DD207185A1 - METHOD FOR THE PRODUCTION OF HIGH-KESELIC ACID-CONTAINING ZEOLITHES II - Google Patents

Abstract

The invention relates to an improved process for the preparation of crystalline hochschlieselsaeururaltige Ziolithen. In this case, a reaction mixture - consisting of alkali and / or alkaline earth metal oxide, alumina, silica and water - crystallized under the addition of ammonia at elevated temperature under pressure. The crystallization products can be used in pure form or in a mixture with a substance other than filler, adsorbent, ion exchanger and catalyst or catalyst carrier application.

Description

237604

22 85

WP C 01 B / 237/604/8

Title of the invention

Process for the preparation of high-siliceous zeolites

Area of application of the invention

The invention relates to a process for the preparation of crystalline siliceous zeolites having a SiO 2 / Al 2 O 3 molar ratio> 10 which can be used both in pure form and in mixtures with various inorganic materials as filler, adsorbent, ion exchanger, catalyst or catalyst support.

Characteristic of the known technical solutions

Silicon-rich zeolites, e.g. Types Y, erionite and uredenite have found application in hydrocarbon conversion catalyst systems. However, it is unfavorable that for these applications, a modification of the zeolites by ion exchange and / or impregnation must be made. Furthermore, the large number of acidic sites, caused by the built-in aluminum lattice building blocks, triggers reactions which lead to inactivation of the zeolites. In recent years, therefore, highly siliceous zeolites have been developed, e.g. the ZSM series, which do not possess these disadvantageous properties. Further advantages of these high-siliceous zeolites over the above-mentioned are the increased thermal stability, the improved stability, favorable for certain catalytic hydrocarbon conversion

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Pore diameters of 0.5 to 0.6 nm and the surfaces designated as hydrophobic «

The silosilicic acid-containing zeolites are prepared by the conventional synthesis technique from a reaction mixture consisting of at least one source of alkali and / or alkaline earth metal oxide, alumina, silica and water in the presence of organic cations, usually ammonium or phosphonium ions or their precursors. The reaction mixture is kept at elevated temperature under autogenous pressure until the formation of corresponding zeolite crystals. The resulting siliceous zeolites are then separated from the mother liquor and worked up by known methods.

As organic cations or their precursors, preference is given to using the organic compounds listed in Table 1 for the synthesis of the high-silica-containing zeolites,

Table 1: Preferably used organic compounds for the preparation of high-siliceous zeolites

Organic connection

 Gholin

pyrrolidone

tetrapropylammonium

Diaraine (G ₂ - Cp ₀ ) tetrapropylphosphonium compounds

primary n-alkylamines 1,4-dimethyl-1j4-azonia 2,2,2-bicyclooctane tetrabutylammonium or -phosphonium compounds tertiary alkylamine and n-alkylsulfate

zeolite literature 2 615 065 ZSM-4 DE-OS 3 702 586 ZSM-5 US-PS 2 817 576 ZSM-5 DE-OS 2 817 577 ZSM-5 DE-OS 2 442 240 ZSM-5 DE-OS 3 692 470 ZSM-10 US-PS

ZSM-11

ZSM-12

U.S. Patent 4,112,056

U.S. Patent 3,832,449

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(Continued from Table 1) Organic compound

zeolite

literature

2- (hydroxyalkyl) -trialkyl- 23M-21 ammonium methyiene diamine or pyrrolidine choline ZSM-34 T et rame methylammonium alpha links tetraethyl beta links 'fetraalkylammonium- Zeta-1 links Tri-n-alkylamine and alkyl Zeta-3 alcohol Tetraalkylammonium or AMS-I B phosphonium

U.S. Patent 4,076,842

DE-OS 2,749,024 US-PS 3,308,069

US-PS 3 308 069 DE-OS 2 548 697 DE-OS 2 643 929 DD-PS 136 831

From Table 1 shows that the known production processes have a significant disadvantage: The organic additives used, mainly ammonium or phosphonium compounds or their precursors, represent very complex compounds and are technologically complicated to manufacture due to this. In view of the necessary quantities, this has a cost-disadvantageous effect on the production processes of high-siliceous zeolites.

