DE2062571A1 - Process for the production of crystalline aluminosihkates - Google Patents

Description

DR. E. WIEGAND DIPL-ING. W. NIEMANN DR.M. KÖHLER DIPL-ING. C GERNHARDT 2062571 MONKS HAMIUKG TELEPHONE: J5 54 7 «8000 MDNCHEN 15, TElEGIAMS! KARPATENT NUSSBAUMSTRASSE 10

18th December 1970

V. 40265/70 - WNe

Mobil Oil Corporation New! Fork, N.X., V.St.A.

Process for the production of crystalline Aluminosilicates

Crystalline aluminosilicates are generally prepared from "i a Keaktionsgemisch, consisting of a mixture of oxides including sodium oxide, '. Alumina, silica and water besteht- General crystallize under alkali see conditions After the gel is formed, the gel in the presence of Leave the mother liquor to stand until the material crystallizes in the presence of the mother liquor. The material is then removed, washed until the pH of the filtrate becomes constant and dried.

It was found that some preparations of crystalline aluminosilicates, especially those with Ratios ^ iC ^ / AlpOy above 6 substantial quantities contained in enclosed silica, whereby

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the final base exchange to a more catalytically active form as well as the catalytic activity and adsorption capacity ultimately obtained are impaired. Soluble silicates that are enclosed in the pores of the zeolites give rise to special problems "if the zeolite subsequently" with a rare one -Earth metal chloride solution is contacted in order to. To produce the forms exchanged with rare earth metals, the enclosed silicates are converted into rare earth metal silicates which, when used for catalytic cracking, show a high tendency to form coke and thereby lower the overall selectivity of the coke catalyst; In general, the enclosed silicic acid prevents or worsens a full ion exchange of the material, since this is a balanced exchange! ;. blocks the incoming exchange. JTherefore

are cash names favorable »by ^ hdi; ^ such crystals Aluisijioelliffet - Zeolite © free 'by Ringesöh | o; ssener ! p.eselsätire pewonneji will be able to V- · 'H,' ^

V. V / - ^: A ^ J-lemei ^ yields $ && | ^ $ j ^ i & g -ein process ^ zu® Seafeeö, dea jiieseisaa ^ eeinselilus ^ if; iiv crystalline "Äiv-Me ^; gr ^ s: se ^

as <^ _: 3eäi $ zm%, ßasi-V ^ pfailr'ei ^ it assists that ':' the aluminum opilicate adtf-an alkali or ammonium salt -._, solution contacts or an alkali «; or Ami in the production reaction mixture for the silicate at a pH-Vert of at least? and preferably above 9: incorporated. ' The process also comprises treating the crystalline aluminosilicate after separation from the mother liquor with an aqueous hatrium hydroxide solution at a concentration lower than that at which substantial destruction of the zeolite occurs.

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In a particularly favorable execution form, results the invention a process for the preparation of crystalline aluminosilicate zeolites, in which the Reaction geiaisch an alkali or ammonium salt in an amount above the stoichiometric requirements of the Reaction devices that prevent the inclusion of silica sufficient contains.

In a further embodiment, according to the invention, an alkali or ammonium salt is used in a sufficient amount Amount preventing silica inclusion in the reaction mixture mother liquor for the crystalline Aluminosilicate introduced in the presence of a gel-forming crystalline aluminosilicate zeolite.

The invention also provides a method of treating a crystalline Aluninosilikats, which is free from mother liquor containing a solution with a pH above 7 and preferably above 9 ₅ a Alkaii- or ammonium salt to the occluded silica from the crystallized crystalline Aluiiiinosilikat to remove.

The invention also provides a method for treating a crystalline aluminosilicate, which is free of mother liquor with an aqueous sodium hydroxide solution at a lower concentration than that where substantial destruction of the crystalline AluminoSilikats occurs.

The present invention provides measures for improvement the activity and selectivity of the catalytic converter Forms of crystalline aluminosilicates by removal the entrapped or occluded silica. The occluded silica becomes the catalytic Activity and selectivity worsened, since catalytic sites for the reaction participants inaccessible

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are accessible by the resistance to the mass transport of the reactants and the products in the crystalline aluminosilicate in and out of this out is increased and the tendency to form undesirable products on or within the crystalline Aluminosilicate during the subsequent ion exchange process is increased.

