KR100351624B1 - A manufacturing method of granulated adsorbent having multi-functions - Google Patents

Abstract

The present invention relates to a method for producing a multifunctional granular adsorption material, and more particularly, a composite material prepared by granulating by mixing chaff and sodium aluminate aqueous solution, undergoing carbonization and activation, and then hydrothermally treating with an aqueous alkali solution. The lipophilic and hydrophilic adsorption characteristics are better than those of ordinary composite materials prepared using expensive raw materials such as activated carbon and binders, so that water treatment agents, deodorants, antibacterial and bactericides, organic material adsorbents, moisture adsorbents, tobacco filter substrates, The present invention relates to a new manufacturing method that enables mass production of multifunctional granular adsorption materials used in a wide range of applications such as air separators.

Description

A manufacturing method of granulated adsorbent having multi-functions

The present invention relates to a method for producing a multifunctional granular adsorption material, and more particularly, a composite material prepared by granulating by mixing chaff and sodium aluminate aqueous solution, undergoing carbonization and activation, and then hydrothermally treating with an aqueous alkali solution. The lipophilic and hydrophilic adsorption characteristics are better than those of ordinary composite materials prepared using expensive raw materials such as activated carbon and binders, so that water treatment agents, deodorants, antibacterial and bactericides, organic material adsorbents, moisture adsorbents, tobacco filter substrates, The present invention relates to a new manufacturing method that enables mass production of multifunctional granular adsorption materials used in a wide range of applications such as air separators.

Zeolites with the general formula _{M 2 / n O · Al 2} O 3 · xSiO 2 · yH 2 O ( and where M is a cation, n is the valence of the cation, x and y are constants determined by the shape of each zeolite) Is displayed. Zeolite has pore diameter of 3 ~ 10 ∼ and shows molecular sieve effect. Especially, it is a hydrophilic adsorbent, and has strong adsorptivity to polar molecules such as water, and has high adsorption power under low partial pressure and high temperature. . Due to these adsorption characteristics, zeolite has been widely applied to various fields such as adsorbents, catalysts and catalyst carriers, molecular sieves, detergent additives, and the like.

So far, much research has been done on zeolite synthesis. For example, in the method of crystallizing aluminosilicate by hydrothermal synthesis, it is generally synthesized by adding organic substances, polyhydric alcohols, polyhydric acids, etc., which may cause various contaminations according to the addition of the substances and control the molar ratio of silica to alumina. It has a disadvantage. In addition, since the reactants are converted into the slurry phase as particles having an average particle diameter of several to several tens of micrometers are formed in the gel phase, the final product must be dried by filtration and washing to obtain the final product. In order to use in the catalytic process has a complex manufacturing process that must be granulated in a certain form again.

In addition, activated carbon is produced by activating in a reducing atmosphere through carbonization process such as palm shell, coal-based, wood, polymer fiber, etc. The form is granular, crushed, powdered, fibrous, etc., fine pore diameter of several hundreds of millimeters It consists of a ball. Activated carbon is a lipophilic adsorbent and has a strong adsorption force on non-polar components, and its specific surface area reaches up to 1,200 m 2 / g or more. Due to these characteristics, activated carbon is currently used as the most extensive adsorbent for refining, food industry, decoloring, deodorization, wastewater treatment, air purification, and catalyst carrier.

In addition, in recent years, studies to complement the mutual adsorption properties of zeolite and activated carbon have been continuously conducted. For example, Japanese Patent Laid-Open No. 54-53669 describes a method for preparing an adsorbent having a complex function using an organic and inorganic binder in a mixture of zeolite and activated carbon, and in Korean Patent Registration No. 124983 of the applicant, There has been reported a method of binding molasses and alkaline earth metal silicates to activated carbon. However, the above manufacturing methods require expensive raw material costs by using zeolite powder and activated carbon powder as starting materials, and it is difficult to control the uniform physical properties of the product by powder mixing. Many problems have been pointed out in the manufacturing process, such as reduced contact area.

