KR102198162B1 - Process for preparing spherical zeolite granule having high strength - Google Patents

Abstract

The present invention relates to a high-strength spherical zeolite molded body and a method for manufacturing the same, and more particularly, as an inorganic binder for zeolite, which is difficult to filtration and washing with water, and a conventional clay binder having poor mechanical strength and adsorption ability. Instead, by mixing a silicone compound and an ultra-high molecular weight polyethylene compound (UHMWPE), it exhibits excellent nitrogen separation ability, abrasion resistance, and external density, so it can be applied very usefully as an adsorbent in a fluidized bed system for a high-purity oxygen generator with a high air volume. It relates to a spherical zeolite molded body and a method for producing the same.

Description

High-strength spherical zeolite granule and its manufacturing method{Process for preparing spherical zeolite granule having high strength}

By mixing a silicone compound and an ultra-high molecular weight polyethylene compound as a zeolite binder, it exhibits excellent nitrogen adsorption ability, abrasion resistance, and external density, and is very useful as an adsorbent for a high-purity oxygen generator, and a method of manufacturing the same.

In the conventional method for producing oxygen by deep cooling, air was cooled to -200°C to liquefy, and oxygen was produced by rectifying and separating using the difference in boiling points between oxygen and nitrogen. This method of producing oxygen requires a large-scale device and high energy cost, so the device could be installed in places where a large amount of gas is used, for example, near a steel mill or a chemical plant, but in places where a small amount of gas is used. Rather than installing and using the device directly, oxygen must be liquefied or filled in a bombe and transported and supplied.

As a method for producing oxygen with improved deep cooling, there are a pressure swing adsorption (PSA) method, a vacuum swing adsorption (VSA) method, and a thermal swing adsorption (TSA) method.

The basic principle of the PSA method, VSA method and TSA method is that the adsorbent in the device adsorbs gas in the pressurization process, and the adsorbed gas is easily desorbed and regenerated in the depressurization process. This method has the advantage of being able to install the manufacturing apparatus by maintaining a certain distance from the environment of use of oxygen, to immediately manufacture and use the required amount, and to easily and semi-permanently supply oxygen at low cost. In addition, the adsorbent of the oxygen generator using the PSA method and the VSA method should have excellent selective adsorption capacity for nitrogen and a large difference in adsorption amount of nitrogen and oxygen, and a synthetic zeolite may be used as a representative example.

Zeolite is a crystalline alumino silicate represented by the following formula (1).

[Formula 1]

M _x/n [(AlO ₂ ) _x (SiO ₂ ) _y ]ㆍwH ₂ O

In Formula 1, M is a cation; n is the valence; w represents the number of molecules of crystal water; x and y are constants that change depending on the crystal structure.

In general, zeolite has a pore diameter of about 3 to 10 Å, exhibits a molecular sieve effect, and has a unique property of selectively adsorbing nitrogen molecules in air due to this structure. In particular, as a hydrophilic adsorbent, it has strong adsorption power with polar molecules such as water, and has an advantage of high adsorption power even under low partial pressure and high temperature. However, although zeolite has the above-described selective adsorption characteristics, it is in the form of a fine powder having an average particle diameter of about several µm, and thus there is a lot of inconvenience in using it for adsorption or catalytic processes dealing with liquid reactants. Therefore, in order to use zeolite as a useful adsorbent in a gas generating device, a binder must be added to form a predetermined shape.

As a general method for shaping zeolite known so far, the zeolite is ion-exchanged with an appropriate cation, dried, and then granulated and molded by adding about 30% by weight or less of a binder per particle, and then calcined at a temperature in the range of 600 to 800 ℃. The method of manufacturing through a process is widely known. As a prior art of this method, calcium ions are exchanged with 4A-type zeolite powder to convert it into 5A-type zeolite, and then injection and molding using natural clays, kaolinite, as an inorganic binder, followed by firing and adsorbent. A technique for manufacturing is known (US Patent Document 1, 5001098 and 5292360, etc.). However, the above technology has a disadvantage in that filtration and water washing are difficult because zeolite particles of several to tens of µm generated after ion exchange exist in a slurry phase. In addition, natural clays, which act as a binder added to increase mechanical strength, are included in the final product as it is, so that the adsorption performance is deteriorated.

In order to improve the above-described disadvantages, a manufacturing method of minimizing the amount of binder added by mixing about 2 to 15% by weight of highly dispersed attapulgite has also been reported (US Patent Document 2, No.6743745). 10% by weight of highly dispersed clay component is contained as an inert component, and the highly dispersed clay component is enclosed in a state that captures the zeolite component, so that the gas component to be separated is transferred to the inside and outside of the molded body. Since it inhibits diffusion, there is a disadvantage in that the speed of adsorption and desorption, which is important in the PSA method or VSA method, is limited.