It has been found that the processes according to the invention for removing the enclosed silica are extremely effective from the catalytic point of view when the SiO _o / Al _{o o} ratio of the crystalline aluminosilicate is greater than 6. Crystalline aluminosilicates with SiCu / Al ^ CU ratios above 6, such as ZSM-4 and ZSM-5, show a great improvement in the catalytic activity compared to identical preparations if no salt is added. Similar experiments with faujasites showed no effect of the added salt in the reaction mixture with regard to the catalytic activity.

In the same way, both the dynamic and the equilibrium adsorption properties are enhanced the removal of the entrapped silica increases which surface areas or adsorption sites are in makes inaccessible to the crystalline aluminosilicate and relocates the pore openings, so that the extent of what the adsorbate adsorbed in the crystalline aluminosilicate is decreased.

The present invention brings about some interesting ones Advantages. It was found that through treatment a crystalline aluminosilicate, which was separated from the mother liquor and mixed with a weak solution a specific salt of those indicated above Kind was washed, the eiligeseniorcone silicic acid de-

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can be removed and that the filterability of the Kateriäls is significantly improved. A preferred method of practicing the present invention is found ;; in that the salt is introduced into the reaction mixture before the Gc -.- formation via one of the preparation solutions. In this case, the presence of the salt serves to prevent the inclusion of the silica in the resulting crystal structure of the zeolite material. In a further embodiment of a particularly favorable type, the salt is introduced into the crystal formation gel, ie into the mother liquor in the presence of the jointly gelled silica-aluminum oxide mixture which i ~. Crystallizes to the desired crystalline aluminosilicate zeolite as a function of time and temperature.

The process of the invention, referred to as "Salts: ¹¹ ", is very effective in increasing the degree of filtration of the zeolite slurry as well as the ease with which soluble contaminants can be removed by washing. The process is both v / irkε2: If the salt is added to the initial crystallization reaction mixture as well as to the slurry of crystallized zeolite, if the salt is added to a sodium ZSH-4 reaction mixture, the ITiI trifle rate is twice as high These improvements in the handling properties of the material are particularly important in the ion exchange of large batches of the material, for example in factory operations I / ac 2U of salt added to a sodium Z zeolite slurry also results in filtration speeds twice as high as when no addition is present hand is. The l'ilti-:; - tion & speed is ^ O% higher than v / ie you ob-

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tetr when an organic flocculant is added to the same purpose is used. Furthermore, there is a very substantial reduction in the time required to Wash out the water-soluble impurities.

The pH of the treatment of the filtered crystalline aluminosilicate after removal from the Solution applied to mother liquor should be above 7 and preferably above 9. If the pH is too high, generally above about a 1N solution, a substantial destruction of the crystalline aluminosilicate occur. On the other hand, if the pH is too low, d. H. below 7 »there is no noticeable removal of the enclosed silica and there is a risk the destruction of the crystalline aluminosilicate »

When working with such a system, it is generally preferred that the amount of Salt to the crystallization reaction mixture is greater than 10% by weight of the weight of the solid, crystalline Is aluminosilicate in the slurry.

In the context of the invention it is also possible to add the alkali and ammonium salts to the reaction mixture to be added during the preparation of the crystalline aluminosilicate in order to reduce the silica inclusion and this also includes mixtures of alkali and ammonium salts, provided that the composition of the mixture the cation equilibrium in the crystallized product is not disturbed and there is no change in the species that crystallized Product of the desired results or the crystallization of the crystalline aluminosilicate prevented.

Zeolites, which according to the invention Processes that can be treated are the synthetic zeolites. These include the zeolites L, T, α, ß, Mcrdo-

BATH ORIGINAL

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nite, synthetic offretite, synthetic erionite, ZSM-4, ZSH-5 and other synthetic zeolites with SiO ^ / AlpO; ratios greater than 6. These zeolites have average pore sizes between about 5 and 15 % and are "particularly advantageous for the present invention, since the effect of the enclosed silica in these zeolites can go so far that these substances become noticeably non-porous. After the porosity has been improved by removing the enclosed silica, the zeolites can be converted into a form, in which they are suitable for catalysis.