The present inventors use expensive zeolite and activated carbon as raw materials when manufacturing multifunctional granular adsorption material using chaff and sodium aluminate aqueous solution containing cellulose and silica components as starting materials to solve the problems of the prior art as described above. It was conceived that the same effect as the obtained adsorption material could be obtained. First, chaff powder and sodium aluminate aqueous solution are mixed and granulated into a suitable form, followed by carbonization and activation to convert the cellulose component contained in the chaff into activated charcoal, and hydrothermal treatment in an aqueous alkali solution to chaff during the initial mixing process. By converting the aluminosilicate produced from the silica and sodium aluminate contained in the zeolite into the zeolite, the zeolite and the activated carbon are uniformly distributed in the matrix, showing excellent multifunctional adsorption performance, and maintaining the granular form by the self-bonding force between carbon and carbon. This completes the process for producing a new multifunctional granular adsorption material that requires no binder at all.

Accordingly, the present invention provides a manufacturing method that fundamentally improves the shortcomings of the conventional manufacturing method of artificially combining zeolite and activated carbon using a binder by directly preparing a composite of zeolite and activated carbon by using chaff and aqueous sodium aluminate solution as raw materials. To provide.

1 is a process diagram schematically showing a multifunctional granular adsorption material manufacturing process according to the present invention,

Figure 2 shows an electron micrograph of the multifunctional granular adsorption material.

The present invention is a method for producing a granular adsorption material, the granular mixture of the chaff powder and sodium aluminate aqueous solution is granulated, and after the carbonization and activation process to produce a multi-functional granular adsorption material prepared by hydrothermal treatment with aqueous sodium hydroxide solution It is characterized by.

Referring to the present invention in more detail as follows.

In the present invention, the chaff and the aqueous sodium aluminate solution are used as starting materials, the mixture is granulated in an appropriate ratio, granulated, and treated with an aqueous alkali solution through carbonization and activation to produce alumino produced from silica and sodium aluminate in the rice husk. The present invention relates to a method for producing a multifunctional granular adsorption material in which a silicate is converted into a zeolite and the zeolite and activated carbon are uniformly distributed in a matrix.

1 is a schematic view illustrating a manufacturing process of a multifunctional granular adsorption material according to the present invention, and will be described in detail for each process as follows.

In the present invention, first, the chaff is pulverized and converted into a powder state of 30 mesh or less, and then the aqueous aluminate solution is added to the crushed chaff at a predetermined ratio and granulated into a spherical shape of 0.5 to 5 mm while sufficiently mixed in a flow share mixer. . At this time, the blending ratio of the chaff powder and the aqueous sodium aluminate solution (75 to 88% by weight, based on the moisture concentration) is preferably 1: 1.2 to 1: 1.5 by weight, because the silica component and the sodium aluminate in the chaff This is because an aqueous solution reacts to form an aluminosilicate gel with an appropriate water content, and this can act as a binder to obtain a granular composition having high strength.

In addition to the flow share mixer used in the present invention, any of the granulation apparatus may be any of a disc granulator, an injection molding granulator, a fluidized bed granulator, and a compression granulator.

Next, the prepared granular composition is continuously injected into a rotary kiln for 0.5 to 2.0 hours at 400 to 700 ° C. to remove moisture and volatile oil, and to maintain the granular form by the carbon-carbon bond. The granular composition of the carbonized state is obtained. At the carbonization temperature below 400 ° C, the pyrolysis reaction of rice hull is not completed and volatile oil remains, resulting in ineffective adhesion to the kiln walls during activation, and at temperatures above 700 ° C, the yield of carbon is reduced by oxidation of carbon. The composition thus treated is composed of 55 to 65% by weight of carbon components, 35 to 45% by weight of aluminosilicate components, and trace components of 1% by weight or less. This carbonized granular composition is continuously injected into a rotary kiln together with water vapor, and is maintained at 750 ° C. to 950 ° C. for 0.3 to 3.0 hours to burn-off about 30 to 50% by weight of all carbons. It was. If the activation temperature is maintained below 750 ℃, the activation is less progressed, the micropore formation is incomplete, if it exceeds 950 ℃ carbon component is rapidly burned off is uneconomical.

Carbonization and activation apparatus which can be used in addition to the rotary kiln used in the present invention include a dissociation kiln, a tunnel kiln, and the like.