On the other hand, a method of producing a zeolite molded body with improved adsorption performance by converting the binder component to zeolite by firing at 600°C or higher after producing a zeolite molded body using a kaolin-based binder and treating it for a long time for 10 days or longer in an alkaline aqueous solution is also reported. (U.S. Patent Literature 3, 4603040), but industrially difficult to implement.

As a technology to improve this manufacturing method, 15% by weight of natural clays (kaolin-based, montmorillonite-based) as a binder is mixed and calcined at about 600°C, and then treated with a mixed aqueous solution of sodium hydroxide and potassium hydroxide within 24 hours. A method of preparing a low-silica X type granular aggregate having a ratio of an inert binder has been reported (Korean Patent Document 1, No. 538961). However, since the above method also uses natural clays as a binder, the mechanical strength of the zeolite molded body is reduced due to the shrinkage of the clays during the firing process, resulting in severe dust generation, and the specific surface area is reduced, resulting in high purity oxygen generation. There are limitations to apply to the device.

In addition, in order to solve the problem of deterioration in strength and separation ability, a spherical molded body was formed by spraying an aqueous colloidal silica solution to a mixture of zeolite powder and a cellulose compound, and then the pores and strength were supplemented through sintering and hydrothermal synthesis. The technology was also reported (Korean Patent Document 2, No. 996260). The spherical zeolite manufactured through such a process has been able to solve the problems of pore formation and deterioration of separation ability to some extent due to the use of the existing inorganic binder, but has an unsatisfactory strength for application to a high air volume treatment system.

An object of the present invention is to solve a problem in which filtration and washing are difficult, mechanical strength and adsorption capacity are poor, which are caused by a binder used for conventional zeolite molding.

Another object of the present invention is to provide a high-strength spherical zeolite molded body that can be usefully applied as an adsorbent for a high air volume oxygen generator and a method for manufacturing the same.

In order to achieve the above object, in one aspect of the present invention

In the method of manufacturing a high-strength spherical zeolite molded article,

1 step of spray-blending an aqueous colloidal silica solution to zeolite powder to produce a spherical molded body;

A second step of classifying only spherical molded articles having a particle diameter in the range of 0.50 to 3.35 mm among the spherical molded articles;

3 steps of drying the classified spherical molded body;

4 step of putting the dried spherical molded body into an aqueous alkali solution and an aqueous solution of sodium aluminate, followed by hydrothermal reaction;

A 5 step of ion-exchanging the hydrothermally reacted spherical shaped body with an aqueous solution of an alkali metal salt or an alkaline earth metal salt;

6 step of firing the ion-exchanged spherical molded body at a temperature range of 350 to 650°C;

7 step of immersing and filtering the fired spherical zeolite molded body in an ultra-high molecular weight polyethylene slurry solution; And

There is provided a method of manufacturing a high-strength spherical zeolite molded body comprising an 8 step of drying the spherical zeolite molded body through the immersion and filtration in a temperature range of 80 to 130 °C.

In addition, in another aspect of the present invention

There is provided a spherical zeolite molded article that simultaneously satisfies the following conditions.

Nitrogen adsorption capacity of 0.90 ml/g or more,

Wear resistance more than 99%,

External density 0.60 g/ml or more,

The amount of oxygen generated in the oxygen generating device by the PSA method is 6.5 ml/min or more per unit mass (g) of the spherical zeolite molded body.

Furthermore, in another aspect of the present invention

An oxygen generating device including the above spherical zeolite molded body is provided.

The method of manufacturing a high-strength spherical zeolite molded article provided in one aspect of the present invention is a simple and easy method for manufacturing a high-strength spherical zeolite molded article, which contains almost no inert binder component, and pores are well formed to the inside of the molded article, resulting in adsorption separation performance. There is an effect of obtaining a spherical zeolite molded body that is excellent, has high external density, and has excellent mechanical strength.

In addition, the spherical zeolite molded body provided in one aspect of the present invention provides a spherical zeolite molded body having a macro pore volume of 0.15 to 0.32 ml/g having a size of 50 to 500 nm. There is an effect of making it permeable to facilitate conversion of the binder component to the desired type of zeolite.

Therefore, the high-strength spherical zeolite molded article provided in one aspect of the present invention reduces the pressure by improving the wear resistance of the zeolite-based absorbent applied in the adsorption tower using the conventional pressure swing adsorption (PSA) and vacuum swing adsorption (VSA) methods. At the same time, it is possible to obtain economical effects such as extending the replacement life due to improved wear resistance, while solving problems in the operation of the system such as, and separating air from high winds.