The following examples serve to further illustrate the invention and to practice the same.

example 1

In order to show the increase in catalytic activity caused by the reduction in silica inclusion, four ZSI-l-4 samples were prepared which differed only in the amount of liatric chloride added to the reaction mixture. The basic method of preparation was to add 180 g of Georgia kaolin, calcined at 927 ° G (17OO F) for 6 hours, to a solution ^{containing Q-grade JG '1} c ITatriuucil-iat, 60 g of KaOE (92.2 ¹ Jo KaOH) and 69 g of a solution with 50% by weight of tetiamethylamrucnium chloride in Vaaser were added. In the case of Verfahr02: using the addition of sodium chloride, the SaIr- was added to the solution from ^{1 of} the clay addition. After thorough mixing in a Waring-II shear, the ac mixture was placed in a polypropylene container and an Lr; register: from

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100 ° C given for crystallization. After the crystallization to ZSIi-4 was practically complete, the material was removed from the steam box, washed free of excess alkali and unreacted soluble silicates and dried at 120 ° C. The dried samples then received six ion exchange treatments, each lasting 1 hour, at 82 to 95 ° C. using 500 g of an NELCl solution with 10% by weight per 50 g of the solid sample. The samples were then washed free of chloride, dried at 120 ° C. and calcined for 1 hour at 53> 8 ° C. in an atmosphere with 5% oxygen which was saturated with water vapor.

There were four samples in this way with 0, 20, 40 and 60 g of sodium chloride within the reaction mixture manufactured. The catalysts obtained in this way were below regarding the catalytic activity Use of the toluene disproportionation test described below at low temperature (LTD) rated. The activities given in the table below clearly show the increase in the catalytic activity, by reducing the silica inclusion due to the addition of salt to the reaction mixture. was caused during zeolite production.

Influence of the salt on the catactic activity · '' _ t ~~ of

UaCl in the reaction

genic, g 0 20 40 60

LTD activity r

k./Hol-Gek. χ 10 ^b 2.4 60 49 82

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BATH ORIGINAL

Example 2

Further evidence of the increase in the catalytic. Activity due to the reduction of the silica inclusion, three ZSli-4 ~ samples were produced, which differed in that in one sample no salt was added to the gel mixture and in the other two samples a Ha ^ S (V ~ addition to the gel mixture The general approach and the manufacturing process were as follows: A silicate solution was made from 1930 g of Q-quality sodium silicate, 374 g of an aqueous ITaOH solution with 50% by weight, 103 g an aqueous tetramethyl ammonium chloride solution with 50% by weight and 952 g of water.An acidic alum solution, which contained 326 g of Alp (SO.)., 14 HpO and 575 S of water, was added to this solution and stirred at the same time The gel mixtures were then placed in polypropylene containers and placed in a steam box for crystallization at 82 to 93 ° C. After the crystallization to ZS M-4 was practically finished, the samples were removed from the steam box, washed free of excess alkali and soluble silicates. The samples then received six internal exchange treatments for 1 hour at 82 to 93 ° C. using 500 g of an IHLCI solution at 5% by weight to 50 g of the dried sample. The samples were then washed free of chloride, dried at 120 ° C. and calcined for 1 hour at 538 ° C. in an atmosphere with 5 ° / ° oxygen which was saturated with water vapor.

These three samples of ZSH-4 were with the addition of 0, 200 and 300 g Na ₂ SO ₄ to the gel mixture before the crisis

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installation made. Those made in this way Catalysts were tested for catalytic activity using the Toluol-Disproportionierversuch.es "rated at low temperature (LTD). The catalytic listed in the table below Activities clearly show the improved activity brought about by the reduction in silica entrapment was obtained.

Influence of salting on the catalytic activity of

'HZSM4

HZSM-4 200 5 300 Including ₂ SO ₂ . in the Reak tion mixture, g 0 50.6 50.4 LTD activity, _g 50.2 Example ;

To further demonstrate the improvement in the catalytic activity resulting from a reduction in the silica inclusion in crystalline aluminosilicates, two samples Ζ3ΓΙ-5, a highly silica-containing, crystalline aluminosilicate with a SiOp / Al ^ O-, y 50, manufactured »The material ZSM-5 is described in the Belgian patent 7Ί3. In one sample, an ITaCl addition was contained in the reaction mixture of the zeolite production, while in the other preparation this was not the case ^. all was. Otherwise the procedures were identical.

These samples were prepared and produced in the following way: A silicate solution was produced which contained 44.7 kg of Q ₁ quality sodium silicate, 5.6 kg of tetra-

^109826/1610 BADORK ₃₁ NAu

propylammonium bromide and 84 kg of water. To this end, a sodium aluminum oxide solution containing 0.56 kg of sodium aluminum oxide (41.8 % Al ₃ O ₇ , 33.5 % Na ₃ O) and 14 kg of H ₂ O were added. A sulfuric acid solution with a content of 4.47 kg H ₂ SO ^ (97 %) and "> 4.0 kg water was added to this mixture. For the sample with added salt, a solution of 16.7 kg NaCl in 20 kg water was added After thorough mixing, the mixture was heated to 93-100 ° G and held at that temperature until crystallization of the ZSH-5 was virtually complete, and the crystalline aluminosilicate samples were then separated from the mother liquor and removed from the excess The crystalline aluminosilicates were then dried and calcined in air for 10 hours at 538 ° C. After the CaI-cinierung, the zeolite samples were subjected to an ion exchange, with 4 contacts at room temperature with an NH ^ Cl solution of 5 w / o using 20 kg of solution per kg of zeolite The crystalline aluminosilicates were washed free of chloride, dried and then treated again for 10 hours i 538 ° C calcined in air.

