DE19815564A1 - High strength optionally honeycomb-structured zeolite bodies useful as adsorbers or in gas drying etc. - Google Patents

Abstract

A shaped body obtained using a reaction mixture comprising a zeolite, plasticizer and binder is such that: (i) the binder is a polysiloxane of formula (I); and (ii) the zeolite is of type 3A, 4A, 5A and/or X. R = methyl or ethyl; and n = 1-10 An Independent claim relates to production of the body by extruding the mixture, and (ii) calcining the extrudate at 180-250 deg C.

Description

The present invention relates to a shaped body which consists of a reaction mixture has been prepared, the zeolite, Plasticizers and binders. Continue to be the present invention relates to a method of manufacture of such a shaped body and its use.

Zeolites are crystalline microporous materials with definite ter pore structure. These can be found in the form of fixed bed fillings diverse technical application, for example in drying gas removal, volatile organic hydrocarbon removal substances from exhaust air flows and the separation of hydrocarbons fractions.

A disadvantage when using fixed bed fillings made of zeolite is above all the abrasion that occurs during operation. This unwanted dust-like abrasion affects the function downstream fittings and devices essential. Furthermore  have fixed bed fillings when flowing gases in the Ver equal to zeolitic honeycomb bodies pressure losses that are significantly larger and can vary during operation.

In order to be able to form zeolitic powders into shaped bodies, additives are added to the powder in a compounding step which give the molding compound a certain plasticity, which in turn is a prerequisite for the subsequent molding exercise procedure. The plasticizer should be finished the shape is as residue-free as possible from the manufactured Form such as an extrudate may be removable because be sorptive and catalyzed table properties of the zeolitic molded body produced affect pers. To obtain a dimensionally stable molded body ten, it is also necessary that the molding compound binder is added. During the subsequent calcination this binder decomposes to form a solid bridges.

A process for the production of hard, unbreakable catalysts For example, zeolites from the Pentasil family are in DE 32 31 498 A1. As a binder Tetramethylorthosilicate (TMOS) used in an amount of 5%. The plasticizer is hydroxyethyl cellulose, which in one Amount of 2% is used. After kneading this mixture these are transferred to an extruder and pressed into strands. After Drying of the shaped body produced in this way becomes this at temperatures in a range from 400 ° C to 800 ° C 2 hours the long calcined.

A disadvantage of the procedure described in this document ren it is above all that due to the high temperatures and the long calcination time the production of the zeolitic Shaped body is very expensive. The Tatsa also contributes to this che that the mixing of the molding compound and the extrusion in separate steps. Furthermore, that is in  binder described in this publication tetramethylorthosi likat a small molecule that is inside the Penta sil zeolites deposits, clogs them and thus their sorptive and catalytic properties impaired.

DE 37 38 916 A1 describes molecular sieve moldings made from zeolites, in which silica sol is primarily used as a binder, the SiO ₂ particles contained in this silica sol having a BET specific surface area of 150 m ² / g. 400 m ² / g. Molding compositions comprising a mixture of silica sol and a mixture of ethyl esters of methyl silicic acids are also described, the latter being added to the silica sol in small quantities. Lubricants are added to the molding compounds, which enable rheological fine-tuning of the molding compound formulation used. The molecular sieve shaped bodies consist of zeolites of the Y type or mordenite type. The molecular sieve moldings are produced by extrusion, the molding composition being mixed and kneaded first and then being transferred to the extruder in a second step. The calcination takes place at 500 ° C to 800 ° C.

It is extremely disadvantageous in the case of DE 37 38 916 A1 Molecular sieve moldings described that these in a dis continuous process at very high temperatures be put. This increases the manufacturing costs of Moldings significantly. It is also disadvantageous that in the used mixture of silica sol with ethyl esters of methyl silica the silica sol is in colloidal form. The It is therefore not possible to form a continuous matrix Lich. The solid binder is difficult to distribute in the Ver equal to the binder in liquid form. Finally, expensive lubricants are added.

Zeolitic molded articles in the form of extrusion to date, honeycomb bodies have not been commercially available.

The object of the present invention is to provide a shaped body Zeolite base and a process for its production for ver to provide, avoid the known disadvantages and in particular which are inexpensive.