Hereinafter, the present invention will be described in detail.

On the other hand, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided in order to more completely explain the present invention to those with average knowledge in the art.

As described above, conventional adsorbents for oxygen generators are prepared by mixing and molding a clay-based inorganic binder with zeolite powder and firing, or by treating the calcined granular composition with an aqueous alkali solution to convert the clay-based inorganic binder component into zeolite. However, impurities mixed in the clay-based inorganic binder are mixed as they are in the granular composition, and there is a limit in improving the adsorption separation performance and mechanical strength.

Therefore, in order to solve the above problem, one aspect of the present invention is to obtain a zeolite which is a desired inorganic binder component by forming a spherical shape using an aqueous colloidal silica solution as an inorganic binder in zeolite, drying it and treating it with an aqueous sodium aluminate solution. Converted directly to. Then, in order to reinforce the strength, it was immersed in an ultra-high molecular weight polyethylene slurry solution and then heat treated to obtain a high-strength spherical zeolite molded body.

As a result, it is possible to manufacture a new spherical zeolite molded body that hardly contains an inert binder component and has excellent pores to the inside of the molded body, which has excellent adsorption separation performance, high external density, and excellent mechanical strength. The spherical zeolite molded article provided in one aspect of the present invention is expected to be very useful as an adsorbent for an oxygen generating device according to the PSA method, the VSA method, and the TSA method in which a large amount of high-purity oxygen must be continuously supplied.

The present invention will be described in more detail as follows.

In one aspect of the present invention, in the method of manufacturing a high-strength spherical zeolite molded body,

1 step of spray-blending an aqueous colloidal silica solution to zeolite powder to produce a spherical molded body;

A second step of classifying only spherical molded articles having a particle diameter in the range of 0.50 to 3.35 mm among the spherical molded articles;

3 steps of drying the classified spherical molded body;

4 step of putting the dried spherical molded body into an aqueous alkali solution and an aqueous solution of sodium aluminate, followed by hydrothermal reaction;

A 5 step of ion-exchanging the hydrothermally reacted spherical shaped body with an aqueous solution of an alkali metal salt or an alkaline earth metal salt;

6 step of firing the ion-exchanged spherical molded body at a temperature range of 350 to 650°C;

7 step of immersing the fired spherical zeolite molded body in an ultra-high molecular weight polyethylene slurry solution and then filtering; And

There is provided a method of manufacturing a high-strength spherical zeolite molded body comprising an 8 step of drying the immersed and filtered spherical zeolite molded body in a temperature range of 80 to 130°C.

Hereinafter, a method of manufacturing a spherical zeolite molded body provided by the present invention will be described in detail for each process.

In the method of manufacturing a spherical zeolite molded article provided in one aspect of the present invention, the first process is a process of shaping the zeolite into a spherical shape, and the zeolite powder is mixed while spraying and injecting the zeolite powder into the molding apparatus through a nozzle. It is a process of manufacturing a molded article of. The spherical molded body thus produced has a particle diameter of 0.20 to 5.0 mm.

As the zeolite, a zeolite selected from NaA-type zeolite, NaX-type zeolite, and Na-K-low silica X-type zeolite can be used, and these have micropores in the crystal, thereby exhibiting a unique molecular sieve effect of adsorbing molecules.

On the other hand, the colloidal silica aqueous solution may be made of a silica (SiO ₂ ) solid content of 25 to 35% by weight, bar, when the content of the silica solid content of the colloidal silica aqueous solution is less than 25% by weight, If the bonding force is weak and exceeds 35% by weight, the viscosity of the solution is high, making normal spraying through the nozzle difficult.

In addition, the device for molding into a spherical shape is not particularly limited to a molding device generally used in the art, but for example, a flowshare mixer, a disk granulator, an injection molding granulator, a fluid bed granulator, and a compression crushing granulator can be selected and used. I can.

In the method of manufacturing a spherical zeolite molded article provided in one aspect of the present invention, the second process is a classification process, and the spherical molded article prepared above is classified by a classifier to have a size of 0.50 to 3.35 mm, more preferably 1.30 to 2.46 mm. It is a process that takes only spherical shaped bodies of the size. At this time, the spherical molded body out of the particle diameter range can be recycled and re-introduced into the molding apparatus in step 1, mixed with newly introduced zeolite, and used as a core in the molded body manufacturing process. Thus, the zeolite powder of step 1 may include 40 to 90% by weight of pure zeolite powder and 10 to 60% by weight of a spherical compact generated in step 2 and recycled, and the spherical compact to be recycled is out of the above range. When mixed, it is difficult to control the particle size, which may cause a difficult problem in the granulation process.