Both ZSH-5 samples were then put on catalytic Activity using n-hexane cracking according to the 'V-Tect rated. The "u" test is from P. B. V / eisz and J. II. Miale in "Journal c f Catalysis", Volume 4, ITr. 4, August 1965, pages 527-529. In the the results of this evaluation listed in the following table again show the improved catalytic activity that results when the silicic acid inclusion by the incorporation of a salt additive in the reaction mixture during zeolite production, v: ird is reduced.

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Influence of salting on the catalytic activity

HZSH-5

NaCl in the reaction

mixture O 16.7 kg

n-hexane-a at 427 ° C 480 620

Example 4-

To show that the increase in the catalytic Activity due to the reduction of silica inclusion is most effective when crystalline aluminosilicates with greater SiOo / AlpO ^ ratios than 6, two samples of faujasite were prepared by the same procedure, using only NaCl was added to the reaction mixture for one sample became.

The basic method of preparation was to mix 30 grams of Georgia kaolin that had been calcined at 927 ° C for 6 hours with 150 grams of Georgia kaolin that had been calcined at 816 ° C for 6 hours. This dry mixture was slowly added to a solution containing 75 g of HaOH (98.2 % NaOH), 61 g of Q-grade sodium silicate, and 69 g of a 50% by weight tetramethylammonium chloride solution in water while stirring in a Waring mixer became. After the addition of clay was finished, the frilly pO was continued for seconds. The mixture was placed in a polypropylene container and crystallized in a steam chamber at 100.degree. After 115 hours, the 1 robe was removed, some of the mother liquor was washed and dried. The X-ray diffraction analysis of the dried product confirmed that the product consisted of synthetic -PauJaeit.

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An identical production took place, with only 60 g of FaCl being added to the reaction mixture during the production of the zeolite added. The crystallized product of this preparation was also identified as i'aujasite.

Both samples were washed free of excess alkali and soluble silicates and dried at 120 ° C. The dried samples were then subjected to four ion exchange treatments for 1 hour each with rare earth metals at 82 to 93 ° C using 400 g of one day of RECl ₅ - OH ₂ O solution on 100 g of the dried zeolite. The samples were then washed free of chloride, dried at 120 ° C. and calcined at 538 ° C. in dry air for 3 hours.

Both catalysts were then evaluated for catalytic activity using the n-hexane-α test. The results of this experiment, together with a comparison of the catalytic activities of crystalline aluminosilicates with higher SiOp / Al ^ O- ratios, with and without addition of salt to the reaction mixture in the preparation of the zeolite, are shown in the following table. The results clearly show that the reduction of the silica inclusion is far more effective in increasing the catalytic activity in the case of the zeolites with a higher SiO ₀ ZAl _n O, ratio (> 6) than in the case of zeolites with a lower SiO, / Al ₀ O ;, Ratio, like IPaujasite, is.

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Influence of salting on zeolites with different SiCu /

A1 _O C> ratio

Crystalline SiOVAl ₀ O-, salts Catalytic ^ activity Alumino- · * cc at U2B k.

^silicates ■ ^ ^0G I / mol-sec. χ

10 ⁶

ZSM-4 6.7 no 2.4

.la 82

ZSM-5. > 50 no 480

yes 620

Paujasite 4.5 to 5.0 no 200

, generally 100

The slight difference in the "α" value in faujasite probably due to the fact that with Salt treated preparation has a slightly higher sodium content after replacing it with rare. Earth metals which results in a lowering of the catalytic activity.

Example $

To demonstrate the improvement in catalytic activity, which is obtained when the enclosed silica is brought into contact with the crystalline zeolite obtained after its separation from the mother liquor with aqueous sodium hydroxide solution, two ZSh-4 samples were obtained manufactured using identical processes.