This object is achieved in that the molded body is produced from a reaction mixture comprising zeolite, plasticizer and binder, the binder being a compound of the formula (I)

comprises, in which R is in each case independently methyl or ethyl and n is a number from 1 to 10, and wherein the zeolite is zeolite 3A, Zeolite 4A, Zeolite 5A or Zeolite x or any Mi Research of the aforementioned types of zeolite.

The moldings according to the invention advantageously have spoken high compressive strengths of, for example, 20 N / mm or more. A was used to determine the compressive strength Tensile / compression testing machine from Zwick, type UP 1455 used. For this purpose, fully cylindrical extrudates with one sample were passed through knife cut from 5 mm to a sample length of 7 mm. For exact and reproducible compressive strength measurements must be based on the Plane parallelism of the end faces of the extrudates must be observed. The measurement is carried out at room temperature. The preload is 1 N. The tests were carried out with a test speed of  1 mm / min. The test force acts on the end faces on.

The moldings according to the invention can be mechanically stressed and are therefore suitable for a wide range of uses. Furthermore, the molded articles according to the invention have abrasion resistance of more than 99%. The abrasion resistance was carried out based on the American Penny Attrition Test (Mitchell WJ et al., US Pat. No. 2,973,327, 1956): 3 g of fully cylindrical zeolitic pellets with D = 5 mm and ^L / D = 1.5 were placed in a sealable plastic container. The container was exposed to a frequency of 60 scale units for 20 minutes in a Retsch (type 3D) vibration screening machine. In order to simulate increased abrasion and a realistic load, there is also a 1 Pfennig piece in the plastic container. The resulting abrasion is then separated off with a sieve with a mesh size of 500 μm at a frequency of 20 SKE over a period of 2 minutes.

Clogging or damage to the molded body aggregates or machines due to abrasion, in particular re occurs in fixed bed fillings based on zeolite not on. This makes the moldings according to the invention special suitable for long-term use in technical devices. This eliminates the need for fixed bed fillings Changing the zeolite material reduces the operating costs of the Devices in which the molded body according to the invention ver is applied. In addition, by using the fiction contemporary moldings a significantly smaller and more defined Pressure loss achievable, which the same for the design respective uses are greatly facilitated.

Surprisingly, it has been shown that the moldings optimally at temperatures below 300 ° C, preferably in a temperature range of about 180 ° C can be calcined to about 280 ° C. This temperature is  far from the previously described in the prior art an area. This makes it possible to reduce the manufacturing costs to drastically lower the molded body according to the invention.

The zeolites mentioned are extremely inexpensive to produce and also versatile, for example se as a drying and separating agent for gases or organi liquids.

Preferably, n is a number in the siloxane according to formula (I) from 3 to 4, preferably the proportion of the radicals R = methyl is larger than that of the radicals R = ethyl. The siloxane has advantageously a very high proportion of methyl groups. Under Moldings produced using such a siloxane have optimal mechanical, sorptive and catalytic properties on.

The binder used in the molded article according to the invention Formula (I) also serves as a lubricant. The inner ones and external lubricants, which according to the prior art for Influencing the rheological properties of the molding compound to be added disadvantageously require in manufacturing process to achieve a uniform distribution high Shear entry and thus long kneading times, which the manufacturer the cost of the molded articles made from it in the amount float. Since reaction mixtures according to the invention with the Ver bond of the formula (I) lowered flow limits and low Have inlet pressure losses in the manufacturing process, that is Deformation behavior of the reaction mixture considerably improved and the addition of other lubricants is not necessary.

The moldings according to the invention have in particular in the form of Honeycomb extrudates due to the large surface area compared to Fixed bed fillings made of zeolite a significantly improved Sorp tion kinetics. So is the increase in water when measuring the Sorption capacity in a climate chamber at T = 23 ° C and one  relative humidity of 10% in the range of 13 wt .-% to more than 17% by weight, based on the shaped body, after three hours Use of a type 4A zeolite.

So far it has been assumed in the professional world that zeolites not using siloxanes as binders, which are relatively expensive compared to the zeolites used, are to be produced because these moldings are only uneconomical were to be manufactured. Zeolites are becoming commercial to this day used only in the form of fixed bed fillings.