Accordingly, the present invention can more easily control the size of the molded body in the granulation process where particle size control is difficult by classification and recirculation processes, and can be manufactured close to a spherical shape to minimize the porosity during filling in the adsorption tower of the oxygen generator. There is an advantage.

In the method of manufacturing a spherical zeolite molded body provided in one aspect of the present invention, the third step is a process of drying the classified spherical molded body at a temperature range of 80 to 120 °C. At this time, it is preferable to use a fluid bed dryer for drying.

In the method for producing a spherical zeolite molded article provided in one aspect of the present invention, in the fourth step, the dried spherical molded article is put in an aqueous alkali solution and an aqueous solution of sodium aluminate, and reacted with hydrothermal reaction to obtain a silica component contained as a binder. It is the process of converting to the desired type of zeolite. The composition of the aqueous alkali solution and the aqueous solution of sodium aluminate is commonly used in the art and is not particularly limited. For example, the composition of a conventional hydrothermal reaction process of converting a silica component, which is a binder component, into zeolite may be followed. More specifically, sodium hydroxide and potassium hydroxide may be used as the aqueous alkali solution.

In addition, it is preferable to put the dried spherical molded body in an aqueous alkali solution and an aqueous solution of sodium aluminate, and aged at about 20 to 50°C for 6 to 24 hours. At this time, if the aging temperature is too low, the treatment time becomes long, resulting in lower production efficiency of the spherical zeolite molded body. If the aging temperature is too high, the zeolite seed is not formed and proceeds directly to the crystallization process. The conversion rate to zeolite is lowered. After undergoing an appropriate aging process as described above, hydrothermal reaction at 70 to 95°C for 4 to 24 hours, the reaction mother liquor is removed and sufficiently washed with water. When the temperature of the hydrothermal reaction is less than 70° C., the hydrothermal reaction occurs very slowly, and when the temperature exceeds 95° C., crystallization proceeds rapidly, and various types of zeolites are mixed, resulting in a problem.

The following Scheme 1 shows a specific chemical reaction that occurs when silica (SiO ₂ ), which is a binder component, is treated with an aqueous alkali solution and an aqueous solution of sodium aluminate in order to convert the desired type of zeolite.

[Scheme 1]

① SiO ₂ + NaAlO ₂ + NaOH + H ₂ O → Na ₉₆ (Si ₉₆ Al ₉₆ O ₃₈₄ )ㆍ216H ₂ O

Binder reaction aqueous solution NaA zeolite

② SiO ₂ + NaAlO ₂ + NaOH + H ₂ O → Na ₈₈ (Si ₁₀₄ Al ₈₈ O ₃₈₄ )ㆍ220H ₂ O

Binder reaction aqueous solution NaX zeolite

③ SiO ₂ + NaAlO ₂ + NaOH + KOH + H ₂ O → Na ₆₅ K ₂₃ (Si ₈₉ Al ₈₈ O ₃₈₄ )ㆍ220H ₂ O

Binder reaction aqueous solution Na-K-low silica X-type zeolite

According to Reaction Scheme 1, since most of the silica components having little adsorption separation ability while serving as a binder are converted to zeolite, the adsorption separation performance of the spherical molded body is improved by passing through this process. In addition, since the reaction mother liquor can easily penetrate into the macro pores present in the spherical molded body before the reaction treatment, the resulting zeolite remains in the pores as it is, thus increasing the external density and strength of the spherical molded body. Will be ordered.

In the method of manufacturing a spherical zeolite molded article provided in one aspect of the present invention, the fifth step is a process of ion-exchanging the spherical molded article subjected to hydrothermal reaction with an aqueous alkali metal salt or an alkaline earth metal salt solution. As the aqueous solution of the alkali metal salt or alkaline earth metal salt, an aqueous solution containing lithium ions and calcium ions may be more preferably used. In other words, the process of ion-exchanging the cations (Na ⁺ and K ⁺ ) existing in the zeolite crystal lattice with Li ⁺ ions or Ca ²⁺ ions by treating the spherical shaped body that has undergone hydrothermal reaction with an aqueous solution containing lithium ions or calcium ions. to be. In this case, a LiCl aqueous solution may be used as the lithium ion aqueous solution, and a CaCl ₂ aqueous solution may be more preferably used as the calcium ion aqueous solution. The spherical molded body subjected to the ion exchange treatment as described above is sufficiently washed with water and then dried. The drying conditions are not particularly limited to conditions generally known in the art, but may be more preferably performed at room temperature or at a temperature condition of 60 to 110° C. and an atmospheric pressure condition.

