DE2061285C3 - Method for increasing the SiO 2 AL2 O3. Molar ratio of large pore crystalline molecular sieve zeolites - Google Patents

Description

35

The invention relates to a method for increasing the SiO2 / Al2O3 molar ratio of large-pore crystalline molecular sieve zeolites by extraction of 4c Aluminum from the spatial network structure of the zeolite with acetylacetone, whereby the silicon / aluminum ratio is well above that of the starting zeolite below Retaining its crystalline character is increased.

More recently, synthetic crystalline 4s have become available Zeolites, especially those with large pores such as Zeolite X, Y, L, and certain synthetic and natural ones Mordenite has been extensively studied and developed as a carrier for hydrocarbon conversion catalysts. These versatile and intricate crystalline Materials have the remarkable ability to move physically and chemically without being To have the destruction of their basic crystalline character largely modified. Accordingly, was over Experiments reported using the silica / alumina ratio of crystalline zeolites by removing aluminum from the crystal structure strong acids to increase. Furthermore, the silica / alumina ratio of zeolites is through at least partial conversion of the starting zeolite into its hydrogen form, hydrolysis of the aluminum to aluminum hydroxide and subsequent physical removal of the displaced aluminum increased (Belgian patent 4,444,432 [1964]).

In the Bull. Soc. Chim. France No. 5 (1967) becomes the Extraction of aluminum from non-crystalline aluminosilicates with the aid of acetylacetone described. Naturally, there could not be the risk of that a crystal structure is destroyed. From CR-Acad. Sei, Paris 269.1345-1347 (1969), is the usage of acetylacetone known for the extraction of aluminum from crystalline zeolites In this process, which starts from the sodium form of the zeolite, can however, only less than 20% of the aluminum atoms are destroyed without destroying the zeolitic crystal lattice will.

The invention relates to a process for increasing the SKVAkOj molar ratio of large-pore crystalline molecular sieve zeolites Extraction of aluminum from the three-dimensional network structure of the zeolites with acetylacetone, which is characterized in that cations are used in such an amount removed from the zeolite that at least 20% of the aluminum atoms of the network structure of the zeolite are not associated with a cation, in the decationized zeolite the OH groups with an infrared stretching frequency in the ranges from 3600 to 3660 cm- 'or 3500 to 3560 cm- 'by heating to a temperature between about 400 ° C and the temperature at which the Crystal is destroyed, at least partially removed from the association with the aluminum ions of the spatial network to be removed and then with acetylacetone and / or a metal acetylacetonate during such a time that aluminum acetylacetonate is formed, which is obtained from the zeolite separates

The invention further relates to the use of the molecular sieve zeolites obtained with an increased SiO ₂ / Al2O3 molar ratio for the hydrogenative cracking or alkylation of hydrocarbons.

The zeolites which are suitably used for the purposes of the invention need not only pores that are at least large enough to adsorb benzene, d. H. be so-called large-pore zeolites, but also have original silica / alumina ratios that are so high that the Zeolite can be significantly decationized and withstands the stresses on the crystal lattice that arise results from dehydroxylation.

The expression "substantially decationized" means that 20% or more of the aluminum atoms of the spatial network of the zeolite, which, assuming zeolitic stoichiometry would usually be associated with a cation, around the electrovalent negative _{resulting from the fourfold coordination with oxygen, ie AlO 4} Balance charge, are not associated with cations, and remain part of the crystal lattice, some of these cations presumably being in the electrovalent neutral form of triple coordination with oxygen.

The term "dehydroxylation" used here means that at least a part, preferably im essentially all OH groups in the zeolite structure, which are dependent on certain structural features of the particular zeolite has an infrared stretching frequency in the range of about 3600 to 3660 cm- 'and about 3500 to 3560 cm- ', usually removed in the form of water. These last-mentioned structural features are not important for the invention. When Once the OH groups have been formed, a cation deficiency or deficiency in the zeolite can be assumed, but the removal of at least a part these OH groups, preferably by thermal means, is necessary before the extraction of Space net aluminum is made. This removal of OH groups can easily be achieved by

the hydroxylated zeolite form to temperatures of about 400 ⁰ C up to the crystal destruction point is preferably heated to a temperature between about 450 and 700 ⁰ C.