The shaped body according to the invention preferably has a binder with an SiO ₂ content of about 50% by weight or more, more preferably about 60% by weight or more, based on the total binder. With such high SiO ₂ contents, extremely high compressive strengths and abrasion resistance are obtained, which make the moldings according to the invention usable for a variety of technical applications.

This preferably contains for the production of the invention Binder used in molded article less than about 10% by weight Solvents, based on the entire binder. Is more preferred a solvent content of less than 5% by weight in the binder, the binder is even more preferably solvent-free. This enables the processing of the binder without consideration setting of solvent-specific safety regulations. Hereby the manufacturing costs of the molded body according to the invention further lowered.

The binder further preferably comprises silicone resins. Ins In particular, methylphenyl silicone resin emuls can be used as silicone resins sions are used. By adding silicone resins the compressive strength values can be set specifically.

The silicone resin is preferably solvent-free. A little Proportion of solvents or their absence both in the silicone  Resin as well as in the siloxane according to formula (I) not only leads to a reduction in production costs due to lower Safety precautions, but about it In addition, there is also a deformation of the moldings in the drying process and avoided in the calcination step. Become binders according to formula (I) with solvent contents greater than about 10% by weight, based on the total binder or solvent Contains silicone resins used, so the quick cursing leads the solvents in the drying process to form bubbles and cracks formation on the honeycomb surface and to a deformation of the extruded molded body by volatilization of the still in this contained solvent, in particular such that with extrudates after leaving the side surfaces descend towards the center (Shrinkage). The moldings according to the invention, however, have extremely high dimensional stability during drying and Calcination on.

The silicone resin preferably has a particle size of approximately 1 µm to about 10 µm. Such silicone resins can be optimal with the zeolites and plasticizers used and Mix and process other binders.

The moldings according to the invention preferably have a compressive strength of approximately 20 N / mm or greater, more preferably approximately 30 N / mm ² or greater.

The moldings according to the invention have a maximum compressive strength during calcination in a temperature range from about 180 ° C. to about 280 ° C. Preferably, the calcination temperature is in a range from about 200 ° C to about 250 ° C, more preferably in a range from about 210 ° C to about 235 ° C. Complete crosslinking of the silicone matrix is achieved in these temperature ranges. A maximum number of covalent bridge bonds are formed in the calcination process, to which the zeolite is also covalently bound. If the temperatures are raised to above approximately 280 ° C., the methyl groups are split off from the binder, as a result of which the matrix formed is weakened and the compressive strength of the moldings according to the invention decreases. A poly amorphous inorganic layer of SiO _{2 is formed} . At temperatures below half of 180 ° C, however, crosslinking of the binder and formation of covalent bonds takes place only to a small extent. The values of the compressive strength of the molded articles according to the invention, which were calcined within the above-mentioned temperature ranges, are far above the compressive strength values of the molded articles which were produced at calcination temperatures outside the specified temperature ranges. Compared to zeolite pellets, which are made on the basis of clay materials such as attapulgite or methylated orthosilicates as binders, the compressive strength is many times higher. The achievable high compressive strengths of the moldings according to the invention advantageously result in the shrinkage observed in the thermal treatment of the moldings and the internal stresses of the extrudates triggered by this being compensated. This avoids cracks or the like in the moldings according to the invention. The result is an excellent surface quality and excellent mechanical properties of the molded articles according to the invention.

The plasticizer is preferably a cellulose ether, a polysaccharide, a polyvinyl alcohol, starch or any mixture of the aforementioned materials. Methylcellulose is particularly preferred as plasticizer. These plasticizers are soluble in water. If the liquid phase of the reaction mixture, consisting of water and plasticizer, for the preparation of the moldings according to the invention has only small proportions of plasticizer, in particular methyl cellulose, an inadequate dimensional stability is obtained after the extruder has left the extruder. When extruding quadratic tables 400 cells / inch ² (about 62 cells / cm ² ) honeycomb bodies according to the invention, a methyl cellulose content of about 10 wt .-% or more, more preferably about 15 wt .-%, based on the added te Amount of water, sufficient. When using methyl cellulose as a plasticizer, the deformation behavior of the reaction mixture is still positively influenced. The flow limit is increased and the inlet pressure loss of the extrudate is significantly reduced, a dimensionally stable extrudate is obtained. This results in a lower pressure drop along the nozzle, which reduces the backflow length in the extruder. As a result, there is less shear in the pressure build-up zone of the extruder screw. Less heat is dissipated and heating of the zeolitic molding compound is avoided.