Likewise, the addition of primary amines as a precursor of the alkylammonium cations to the reaction mixture, as described in DE-OS No. 2,442,240, would lead to an increase in the price of the desired end products, since the preparation, separation and purification of the primary amines requires special processes and thus increases the cost.

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In DE-OS 2,913,552 a process for the preparation of high-siliceous zeolites is described which is based on the combined use of a primary alcohol ROH (R β C ₁ -Cc) and ammonia. This process, which is improved compared to the processes listed in Table 1, replaces the use of the costly and laborious amine or ammonium products by the cheaper substances alcohol and ammonia. A disadvantage, however, is the need to add an organic component (in this case a primary alcohol) to the reaction mixture as a structural link, since the use of organic substances in inorganic processes places increased demands on the safety technology.

According to the process described in DE-OS 2,704,039, zeolitic-containing molecular sieves containing high-silicic acid can be obtained from reaction mixtures which are free of organic and / or H-containing components. However, the resulting products are not identical to the high-silica zeolites of the ZSM series or similar zeolites (Ultrasil, Fu, Hy) because they have other surface properties that can be characterized by IR analysis. The applications, e.g. as adsorbent or catalyst, these products are severely limited due to this property picture.

Object of the invention

The aim of the invention is to find an improved process for the preparation of high-siliceous zeolites having a Si0 ₂ / Al ₂ 0 ~ -Molverhältnis> 10, which is technically simple to perform and inexpensive.

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Presentation of the essence of the invention

The invention has for its object to find a method for the preparation of crystalline siliceous zeolites having a SiO 2 / AlgO ^ molar ratio> 10 by the use of technically readily available substances with structurally-guiding properties.

According to the invention, this object is achieved in that for the production of high-siliceous zeolites with a SiOg / AlgO-j-molar ratio ^> 10 an aqueous reaction mixture is kept at elevated temperature under pressure necessary for the crystallization time, wherein the aqueous reaction mixture of at least one source for alkali and / or alkaline earth metal oxide, at least one source of alumina, at least one source of silica and ammonia.

As a source, e.g. serve:

   alkali metal or alkaline earth metal hydroxides and / or alkali metal or alkaline earth metal salts,

7 alumina hydrated or hydratable alumina, aluminates and / or aluminum salts,

fumed silica or precipitated silica, silica sols, silica gels, alkali metal silicates and / or

'Aluminosilicates,

- For ammonia ammonia in the gas state or in aqueous solution.

The mixing of the components may be carried out batchwise in the vessel intended for the reaction or continuously in a step upstream of the crystallization.

Typical reaction conditions for the synthesis of the high-silica zeolites according to the process of the invention are a composition of the reaction mixture, expressed in molar ratios of the oxides of

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₂₂ O ₃ = 15 to 300

M _{2 / n} 0 / Si0 ₂ = 0.05 to 1.00

H ₂ 0 / Si0 ₂ = 5 to 200

HH ₃ / Si0 ₂ β. 0.1 to 1.0,

wherein M is an alkali or alkaline earth metal and η its valency, a crystallization temperature of 80 to 220 ⁰ C, preferably 150 to 180 ⁰ C, and a crystallization time of 5 to 300 h, wherein the crystallization is carried out under autogenous pressure. The resulting siliceous zeolite crystals are then separated from the mother liquor and worked up. These include those skilled in the art "known methods of drying, processes for the removal of ammonia from zeolitic products containing high siliceous, methods of ion exchange, methods of loading or impregnation with special, for catalytic processes, for example desired metal species and methods for the deformation of these products.

The products obtained by the process mentioned are free of organic constituents, so that in the calcination process, no coking reactions can take place to remove the ammonia from the zeolites, which carbon deposits to the poles and thus leads to the inactivation of the zeolites.

The obtained crystalline siliceous zeolites are characterized by the following values of the typical X-ray diffraction lines and IR absorption bands given in Tables 2 and 3.