In general, the higher the molar ratio of S1O2 / Al2O3, the greater the relative degree of decationization and dehydroxylation that the crystal structure can tolerate Structure are no longer associated with a cation, the SiCVAljQr molar ratio of the starting zeolite must be greater than 3, preferably greater than 3.5. To achieve lower degrees of decationization, SiO2 / Al2O3 molar ratios of 2 to 3 are suitable. Examples of zeolites that can be used for the preparation of the products according to the invention are zeolite Y (described in detail in US Pat. No. 31 30 007), Zeolite L (described in US Patent 32 16 789), Zeolite X (described in US Patent 28 82 244) and Zeolite Ω, which is described in DT-OS 16 67 759 of the applicant, as well as synthetic mordenite, the in U.S. Patent 34 36 174 is described.

A cation exchange of the molecular sieve using solutions containing ammonium ions is preferred as the first stage for preparing the new zeolites according to the invention. This Exchange can be carried out in batches, the molecular sieve being slurried in an aqueous ammonium salt solution. The ion exchange can also be done continuously, taking a solution of ammonium cations over a column of the zeolite and the effluent containing the salt formed is continuously removed.

The latter method is preferred because of the high degree of ion exchange. For example, to achieve 85-100% removal of the zeolite cation by ion exchange, a continuous exchange process carried out with heating is expedient. In general, repeated batchwise ion exchanges are necessary in order to remove the additional zeolite cations. To achieve a higher ion exchange, ie, over 50%, a batch-type ion-exchange at elevated temperatures of about 80 to 100 ⁰ C more effective than a similar exchange at room temperature.

Any soluble ammonium salt can be used to exchange the zeolite cation, provided that the salt formed during the ion exchange is soluble. If the salt formed is insoluble it would be very difficult to remove by washing. Since most of the common ammonium salts are water-soluble, this limitation primarily applies to the zeolite cation to be exchanged, ie a silver-exchanged zeolite which is exchanged with an ammonium chloride solution would lead to the formation of insoluble AgCl. In this case, an ammonium nitrate solution would be preferred, since AgNO ₃ is soluble in H ₂ O, the preferred exchange medium. B. the various methylammonium ions can also be used for the purposes of the invention.

Since most molecular sieve zeolites are synthesized in the form of the alkali metal cation, the Ion exchange is done in most cases with these cations, however, there is an ion exchange with zeolites containing other cations, possible within the clear limits mentioned above.

It may at times be appropriate to use zeolites within the limitations of this process before Ammcnium ion exchange with acid wash to a hydrogen cation exchange up to one to undertake to a certain degree. More importantly, this is also used to remove difficult-to-remove ones Impurities in the zeolite, e.g. sodium silicate, sodium aluminate or sodium hydroxide, resulting from the Synthesis of the zeolite retained in this can happen. This measure thus serves as a Pre-cleaning process.

As already mentioned, the removal or destruction is the ammonium or hydrogen cations of the ion-exchanged molecular sieve obtained by the zeolite to a temperature of more than about 400 ⁰ C to the temperature at which a largely crystal degradation occurs, ie, about 1000 generally ° C, is heated. It has been found that, for reasons not yet fully understood, temperatures of at least about 400 ° C. must be used for the purposes of the invention. The amount of aluminum that can subsequently be extracted runs almost linearly with the calcination temperature, while this is increased from 400 to about 700 ° C. At 700 ° C, the amount of aluminum that can be extracted asymptotically reaches the quantum associated with non-metallic cations prior to calcination. An aluminum atom in the three-dimensional network structure which is still associated with a cation or a hydroxyl group cannot therefore be extracted within the scope of the invention. The duration of the heating should be at least 0.1 hour, preferably at least 2 hours within the above-mentioned temperature range.

If only aluminum is removed from the zeolite's spatial network without any other metal being introduced into the zeolite To be extracted, acetylacetone is used as the extractant. This compound is obviously unique for this purpose, as the closely related related compound 2,5-hexanedione was found to be ineffective.