The reaction mixture preferably further comprises as a slip medium wax emulsions and / or fatty acid mixtures. With these can a rheological fine-tuning of the invention Moldings are made. However, such can also alone by adding a compound of formula (I) be. Since the lubricants are relatively expensive, can Dispensing with this the manufacturing costs of the invention Shaped body can be further reduced.

The used for the production of the shaped body according to the invention The reaction mixture preferably contains the binder in one Portion from about 1 to about 35% by weight, zeolite in one portion from about 40 to about 90% by weight and the plasticizer in a proportion of about 5 to about 40 wt .-%, each based on the entire reaction mixture. When using such a reak tion mixtures for the production of the molding according to the invention pers become moldings with excellent sorptive, catalytic and mechanical properties. Preferably the compound of formula (I) in a proportion of about 2 to about 25% by weight, more preferably about 5 to about 20% by weight on the reaction mixture, present in the reaction mixture. The reaction mixture containing the compound of formula (I) exhibits an optimal deformation behavior with these quantities  during the shaping. The moldings according to the invention achieve maximum compressive strength values in this area.

The binder preferably consists of a compound of Formula (I). By foregoing additional binders as well Lubricants are the manufacturing cost of the invention Molded body lowered. Furthermore, they only show a compound of formula (I) prepared according to the invention Moldings have excellent sorptive and catalytic properties mechanical strength. Because of the excellent Deformation properties of the reaction mixture during the Shaping process are low pressure losses along the Wa measuring tool (47 bar at m = 4 kg / h).

The shaped body according to the invention preferably has the shape of a Honeycomb body. Honeycomb bodies with a high cell density have an ex Extremely large surface area compared to other moldings for example in the form of plates, whereby the catalytic and adsorptive properties, especially the kinetics of Ad sorption, the molded article according to the invention improved drastically are. Of course, the molded body according to the invention also in the form of tubes, cylinders, spheres, tablets, rin gene, plates or the like can be produced.

The invention further relates to a process for the production of a shaped body obtained from a reaction mixture, the zeolite, plasticizer and binder having the formula (I)

in which R is each independently methyl or ethyl and n is a number from 1 to 10, in this process

• in a first step a reaction mixture of zeolite, Plasticizer and binder is made;
• - In a second step, this reaction mixture is extruded becomes; and
• - in a third step, the extrudate at one temperature calcined in a range from about 180 ° C to about 280 ° C becomes.

The main advantage of the method according to the invention lies in that the calcination at temperatures in a range from about 180 ° C to about 280 ° C.

Both commercially available fixed bed fillings made of zeolite as well as molded articles described in the prior art Temperatures of at least 400 ° C or more, usually at Temperatures between 500 ° C and 700 ° C, calcined. These high Temperatures cause a very high energy consumption at the Production of the fill or shaped body. By avoiding it these high temperatures in the process according to the invention can drastically reduce the manufacturing costs of the moldings become.

Furthermore, the calcined in this temperature range Moldings have excellent mechanical and sorptive properties on.

The extrusion can be carried out in a single or twin screw Ex truder as well as in a piston extruder.

Preferably, the first and second step of the invention carried out according to the method continuously. This continuously  Implementation, d. H. compounding of the individual recipe components and the shaping of the shape mass happens in one step, for example with one two-screw extruder rotating in the same direction the. The co-rotating, closely intermeshing twin-screw sex With this concept, truder acts simultaneously as a mixing unit and pressure generator for extruding the honeycomb extrudates. The individual components of the reaction mixture are in the case of components in powder form (plasticizers and Zeolite) fed via gravimetric doses, the rivers liquids (water and binders) via membrane or flasks pump. The continuous production of the moldings according to the The inventive method increases the economy of entire procedure considerably. This prevents the kneaded reaction mixture in an additional step in an extruder must be transferred. This step is difficult dig and can possibly contaminate the kneaded Reaction mixture lead to changes in the rheological Lead the properties of the mixture after kneading (storage time).

