DD219639A3 - METAL CONTAINING CRYSTALLINE SILICATE - Google Patents

Abstract

The invention relates to a metal-containing crystalline silicate (LZ 40). The aim of the invention is a new metal-containing crystalline silicate with a defined lattice and pore structure, which requires very short crystallization times and technically easily accessible and environmentally friendly substances to achieve phase-pure and well-crystallized products. The object to develop such a silicate, which is due to its uniform lattice and pore structure of its phase purity as adsorbent and / or catalyst component for many applications, is solved, according to the invention, the molar ratio SiO2: MexOy in the metal-containing crystalline silicate 30 and the SiO2 content in the anhydrous product is 92% by mass and the X-ray diffraction pattern has the following reflections: d-values in nm intensity, nominated1,115 very strong1,030 very strong1,025 strong0,997 weak0,605 weak0,575 weak0,562 weak0,427 weak0,388very strong0,384m strong0,377max0 , 373multidot0.366, weak, 0.346, weak, 0.336, weak, 0.306, weak, 0.330, and that the sorbent capacity of the anhydrous material at 298 K for benzene is 7% by mass, for n-hexane 9% by mass, and 8% by mass for the saturation vapor pressure of the sorbate. The silicate contains surface active substances of anionic and / or nonionic type but is free of organic cations.

Description

FIELD OF THE INVENTION The invention relates to a novel metal-containing crystalline silicate having a defined lattice and pore structure which is suitable as a catalyst component or adsorbent. .

Characteristic of the known technical solutions

Silicon-rich crystalline aminosilicates (zeolites) have been known for some time. They differ by their synthesis parameters and / or their physicochemical properties. For the synthesis of zeolites of the ZSM family, for example, organic cations, such as quaternary ammonium or phosphonium compounds (US Patent 3702886), or precursors thereof, such as primary amines (DE-OS 2442240) or mixtures of alcohols NH ₃ (DE -OS 2913552). · '

Aluminum-modified crystalline silicic acid are finally described in DD-PS 144397 and 144398, which require tetraalkyl orthosilicate or silica gel for their synthesis. The products described are outstandingly suitable as adsorbents or catalyst components.

In order to ensure the particularly important selectivities, it is endeavored to obtain very phase-pure products. In order to arrive at phase-pure and well-crystallized products, usually.Lange crystallization times (at least 24 to over 100 hours) and / or special complicated and thus valuable, technically difficult to access organic compounds are required, which are from safety and environmental point of concern from dangerous to dangerous and therefore force them to costly recovery ^ and / or harmless. _ά

Object of the invention

The aim of the invention is a new metal-containing crystalline silicate with a defined lattice and pore structure, which requires to achieve phase-pure and well crystallized products very short crystallization times and technically easily accessible and environmentally friendly substances.

Explanation of the essence of the invention

It was therefore the task of developing a new metal-containing crystalline silicate, which due to its uniform

Grid and pore structure and its phase purity as Adsrobenz and / or catalyst component suitable for many applications.

This object is achieved by a metal-containing crystalline silicate in which, according to the invention, the molar ratio of SiO ₂ : Al ₂ O ₃ in the metal-containing crystalline silicate is> 30 and the SiO ₂ content in the anhydrous product is> 92% by mass and the X-ray diffraction pattern is as follows Reflexes has:

d-values in η m intensity, normalized

1,115 · very strong

1,030 very strong

1.025 strong

0.997. weak

0.605 weak

0.575. weak

0.562 weak ^Λ

Example 2

300g, calculated as anhydrous material, an X-ray amorphous Alumosilicathydrogels with a SiO ₂ / Al ₂ 03 molar ratio of 55 to 60g NaOH, is suspended with vigorous stirring in a solution containing 10 g sodium aluminate solution (29OgI ^-1 AI ₂ O _3; 27391 ^"1 NaOH -) and 20g of a commercially available Oleylmethyltaurits (Metaupon) in 21 water.

The mixture is placed in an autoclave and added with further intensive stirring 300ml ammonia solution (250gl ~ ¹ NH ₃ ), the autoclave immediately closed and heated with constant stirring within about 4h to 480K and left for 5 h at this temperature.

After filtering off, washing and drying, the product shows an X-ray diffractogram according to Table 1 with low amorphous contents. (Table 2, comparison)

The average particle size of the crystalline particles was 0.5 to 2μιη. Here, too, elemental analysis showed a proportion of 1.1% by weight of C and 0.2% by weight of H.

After annealing at 873K for 5 hours, the chemical analysis gives the following composition:

SiO ₂ : 95.7% by mass

Al ₂ O ₃ : 2.4Ma .-%

Na ₂ O: 1.8% by mass "

It is absorbed at 298 K:

9.5Ma .-% n-hexane 10.1 Ma .-% benzene

7.0% by weight of water.

