KR20020011561A - A mesoporus zeolite honeycomb and a method for producing thereof - Google Patents

Abstract

PURPOSE: A mesoporous zeolite honeycomb monolith of the present invention can be effectively used to catalytic elimination of macromolecular organic materials such as dioxin and furan, because it has relatively large pore size of 20 to 100Å and specific surface area higher than 1000m¬2/g, leading to an increased adsorption rate to macromolecular organic materials. CONSTITUTION: The method for preparing a mesoporous zeolite honeycomb monolith includes: (i) homogeneous mixing of 60-90wt.% mesoporous zeolite with 9-35wt.% solid inorganic binder; (ii) adding 1-5wt.% of liquid inorganic binder such as alumina sol or silica to prepare a 100wt.% of mixed solution; (iii) adding 2-10wt.% of an organic binder, 1-8wt.% of a plasticizer, 0.3-5wt.% of a lubricant, and 50-200wt.% of water, based on the weight of the mixed solution; (iv) aging the prepared mixture at an ambient temperature for about 1 day; (v) shaping the aged mixture into a honeycomb monolith followed by drying; (vi) baking the honeycomb monolith in the temperature range of 650 to 800deg.C for 4-6hrs.

Description

Mesoporus zeolite honeycomb structure and method for producing the same

The present invention relates to a mesoporous zeolite honeycomb structure and a method for manufacturing the same, and more particularly, to a mesoporous zeolite honeycomb structure and a method for producing the same for applications such as adsorption, separation and catalysis of large organic molecules such as dioxins.

Flue gases generated in industrial processes typically include large organic molecules such as particulate matter, gaseous pollutants or dioxins. However, in order to adsorb and remove giant organic molecules such as dioxins, conventional zeolites could not be directly applied as they are. This is because micropores of conventional adsorbents are so small that giant organic molecules such as dioxins can be adsorbed onto the micropores. Because it was not. In order to overcome this phenomenon, inevitably, the raw material (mesoporous zeolite) with larger micropores must be used, but in this case, the hydrothermal stability and mechanical strength of the raw material (mesoporous zeolite) itself are insufficient during the molding process. Not only the pore structure of the material is destroyed by the high heat treatment at the time of pressure or firing, but also the internal surface area is drastically reduced to lose the adsorption characteristics of the material, and there is also a problem that the metal catalyst component is released. In addition, since the specific surface area of the mesoporous zeolite material itself is very large and there is almost no caking, it was not easy to form a honeycomb structure because the moldability is poor even if the inorganic binder and the organic binder are simply added. Therefore, despite the need to develop an adsorbent using mesoporous zeolites, honeycomb molding techniques using mesoporous zeolite materials and specific applications using the same have not been published.

The present inventors earnestly analyze the above-described problems and undergo several repeated experiments, and based on mesoporous zeolite material as a basic composition, dry mixing them with a specific inorganic binder in a proportion, and then again with a specific organic additive. Liquid alumina sol and silica sol, which are inorganic binders, are added alone or in a mixed composition in a proportion with mixed water and uniformly wet mixed to prepare initial clay, and the above initial clay is aged for about one day. The present invention is made by manufacturing a honeycomb molded body by extruding aged clay, and confirming that a mesoporous zeolite honeycomb structure having excellent properties such as specific surface area and strength is produced when the molded body is dried and calcined at a high temperature. It was completed.

Accordingly, an object of the present invention is to provide a honeycomb structure made of mesoporous zeolite which can be effectively used for adsorption removal of large organic molecules such as dioxins and the like, and a method of manufacturing the same.

1 is a schematic manufacturing process diagram of mesoporous zeolite honeycomb

2 is an XRD measurement result of mesoporous zeolite powder according to each firing temperature in the firing step of the manufacturing process of the present invention.