The third step of the method according to the invention is before pulls at a temperature in a range of about 200 ° C to performed about 250C °. Is the calcination in this TemPe temperature range, so the compressive strength of the mold receive bodies that are significantly higher than in calcination outside this temperature range. Also the sorptive and exhibit catalytic properties of the molded articles produced optimal values in this area.

Of course, you can choose between the second and third step an additional drying of the process according to the invention Extrudates are made.

The invention further relates to the use of the Invention contemporary moldings for drying, conditioning, cleaning and Separation of gases, liquids and vapors. The regeneration  the shaped body used in this way can either by Pressure swing process, heat treatment or cleaning with Lö agents and subsequent drying.

The zeolitic shaped bodies according to the invention can, for example with a rotor absorber as a second stage for removal the residual moisture can be used.

The zeolite moldings can also be used for drying Compressed air can be used. The one with the fresh air in the pressure Air system moisture condenses during compression / decom pression and can damage the radio by subsequent corrosion tion of the system. So by installing the Zeolite shaped body according to the invention as the adsorbent Water from brake air systems, pneumatic drives and tax stanchions are removed and thus corrosion is suppressed.

Furthermore, the molded body according to the invention can be used in the cold drying in CFC-free cooling units. In in this case there is no regeneration of the form according to the invention body necessary because its capacity is ten to fifteen years is. When closing a refrigerant system during the During assembly, moisture is regularly introduced. By the use of the shaped body according to the invention for drying of the refrigerant, the resulting disadvantages are ver avoided.

The drying and thus the reuse of used Refrigerant can with the help of the molded body according to the invention Adsorber done. The regeneration of the adsorber is carried out reached a heat treatment.

These moldings according to the invention can also be used for desulfurization treatment (odor suppression) of liquid hydrocarbons can be used as a spray can propellant (e.g. butane). A brisk generation is out of the question here.  

Another application of the shaped bodies according to the invention is in Air separation plants can be seen in which nitrogen adsorbs and thereby an oxygenation z. B. the breathing air instead finds. The regeneration can take place thermally.

Furthermore, the molded body according to the invention can also be used in climates systems can be used. The adsorption or Evaporation enthalpies used to generate heat or around to cool.

Finally, the shaped body according to the invention can be used as ions Use exchangers in water softening systems where the desired effect achieved by a calcium-sodium exchange becomes.

These and other advantages of the present invention are disclosed in further illustrated using the examples and illustrations.

The pictures show in detail:

Fig. 1 Influence of methylsiloxane on the rheological parameters flow limit and inlet pressure loss;

Fig. 2 compressive strengths of the moldings according to the invention, made of zeolite NaX;

Fig. 3 shrinkage of honeycomb extrudates from zeolite NaX during drying at different microwave power lines;

Fig. 4 adsorption behavior of pellets, made of Zeolith NaX;

Fig. 5 compressive strengths of the moldings according to the invention, made of zeolite 4A;

Fig. 6 adsorption behavior of pellets, made of Zeo lith 4A;

FIG. 7 shows the adsorption behavior of honeycombed extrudates produced from zeolite 4A;

Fig. 8 screw concept for a continuous implementation of the method.

In the following examples, methyl cellulose MC 12000 (company Aqualon) used as a plasticizer. Another component the reaction mixture is water.

Methylsiloxane ether MSE 100 (Wacker, sold under the name SILRES OR). This me thylsiloxane ether corresponds to the formula (I) with n equal to 3 to 4, where the radicals R are predominantly methyl radicals. The molecular ge weight is about 480 g / mol to about 600 g / mol. The solvent proportion of the methyl siloxane ether MSE used in the examples 100 is a maximum of 1.7%, but this can be methylsiloxane ether can also be obtained solvent-free from Wacker. At The use of MSE 100 as a binder is the addition of sili Resins not necessary.