Since the heat of adsorption of acetylacetone on a molecular sieve zeolite is relatively high It is advantageous to first adsorb a stable liquid such as benzene on the thermally treated zeolite in order to avoid possible self-condensation of the acetylacetone. The temperature of the extraction stage is not very critical, but should be chosen be that the acetylacetone is in the liquid state. Preferably, the extraction is at a Temperature in the range of 0 ° to about 200 ° C carried out. Pressure is also not critically important, but should be chosen so that the Acetylacetone is in the liquid state in the selected interrelationship between pressure and temperature.

The extraction can be performed dynamically or statically. Dynamic ones are preferred Methods, e.g. B. the normal procedure using a Soxhlet extraction apparatus, but mere immersion of the decationized is also possible and dehydroxylated zeolite crystals in acetylacetone are effective. Time is not critically important, however in general, static methods work with a contact time of at least 2 hours. A little less time, namely at least about 0.5

Hours is required for the dynamic methods. Generally, no extraction times longer than about 24 hours are required. The ratio of acetyl acetone to zeolite is not critical. Preferably, however, about 14 to 20 moles of acetylacetone per 100 g of zeolite (anhydrous basis} Complete removal using the product of the chelation reaction of the aluminum and acetylacetone ^ Al (CsH ₇ O ₂₎ * from the zeolite by conventional desorption, preferably by washing with further acetylacetone or with an organic solvent, e.g. benzene, xylene or acetone

After the aluminum has been extracted, the zeolitic molecular sieve can be used in the same manner as conventional zeolite molecular sieves are treated, i.e. they can be subjected to ion exchange, decationized (if they are not yet fully decationized) activated with steam treated pelletized, with or without active or inert diluent or Expanded material can be agglomerated and loaded with metal. The zeolites according to the invention with increased ratio of silicon to aluminum are therefore still quite suitable for selective adsorption processes, however, have their greatest value as catalysts or catalyst supports for conversion of hydrocarbons.

When aluminum is extracted from the spatial network of the zeolite crystal and at least a part of it If aluminum is to be replaced by another metal, the extractant contains a metal acetylacetonate either alone or in combination with acetylacetone and / or other solvents such as Benzene. It is believed that the reaction between the metal acetylacetonate and the zeolite proceeds by one of two mechanisms or a combination of these two mechanisms. the first mechanism is a metathesis in which the metal of the metal acetylacetonate and the aluminum are exchanged for each other, and the second mechanism is the reaction of the metal acetylacetonate with the zeolitic hydrogen, which is formed by the previous extraction of the aluminum Network structure is adopted by acetylacetone. It is thus possible to use a different metal than To introduce aluminum into the spatial network structure of the zeolite, namely a) directly by treating the decationized and dehydroxylated zeolite in the manner described above with a metal acetylacetonate in the absence of acetylacetone or b) by a multi-stage process in which the decationized so and dehydroxylated zeolite is first treated with acetylacetone to make aluminum atoms of the network structure to extract, and then treated the extracted zeolite with a metal acetylacetonate will. The use of acetylacetone and a metal acetylacetonate in combination with or without other inert solvents are found to be effective in extracting aluminum from the network structure and introduce another metal into the zeolite. Presumably the mechanisms of the do run both reactions described above from the same time.

The term “metal acetylacetonate” was used above in the description of an embodiment of the invention, but this term also includes metal complexes such as vanadyl acetylacetonate, titanylacetylacetonate and uranylacetylacetonate, which contain fewer than the number of acetylacetonyl components necessary to maintain the valence of the respective metal of the complex to saturate. Any metal acetylacetonates are suitable, but acetylacetonates of metals which form oxides in their trivalent, tetravalent or five-valent form which are thermally stable ^{at 6CIO 0 C are particularly preferred.}

Suitable acetylacetonates for the purposes of the invention are, for example, those of the formula

M (AA) _n ,

in the (AA) for the acetylacetonyl component (C5H7O2), M for V + ³ , VO + ² , TiO + ² , UO ₂ ⁺² , Ba ⁺² , Be ⁺² , Cd ⁺² , Ca + ² , Cs + ¹ , Ce + ³ , Cr + ³ , Co + ² , Co + ³ , Cu + ² , Fe + ³ , Fe + ² , Pb + ² , Mg + ² , Mn + ² , Mn + ³ , MoO ₂ + ² , Ni + ² , Pd + ² , Re + ³ , Rh + ³ , Rb + ³ , Na + ¹ , Sr + ² , Tl + i, Th + ⁴ , Zn + ² , In + ³ , La + ³ , Nd + ³ , Sm + ³ , Yb + ³ , Y + ³ , Er + ³ , Gd + ³ , Pr + ³ , Dy + ³ and Zr + ⁴ and π is the valence of the metal component, ie the remainder of the complex after the theoretical removal of the acetylacetonyl component or components.