The activated granular composition is then hydrothermally treated to convert the aluminosilicate evenly distributed inside and outside the micropores of the activated carbon component into zeolite. The hydrothermal treatment process of the present invention includes an aging process and a crystallization process, which is placed in an aqueous alkaline solution having a concentration of 3 to 8% (w / w), aged at 10 to 60 ° C. for 3 to 72 hours, and then 80 to 80 Crystallize at 110 ° C. for 2 to 36 hours. Subsequently, the alkaline mother liquor is removed, washed with sufficient water and dried to prepare a multifunctional granular adsorption material composition. At this time, the alkaline mother liquor and the washing liquid are recovered and reused in total quantity, thereby reducing manufacturing costs and generating no waste water.

In order to evaluate the structure and physical properties of the multifunctional granular adsorption material thus prepared, the specific surface area and pore volume, moisture adsorption capacity, ammonia adsorption capacity, iodine adsorption capacity, and packing density were measured by X-ray diffraction analysis (XRD) and BET method.

The multifunctional granular adsorption material produced by the present invention is uniformly distributed zeolite inside and outside the pores of activated carbon [see Fig. 2], and the characteristics of activated carbon and zeolite as a composite functional material containing no binder at all Since both of the hydrophilic and lipophilic adsorption properties are provided at the same time, it can be usefully used in a wide range of applications such as water treatment agents, deodorants, antibacterial and bactericides, organic adsorbents, moisture adsorbents, substrates for tobacco filters, and gas separation agents.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1

4 kg of sodium hydroxide (NaOH, 99% or more of Tedia) is added to 15.2 kg of water, and then dissolved. Then, 2.8 kg of aluminum hydroxide (Al (OH) ₃ , manufactured by Korea Integrated Chemical Co., Ltd.) is added thereto and stirred at 105 ° C. for 30 minutes. After dissolving, 6.4 kg of water was added and diluted to prepare an aqueous sodium aluminate solution. Meanwhile, 20 kg of chaff powder pulverized to 30 mesh or less was quantified using a vibration rod mill (manufactured by Youngjin Machinery Co., Ltd.) and placed in a 130 liter flow share mixer (manufactured by Loige, Germany). One aqueous sodium aluminate solution was kneaded while sprayed for 8 minutes and granulated for 20 minutes to obtain 48.4 kg of a granular composition having an average particle diameter of 2.8 mm.

Next, the granular composition was put into a rotary kiln (manufactured by KOREA CORPORATION) under a nitrogen atmosphere and kept at 500 ° C. for 30 minutes to remove moisture and volatile oil to obtain a 17.8 kg carbonized granular composition. The sample thus treated was placed in a rotary kiln (made by Korea Co., Ltd.) together with water vapor and stayed at 850 ° C. for 1 hour to obtain 13.1 kg of activated granular composition. In this process, about 43% by weight of the carbon component of the carbonized granular composition was burned off.

39.3 kg of a 5% (w / w) sodium hydroxide solution was added to the activated granular composition, aged at 25 ° C for 4 hours, and then heated to 100 ° C and crystallized for 3 hours. Next, the alkaline mother liquor was separated, washed with distilled water sufficiently, and dried at 110 ° C. for 3 hours to obtain 10.1 kg of the final product.

The physical properties of the samples thus obtained are shown in Table 1 below.

Example 2

After dissolving 3.2 kg of sodium hydroxide (NaOH, made by Tedia 99% or more) in 12.1 kg of water, 1.8 kg of aluminum hydroxide (Al (OH) ₃ , manufactured by Korea Integrated Chemical Co., Ltd.) was added thereto and stirred at 105 ° C. for 30 minutes. After dissolving, 9.5 kg of water was added and diluted to prepare an aqueous sodium aluminate solution. Meanwhile, 20 kg of chaff powder pulverized to 30 mesh or less was quantified using a vibration rod mill (manufactured by Youngjin Machinery Co., Ltd.) and placed in a 130 ℓ flow share mixer (manufactured by Loige, Germany). One aqueous sodium aluminate solution was kneaded while sprayed for 8 minutes and granulated for 20 minutes to obtain 46.6 kg of a granular composition having an average particle diameter of 2.8 mm.

Next, the same method as in Example 1 was carbonized and activated to obtain a 12.5 kg sample.

37.5 kg of an aqueous sodium hydroxide solution at a concentration of 4.5% (w / w) was added to the sample thus treated, aged at 25 ° C. for 12 hours, and then heated to 100 ° C. and hydrothermally treated for 8 hours. Next, the alkaline mother liquor was separated, washed with distilled water sufficiently and dried at 110 ° C. for 3 hours to obtain 9.4 kg of the final product.