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Table 2% 'of the characteristic X-ray diffraction lines of the produced siliceous zeolites

Hetae plane distance / "" nm_7 relative intensity

1,12 + 0,025 st

1,00 + 0,025 st

0.38? + O ₉ OO? sst

0.383 + 0.006 st

0.376 + 0.005 st

 Q »373 + 0.005 st

0.366 + 0.005 m

s strong, s t = very strong, m = medium

Table 3s Y / erte the characteristic IR absorption bands of the produced high-siliceous zeolites

Absorption band / ~ cm "* J relative intensity

440 + 3 st

520 +3 st

780 + 3 m.

1080 ± 3 sst

1220 +4 sst

1630 + 5 m

3440 + 6 st

3650 + 7 m

st = s strong, sst = very strong, m β medium

- 8 embodiments

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An aqueous solution prepared from 10.5 g of NaOH ₉ 5.07 g of aqueous ΝΗ, ΟΗ solution (about 25 Ifa .- # IHo), 100 g of a wäßri sodium sodium silicic acid (about 30 Ma .- $ SiO ₉ ) and 54 g of H ₉ is mixed with a solution _s consisting of 50 g of HgO ₉ 10.2 g of concentrated, H and 2.8 g of aqueous sodium aluminate solution (about 20 Ma .- # ₂₃ ", mixed and" bis The composition of the reaction mixture thus obtained, expressed in molar ratios of the oxides, is:

₃ = 88.4 gg. »0.29 H ₂ 0 / Si0 ₂ « 20.6 UH ₃ / Si0 ₂ ». '0.17.

The reaction mixture is introduced into a steel autoclave and kept at 175 ⁰ C under time pressure until crystallization, After 8 h the product is obtained which is determined by X-ray standard methods, about 40 Ma · - ^ described ZSM-5 (referred to in Example 2 Product).

Example 2

The preparation of the reaction mixture and the crystallization conditions correspond to Example 1. However, the crystallization is stopped only after 24 h »

The product obtained is X-ray free phase-free ZSM-5. üs, after thermal activation for 3 to 4 h at 600 ⁰ C at a water vapor partial pressure of 80 Pa and room temperature has an equilibrium water adsorption capacity of 3.82 Ma _# -%, the maximum Benzenaufnahme at room temperature and a gasoline partial pressure of 2.40 kPa is 8,21 Ma. "%. The product shown shows the values of the X-ray diffraction lines contained in Tables 2 and 4 and the IR absorption bands given in Table 3.

Table At values of the X-ray diffraction lines of the crystallizate of Example 2

Net interplanar distance / ~ nni relative intensity

1,106 0,992 0.966 0.912 0.630 0.597 0.566

0.555 0 _s 498 0.460 0.435 0.425 0.407 0.388 0.383 0.381 0.372 0.3771 0.363 0.347 0.343 0.334 0.330 0.304 O _s 297 0.293 43 52 26 15 11

17 12

H 10

7. 11

8 4 8

100 91 65 68 37 9

14 12 16 17 22 8

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Example β

According to Example 1, a reaction mixture of the composition, expressed in molar ratios of the oxides, of

SiO ₂ ZAl ₂ O ₃ = 88.4

Na ₂ OZSiO ₂ = 0.29

H ₂ OZSiO ₂ = 20.6

M ₀ ZSiO ₀ = 0.70

j fL ·

and crystallized for 24 h at 175 ⁰ G. The product consists of 80% by mass of ZSM-5. In addition, amorphous shares can be detected. The characteristic X-ray diffraction lines of the product are 1.11 nm (I »72 %), 0.99 nm (I = * 94%), 0.383 nm (I = 100.%), 0.372 nm (I = 64 %) and 0.365 nm (I = »55%).

The positions of the IR absorption bands correspond to those of Example 2. The adsorption equilibrium capacity at room temperature for water vapor at 80 Pa is 3.60 Ma, ~% and for gasoline vapor at 2.40 kPa 8.34 Ma.%.