Just as in the case of a simple extraction of aluminum from the spatial network structure without replacement against another metal, the proportions of zeolite to metal acetylacetonate are not decisive important. Both reactants can be used in large stoichiometric excess. the The same reaction conditions with regard to time, temperature and pressure can be used in both cases.

example 1

A. A series of samples of decationized zeolite X and zeolite Y with various SiO ₂ ZAl ₂ Os molar ratios and degrees of decationization were prepared in a conventional manner. In each case the starting zeolite in the sodium form was slurried in distilled water and formed into a filter cake in a Buchner funnel. Using a slightly reduced pressure under the filter cake, an aqueous NH ^ Cl solution was sucked through until the desired amount of sodium ^{ions had been replaced by NhU +} ions, determined by the depletion of ammonium ions in the ion exchange solution. The zeolite obtained as the product was then washed with distilled water until it was free of chloride ions, dried in the air, pressed into tablets with a diameter of about 4.8 mm and ^{kept at 550 °} C. for 6 hours in an oven with air circulation.

B. The zeolite samples prepared according to Section A were saturated with benzene and placed in a Soxhlet extraction apparatus which contained acetylacetone as the extractant. The extraction was carried out at the reflux temperature, ie at about 139.degree. C., for 6 hours. The removal of aluminum from the spatial network of the zeolite was clearly recognizable by the formation of a light orange color in the extractant. This is due to the presence of the complex of an aluminum molecule with three acetyl acetone molecules, hereinafter referred to as AI (AA) ₃ . The extraction was terminated when the development of the orange color stopped. The extracted zeolite tablets were rehydrated in air and chemically analyzed. Portions of each sample were calcined at 550 ° C. for 6 hours and subjected to X-ray analysis. The results obtained are shown in Table 1 below.

Table I. Example / eolith

Ammonium exchanged forms SiO - '/ ΛΙ.Όι cations per 100 Al

Na ⁺ Calcined and extracted to form

S1O2 / AI2O1 Na ⁺ cations per 100 Al

10

11th

12th

13th

14th

15th

16

17th

18th

19th

20th

21

22nd

NH4 X

NH4 X

NhU

NH4

M-U

NH4

NH4

NhU

NHU

NH4

NhU

NhU

NhU

NhU

NhU

NhU

NhU Y

NhU Y

NhU Y

NhU Y

NhU Y

NhU Y

X
X
X
X
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y

2.49 2.48 2.48 2.54 2.49 2.48 4.98 4.94 4.94 4.91 5.16 5.03 4.86 4.92 4.88 4.94 4.77 4.84 4.92 4.83 4.94 4.90

52.7 48.3 41.8 39.0 37.0 33.2 74.4 56.7 49.7 42.0 37.6 33.4 16.6 78.7 73.6 57.6 55.2 47.6 31.6 25.2 24.8 19.7

The X-ray examination confirmed that the crystallinity of the extracted zeolites was retained.

Example 23

The experiment described below was carried out to demonstrate that another Ion exchange of the zeolites extracted with acetylacetone according to the invention is possible, and that this Zeolites have good catalytic activity.