The present invention weighs 60 to 90% by weight of mesoporous zeolite, 9 to 35% by weight of inorganic binder in solid state, and 1 to 5% by weight of inorganic binder in liquid phase (based on solid content), and then 60 to 90% of mesoporous zeolite. 90% by weight of the inorganic binder in a solid state and 9 to 35% by weight are uniformly dry mixed, and then 1 to 5% by weight of the liquid inorganic binder, alumina sol or silica sol, and 2 to 10 organic binders based on the mixture. Wet by kneading again by weight, plasticizer 1 to 8% by weight, lubricant 0.3 to 5% by weight, and mixed water 50 to 200% by weight uniformly to prepare the initial clay, and the initial clay was aged at room temperature for about one day, After forming the aged clay, the mesoporous zeolite honeycomb structure is completed by drying and firing at 650 to 800 ℃ for 4 to 6 hours.

The present invention also includes a). A mixing step of forming initial clay by mixing zeolite as a raw material and inorganic binder lubricant water as a subsidiary material; b). Aging step of aging the initial vomiting at room temperature for about one day; c). a molding step of molding the aged clay in an extrusion molding machine; d). A method of manufacturing a zeolite honeycomb structure comprising a firing step of drying and hot-firing the molded body, wherein in the mixing step a). 60 to 90% by weight of mesoporous zeolite and 9 to 35 inorganic binder in solid state After weighing 1% by weight and 1-5% by weight of the inorganic binder (solid content basis), dry mixing is performed to uniformly mix 60-90% by weight of the mesoporous zeolite and 9-35% by weight of the inorganic binder. And from 1 to 5% by weight of the liquid inorganic binder, alumina sol or silica sol, and 2 to 10% by weight of organic binder, 1 to 8% by weight of plasticizer, 0.3 to 5% by weight of lubricant, based on the mixture. Adding a water 50 to 200% by weight and kneading again uniformly to produce a wet kneading step; The d). Firing step of the mesoporous zeolite honeycomb structure of the mesoporous zeolite honeycomb structure comprising the step of adopting the internal drying method to be dried from the inside of the molded body, and firing the dried molded body for 4 to 6 hours in the temperature range of 650 ~ 800 ℃ It provides a manufacturing method.

Hereinafter, the present invention will be described in more detail. 1 is a conceptual diagram schematically showing a method for manufacturing a mesoporous zeolite honeycomb structure according to the present invention.

In the present invention, the main raw material is 60 to 90% by weight of mesoporous zeolite having a pore size of about 20 to 100 mm 3 and a specific surface area of about 1000 m 2 / g or more than conventional zeolite materials. At this time, when the mesoporous zeolite is used in an amount of 60% by weight or less, the adsorption performance of macroorganic molecules is extremely low, and when the mesoporous zeolite is used in an amount of 90% by weight or more, the formability is extremely poor and the strength of the final product is not preferable. .

In the present invention, the submaterial uses an inorganic binder in a solid or liquid state, an organic binder, a plasticizer, a lubricant, and a mixed water, and these are divided into dry mixing and wet kneading. First, 60 to 90% by weight of mesoporous zeolite, 9 to 35% by weight of inorganic binder in solid state, and 1 to 5% by weight of inorganic binder in liquid phase (based on solid content) are weighed, and then 60 to 90% by weight of mesoporous zeolite. Dry mix the% and inorganic binder 9 to 35% by weight uniformly. Inorganic binders may be used alone or in combination of clay or bentonite. At this time, when the amount of the inorganic binder is increased, the strength after firing is increased, but the specific surface area is decreased. On the contrary, when the amount of the inorganic binder is added too little, it does not function properly as the inorganic binder. Once dry mixing is completed, 1 to 5% by weight of the liquid inorganic binder, alumina sol or silica sol, and 2 to 10% by weight of organic binder, 1 to 8% by weight of plasticizer, and lubricant 0.3 based on the mixture. ˜5% by weight, and 50-200% by weight of mixed water are added, and the wet kneading process is continued so that all of the above components are uniformly mixed to prepare initial clay. At this time, as the organic binder, polyvinyl alcohol and carboxymethyl cellulose are preferable. If the content is less than 2% by weight, the performance as a binder is weak and easily broken in the molding step, and if it is used more than 10% by weight, the amount of volatilized in the firing step increases, which is not preferable because the physical properties of the final product are weak. Glycerin and ethylene glycol are used as a plasticizer, and stearic acid, a wax emulsion zone, polyethyleneglycol, etc. are used as a lubricant. If these are used less than the minimum amount, the expected performance may not be exhibited. On the other hand, if the amount is used more than the maximum amount, the shape of the molded body may be distorted in the forming step, which is not preferable. In addition, the liquid alumina sol and silica sol may be used alone or in combination. In mixed use, the two materials react in the firing step to form alumina silicate components similar to the zeolite materials in the matrix.