In the method of manufacturing a spherical zeolite molded body provided in one aspect of the present invention, the sixth step is a process of firing the ion-exchanged spherical molded body at a temperature range of 350 to 650 °C, and the ion-exchanged spherical molded body is continuously Put in a sintering apparatus, while sufficiently injecting air from which moisture and carbon dioxide have been removed, it is activated at 350 to 650° C., more preferably at 400 to 550° C. for 0.3 to 3.0 hours, to produce the desired final spherical zeolite molded body. At this time, when the sintering temperature is less than 350° C., crystal water is not well removed, and when the sintering temperature exceeds 650° C., the adsorption capacity decreases due to pore sintering of the spherical zeolite molded body.

The firing apparatus is not particularly limited to an apparatus generally used in the art, but for example, a rotary kiln, a batch kiln, a tunnel kiln, a high frequency heating furnace, and a Harry Schoff kiln may be used.

In the method of manufacturing a spherical zeolite molded body provided in one aspect of the present invention, the seventh step is a process of immersing the fired spherical zeolite molded body in an ultra high molecular weight polyethylene slurry solution and filtering, the concentration of the slurry solution is 3 to 30 weight It is desirable to maintain the% range and the temperature of the solution in the range of 60 to 80 °C. In the filtration process, the immersed spherical zeolite molded body is removed using a sieve. The ultra-high molecular weight polyethylene of step 7 is added to maintain porosity and high strength.

The molecular weight of the ultra-high molecular weight polyethylene is preferably 1 million to 6 million g/mol, more preferably 2 million to 4 million g/mol.

The concentration of the slurry solution is preferably 3 to 30% by weight, more preferably 3 to 20% by weight, preferably 4 to 15% by weight, more preferably 4 to 10% by weight, and 4 to It is most preferably 7% by weight. If the concentration of the slurry solution is out of the above range, the nitrogen adsorption capacity is deteriorated, and when the slurry solution is applied as an adsorbent of an oxygen generator, there is a problem that the amount of oxygen generated is insufficient.

In the method of manufacturing a spherical zeolite molded body provided in one aspect of the present invention, the eighth process is a process of drying the spherical zeolite molded body that has been subjected to the immersion and filtration process at a temperature range of 80 to 130°C. It is preferable to use a rotary dryer so that the ultra-high molecular weight polyethylene components immersed in the inside can sufficiently spread evenly inside the molded body.

The high-strength spherical zeolite molded article produced by the present invention may be an A-type zeolite, an X-type zeolite, and a low-silica X-type zeolite ion-exchanged with an alkali metal salt or alkaline earth metal. In addition, the spherical zeolite molded body may include 93.0 to 99.9% by weight of zeolite and 0.1 to 7.0% by weight of silica.

The spherical zeolite molded body has a nitrogen adsorption capacity of 0.80 ml/g or more (more specifically 0.81 to 1.20) at 25° C. and 1 Torr, and a wear resistance (8×12 ASTM Mesh) of 99% or more (more specifically 99.0 to 99.7). The external density (8×12 ASTM Mesh) is 0.65 g/ml or more (more specifically 0.65 ~ 0.75), and as a result of charging and operating the adsorption tower of the oxygen generator by the PSA method, oxygen at room temperature and pressure (NTP) It was shown that the generated amount was 8.2 ml/min or more (more specifically, 8.2 to 9.5) per unit mass (g) of the high-strength spherical zeolite molded body.

The high-strength spherical zeolite molding agent provided in one aspect of the present invention exhibits excellent nitrogen separation ability, abrasion resistance, and outer shape density, and thus has a useful effect as an adsorbent for high-flow oxygen generators such as PSA and VSA methods, which will be described later in Examples. , Can be directly supported by the experimental example.

In another aspect of the present invention

A spherical zeolite molded body is provided which simultaneously satisfies the following conditions:

Nitrogen adsorption capacity of 0.90 ml/g or more,

Wear resistance more than 99%,

External density 0.60 g/ml or more,

The amount of oxygen generated in the oxygen generating device by the PSA method is 6.5 ml/min or more per unit mass (g) of the spherical zeolite molded body.

Hereinafter, a spherical zeolite molded article provided in another aspect of the present invention will be described in detail.

The nitrogen adsorption capacity may be 0.70 ~ 1.30 ml/g, 0.75 ~ 1.25 ml/g, 0.80 ~ 1.20 ml/g, 0.90 ~ 1.20 ml/g, 0.90 ~ 1.15 ml/g May be, 0.92 to 1.15 ml/g, 1.10 to 1.20 ml/g, 1.10 to 1.18 ml/g, and 1.10 to 1.15 ml/g.

