DD268122A3 - METHOD FOR PRODUCING MOLECULAR SUGAR GRANULES - Google Patents

Abstract

The invention relates to a process for the preparation of molecular sieve granules. The aim of the invention is the deformation of molecular sieve powder with formation of a binder matrix, wherein for the specific application, such granules arise, which have both good adsorptive and good mechanical properties. According to the invention, by mixing a montmorillonite-rich and a kaolinite-rich clay, a binder is formed which, when forming molecular sieve powder with the addition of water, drying and calcination, leads to the formation of a binder matrix, the granules having both good adsorption and good strength properties. It has been found that the proportion of montmorillonite-rich clay in the order of 5 to 30% and that of the kaolinitreichen clay must be in the range of 95 to 70%.

Description

The invention; relates to a process for the preparation of molecular sieve granules which are incorporated in the art for selective adsorption and separation processes under dynamic and static conditions as well as on the Kavalysegobiet. All the natural and synthetic zeolites inirage, which have a system of micropores of uniform diameter and can be shaped into granules with the addition of binder, are used for the shaping process.

Oharakteriatik the known technical solutions

As a binder for the deformation of molecular sieves mainly clays are used. Zeolite particles are incorporated in the binder matrix in the granulate which has been used for practical purposes. The formation of the binder matrix has a stimulating effect on the mechanical and adorptive properties of the molecular sieve granules.

It is known to produce zeolite granules by means of additions to the binder in the shaping process, which

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have neither excellent mechanical properties or show particularly dynamic active effect. The table gives examples.

Table;

^ finding effect principle

DE-AS 1,203,238 SiO-bonded moldings are under

Aluminate and NaOH addition recrystallized.

SU-UHS 210.104 Granules of kaolin and zeolite

is recrystallized in alkaline solution.

DE-OS 2,016,838 A zeolite A, X or a mixture

Both are bound with Kieaelsol and recrystallized by a corresponding synthesis route to a binder-free granules.

DE-OS 2,055,476 Mordenite powder is mixed with clay

and the mixture prior to granulation silica sol added as a hardener component.

US Pat. No. 3,382,187 A clay-bound molecular sieve granulate is impregnated with potash spirits as hardener component and then fired again.

US-PS 3,234. "A sound-formed and burned clay

Molecular sieve granules are hardened with alkali silicate solution.

DE-OS 2,036,821 A zeolite-clay mixture is with a

Al (OH) o sol mixed, granulated and fired ·

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Continuation of the table;

DD-PS 55.326 Use of pore filling substances during

the deformation process, which burn out during the annealing of the granules.

DD-PS 121.092 Use of clay binders with

BET outer surface area between 10 and 40 m ² / g.

DD-PS 116.2Q7 Natural binders with a partial

0 size of 250 - 500 A are for the

Deformation process preferred.

In addition, if silicate- or alumina-based hardness formers are added to the zeolite-clay mixture, the static and dynamic adsorption capacity of the zeolite granules is reduced. In most cases, the addition of a hardener and the Nachkristallisation associated with the increase in technological complexity.

It is known that montmorillonitreiche or montraorillonitillitreiche hochquellfähige Tono, so-called. Clays with mixed-layer content, in the plastic deformation of molecular sieve powder with water result in particularly solid granules, which have poorer dynamic Adsorptionskapzitäten. In contrast, the zeolite granules that have been deformed with kaolinite-rich clays have the merit of excellent dynamic adsorption capacity and low pungency indexes.

Since the clay substances to be selected for BET and particle size according to the specified tone value ranges can be both kaolinite and montmorillonite-rich, the choice of these parameters is not a criterion for the formation of zeolite granules having preferred mechanical and adsorptive properties.

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Object of the invention

The aim of the invention is the deformation of molecular sieves to form a binder matrix for the specific application for the production of zeolite granules which have both good adsorptive and good mechanical properties.

Explanation of the essence of the invention

It has been found that with a composite mixture of different clays which differ in mineral composition, granules can be prepared by the plastic deformation method with the addition of water having good adsorption and strength properties.