In the present invention, the aging step and the forming step are carried out according to a conventional procedure. Therefore, in the above aging step, the initial clay after the mixing step is left to stand at room temperature for about a day to fully mature, and the above-mentioned aging clay is kneaded two or three times in a conventional extrusion molding machine and then extruded into a predetermined shape. .

In the present invention, the molded article is sufficiently dried by adopting an internal drying method which is dried from the inside thereof. When the internal drying method is dried from the outside of the molded body, the internal stress is generated due to the difference in the drying speed between the surface and the inside, thereby causing cracks or cracks in the molded body, thereby preventing this phenomenon. In order to dry slowly from the inside of the molded body. The sufficiently dried molded product is fired for 4 to 6 hours at a temperature range of 650 to 800 ° C. If the firing temperature is not higher than 650 ° C, it is not sufficiently fired, whereas if the firing temperature is higher than 800 ° C, the strength is remarkably increased, but the crystal structure of the mesoporous zeolite material after the firing process is collapsed, which is not preferable. . In fact, after firing the molded body at a temperature range of 650 ° C. to 1050 ° C., the mesoporous zeolite powder was measured by XRD, and the result was as shown in FIG. 2. According to FIG. 2, the zeolite crystal structure was completely collapsed at the firing temperature of 950 ° C. or higher, and the firing temperature of the mesoporous zeolite molded body was set at a temperature range of 650 to 800 ° C. in the firing step.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are only presented on the basis of the most preferred embodiments so that the technical idea of the present invention can be easily carried out by those skilled in the art, the scope of the present invention is limited to the following examples It is self-evident.

<Example 1>

170 g of synthetic mesoporous zeolite powder having a specific surface area of at least 1000 m 2 / g and an average particle diameter of 1.0 m and 26 g of bentonite as an inorganic binder were weighed, and then thoroughly mixed in a high-speed kneader, followed by carboxymethyl as an organic binder. 6 g of cellulose, 4 g of glycerin as a plasticizer, 7 g of wax emulsion as a lubricant, and 120 g of distilled water, and 124 g of mixed water in which 4 g of silica sol was applied as a solid content based on silica sol as an inorganic binder were added, followed by wet kneading. Prepared. Thereafter, the initial clay was left to stand at room temperature for one day to ripen to uniformly disperse moisture and organic additives. The aged clay was put into a vacuum extrusion molding machine and kneaded two or three times. Then, a honeycomb mold having a cell size of 200 cells / in ² was attached and extruded to form a mesoporous zeolite honeycomb structure. The mesoporous zeolite honeycomb molded body was sufficiently dried through a working process, and then calcined in an electric furnace at a baking temperature of 650 ° C. 700 ° C. 750 ° C. 800 ° C. for 5 hours, respectively, to prepare a mesoporous zeolite honeycomb structure. For each honeycomb structure completed through the above process, the specific surface area and the compressive strength, which are physical properties thereof, were measured, and the measurement results are shown in Table 1 below.