169.7 g of zeolite Y, which had been decationized to about 40% and had a SiCVAlE ratio of 4.94, were placed in the form of tablets with a diameter of 4.8 mm in an extraction tube which was equipped with a cooler for condensing water was provided. 100 ml of acetylacetone were placed in a 250 ml round bottom flask which was heated with a heating mantle. This flask was connected to the apparatus consisting of the extraction tube and condenser. The acetylacetone was heated to reflux temperature so that the condensed solvent collected and flowed over the zeolite tablets. The extraction was carried out for about 6 hours. After this time, the solvent complex A1 (AA) 3 was separated from the zeolite by extracting twice with benzene. The treated zeolite was dried and then calcined a ventilated oven with temperature control has been placed. During calcination per hour were 2.124 to 2 ^ 66 m ³ of air passed through the zeolite is heated to about 250 ⁰ C and held for 2 hours at this temperature. Finally it is heated to 550 ° C. and kept at this temperature for 2.5 hours. Analysis of samples of the extracted product showed a SiCVAWs molar ratio of 6.94 and a Na ₂ O / Al 4 a molar ratio of 0.721. The amount of aluminum acetylacetonate complex extracted was 0319 g / g zeolite. The X-ray analysis

30.0 34.4 39.1 41.1 42.7 47.8 12.9 28.7 37.7 44.4 57.8 61.5 71.8 8.14 13.8 31.0 38.0 47.6 60.5 69.0 72.2 77.4 3.26 330

438 4.26 3.89 4.23 5.02 5.74 6.79 8.32 9.54

11.1

16.7 4.81 4.87 5.94 6.68 6.93 9.84

10.5

11.59

14.32

62.6 60.0 71.5 65.8 61.6 58.8 74.6 66.9 72.1 73.8 75.7 77.8 69.7 92.4 79.4 79.7 77.3 74.8 69.6 63.4 62.5 59.8

se of the extracted product after calcination showed that the crystallinity was retained ^{to more than 2} Ii. A portion (41 g, based on the hydrated product) of the extracted product was treated with an aqueous ammonium chloride solution. Four ion exchanges were carried out batchwise using 4 equivalents of NH4 ⁺ cation per equivalent of aluminum in the zeolite. The slurry of zeolite and ammonium chloride solution was stirred continuously for 2.5 hours at room temperature, whereupon suction filtered and the solid was washed with distilled water. This was repeated four times, each time using fresh exchange solution. After the last wash, the solids were dried in a heating cabinet at 124 ° C, granulated and bottled.An analysis of the product after the ion exchange gave the following values:

SKVAl ₂ O ₃ 6.93

Cations per 100 al Na 0.081

NH4 0.766

The X-ray analysis of the calcined product revealed that the crystal structure of zeolite Y was preserved. The product was caldniert 4 hours at 550 ⁰ C and tested for its activity for the alkylation according to the following procedure:

The catalyst product (5.0 g) was suspended in 200 ml of benzene. Under the surface of the suspension, propylene gas was introduced in an amount of 400 ml / minute with stirring. The activity was increased measured by the rate of disappearance of unreacted benzene under standard reaction conditions, namely normal pressure and adiabatic temperature conditions, starting from Room temperature, was observed. The reaction is continued until the exothermic reaction has ended and the temperature begins to drop

The following results were obtained from analyzes of the products taken at certain time intervals received:

Minutes

Composition of the reaction mixture? ».

Wt%

benzene

Isopropyl benzene
Mono di

Tri-

Tetra

72.2
56.9
44.2
14.6
OJ

21.8 27.3 29.7 20.8 0.6

13.1 19.9 30.9 10.3

0.5

2.5

5.7

24.8

76.9

0.2

0.5

3.9

11.4

10

The rapid conversion of the benzene into several alkylated benzenes leaves the high kai alytische activity recognize this high silica zeolite product of the invention.

Example 24

A partially ammonium-exchanged zeolite Y with a SiCVAbOs molar ratio of 5.0 ± 0.1 was prepared by batch-wise exchange with 0.6 NH ₄ CI equivalent per equivalent of the base exchange capacity of the zeolite.The analyzes had the following results:

Koinnoncnlc Found, wt%

Calculated on an anhydrous basis

Disproportions

SiOj

ALOf

OK

(NHi) jO

Loss on ignition

49.3

16.9

5.7

3.3

28.1

65.5

22.5

7.6

4.4 NaK): AIjOi = 0.555 (NHt) K): AbOi = 0.383 SiOi: AIjOj = 4.96

This material was made into tablets 4.8 mm in diameter and 4.8 mm in length to facilitate calcination and extraction. The calcination was performed by heating the material was kept in an oven with air circulation for 2 hours at 232 ° C and further 2 to 3 hours at about 550 ⁰ C. After wetting with benzene, the anhydrous tablets were extracted continuously with acetylacetone in a Soxhlet extraction apparatus until the extractant was colorless. The extracted zeolite was then exposed to atmospheric moisture and allowed to rehydrate.