Example 4

A dilute sodium waterglass solution .-% ^s i prepared by mixing 75 s V / asserglas (about 28 ° Ma ^ 2 and-94 g of water. Into this solution, 19.8 g of aqueous UH ^ OH-solution (ca 25 Ma. % NH,) and then a solution consisting of 114 g H ₂ O, 2.55 g Al ₂ (SO ₄ ) ₃ .18 HgO and 6.05 g concentrated H ₃ SO ₄ slowly added with stirring so that a homogeneous reaction mixture having a composition, expressed in molar ratios of the oxides of

SiO ₂ ZAl ₂ O ₃ = 93.5 = 0.09

₂₂ ; ₃ = 41.5 ^ o.; .. v, .. k \ _; JiH-ZSiOp = 0.39

arises.: The crystallization, is at a temperature of 175 ⁰ G ί after; 48 h ended. _t ^: , >.,;:::;;', _: m ^ / ^ i;. \: ^ _K ±; The product contains, based on the X-ray intensity of the product in Example 2, 85% by weight of ZSM material.

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X-ray, IR and adsorption data correspond to those of Example 2.

According to Example 4, a reaction mixture with the composition, expressed in molar ratios of the oxides of

Z ₃ '* 300 s 0.5

₂ Z ₂ = 100 KH ₃ ZSiO ₂ '»0,17

from 100 g of sodium waterglass (about 28 % by mass of SiO 2), 0.96 g of Al ₂ (SO 4) - . 18H ₂ O, 5.65 g of aqueous NH, OH solution (about 25 Ma. - ^ NH-) and 1.99 g könz. H ₂ SO ₄ produced. The

Crystallization is carried out at 175 ⁰ C. After 16 h, a product which contains 60 Ma, # ZSM-5 (based on Example 2) crystallizes. In addition, amorphous shares can be detected. The X-ray and IR data of the ZSM fraction are the same as in Example 2. The water vapor absorption capacity was found to be room temperature and 80 Pa to 3.20 Ma .- $.

Example 6

According to Example 4, a reaction mixture with the Zusaminensetzung, expressed in molar ratios of the oxides of

SiO ₂ ZAl ₂ O ₃ * 96

Na ₂ OZSiO ₂ s 0.12

CaOZSiO ₂ = 0.05

H ₂ OZSiO ₂ = 45.5

NH ₃ ZSiO ₂ = 0.56

prepared and exposed for 22 h of crystallization at 190 ⁰ G. The product obtained is 75 Ma. -% (based on Example 2) from ZSM-5. Furthermore, amorphous and

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structurally unknown layer silicate components are detected. The X-ray diffraction lines of the ZSM-5 fraction correspond to those of Example 2 _e

Claims (3)

237604 8 r Γ i η (I η gsa η s ρ ruch 1. A process for the preparation of high-siliceous zeolites having a SiO ₂ Al ₂ O ₃ molar ratio> 10, wherein an aqueous reaction mixture is kept at elevated temperature under pressure necessary for the crystallization time, g e k e η. The aqueous reaction mixture consists of at least one source of alkali and / or alkaline earth metal oxide, at least one source of alumina, at least one source of silica and of ammonia. 2. Method according to item 1, η η ζ ei without t in that the composition of the reaction mixture, expressed in Llolverhältnissen of the oxides, in the ranges SiO ₂ Al ₂ O ₃ = 15 to 300 M _{2 / n} O / SiO ₂ = 0.05 to 1.0 H ₂ 0 / Si0 ₂ = 5 to 200 M ₃ ZSiO ₂ = 0.1 to 1.0. 3. The method according to points 1 and 2, characterized in that the resulting high-siliceous zeolites by the following typical values of the X-ray diffraction lines 237604 IT grid spacing / ~ iimJ7 relative intensity 1,12 +0,025 st 1,00 Hh 0,025 pc 0.387, + 0.007 sst 0.383 + 0.005 st 0.376 + 0.005 st 0.373 + 0.005 st 0.366 + 0.005 m " st a strong, sst - very strong, m = medium and IR absorption bands - 1-r Absorption band £ cm J relative intensity 440 +3 st 520 +3 st 780 + 3 m 1080 +3 sst 1220 +4 sst 1630 +5 m 3440 +6 st 3650 +7 m st β strong, sst == are very strongly characterized in medium.