In Fig. 1, the influence of the methylsiloxane ether MSE 100 on the rheological parameters yield point and inlet pressure loss of the reaction mixture is shown. Reaction mixtures without methylsiloxane ether have a high yield point and an extraordinarily high pressure drop in the entrance area of the extruder. By adding the methyl siloxane ether MSE 100, the deformation behavior of the reaction mixture improves significantly. At a content of about 15% by weight of methylsiloxane ether MSE 100, based on the amount of zeolite added, reduced values are obtained both for the flow limit and for the inlet pressure loss. MSE 100 is therefore an excellent lubricant and the reaction mixture does not require any further addition of other lubricants. Furthermore, methylsiloxane ether MSE 100 advantageously does not crosslink during compounding and shaping. Crosslinking takes place only in the calcination step.

An exemplary general reaction mixture for the Her position of the molded body of a zeolite X type contains 200 g of a zeolite X type, this 10% by weight Water contains 10 to 40 g of methyl cellulose MC 12000, preferred 25 g, methyl siloxane ether MSE 100 10 to 90 g, preferably 20 g, and 100 to 250 g water, preferably 170 g. Becomes a zeolite X type used with a lower or higher water content, so more or less water must be added accordingly. The amount of water added depends on the degree of loading of the use zeolite powder.

A general exemplary reaction mixture for the manufacturers development of moldings according to the invention from a zeolite of A-type contains 200 g of A-type zeolite, methyl cellulose MC 12,000 in a proportion of 10 to 40 g, preferably 25 g, methyl siloxane ether MSE 100 in a proportion of 10 to 80 g and one Water content of 70 to 200 g, preferably 100 g, when used of zeolite powder with a water load in the range of 18 wt .-%, based on the total mass of the zeolite.

A tensile / compression test was used to determine the compressive strength machine from Zwick, type UP 1455. For this purpose fully cylindrical extrudates with a sample diameter of 5 mm cut to a sample length of 7 mm. For exact and reproduc zable compressive strength measurements must be on the plane parallelism of the end faces of the extrudates. The measurement takes place at room temperature. The preload is 1 N. The ver searches were carried out at a test speed of 1 mm / min guided. The test force acts on the end faces.

example 1

A molded body consisting of a reaction mixture was formed from zeolite NaX in an amount of 200 g, methyl cellulose MC 12000 in an amount of 25 g, methyl siloxane ether MSE 100 in an amount of 63 g of MSE and water in a proportion of 160 g manufactured. The compounding and shaping into a honeycomb body was carried out in a ZSK 30 twin-screw extruder from Werner & Pfleiderer at a speed of 50 rpm, the Cylinder sections of the extruder have a temperature of 15 ° C sen. Sufficient cooling of the Cylinder shots are respected because methyl cellulose at tempera doors above 40 ° C and partially their water return holding power loses. The molded article produced in this way was dried without previous drying at a temperature of 225 ° C for 60 min. calcined. It had a compressive strength of about 46.7 N / mm.

In FIG. 2, the course of the compressive strength is shown as a function of calcination temperature. For comparison, the dependence of the compressive strength on the calcination temperature is given for a molded article which contains MSE 100 attapulgite, a clay-based binder or tetramethyl orthosilicate (TMOS) instead of methyl siloxane ether. Furthermore, the influence of an increased amount of methylsiloxane ether MSE 100 (35 g) on an otherwise identical formulation on the compressive strength is shown. As can be seen in FIG. 2, the compressive strength has a maximum pressure strength in a range from 200 to 225 ° C. In the entire temperature range examined, the compressive strengths of the shaped body are significantly higher than those of the shaped body produced using attapulgite or TMOS. In the compressive strength maximum of the shaped body, the compressive strength of the shaped body produced according to the invention exceeds that of the shaped body based on the clay binder or TMOS by a multiple. When using the MSE 100 methylsiloxane ether in comparison with clay-based binders or TNOS, significantly higher and excellent strength values can be achieved with a lower binder content. As a result, the proportion of adsorptively active zeolite in the shaped body can be increased and thus the adsorptive properties of the shaped body increased.