<Example 2>

Except for using 160g of the synthetic mesoporous zeolite powder and 46g of the bentonite as the inorganic binder, it proceeded in the same manner as in Example 1, and the results are shown in Table 1 below. It was like

<Example 3>

Except that 150g of the synthetic mesoporous zeolite powder and 56g of bentonite, the inorganic binder, were used in the same manner as in Example 1, and the results are shown in Table 1 below. It was like

<Example 4>

Except for using 140g of the synthetic mesoporous zeolite powder and 66g of the bentonite as the inorganic binder, it proceeded in the same manner as in Example 1, and the results are shown in Table 1 below. It was like

Water composition Specific surface area (㎡ / g) Compressive strength (kg / ㎠) 650 ℃ 700 ℃ 750 ℃ 800 ℃ 650 ℃ 700 ℃ 750 ℃ 800 ℃ Example 1 736.3 635.6 588.1 403.3 13.5 14.3 20.4 33.9 Example 2 776.2 665.7 612.3 358.0 15.2 16.1 22.5 35.7 Example 3 712.2 614.5 580.5 352.1 16.4 17.7 24.6 38.2 Example 4 534.2 427.2 349.9 302.7 19.6 19.9 29.8 45.6

Example 5

In Example 1 above, except that 120 g of distilled water was used as an inorganic binder and 2 g each of a liquid silica sol and an alumina sol were used as a solid content basis, thereby making 124 g of mixed water and kneading by adding the mixed water. It proceeded in the same manner as in Example 1. The honeycomb structure completed through the above process was measured by measuring the specific surface area and the compressive strength, respectively, its physical properties, and the measurement results are shown in Table 2 below.

<Example 6>

In Example 2 described above, except that 120 g of distilled water was used as an inorganic binder and 2 g each of a liquid silica sol and an alumina sol were used as solid standards, and thus 124 g of mixed water was added and kneaded by addition of the mixed water. It proceeded in the same manner as in Example 2, the results were as shown in Table 2 below.

<Example 7>

In Example 3 above, except that 120 g of distilled water was used as an inorganic binder and 2 g each of liquid silica sol and alumina sol were used as a solid content basis to make 124 g of mixed water and kneaded by adding the mixed water. It proceeded in the same manner as in Example 3, the results were as shown in Table 2 below.

<Example 8>

In Example 4 above, except that 120 g of distilled water was used as an inorganic binder and 2 g of silica sol and alumina sol, respectively, as a solid content standard, 124 g of mixed water was added, and the mixed water was added and kneaded. It progressed in the same manner as in Example 4, the results were as shown in Table 2 below.

Water composition Surface Area (㎡ / g) Compressive strength (kg / ㎠) 650 ℃ 700 ℃ 750 ℃ 800 ℃ 650 ℃ 700 ℃ 750 ℃ 800 ℃ Example 5 737.9 636.9 589.2 405.8 12.7 13.9 19.6 32.8 Example 6 778.8 669.8 615.6 360.1 14.5 15.7 21.1 33.4 Example 7 715.1 615.7 582.9 354.2 15.3 16.8 23.9 37.5 Example 8 537.4 430.3 353.1 305.9 19.1 20.1 29.6 43.3

In analyzing the above examples, it can be seen that under the same firing temperature conditions, as the composition ratio of the inorganic binder gradually increases, the surface area of the honeycomb structural body, which is the final product, decreases, while its compressive strength increases. In addition, under the same ratio of raw material conditions, as the firing temperature increases, the specific surface area of the honeycomb structure decreases, whereas the compressive strength of the honeycomb structure increases significantly. On the other hand, if the addition of alumina sol and silica sol in addition to the bentonite as an inorganic binder, the specific surface area is slightly increased than when only silica sol alone is added, it can be seen that there is no significant difference in the compressive strength.