Example 3

The procedure in the crystallization is the same as in Example 1. As the nonionic type surfactant, an industrially available alkylphenyl polyethylene oxide (Praewozell ON) in an amount of 50 g is added. The synthesis time is 10h at 430 K. It becomes a phase-pure and 100% crystalline product with an average crystallite size

/ on 1,5-3μΓη received. ,

Elemental analysis of the crystalline product showed 1.3 mass% C and 0.2 mass% H.

The X-ray diffraction pattern is identical to that shown in Tab.

The crystalline product has the following chemical composition after the thermal treatment (5 h at 873 K):

SiO ₂ : 95.2% by mass

M ₂ O ₃ : 2.6Ma.- ° / o

Ma ₂ O: 2.2Ma .-%

and absorbs at 298K 10%, 9% by weight of η-hexane, 10.4% by weight of benzene, and 6.8% by weight of water.

Example 4

After addition of a mixture of 30 g of polyvinyl alcohol and 10 g of E30 dissolved in 1000 g of H ₂ O, a solution containing 25 g of sodium aluminate (29OgT ¹ Al ₂ O ₃ ; 273 g ¹ NaOH) and 50 g of cobaltous sol (28OgP ¹ SiO ₂ ) are added KOH in 500ml of water snthält. After thorough mixing, 1000 ml of an ammonia solution (12OgT ¹ NH ₃ ) are added with stirring and the reaction mixture heated in a stirred autoclave with continued stirring within about 3 h to 480 K and left for 15h at this temperature. The washed and dried product is highly crystalline at a particle size of m average 3 to 5 / xm. Its X-ray diffractogram corresponds to that of Table 1, but shares of α-quartz are observed.

After annealing at 873 K in air for 5 h, the product shows the following chemical composition:

SiO ₂ 97.1% by mass

M ₂ O ₃ 1.7Ma .-%

^ Yes ₂ O 1,1 Ma .-% '

At 298K, 9.3 mass% of η-hexane, 7.5 mass% of benzene, and 5.3 mass% of H ₂ O are absorbed.

Example 5 "

The crystalline silicate from Example 1 is subjected in a known manner to an ion exchange with NH ₄ ⁺ ions, washed irtd dried. With the addition of 30% by weight of a boehmite-type alumina ladder and 3% by weight of calcium stearate (as binder and lubricant), it is then pressed into 5 × 5 mm cylinder moldings, which are then air-annealed at 823 ° K. for 5 hours , Under the following conditions, the cylinder moldings are catalytically tested in the methanol conversion reaction:

Raw material: methanol techn.

associated gas: hydrogen

) jerk:, '1,0VIPa

Load: 2g / g-h

At a temperature of 648 K, the reaction mixture consists of 70% by volume of an aqueous and 30% by volume of an organic hare. The content of aromatic hydrocarbons in the organic phase is 56% by volume.

Example 6

In the same conditions as in Example 5, the crystalline silicate of Example 3 is ion-exchanged, deformed and alloyed.

In the following conditions, the cylindrical moldings are tested catalytically: Solvent: Hydro-refined DK cut of the boiling point 453 to 633 K Inert gas: Hydrogen

) jerk: 3.8 MPa /

load: 5I / I h

ias / product ratio: 200: 1 Nl / l

At a temperature of 653 K, the cold behavior of the raw material was influenced as follows: Is sink: the pour point from 264K to 235K the BPA point from 271K to 249K.

0,427 "weak

0.388 very strong

0.384 strong ''

0.377 "medium strong.

0.373 medium

0.366 weak

0.346 weak

0,336. weak.

0.306 weak. ·

0.300. weak

and in which the sorbent capacities of the anhydrous material at 298K for benzene are 2 7% by mass, for n-hexane 2 9% by mass and for water <8% by mass at the saturation vapor pressure of the sorbate and in which the silicate (acc crystallization) contains surface-active substances of the anionic and / or nonionic type, but is free from organic cations. 'I'

The metal-containing crystalline silicate, as a metal capable of forming a space network structure, advantageously contains aluminum. It is particularly favorable if the size of the silicate crystallites is <5 .mu.m.

The metal-containing crystalline silicate according to the invention, referred to below as LZ 40 for short, is outstandingly suitable as an adsorbent and / or catalyst component, with the by-products of crystallization not requiring any elaborate reclamation and detoxification technology.

The metal-containing krsitalline silicate (LZ 40) according to the invention is distinguished by high phase purity and outstanding crystallinity and also differs from known zeolites of the ZSM type by its characteristic X-ray diagram. The preparation can be carried out such that a crystallization mixture consisting of: at least one compound of metals which are capable of forming Raumnetzstrukturen, an inorganic silicon compound of at least one inorganic base and a surface-active substance of the anionic and / or nonionic. Type of hydrothermal crystallization with a crystallization time of <20 h subject. ^;

After separation from the mother liquor and removal of the adhering solution, the LZ 40 contains, in addition to the base, surprisingly proportionate amounts of the surface-active compounds added to the crystallization mixture

Apparently, this physical adsorption of both the bases and necessarily the surface-active substances is the decisive prerequisite for the formation of LZ 40. LZ 40 is free of organic cations, nor are these or their precursors needed for its crystallization. ' s