180 g of Georgia kaolin, which had been calcined for 6 hours at 927 ° C., was added to a solution of 361 g of Q-grade sodium silicate, 60 g of NaGH (98.2 % NaOH) and 69 g of a tetramethylammonium chloride solution at 50% by weight. added in water. After thorough mixing

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on a varing mixer, the genic was turned into a Polypropylene container and placed in a pan brought to crystallization of 100 ° G. After 42 hours, the material was removed from the steam box and some of the excess alkali was washed free and dried.

One of the samples received the following additional treatment:

59 g of the washed sample were used five times during 1 hour each at room temperature using Subjected to 1 liter of In-KaOH with each contact. The material was then washed HaOH-free and at 120 ° C dried.

Both dried samples were then ion-exchanged six times for 1 hour each time at 82 to 95 ° C. using 500 g of an IHLG1 solution at 10% by weight per 50 g of the solid sample. The sample was washed free of chloride, dried at 120 ° C., pelletized and calcined for 1 hour at 538 ° C. in an atmosphere with 5 vol. Oxygen which was saturated with water vapor.

Both samples were then catalytically seen Activity using the toluene disproportionation test rated at low temperature (LTD). The Activity of Without Ilatriua Hydroxide Treatment sample produced was 2.4 10 "1 / Iiol-sec., while the sample that received the treatment with sodium hydroxide had a Vert of 5.1 χ ΊΟ ^ l / Hol-Gek. showed so an order of magnitude higher. Diec clearly shows the advance in catalytic * activity with a reduction in entrapped silica HZLI1-4

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Example 6

To see the real improvements in filtration and washing the zeolite designated ZSM-4 " To show, two ZSM-4 samples were produced, one batch being 7 * 5% by weight, based on the reaction mixture, of added sodium chloride in the reaction gel before crystallization. A filter leaf examination was carried out with the synthesized form of sodium ZSM-4, which was present as a slurry in the mother liquor. The slurry concentrations varied between 8.1 and 8.6% by weight after adjustment with water. Equipment and procedures for performing the Filter sheet test corresponded to "Chemical Engineer's Handbook", 4th Edition, Perry, Chilton and Kirkpatrick, Pages 19 to 59 · A 0.0095 ni (0.1 square foot) filter sheet was used. The filter sheet consisted of a nylon cloth. In all subsequent experiments, a vacuum of 45 cm (18th inches) and submerging the cake deposit for 40 seconds and applied 80 seconds for dehydration to the atmosphere. The weight of the filtrate and the Solids are given in Table I. The larger values in the experiments in which sodium chloride im Reaction mixture was applied, show that a larger slurry has been filtered \ irar. This is due to the better filterability of the material the flocculation effect of the salt on the dispersed, crystalline aluminum silicate. The filter

■ ψ

'media, d. H. Nylon cloth and deposited ZSH-4 zeolite are much more porous than the samples, where no salt is added during crystallization and formation of the Zeolite took place. The following statements prove that

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the slurries containing sodium chloride one have a much higher filtration speed, especially at higher temperatures of -approx. 71 ° C. Additionally it should be pointed out that the physical properties of the collected filter cakes are also great Showed differences. Those preparations in which there was no addition of sodium chloride gave one Filter cake which, as usual, was thixotropic, d. H. "ctre * were generally in a dense phase. In the case of the preparations using sodium chloride, a solid, however, porous hats were obtained which were easy to handle in subsequent operations. The essential lower water content of the filter cake, which is in the preparations obtained using the salt method according to the invention is also advantageous.

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80 • ■ ² . 80 , 6 292 ,1 . 666 , 9 67 ,1 135 , 7 37 80

Table I. Filter leaf examinations during the filtration of ZSIi-4

NaCl - 7.5% by weight

Temperature ^{room- 67 room- 67 0} CC ⁰ F) tempe- (152) tempe- (152)

rature rature

Filtration

time in the

Slurry 40 40, 40 40

(Sec.)

Dry (sec.) 80. 80
Rapid Council (1) 141.6 235.5

Wet cake 64.2 99.2

(D (s)

Solid in the 30.5 48.9
Cake (g)

Kitchen thickness 3.2 4.7 4.7 11.1 (mm) (1/8 ") (3/16") (3/16 ") (7/16")

Solids content 47.5 4-9.3 ■ -55.4 59.5 content des
Cake, G-ew.%

Condition t Thixotropic cake hard and porous

(1) Average of three determinations.

Disproportionation test with liquid toluene

The disproportionation test with liquid toluene (LTD) as used here has been applied a microreactor (less than 20 cm ^ catalyst) and full size catalyst particles developed that

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result in kinetically constant values. The range of the catalyst volume and the liquid flow rates were above the range where axial diffusion effects can become significant and below the area where, by passing, short cycle or excessive backmixing, incorrect results can be obtained.