The wear resistance may be 95 to 99.9%, 97 to 99.9%, 98 to 99.9%, 98.2 to 99.8%, 98.5 to 99.7%, and 99.0 to 99.6%, and , It may be 99.2 to 99.5%.

The external density may be 0.40 ~ 0.80 g/ml, 0.45 ~ 0.79 g/ml, 0.50 ~ 0.78 g/ml, 0.55 ~ 0.76 g/ml, 0.60 ~ 0.75 g/ml May be, 0.62 to 0.73 g/ml, 0.65 to 0.70 g/ml, and 0.66 to 0.68 g/ml.

The amount of oxygen generated in the oxygen generator according to the PAS method per unit mass (g) of the spherical zeolite molded body may be 5.0 to 12.0 ㎖/min, 5.3 to 11.7 ㎖/min, and 5.6 to 11.5 ㎖/min. May be, 5.9 to 11.3 ㎖/min, 6.2 to 11.1 ㎖/min, 6.5 to 10.9 ㎖/min, 6.8 to 10.7 ㎖/min, and 7.1 to 10.5 ㎖/min May be, 7.4 to 10.3 ml/min, 7.7 to 10.1 ml/min, 8.0 to 9.9 ml/min, 8.2 to 9.7 ml/min, and 8.4 to 9.5 ml/min I can.

The spherical zeolite molded body may be characterized in that it has a composition ratio of 93.0 to 99.9% by weight of zeolite and 0.1 to 7.0% by weight of silica, and also A zeolite, X zeolite or low silica ion-exchanged with an alkali metal salt or alkaline earth metal. It can be characterized by being an X-type zeolite.

In another aspect of the present invention, an oxygen generating device including a spherical zeolite molded body is provided.

As a method of producing oxygen in an oxygen generator, a method using an adsorbent (Pressure Swing Adsorption: PSA) mainly uses zeolite with excellent nitrogen adsorption properties. The oxygen generator of the PSA type includes an adsorber filled with zeolite, a compressor that supplies air to the adsorber, and a plurality of valves that control gas flow. When external air is introduced into the adsorber by the compressor, gases (mostly nitrogen) from the air introduced into the adsorber except oxygen are adsorbed to the zeolite. The gas adsorbed on the zeolite is separated from the zeolite through a desorption process and discharged to the outside of the adsorber. The oxygen generator of the PSA method produces oxygen by repeating this adsorption and desorption process. By using the high-strength spherical zeolite molded body provided in the present invention for the PSA type oxygen generating device using such an adsorbent, oxygen gas having a higher purity than the conventional PSA type oxygen generating device can be obtained.

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples to be described later.

However, the examples and experimental examples to be described later are merely illustrative of the present invention, and the present invention is not limited thereto.

<Example 1> Preparation of a spherical zeolite molding agent comprising the process of immersing in a 10% by weight ultra-high molecular weight polyethylene slurry solution

NaA type zeolite powder (moisture content 5.4 wt%) 9.7 kg (moisture content 25 wt%) recycled zeolite spherical molded body (particle diameter less than 1.30 mm) to 8.2 kg and rotated on the main spindle The powder was mixed for 1 minute at a speed of 180 rpm and a chopper rotation speed of 3600 rpm. After that, a solution prepared by mixing 5.5 kg of colloidal silica aqueous solution (SiO ₂ : 30% by weight) and 0.5 kg of water was kneaded while injecting into the powder mixture through a nozzle, and then spheroidized for 15 minutes so that the particle diameter is 0.20 ~ A spherical molded body of 5.0 mm was obtained.

The above spherical molded body was classified with a vibration classifier to obtain 14.8 kg of a spherical molded body with a size of 1.30 to 2.46 mm, and a spherical molded body of 1.30 mm or less was recycled to the molding process, and spherical molded bodies of 2.46 mm or more were dried and then pulverized and recycled. And used.

The spherical molded body of 1.30 to 2.46 mm size separated in the above classification process was dried in a fluidized bed dryer at 90°C, placed in a rotary calcination furnace maintained at 600°C (manufactured by Lindberg, USA) and continuously fired, and then sufficiently left in the atmosphere. 10.9 kg of a spherical molded body (NaA type) was obtained.

The thus-obtained spherical molded body was put in an aqueous solution dissolved by adding 2.2 kg of sodium hydroxide and 1.7 kg of sodium aluminate to 21.8 kg of water, and aged at 35° C. for 12 hours. Next, the temperature of the entire reactant was raised to 90° C. and subjected to a hydrothermal reaction for 8 hours, and then the reaction mother liquor was removed and sufficiently washed with water.

