.3 18.8 17.8 '7.1 16.3 17.8 18.5 19.3 52.7 49.4 46.8 44.3 10.4 12.3 14.2 1 6,0 0.60 0.66 0.90 1, 08

992 1 014.1 985.1 1 018,2 6.9 8.4 6.6 8.7 2.89 2.96 2.69 2.78 6.29 4.88 6.63 5.00 86.6 94.9 99.1 103.4 70.3 79.5 85.6 92.6 54.1 64.1 72.5 81, 9 8.0 10.3 15.1 18.5 45, 5 309.0 317.01 333.0

CS 271 488 B2

Example 3

A solution of 2.5 g of boric acid BO BO- and 7.5 g of sodium hydroxide in 600 ml of water is prepared. 94.3 g of tetra-n-propylammonium bromide are then added and allowed to dissolve and 114.5 g of aqueous colloidal silica sol (30% solids content) are added with vigorous stirring.

The resulting mixture was placed in a reaction vessel and sealed. The sealed vessel is left in an oven at 165 ° C for 7 days.

After washing and drying the solid obtained as described in Example 1, crystalline borosilicate is identified as AMS-1B; it is characterized by an X-ray diffractogram similar to that of Table II.

Example 4

The borosilicate produced by the procedure of Example 1 was calcined at 593 ° C and analyzed to determine its total composition. The results are as follows:

Ingredients (w / w) silica SiO ₂ 94.90 boric oxide ®2θ3 sodium oxide Na ^ 0.97 aluminum oxide Al ₂ 0 ₃ 0.057 ferric oxide Fe ₂ C> ₃ 0.029 volatile components +) 2 total 100,000 estimated value to give total the sum was 100%

SiO ₂ / B ₂ O ₃ »04,5 IfagO / B ^ O ^ '"O SiO ₂ (Al ₂ O ₃ 2 824.4 SiO ₂ ZPe ₂ O ₃ 8 787.0 SiO ₂ / (Al ₂ O ₃ + Pe ₂ O ₃ ) 2 146.2

Using the procedure of Example 1, other borosilicates are prepared, but the boric acid content of H ₃ BO ₃ is varied, resulting in molar ratios of silica to boron trioxide SiO ₂ / B ₂ O ₃ , which are prior to boronate ion exchange - ranging from 50 to 160 or more. After exchange with suitable catalyst materials, the molar SiO ₂ / B ₂ O ₃ molar ratio generally increases to 80-100 for borosilicate, which as it was produced had a SiO ₂ / B ₂ C ₃ molar ratio of about 50.

Example 5

Three borosilicate materials were prepared as in Example 1. These materials were calcined at 535 ° C and then analyzed for boron and silicon content; the results are shown below:

borosilicate  wt. % of boron . SiO ₂ / B ₂ O ₃ molar ratio AND 0.66 47.4 В 0.64 49.1 C 0.71 . 44.5 After ion exchange with ammonium acetate, the borosilicate is calcined at 535 ° C. After calcination is the found molar ratio SiO ₂ / B ₂ O _{3 as} follows: borosilicate SiO ₂ / B ₂ O ₃ molar ratio AND 75.1 В 71.2 C 64.2

CS 271 488 B2

After calcination at 535 ° C, but prior to ion exchange, samples of the above borosilicates in powder form are subjected to analysis to obtain X-ray diffractograms. The obtained diffractograms are further shown at relative intensities (Ι / Ιθ) of 10 or greater · Interplanar distances are shown in Table III above, as determined on a paper strip for two borosilicate batches after calcination at 535 ° C but before ion exchange ·

Claims (4)

SUBJECT OF THE INVENTION Process for catalytic isomerization of a xylene feedstock, characterized in that the xylene feedstock is contacted with crystalline borosilicate under isomerization conditions as a catalyst having a molar ratio of oxides (0.9 + 0, 2) M _{2 / n} 0; B ₂ O ₃ : Y SiO ₂ : ZH ₂ 0, where M is at least one cation having a C8 -C12 tetraalkylammonium cation, an ammonium cation, a hydrogen cation, an alkali metal cation, or mixtures thereof; Y has a value of 4 to 500 and Z has a value of 0 to 160, wherein this crystalline borosilicate is characterized by the following X-ray diffractogram and associated intensities interplanar distance d (2) relative intensity associated insulin 11,3 i 0,2 38 M 10.1 and 0.2 30 M 6.01 - 0.07 14 w 4.35 - 0.05 1 1 w 4.26 - 0.05 14 w 3.84 - 0.05 100 ALIGN! vs 3.72 0,0 0.05 52 MS 3.65 - 0.05 31 M 3.44 - 0.05 14 w 3.33 - 0.05 16 w 3.04 - 0.05 16 w 2.97 - 0.02 22nd M 2.48 1 0.02 1 1 w 1.99 and 0.02 20 May M 1.66-0.02 12 w 2. The method of claim 1, wherein the method is xylene the raw material under the conditions isomerization in contact with crystalline borosilicate catalyst of said composition, wherein Y has a value of 20 to 500 and Z has a value of 0 to 40. The method of claim 1, wherein the isomerization conditions include a temperature in the range of 121 to 482 ° C, an overpressure in the range of 0 to 7.03 MPa, a molar ratio of hydrogen to hydrocarbon in the range of 0 to 20, and a mass hourly flow in the range. 1 to 20 · 4. The process of claim 3, wherein the xylene feedstock is contacted with the crystalline borosilicate catalyst of the composition of claim 1 wherein Y is from 40 to 500 and Z is from 0 to 40 under said isomerization conditions.