The apparent activation energy for the disproportionation of toluene in the liquid phase is 24 kcal / g mol. H. the Extent of the drop in the reaction rate of the second order in terms of the period on the stream, turned out to be a drop of the first order with two different changing speeds within a 24-hour space.

Experimental procedure

The experimental evaluations were made using a microreactor (15 c ^ maximum volume) and with analytical grade toluene (percolated by aluminum oxide). The procedure was that the entire reaction system was filled with liquid at room temperature, then the temperature was raised to the operating temperature in 40 minutes or less. After the catalyst bed reached the reaction temperature, this value is taken as the zero time. The product was collected continuously in the course of the experiment, but only the product that was collected during the final 5 minutes of the specified period was used for product analysis. This means that the product analysis given on the stream for a sample after 1 hour gives the value for the sample taken within the period of 55 to 60 minutes.

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The product analysis was carried out by means of a gas phase chromatograph using the F&M model 5754 with a temperature program from 80 to 125 ° C. at 4 ° C./min. And using helium as the carrier gas at 50 cm.VMn m was used, the one with 4 % diisodecaphthalate, 4 % Bentone 34, worn on Chromosorb V HTtDS with

a fineness corresponding to a mesh count / cm of 576 to 1225 ^ loaded wai%.

Results and discussion

The kinetic model used to implement it was as follows

-1

CH.

GH-

which is a second order reaction in toluene, assuming that all three xylenes are behave as the only kind. The built-in rate equation is easily obtained or can be omitted find some reference texts. Using the same equilibrium values for Beakti011 participants and Products becomes the following equation for the reaction rate constant k ^. obtain:

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BATH ORIGINAL

1 (0.073 m 0.16 (^ §§Ξ§)

t is the residence time in seconds and X is the toluene conversion in% by weight

indicates.

The process according to the invention is "particularly for the preparation of coinosition catalysts which Containing alumina, and new zeolites designated as ZSM-4 "are suitable. The ZSH-4 compositions leave are represented as the molar ratios of the oxides in the following way:

0.9 + 0.2 M ₂ O: W ₂ O ₃ : 6-20 1O ₂ : zH ₂ O, η

where M is a cation, η is the valence of the cation, W is aluminum or gallium, Y is silicon or germanium and ζ mean a value from 0 to 20. In the synthesized aluminosilicate form, the zeolite has a formula as Molar ratios of the oxides, of the following kind:

0.9 ± 0.2 M ₂ O: Al ₂ O ₅ : 6-20 SiO ₂ : zHgO, η

wherein II is a mixture of letramethylammonium cations and Alkaline cations, especially sodium, means. The original cations can be present in such a way that the amount of tetramethylammonium ions between 1 and 50% the total of the original cations. Thus, the zeolites can be described by the following as Represent the molar ratios of the oxides:

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0.9 t 0.2 ZxR ₂ O + (i-2c) M ₂ Q7: V ₅ O ₅ : 6-20 YO ₂ : 0-20

wherein V and Ί have the meanings given above, R the tetramethylammonium cation, H an alkali cation and χ a value between 0.01 and 0.50.

The members of the family of ZSM-4 zeolites possess a pronounced crystalline structure, the X-ray diffraction pattern of which has the following values:

+ 0.2 I-A + 0.1 Relative intensity Tabel + 0.1 VS Interplanar distance d (A) + 0.07 mw 9.1 + 0.05 m 7.94 + 0.05 S. 6.90 + 0.05 mw 5.97 + 0.05 raw 5.50 + 0.05 mw 5, -27 + 0.05 W. 4.71 + 0.05 W. 4.39 + 0.05 ~ S. 3.96 0.05 m 3.80 + 0.05 m 3.71 + 0.05 S. 3.63 + 0.05 m 3.52 + 0.05 S. 3.44 + 0.05 m 3.16 + o, C5 m 3.09 m 3.04 S. 2.98 2.92

These values were obtained according to standard procedures. The irradiation took place with the K-a doublet of copper and a Geiger counting spectrometer with a strip card and the record was used. The top heightii I and the positions in a function of 2x0, in which 0 represents the Bragg angle, the spectro-

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Meter map read. From this the relative intensities were 100 I / I, where I is the intensity of the strongest Line or of the summit, and d (obs.), The interplanar distance in S, corresponding to those recorded Lines, calculated. In Table I-A the relative intensities are with s = strong, m * = medium, ms = medium, mw «medium-soft and vs = very strong.