A 2 M CaCl ₂ aqueous solution was heated to 70° C. to the hydrothermal reaction-treated spherical body, contacted at a flow rate of 1.2 L/min, ion-exchanged, washed sufficiently, and dried in a fluid bed dryer at 90° C.

The ion-exchanged spherical molded body was placed in a rotary kiln (manufactured by Lindberg, USA) maintained at 500°C, and was continuously fired while sufficiently introducing air from which moisture and carbon dioxide had been removed.

Then, the fired spherical molded body was immersed in 10 L of a 10% by weight ultra-high molecular weight polyethylene slurry solution for 2 hours and then filtered.

The immersed and filtered spherical shaped body was dried for 3 hours in a dryer maintained at 90°C.

After drying, 8.7 kg (CaA type) of a high-strength spherical molded body subjected to activation treatment while flowing high-purity nitrogen into a sealed container was obtained.

<Example 2> Preparation of a spherical zeolite molding agent comprising immersion in a 5% by weight ultra-high molecular weight polyethylene slurry solution

8.0 kg of a spherical molded body (CaX type) was obtained under the same conditions as in Example 1, except that the treatment was performed using a 5% by weight slurry solution during the immersion process of the ultra-high molecular weight polyethylene slurry solution.

<Example 3> Preparation of a spherical zeolite molding agent comprising the process of immersing in a 20% by weight ultra-high molecular weight polyethylene slurry solution

In the process of immersing the ultra-high molecular weight polyethylene slurry solution, 9.1 kg of a spherical molded body (CaX type) was obtained by performing the same conditions as in Example 1, except that the treatment was performed using a 20% by weight slurry solution.

<Comparative Example> Preparation of a spherical zeolite molding agent including microcrystalline cellulose in a binder and immersing it in an ultra-high molecular weight polyethylene slurry solution

130 ℓ of 9.7 kg (moisture content 25 wt%) and micro crystalline cellulose (MC) 0.8 kg recycled to 8.2 kg of NaA-type zeolite powder (moisture content 5.4 wt%). The powder was mixed for 1 minute in a flowshare mixer (manufactured by Lodige, Germany) of the size and under the conditions of a spindle rotation speed of 180 rpm and a chopper rotation speed of 3600 rpm. After that, a solution prepared by mixing 5.5 kg of colloidal silica aqueous solution (SiO ₂ : 30% by weight) and 0.5 kg of water was kneaded while injecting into the powder mixture through a nozzle, and then spheroidized for 15 minutes so that the particle diameter is 0.20 ~ A spherical molded body of 5.0 mm was obtained.

The above spherical molded body was classified with a vibration classifier to obtain 14.8 kg of a spherical molded body with a size of 1.30 to 2.46 mm, and a spherical molded body of 1.30 mm or less was recycled to the molding process, and spherical molded bodies of 2.46 mm or more were dried and then pulverized and recycled. And used.

The spherical molded body of 1.30 to 2.46 mm size separated in the above classification process was dried in a fluidized bed dryer at 90°C, placed in a rotary calcination furnace maintained at 600°C (manufactured by Lindberg, USA) and continuously fired, and then sufficiently left in the atmosphere. 10.9 kg of a spherical molded body (NaA type) was obtained.

The thus-obtained spherical molded body was put in an aqueous solution dissolved by adding 2.2 kg of sodium hydroxide and 1.7 kg of sodium aluminate to 21.8 kg of water, and aged at 35° C. for 12 hours. Next, the temperature of the entire reactant was raised to 90° C. and subjected to a hydrothermal reaction for 8 hours, and then the reaction mother liquor was removed and sufficiently washed with water.

The hydrothermal reaction-treated spherical compact 2 M CaCl ₂ aqueous solution was heated to 70° C., contacted at a flow rate of 1.2 L/min, ion-exchanged, washed sufficiently, and dried in a fluid bed dryer at 90° C.

Put the ion-exchanged spherical molded body in a rotary kiln (manufactured by Lindberg, USA) maintained at 500 ℃ and continuously sinter while sufficiently introducing air from which moisture and carbon dioxide have been removed. 8.3 kg (CaA type) of the obtained spherical molded body was obtained.

<Experimental Example> Measurement of physical properties of zeolite

For each of the samples prepared in Examples 1 to 3 and Comparative Examples, physical properties were measured in the following manner. The results are shown in Table 1 below.

1) Measurement of nitrogen adsorption capacity: After degassing the measured sample at about 350 ℃ for a sufficient time, the nitrogen adsorption isotherm was calculated from 25 ℃ to 760 torr. At this time, in Table 1 below, the nitrogen adsorption capacity at 25° C. and 745 torr is described.