Fig. 3 shows the dependence of the change in length (L ₀ -L _n ) / L _{0 of} the honeycomb body produced according to Example 1 in percent as a function of time at different microwave powers. There were two wafer bodies 1 and 2 produced according to Example 1 Measure two different measuring points 1 and 2 , which are rotated by 90 ° to each other (designation: honeycomb body 1 , measured at measuring point 1: 1/1; honeycomb body 1 , measured at measuring point 2: 1/2, etc.). The change in length is a measure of the shrinkage and the induced internal stresses in the honeycomb body. The investigated extruded honeycomb bodies have a cell density of 400 cells / inch ² (approximately 62 cells / cm ² ) and a square cross section with an edge length of 40 mm. With a microwave power of 450 watts, after about 25 min. no further change in length was observed. The maximum change in length is approximately 1.7%. With a microwave power of 900 watts, on the other hand, a change in length is no longer detectable after just 12 minutes; the maximum value for the change in length is also about 1.7%. These results show that the shaped body is subject to minimal shrinkage during the drying step and the calcination. The residual stresses caused by the shrinkage are balanced out by the excellent mechanical compressive strengths. The molded body has a smooth, crack-free surface.

The molded article (NaX pellets) was characterized by adsorption in such a way that it was exposed to a relative humidity of 50% and a defined temperature of 23 ° C in a climatic chamber. The water absorption of the zeolitic shaped body was measured by the same weight gain. This enables statements to be made about the sorption capacity and the sorption kinetics of the extruded molded body. The molded body was first activated at a temperature of 210 ° C over a period of 2500 min and then the measurement was carried out. As can be clearly seen in FIG. 4, the shaped body has a loading of water of approximately 18% by weight, based on the mass of the shaped body. A molded body produced using 63 g of methyl siloxane ether MSE 100 with an otherwise identical recipe and process has a loading of about 20% by weight of water. With both recipes, the loading maximum is reached after about 7.5 hours.

Example 2

A molded body in the form of honeycomb bodies and pellets was produced using 200 g of zeolite A with a water loading of 5% by weight, based on the zeolite powder, 25 g of methyl cellulose MC 12000, 35 g of methyl siloxane ether MSE 100 and 100 g of water. This reaction mixture was extruded in a twin-screw extruder as described in Example 1 at a temperature of 14 ° C. The molded body was then calcined in the case of the production of honeycomb bodies at 200 ° C. for 60 min, in the case of the production of pellets at 100 ° C., 200 ° C., 250 ° C., 300 ° C., 350 ° C. and 400 ° C. . Honeycomb bodies with 400 cells / inch (approximately 62 cells / cm ² ) were produced.

As can be seen from FIG. 5, the molded body (pellet or honeycomb body) produced in this way has a maximum compressive strength in a range between 200 and 225 ° C. Its maximum compressive strength is approximately 43 N / mm ² at 210 ° C.

The adsorption behavior of the pellets obtained is shown in Fig. 6. The measurements were carried out at a temperature of 23 ° C and a relative humidity of 50%. Various adsorption curves were recorded at different pellet calcining temperatures. The activation took place at 200 ° C and an activation time of 60 minutes. As can be seen from FIG. 6, the differently calcined samples have a maximum value of the loading with water after about 50 hours. In the case of calcination at 400 ° C., the maximum load is about 15% by weight of water, based on the total mass of the shaped body. However, calcined moldings of this type have relatively poor mechanical properties, in particular compressive strength values. Samples calcined at 250 ° C have a loading of water in the range of about 13 wt .-%, based on the total mass of the molded body.

Fig. 7 shows the adsorption behavior of the honeycomb body made according to Example 2 ago. The maximum loading of the zeolitic honeycomb body with water is reached after only 3 hours. The loading is, depending on the activation parameters (between one activation for 18 hours at 180 ° C to four activation between 180 ° C to 240 ° C over 18 and 24 hours) between about 14 and about 17 wt .-% water , based on the total mass of the molded body. In comparison to FIG. 6 it can be seen that the honeycomb extrudate has a kinetics which is significantly improved compared to the pellets due to its larger surface area.

Fig. 8 shows an exemplary screw concept for the continuous process according to the invention for the production of zeolite moldings (KB: kneading block, SME: Schneckenmischele element). Using such a screw concept, the zeolite moldings can be produced inexpensively and easily, since the reaction mixture, which is generally produced by kneading the mixture, and the extrusion of this reaction mixture are carried out continuously.