The ZSM-4 zeolites can be conveniently prepared by preparing a solution containing ^ ⁰ '

Contains sodium oxide, an oxide of aluminum or gallium, an oxide of silicon or germanium and water and a composition in terms of molar ratios of the oxides owns within the following areas:

Table II

Broadly preferred

Na ₂ 0 / (R ₂ 0 + Na ₂ O) 0.51 to 1 0.75 to 0.99 O + Na ₂ O) AO ₂ 0.05 to 0.90 0.15 Ms 0.75

Y0 ₂ / W ₂ 0 ₃ 3-to 60 6 to 30

H ₂ OZ (E ₂ O + Na ₂ O) 15 to 600 20 to 150

where E is the tetramethylammonium cation, W is aluminum or gallium and Y is silicon or germanium, followed by the mixture is held until the crystals of zeolite are formed. The crystals are then separated from the liquid and recovered. SSM-4 will preferably formed as an aluminosilicate.

The inventive method is also particularly suitable for the production of composition catalysts, obtained from aluminum oxide, and from relatively new zeo-

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Iiths referred to as ZSM-5. The ZSM-5 masses can be expressed as molar ratios of the oxides in the following terms:

0.9 + 0.2 M _p 0: M ₀ O ₇ ,: 6-100 T0 _p : zH _p O,

- ι CL CL O CL CL

where M is a cation, η is the valency of the cation, V Aluminum or gallium, Y silicon or germanium and ζ denote a number from 0 to 40. In the preferred The zeolite has the synthesized form as: Mo! ratios the oxides die. following formula:

0.9 + 0.2 H ₂ O: Al ₂ O _3: 6-100 SiO

where M a mixture of alkali cations, especially sodium, and G} is etraalkylaiiimoniumkationen, their Alkyl groups preferably contain 2 to 5 carbon atoms.,

The members of the family of ZSM-5 zeolites possess a pronounced distinctive crystalline structure, the X-ray diffraction pattern of which has the following significant Lines shows:

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+ 0.3 "^" 2062571 + 0.3 Table III + 0.2 d (A) Relative intensity ϊ 0.2 S. Interplanar distance ; ο, 2 S. 11.1 + 0.2 W. 10.0 + ϊ 0.2 W. 7.4 + 0.1 W. 7.1 + 0.1 W. 6.3 + 0.1 W. 6.04 + 0.1 W. 5.97 + 0.1 W. 5.69 + 0.1 W. 5.56 + 0.1 W. 5.01 + 0.05 W. 4.60 + 0.05 W. 4.35 + 0.05 VS 4.25 + 0.05 S. 3.85 + 0.05 S. 3.75 + 0.05 m 3.71 W. 3.64 W. 3.04 w 2.99 2.94

These values were obtained according to standard procedures. Irradiation was with the Ka doublet of copper and a scintillation counting spectrometer with a strip card and peder record was used. The peak heights I and the positions as a function of 2x0, where Q is the Bragg angle, have been placed on the spectrometer map. From this the relative intensities, 100 I / I, where I _{0 is} the intensity of the strongest line or "peak, and d (obs.), The interplanar distance in S, according to the recorded lines, were calculated. In Table III the relative intensities Intensities indicated with ε = strong, m. = Medium, ms = medium strong, iaw = medium soft and vs = very strong.

The ZSH-5 zeolite can be manufactured in a cost-effective manner by preparing a solution containing TetrapropylammoniuahydroxLd, sodium oxide, a üvdd of

10 9 8 2 6/1610

Aluminum or gallium, an oxide of silicon or germanium and contains water and a composition within of the following areas:

Table IV

Broadly Preferred Particularly

preferred

OH "AO ₂ 0.07-10.0 0.1-0.8 0.2-0.75

R ₄ M ⁺ (E ^ ₊ ^{ITa +} ) 0.2-0.95 0.3-0.9 0.4-0.9

H ₂ 0 / 0H "10-3OO-10-3OO 10-3OO

₂ O ₇ 5-100, 10-60 10-40

where E is the propyl group, V is aluminum or gallium and Y is silicon or germanium, whereupon the mixture is held until the crystals of the zeolite are formed. It should be noted that an excess of tetrapropylamrioniurahydroxide can be used, which can increase the value of OH ⁷ YlOp above the ranges given above. Of course, the excess of Hydro :: id does not take part in the implementation. The crystals are then separated from the liquid and recovered. The typical reaction conditions consist of heating the above reaction mixture to a temperature of about -.00 to .75 ° G for a period of about 6 hours to 60 days. A more preferred temperature range is between approximately 150 and 175 ^° C., the time period at a temperature in this range being within approximately 12 hours to 8 days.