The ammonium form of the extracted zeolite was produced by ion exchange with an NH ₄ Cl solution. The replacements were made 5 times in batches with four equivalents of NH ₄ ⁺ per aluminum equivalent present to ensure a high level of sodium replacement. The following analysis values were determined:

component Found. Wt% Calculated on Molar ratios anhydrous base SiOj 58.4 74.4 NajO / AbOi = 0.06 AIjOi 13.7 17.5 (ΝΗφΟ / AbO) = 0.846 NajO 0.5 O.o4 SiOi / AbOi = 7.23 (NHi) K) 5.9 7.5 Loss on ignition 27.4

A portion of this material was loaded by ion exchange with Pd (NH ₃ J ₄ ⁺² with 0.5 wt .-% Pd, calcined at 550 ⁰ C and tested as a catalyst for hydrogenating Kxackung (hereinafter referred to as catalyst "A" hereinafter).

Another part of the ammonium-exchanged form was exchanged back with a solution of 3.1 equivalents of MgSO ₄ per aluminum equivalent present. The analyzes had the following results:

component Found, wt% Calculated on Molar ratios anhydrous base SiOj 55.5 74.4 Na2O / AljO = 0.05 AbOi 13.2 17.7 (NHi) 2O / AbOi = 0.40 NajO 0.4 0.54 MgO / AbO3 = 0.52 (NHi) jO 2.7 3.5 S1O2 / AI2O3 = 7.1 MgO 2.7 3.5 CaO 0.1) 0.13 Loss on ignition 28.1

*) Present as an impurity in the starting zeolite.

This back-exchanged with magnesium catalyst was loaded with 0.5 wt .-% of palladium, calcined at 550 ⁰ C and tested as a catalyst for hydrogenating cracking. The catalyst will hereinafter be referred to as "Catalyst B". The results shown in Table II below were obtained with the two catalysts prepared by the procedure of this Example using a feed for the hydrocracking which had previously been hydrofined and had a boiling point of 454 ° C.

Table II

Temperature in "C for catalyst 1! JO ₁ YY 50% conversion Λ Analyzer weight, g 249 / Ii Ucn / inprodukl 28.90 257 257 me 10 hours 260 257 25 hours 262 - 50 hours 264 75 hours 267 100 hours 271 125 hours

Example 25

Zeolite Y with an original S1O2 / Al2O3 ratio of 5.0 was decationized, dehydroxylated, extracted with acetylacetone and subjected to ion exchange with magnesium and cerium cations. A total of 10 samples were prepared, namely 5 samples containing magnesium ^{cations and 5 samples containing Ce + 3} cations. The activated samples (4 hours at 550 ° C. (calcined) were tested for their catalytic activity in the alkylation of benzene with isopropylene as in Example 23. The results are given in Table III below.

Table III

Sample exchanged with Mg ^{+ - '}
Mg ^{+ 2} equivalents / 100 Al
Na ^{+ 1} equivalents / 100 Al
SiCh / AliCh molar relationship
Response time, min.

Product distribution. Wt%
benzene

Monoisopropybenzene
Diisopropylbenzene
Triisopropylbenzene

Ml Ce ¹ 'exchanged sample

Ce ⁺ »equivalents / 100 Al
Na + 'equivalents / 100 AI
SiO2 / Al2Oi molar ratio
Response time, min.