As the inorganic silicon component is preferably an X-ray amorphous aluminosilicate or hydrogel having a SiO ₂ / Al ₂ O ₃ ratio of 1 to 1000. Further, water glass, silica hydrogel or silica gel can be used. · '»

As surface-active substance of the anionic type are particularly well detergent bases, such as. N-alkanesulfonates or taurites. '^;

Advantageously, amphoteric surfactants (betaines), as z. As used in the cosmetic industry, can be used, since they are effective in the alkaline crystallization medium as anionic surfactants. As a surfactant of nonionic type can be successfully z. As textile auxiliaries such as Alkylpheriylpolyethylene or polyvinyl alcohol can be used. As a metal compound capable of forming space network structures, X is preferably used an aluminum compound which may be aluminum nitrate or sodium aluminate. 'Ammonia and / or alkali and or alkaline earth and / or alkali aluminate can be used as inorganic base.

The preferably crystallization temperature is 400 to 480 K, preferably the crystallization time 5 to 15h. The metal-containing silicates prepared according to the invention are excellently crystallized and are outstandingly suitable as catalyst components or absorbents. The following examples are intended to explain the subject matter of the invention in more detail:

Exemplary embodiments Example 1

In a Schuettelautoklaven 880g of water glass (35OgI " ¹ SiO ₂ , 13OgI ^-1 NaOH) mixed with 1150g of water is added to a solution containing as an anionic surfactant an industrially available n-Alkylsulfonät with a chain length of C ₁₂ -C ₁₈ (E30) in an amount of 40 g, water in an amount of 500 g and ammonia (φ = 0.91 Ogi " ¹ ) in an amount of 240 g. , <

Finally, a solution is also added, with stirring, which is prepared by dissolving 40 g of Ai (NO ₃ ) ₃ .9H ₂ O in 1000 g of water and 185 g of nitric acid (.PHI. = 131 gL ^-1 ). After closing, the autoclave is heated to 460 K within 4 hours and held at this temperature for 10 hours. After cooling the autoclave, the crystallizate is filtered and washed and the filter cake dried at 393K. There is obtained a 100% crystalline product with a low a-quartz and cristobalite content. The crystallite size is 1 to 2 / xm. , ,

The crystalline product may contain, by elemental analysis, 1.3 mass% C and 0.3 mass% H, corresponding to the amount of surface active agent absorbed.

The product has the following chemical composition after the thermal treatment (5 h at 873 K): SiO ₂ - 95.8 Ma .-%

Al ₂ O ₃ - 2.9% by mass. ,

Na ₂ O - 1.3Ma .-% _v ,. :. ,

The annealed sample absorbed at 298K10.3Ma% n-hexane, 8.8 mass% benzene, and 6.3 mass%, and 6.3 mass% water. : Table 1 contains the X-ray diffraction pattern for the unannealed product.

The liquid yield was 94.3% by mass and, as a result of the reaction, 5% by mass of C ₃ , C 1 hydrocarbons were formed. In Table 2, the Beugüngsdiagramm for a known zeolite (ZSM5, according to US-PS 3702886) is shown (Vergieichsdarstellung for inventively crystalline silicate LZ40).

Table 1 Intensity, normalized ' US-PS 370288b d-Werteinnm sst 1.115. sst Intensity, normalized 1,030 St St 1,025 - .S. St 0.997 S S 0.605 s S 0,575 S S 0.562 S S 0.427 sst S 0,388 ' St S 0.384 m 's 0.377 m S 0.373 S sst 0,366 S St 0.346 S S 0,336 S S 0.306 S 0,300 sst = very strong st = strong s = weak m = medium strong Table 2 ZSM5 according to (Comparison) d-Werteinnm 1,115 · :. i ooi 0.744 0.708 0.636 0,599 0.556 0.499 0.461 0.426 0.384. 0,372 0,305 0,298

Claims (2)

Invention claims: 1. Metal-containing crystalline silicate (LZ 40) with defined Raumnetz- and pore structure, which is suitable as adsorbent and / or catalyst component, characterized in that the molar ratio SiO ₂ : Al ₂ O ₃ in the metal-containing crystalline silicate> 30 and the SiO ₂ content in the anhydrous product S is 92 mass% and the X-ray diffraction pattern has the following reflexes: d-values in η m intensity, nominated 1,115 very strong · .. 1,030 very strong, 1.025 strong 0.997 weak 0,605 - weak 0.575 weak 0.562 weak 0,427 weak 0.388 very strong [ 0.384 strong _Λ 0.377 medium 0.373 medium 0.366 weak 0.346 weak 0.336 weak. . 0.306 weak 0.300. weak " and that the Sorbtionskapazitaten the anhydrous material at 298 K for benzene> 7% by weight, for n-hexane> 9% by weight and for water <8% by mass at the saturation vapor pressure of the sorbate and that the silicate surfactants of anionic / and / or nonionic type physically bound, but is free of organic cations. 2. Metal-containing crystalline silicate according to item 1, characterized in that the size of its crystallites is <5 / zm.