In accordance with the invention, a binder is formed by mixing a non-moromium-rich clay and a kalolinite-rich clay to form a binder matrix upon forming molecular sieve powder with the addition of water, drying and annealing, which guarantees the granules good peat and adsorptive properties.

It has been found that the proportion of the montmorillonite-rich clay in the order of 5 to 30 % and that of the kaolin-rich clay should be in the range of 95 to 70 % .

The Gesaratbindemittelgehalt in the granules moves in the limits known from the literature.

Montmorillonite-rich clays are to be understood as meaning those raw materials which comprise at least 50% highly swelling montmorillonite. The kaolins to be used should have at least 50 % kaolinite content.

The advantage of the method is that the properties of the zeolite granules are specifically changed for the specific application by the composite binder.

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can, so that economic advantages in the operation of adsorption and separation plants are recorded. For the process according to the invention, it is possible to use all zeolite types in various cation forms.

embodiment

1. A NaGtJl zeotith is dry mixed homogeneously with 22% clay binder, the calculation refers to anhydrous substances. The binder is composed of various proportions of a montraorillonitreichen and kaolinitieichen clay. After homogenization, the powder mixture is plasticized with water and pressed into strands of 3 mm diameter. After the subsequent drying and annealing process, the mechanical and adsorptive indices are determined. Depending on the composition of the clay binder, the qualitative indices of the zeolite granules change, as indicated in the table on page 6.

It can be seen from the table that in the proportion of 5 to 20 % of montmorillonite-rich clay in a composite clay binder both good adsorption properties and good strengths have been achieved. Compressive strengths above 10 MPa and abrasion below 10 Ma. -% are required for industrial use of molecular sieve granules.

2. A NaMg20A zeolite is processed and tested with 20 % clay binder composed of various proportions of a montmorillonite-rich and kaolinite-rich clay as indicated in 1. above. Depending on the composition of the clay binder, the adsorptive and mechanical properties of the zeolite granules change, as indicated in the table on page 7.

Table:

Composition of the clay binder in % kaoliniti- montmorillon clay Ionitisci clay 0 ⁺ Water vapor adsorption capacity in Ma. -% ^{h +} n-pentane retention ml / g zeolite granules Breakthrough capacity for normal paraffins in the C number range C ₁ Q to CpQ under normal pressure and 380 ⁰ C (wt%) Compressive strength in MPa Abrasion in % 100 5 16.1 110 6.0 9.8 35 95 10 16.4 117 6.2 13.6 12 90 20 16.5 131 6.4 15.7 5.8 80 40 15.9 135 6.4 17.9 5.2 60 80 16.0 117 6.3 28.2 4.5 20 15.8 118 6.1 45.4 3.0

⁺ Determination according to standard BDR TGL 22309 Gas Chromatography determined retention volume

ts

ro v *> VD ON

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Table:

Composition of the montmorillonite ^x water ^ separation ^x print ^x abrasion Tonbinder in % loniti- steam- factor strength strength in % kaolini- Seer sound adeorp- in Roommate TION MFa volume capacitive 10 in 20 Ma. -% 90 30 20.8 48.5 6.5 30 80 40 21.1 167.0 8.0 24 70 80 20.9 175.5 11.0 20 60 100 20.6 137.2 18.3 14.5 20 20.8 14.4 25.4 16.0 0 20.7 13.0 32.3 13.0

Determination according to standard DDR TGL 22309

separation factor

adsorbed amount of propene to 1 g of zeolite adsorbed amount of propane to 1 g of zeolite

From the table it can be seen that at proportions of 10 to 30 % montmorillonite-rich clays in a composite clay binder, the separation of the propane-propene mixture is most effective, the granules having sufficient mechanical properties.

Claims (2)

1. A process for the preparation of molecular sieve granules by mixing zeolites and clay as a binder in the powdery state, plasticizing with water, deformation, Tro and annealing, characterized in that are used as binders Tongemischsi based montmorillonitreicher and kaolinitreicher clays. 2. The method according to item 1, characterized in that a clay mixture of 5 to 30 % montnorillonitreiehern clay and 95 to 70 % kaolinitreichem clay is used.