Product distribution,% by weight
benzene

Monoisopropyl benzene
Diisopropylbenzene
Triisopropylbenzene

Example 26

A dehydroxylated, 58% decationized sample of zeolite Y with a SiCVA ^ Ch mole ratio of 5 and a weight of about 10 g will take about 30 hours at the reflux temperature of about 250 g a xylene solution containing 2 g of vanadyl acetylacetonate and about 5 g of acetylacetone, kept in contact. During the contact time the solution changed its color from blue to green. The zeolite was then separated from the solution and washed with benzene until the washing liquid was colorless. The following analysis values were determined:

50 10 66 10 20th 34 10 10 20th 62 60 10 10 20th 22nd 87.2 16 89.8 85.2 25th 88.3 87.1 87.7 21 9 93.3 88.0 91 5.74 10.9 5.74 12.7 12.7 6.97 11.0 11.8 9.8 8.32 16.65 5.6 9.3 7.5 0.6 1.3 0.8 0.7 1.1 0.6 10 20 0.3 1.1 0.8 0.1 0.1 0.1 88.3 - 0.2 64 10.4 - 56 18th 0.8 - / 6.97 16.65 20th 20th 64 20th 82.9 85.1 17th 85 14.1 12.7 8.32 10.9 0.7 1.3 10 20 1.15 0.1 0.1 78.4 - 0.2 17.7 - 2.8 - 0.2 -

component

% By weight, found

% By weight on an anhydrous basis

S1O2 50.4 ± 0.5 Atomic ratios: 69.5 A12O3 15.2 + 0.5 20.9 Well> O 3.8 ± 0.2 5.2 V2O5 Z4 ± 0.3 3.3 Loss on ignition 27.4 ± 0.5 Si / Al = 2 # 3 (2 ^ 0 in the starting material) Si / (A1 + V) = 2.57

Si (Al + V) ratio almost the same as in the starting material was. Al was clearly removed. An X-ray analysis showed that the crystallinity typical of zeolite Y had been preserved in excellent measure. The X-ray diffraction pattern showed no new lines.

Example 27

10 g of zeolite Y, from which previously the aluminum by extraction with acetylacetone to such an extent had been removed that the product had an S1O2 / Al2O3 molar ratio of 10.4 and a Na 2 O / Al 2 O 3 molar ratio of 0.74 was combined with about 2 g of chromium acetylacetonate in 250 g of xylene. The mixture was boiled at normal pressure until almost all of the solvent had distilled off. Fresh xylene was made added and the process repeated three times. The zeolite was then washed with benzene. the Analysis of the zeolite product had the following results:

component

% By weight, found

% By weight
anhydrous
Base

These analytical values show that almost as much vanadium was incorporated as Al was removed, since the

SiO-2 56.2 ± 0.5 AI2O3 9.2 ± 0.5 Na2O 4.1 ± 0.2 Cr ₂ Os 3.4 + 0.2 Loss on ignition 25.7 ± 0.5

75.6

12.4

5.5

4.6

Molar ratio of the oxides:

SiO ₂ / Al ₂ O ₃ = 10.4 as in the starting material Na ₂ OZAl ₂ O ₃ = 0.74 as in the starting material SiO ₂ Z (Al ₂ O ₃ H-Cr ₂ O ₃ ) = 8.35

An X-ray diffraction pattern of this product showed that

the basic structure of zeolite Y was retained , although the presence of some amorphous material was evident. New lines attributable to hydrated or anhydrous chromium oxides were not observed.

Claims (3)

Patent claims: 1. A method for increasing the SiO ₂ / Al ₂ O ₃ -MoI ratio of large-pore crystalline molecular larsie zeolites by extraction of aluminum from the spatial network structure of the zeolites with acetylacetone, characterized in that cations are removed from the zeolite in such an amount, that at least 20% of the aluminum atoms ι ο of the spatial network structure of the zeolite are not associated with a cation, in the decationized zeolite the OH groups with an infrared stretching frequency in the ranges from 3600 to 3660 cm- ¹ or 3500 to 3560 cm- 'by heating to a Temperature between about 400 ° C and the temperature at which the crystal is destroyed, at least partially removed from the association with the aluminum ions of the spatial network to be removed and then kept in contact with acetylacetone and / or a metal acetylacetonate for a time such that aluminum acetylacetonate is formed which is separated from the zeolite. 2. The method according to claim 1, characterized in that the zeolite after extraction with acetylacetone with a metal acetylacetonate, the metal forms a thermally stable at 600 ⁰ C 3-, 4- or 5wertiges oxide is brought into contact. 3. Use of the molecular sieve zeolites with an increased S ^ / AliOa molar ratio according to claim 1 or 2 for hydrocracking or alkylation of hydrocarbons.