Claims (24)

1. Shaped body obtained from a reaction mixture comprising zeolite, plasticizer and binder, characterized in that the binder is a compound of formula (I)
in which R is in each case independently methyl or ethyl and n is a number from 1 to 10,
and that the zeolite comprises zeolite 3A, zeolite 4A, zeolite 5A or zeolite x or any mixture of the above types of zeolite. 2. Shaped body according to claim 1, characterized in that the binder has an SiO ₂ content of about 50 wt .-% or more, preferably about 60 wt .-% or more, based on the total binder. 3. Shaped body according to claim 1 or 2, characterized in that that the binder is less than about 10% by weight the entire binder, contains solvent. 4. Shaped body according to one of claims 1 to 3, characterized ge indicates that the binder comprises silicone resins.   5. Shaped body according to claim 4, characterized in that the Silicone resin is solvent free. 6. Shaped body according to claim 4 or 5, characterized in that that the silicone resin has a particle size of about 1 micron to has about 10 microns. 7. Shaped body according to one of claims 1 to 6, characterized in that the shaped body has a compressive strength of about 20 N / mm ² or greater, preferably about 30 N / mm ² or greater. 8. Shaped body according to one of claims 1 to 7, characterized ge indicates that it is at a temperature in a range from about 180 ° C to about 280 ° C. 9. Shaped body according to one of claims 1 to 8, characterized ge indicates that the plasticizer is cellulose ether, Polysaccharide, polyvinyl alcohol, starch or any Mixture of the aforementioned compounds comprises. 10. Shaped body according to claim 9, characterized in that the Plasticizer includes methyl cellulose. 11. Shaped body according to one of claims 1 to 10, characterized ge indicates that the reaction mixture as a lubricant Wax emulsions and / or fatty acid mixtures. 12. Shaped body according to one of claims 1 to 11, characterized ge indicates that the binder in a proportion of about 1 to about 35 wt .-%, the zeolite in a proportion of about 40 to about 90% by weight and the plasticizer in one Proportion of about 5 to about 40% by weight, based on each the entire reaction mixture, in the reaction mixture are included.   13. Shaped body according to one of claims 1 to 12, characterized ge indicates that the compound of formula (I) in one Proportion of about 2 to about 25% by weight, preferably about 5 to about 20 wt .-%, based on the reaction mixture in the Reaction mixture is present. 14. Shaped body according to one of claims 1 to 13, characterized ge indicates that the binder from the compound of Formula (I) exists. 15. Shaped body according to one of claims 1 to 14, characterized ge indicates that it is a honeycomb body. 16. A process for producing a molded body from a reaction mixture comprising zeolite, plasticizer and binder of the formula (I)
in which R is in each case independently methyl or ethyl and n is a number from 1 to 10, the process comprising the following steps:

• - In a first step, the preparation of a reaction mixture of zeolite, plasticizer and binder;
• - In a second step, the extrusion of this reaction mixture; and
• - In a third step, calcining the extrudate at a temperature in a range from about 180 ° C to about 280 ° C.

17. The method according to claim 16, characterized in that the first and second steps are carried out continuously. 18. The method according to any one of claims 16 or 17, characterized ge indicates that the third step at a temperature in in a range from about 200 ° C to about 250 ° C becomes. 19. Use of a shaped body according to one of claims 1 to 15 for drying gases, the loaded molded body preferably either by heat treatment or by a pressure swing process is regenerated. 20. Use of a shaped body according to one of claims 1 to 15 for drying liquids and vapors, the loaded molded body can be thermally regenerated, ins especially when processing refrigerants, or in is not used in a regenerative mode of operation, ins especially when drying the refrigerant in closed Circulation. 21. Use of a shaped body according to one of claims 1 to 15 for the desulfurization of gases, especially propellant for spray cans, preferably butane, the swiss feld-containing connection preferably through the molded body is adsorbed. 22. Use of a shaped body according to one of claims 1 to 15 as nitrogen adsorber in an air separation plant, especially for generating oxygen-enriched breath air.   23. Use of a shaped body according to one of claims 1 to 15 in air conditioning systems as adsorbers / desorbers, the Adsorp enthalpy of vaporization and evaporation, especially for heating and cooling are used. 24. Use of a shaped body according to one of claims 1 to 15 in water softening systems based on the principle of Calcium-sodium ion exchange work, the ion being exchange takes place in particular in the molded body.