In the case of the conventional honeycomb structured manufacturing method as described above, the hydrothermal stability and mechanical stability of the mesoporous zeolite material itself is insufficient, the molded body is broken by the molding pressure during the molding process, or high heat treatment in the firing process Although the pore structure of the final product was destroyed by the present invention, the present invention simplified the manufacturing process of mesoporous zeolite honeycomb structure by directly adding the inorganic binder without colliding in the initial mixing step, and also bentonite as the inorganic binder. In addition, by adding silica sol or the like, the specific surface area of the mesoporous zeolite honeycomb structure after firing was greatly improved, and the compressive strength was also significantly improved.

In addition, the conventional zeolite molded body has a pore size of less than 10 μs, which limits the size of the reactants. Therefore, the zeolite molded body was not applicable to the adsorption or separation of large organic molecules, the reaction of catalysts, or the reaction with a large effect of mass transfer rate. The honeycomb structure by using mesoporous zeolite material having a pore size of about 20 to 100 mm 3 and a specific surface area of about 1000 m 2 / g or more than conventional zeolite material can be easily diffused, thereby adsorbing, separating and catalyzing large organic molecules. In addition to the reaction, effects that can be widely used for reforming petroleum, synthesizing large organic molecules, and removing industrial gas waste are expected.

Although the present invention has been described above by way of example drawings and examples, this is only for describing the most preferred embodiments of the present invention, it is obvious that the present invention is not limited thereto. In addition, anyone of ordinary skill in the art will be able to make various modifications and imitations by the description of the present specification, but it will be apparent that this is also outside the scope of the present invention.

Claims (4)

After weighing 60 to 90% by weight of mesoporous zeolite, 9 to 35% by weight of inorganic binder in solid state, and 1 to 5% by weight of inorganic binder in liquid state, first, 60 to 90% by weight of mesoporous zeolite and 9 to inorganic binder Dry mixing 35% by weight uniformly, and then 1 to 5% by weight of the liquid inorganic binder alumina sol or silica sol and 2 to 10% by weight of the organic binder, 1 to 8% by weight of the plasticizer, 0.3-5% by weight of lubricant and 50-200% by weight of the mixed water were uniformly wet kneaded again to prepare initial clay, and the initial clay was aged at room temperature for about one day, and then the aged clay was molded and then dried. Mesoporous zeolite honeycomb structure is completed by baking for 4 to 6 hours at 650 ~ 800 ℃. The mesoporous zeolite honeycomb structure according to claim 1, wherein the mesoporous zeolite has a pore size of about 20 to 100 GPa and a specific surface area of about 1000 m 2 / g or more. a). a mixing step of mixing initial zeolite as an ingredient and inorganic binder lubricant water as an ingredient to form initial clay; b). Aging step of aging the initial vomiting at room temperature for about one day; c). a molding step of molding the aged clay in an extrusion molding machine; d). A method of manufacturing a zeolite honeycomb structure, comprising a firing step of drying the molded body and baking at a high temperature, In the mixing step a). 60 to 90% by weight of mesoporous zeolite, 9 to 35% by weight of inorganic binder in solid state and 1 to 5% by weight of inorganic binder in liquid state are weighed, and then 60 to 90% of mesoporous zeolite is used. Dry mixing step of uniformly mixing 90% by weight and 9 to 35% by weight of the inorganic binder, 1 to 5% by weight of the liquid inorganic binder, alumina sol or silica sol and the organic binder based on the mixture 2 to 10 wt%, 1 to 8 wt% of a plasticizer, 0.3 to 5 wt% of a lubricant, and 50 to 200 wt% of a mixed water, followed by uniformly kneading to prepare a wet kneading step for preparing an initial clay; In the step d). The firing step adopts an internal drying method that is dried from the inside of the molded body, mesoporous comprising a step of firing the dried molded body for 4 to 6 hours in the temperature range of 650 ~ 800 ℃ Method of manufacturing zeolite honeycomb structure. The method of claim 3, wherein the mesoporous zeolite has a pore size of about 20 to about 100 microns and a specific surface area of about 1000 m 2 / g or more.