10 9 8 2 6/1610 ^BAD

Claims (16)

Patent claims Process for preventing or reducing the pore coverage by silica in synthetic, crystalline aluminosilicate zeolites with a Siü ₂ / Al ₂ C ratio greater than 6, characterized in that the crystalline aluminum silicate or a precursor thereof with a solution of an alkali or ammonium salt a pH of at least 7 is contacted. 2. The method according to claim 1, characterized in that a normality of the salt solution of less than 1 'is applied. 3. The method according to claim 1 or 2, characterized in that that as a precursor a reaction mixture, which contains the constituents constituting the zeolite is used. 4 ·. Method according to claim 1 or 2, characterized in that that the synthetic, crystalline aluminosilicate is used in the crystallization Hutterlauge will. 5. The method according to claim 1 to A-, characterized; that a sodium salt is used as the salt. 6. The method according to claim 5 »characterized in that that the salt used is sodium chloride. 7. The method according to claim 5 »characterized in that that the salt used is sodium sulphate. 8. The method according to claim J, characterized in that that as Eeaktionsgerriisch a precursor of zeolite ZSH-A- is used that contains the following substances, specified as oxides in the No! ratios, contains: 109826/1610 bad original Ua ₂ 0 / (R ₂ 0 + Ka ₂ O 0.31 to <1 + ITa ₂ O) ZlO ₂ 0.05 to. 0.90 ₂ O ₃ 3 to 60 ₂₂ O + Ia 0) 15 to 600 where E is the tetramethylammonium cation, W is aluminum or gallium or Y is silicon or germanium. 9. The method according to claim 8, characterized in that the following ratios are used: ₂₂ O + Ka ₂ O) 0.75 to 0.9? (R ₂ O + Ka ₂ O) ZYO ₂ 0.15 to 0.75 6 to 30 ₂₂ + Ka ₂ O) 20 to 15O 10. The method according to claim 3? characterized, that as E eak ti ons a precursor for zeolite ZSM-5 is used, which contains the following ingredients in the following pick-up ratios: OHVYO ₂ 0.07 to 10.0 E ₄ K ⁺ Z (S ₄ K ⁺ + Ka ⁺ ) 0.2 to 0.95 Z "10 to 300 ₇ 5 to 100 where H is the propyl group, w aluminum or gallium and Y mean silicon or germanium. 11. The method according to claim 10, characterized in that the following oil ratios are used: 109826/1610 BAD original 0H ~ / Y0 ₂ "0.1 to 0.8 R ₄ N ⁺ / (R ₄ If ₊ Ha ⁺ ) 0.3 to 0.9 H ₂ 0 / 0H "10 to 300 YO ₀ ZW ₀ O _x 10 to 60 12. The method according to claim 1 or 2 and 4 to 7 * characterized in that a crystalline zeolite is used which has a composition specified as the holing ratios of the oxides, according to the following formula: 0.9 + 0.2 M ₂ O: W ₂ O-,: 6-20 YO ₂ : ζ H ₅ O, η where ΓΙ is a cation, η is the valence of the cation, W aluminum or gallium, Y silicon or germanium and ζ is a number from 0 to 20, the zeolite having the X-ray diffraction according to Table I-A. 13. The method according to claim 1 or 2 and 4 to 7 » characterized in that a crystalline zeolite is used with the following composition, given as the holing ratios of the oxides: 0.9 + 0.2 M ₂ O: W ₃ O ₇₅ : 6-100 YO ₂ : ζ H ₂ O, ΐϊ where ΓΙ is at least one cation, η is the valency of the cation, W aluminum or gallium, Y silicon or Gsrmanium and ζ is a number from 0 to 40, the zeolite having the X-ray diffraction according to Table II. 14. Procedure for lowering the Ki es el acid eir, .- conclusions in a synthetic zeolite with a ratio oiOVAloO- of at least 6, thereby licensed- 10 9 8 2 6/1610 _BA t> ORIGINAL draws that the zeolite with an aqueous solution a sodium compound that has a pH of at least 7 owns, is contacted. 15 · The method according to claim 14-, characterized in that the alkalinity of the solution has a value
of 1-normal does not exceed. 16. The method according to claim. 14 or 15 _? characterized in that sodium hydroxide is used as the sodium compound. BAD QRSGiMAL 1098 26/1610