The physical properties of the samples thus obtained are shown in Table 1 below.

Example 3

Into 9.6 kg of water, add 2.5 kg of sodium hydroxide (NaOH, 99% or more of Tedia), dissolve it, add 0.6 kg of aluminum hydroxide (Al (OH) ₃ , Korea Integrated Chemical Co., Ltd.), and stir at 105 ° C for 30 minutes. After dissolution, 11.9 kg of water was added thereto and diluted to prepare an aqueous sodium aluminate solution. Meanwhile, 20 kg of chaff powder pulverized to 30 mesh or less was quantified using a vibration rod mill (manufactured by Youngjin Machinery Co., Ltd.) and placed in a 130 liter flow share mixer (manufactured by Loige, Germany). One aqueous sodium aluminate solution was kneaded while sprayed for 8 minutes and granulated for 20 minutes to obtain 44.6 kg of a granular composition having an average particle diameter of 2.8 mm.

Next, the same method as in Example 1 was carbonized and activated to obtain a 11.6 kg sample.

34.8 kg of an aqueous sodium hydroxide solution at a concentration of 4.2% (w / w) was added to the sample thus treated, aged at 25 ° C. for 48 hours, and then heated to 100 ° C. and hydrothermally treated for 24 hours. Next, the alkaline mother liquor was separated, washed with distilled water sufficiently and dried at 110 ° C. for 3 hours to obtain 8.6 kg of the final product.

The physical properties of the samples thus obtained are shown in Table 1 below.

Comparative Example 1

4A zeolite powder 12.0 kg (4.9% moisture), activated charcoal powder 8.0 kg (3.0% moisture) and 5.0 kg bentonite powder (2.0% moisture) were placed in a 130 liter flow share mixer (made by Loige, Germany). After the powder was mixed for a minute, 9.5 kg of 2.0 wt% CMC aqueous solution was spray-injected for 8 minutes through a nozzle, and then operated for 20 minutes to obtain a granular composition having an average particle diameter of 2.5 mm. The granulated composition was injected into a rotary firing furnace (manufactured by Korea Co., Ltd.) under a nitrogen atmosphere and kept at 650 ° C. for 1 hour to obtain a composition in which the zeolite and activated carbon mixture was granulated by a binder. The sample thus obtained was measured by X-ray diffraction analysis (XRD), zeolite content, specific surface area, pore volume, moisture adsorption capacity, ammonia adsorption capacity and iodine adsorption capacity, layer density, and the results are shown in Table 1 below.

As described above, the present invention is a method for producing a multi-functional granular adsorption material, granulated by mixing the chaff and sodium aluminate aqueous solution, and the hydrothermal treatment in aqueous sodium hydroxide solution through the carbonization and activation process to uniform the zeolite and activated carbon composite It is composed of a form, which shows superior adsorption characteristics compared to the mixed composition prepared by adding a binder to zeolite and activated carbon as a starting material, and in particular, the raw material cost is low, and a separate binder is not used, which significantly increases the production cost of the product. There is an effect that can be reduced.

Claims (5)

In the method for preparing the granular adsorption material, the chaff powder and the sodium aluminate aqueous solution are mixed in a weight ratio of 1: 1.2 to 1: 1.5, granulated, carbonized and activated, and then hydrothermally treated with an aqueous sodium hydroxide solution. Method for producing granular adsorption material. The method of claim 1, wherein the carbonization process is performed at 400 to 700 ° C. for 0.5 to 2.0 hours. The method of claim 1, wherein the activation process is performed at a temperature of 750 to 950 ° C. for 0.3 to 3.0 hours under steam injection. 2. The hydrothermal treatment process according to claim 1, wherein the hydrothermal treatment process comprises adding 3 to 8% by weight of an aqueous alkali solution and aging for 3 to 72 hours at 10 to 60 ° C and for 2 to 36 hours for crystallization at 80 to 110 ° C. Method for producing a multifunctional granular adsorption material. The method of claim 1, wherein the adsorption material has a zeolite content of 55A to 70% by weight and a activated carbon content of 30 to 45% by weight of 4A, X or Y type. .