2) Abrasion resistance measurement: The abrasion resistance of the sample was carried out according to the hardness test method of granular material of KS-M-1802 (JIS-K-1474). In the test, the sample was put together with a steel ball, shaken in a hardness tester, classified, and the mass of the sample remaining on the upper part was measured, and the hardness value was calculated from the mass ratio with the first sample.

[Equation 1]

H = (W ÷ S) × 100

In the above equation, H is the wear resistance (hardness, %); W is the weight (g) of the sample remaining on the top of the sieve; S is the sum (g) of the weight of the sample remaining in the standard sieve and the weight of the sample remaining in the receiving bowl.

3) Measurement of external density: 100 samples The volume (V, ml) and weight (W, g) were measured and calculated from the following equation after sufficiently tapping at a certain height in a ㎖ mass flask.

[Equation 2]

Bulk density = W/V

4) Oxygen generation amount measurement: To measure the oxygen separation performance of the sample, an oxygen generating device adopting a two-barrel normal pressure regeneration method was used. The experiment method is as follows.

Air was blown into each adsorption vessel filled with 9.0 kg of adsorbent only with an air compressor, and the pressure was pressurized to 3 kgf/cm 2 to perform adsorption. At this time, each of the adsorption vessels was periodically repeatedly performed while forming one step of increasing pressure, adsorption, backwashing, and decompression to generate oxygen, and the time of each step was about 2 minutes. Concentrated oxygen measures the flow rate through a flow meter, is sent to an oxygen analyzer (Teledyne, 326AI20-2X) to measure the concentration of oxygen, and converts the amount of pure oxygen generated from NTP to volume (ml) and adsorbent unit mass (g) It was calculated on the basis of.

As shown in Table 1, by mixing and using ultra-high molecular weight polyethylene to increase the abrasion resistance of the zeolite, a spherical zeolite molded body was prepared, as compared to the comparative example of a spherical zeolite molded body manufactured by the conventional technology, excellent nitrogen adsorption ability, It was confirmed that abrasion resistance and external density were shown. Accordingly, it is expected that the high-strength spherical zeolite molded article according to the present invention can be very usefully applied as an adsorbent for a high-purity oxygen generator.

Claims (12)

In the method of manufacturing a spherical zeolite molded body,
1) 1 step of spray-blending zeolite powder and colloidal silica aqueous solution to produce a spherical molded body;
2) a second step of classifying only spherical molded articles having a particle diameter in the range of 0.50 to 3.35 mm among the spherical molded articles;
3) 3 steps of drying the classified spherical molded body;
4) step 4 of putting the dried spherical shaped body into an aqueous alkali solution and an aqueous solution of sodium aluminate, followed by a hydrothermal reaction;
5) a 5 step of ion-exchanging the hydrothermally reacted spherical shaped body with an aqueous solution of an alkali metal salt or an alkaline earth metal salt;
6) 6 step of firing the ion-exchanged spherical molded body at a temperature range of 350 to 650°C;
7) 7 step of immersing and filtering the fired spherical compact in 5 to 10% by weight of an ultra-high molecular weight polyethylene slurry solution; And
8) 8 step of drying the filtered spherical molded body in a temperature range of 80 ~ 130 ℃; characterized in that consisting of,
Method for producing a spherical zeolite molded body.
The method of claim 1,
The zeolite of the above step 1,
Method for producing a spherical zeolite molded article, characterized in that selected from NaA-type zeolite, NaX-type zeolite, and Na-K-low silica X-type zeolite.
The method of claim 1,
The zeolite powder of the first step,
Method for producing a spherical zeolite molded body, characterized in that it comprises a spherical molded body having a particle diameter outside the range of 0.50 to 3.35 mm generated and recycled in the second process
The method of claim 3,
The zeolite powder,
A method for producing a spherical zeolite molded body comprising 40 to 90% by weight of pure zeolite powder and 10 to 60% by weight of a spherical molded body generated in the second step and recycled.
The method of claim 1,
The method of manufacturing a spherical zeolite molded article, characterized in that the colloidal silica aqueous solution of step 1 comprises 25 to 35% by weight of silica (SiO ₂ ) solid content.
The method of claim 1,
The method for producing a spherical zeolite molded article, characterized in that the ultra-high molecular weight polyethylene molecular weight in the seventh step is 1 million to 6 million g/mol.
delete The method of claim 1,
The drying process of the 8 steps is a method of manufacturing a spherical zeolite molded body, characterized in that drying is performed by maintaining 80 ~ 130 ℃.
delete delete delete delete