KR20200021241A - Preparation of pellet composition containing a catalyst for removing harmful gas and recycle method thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a pellet composition containing a catalyst for removing harmful gases and a method for recycling the same. More specifically, the present invention relates to: preparation of a pellet composition containing a catalyst for removing harmful gases which has improved strength, thereby not being easily damaged and exhibiting excellent gas removal properties; and further, a method for recycling a carrier comprising silica particles, etc., constituting the pellet composition, which is used for a long time and reached end of lifespan thereof, in a simple manner. The pellet composition of the present invention contains the catalyst for removing harmful gases, silica microparticles, silica nanoparticles, and clay.

Description

Preparation of pellet composition containing a catalyst for removing harmful gas and recycle method

The present invention relates to a method for preparing a pellet composition containing a catalyst for removing harmful gases and a method for recycling the same, and more particularly, the catalyst containing the catalyst for removing harmful gases, which exhibits excellent gas removal properties due to its improved strength and is not easily broken. The present invention relates to a method for preparing a pellet composition, and furthermore, a method for recycling a carrier containing silica particles or the like constituting the pellet composition which has been used for a long time and has reached the end of its life.

Harmful or unpleasant hazards to humans such as carbon monoxide, nitrogen oxides, sulfur oxides and volatile organic compounds in everyday living spaces, markets, stores, automobiles, industrial sites, chemical plants, power plants, incinerators, boilers, underground roads, tunnels and underground parking lots. The state contains harmful gas components, and adsorbents or catalyst materials are mainly used for selective removal of such harmful gases.

Activated carbon, zeolite, and the like are commonly used as the adsorbent. However, since the adsorbent has a limit in adsorption capacity, the adsorption capacity is significantly lowered or extinguished after a certain time, and there is a disadvantage in that it is not easy to reuse. In particular, activated carbon has a problem in that it does not adsorb various harmful gases.

 As the catalyst material, precious metals such as platinum (Pt), gold (Au), and palladium (Pd) or transition metals such as manganese (Mn), cobalt (Co), iron (Fe), and the like, have a large surface area such as alumina, silica, and titania. Catalyst materials for oxidation reaction prepared by being supported on such carriers are mainly used.

On the other hand, the noble metal-containing catalyst shows an excellent removal performance compared to the transition metal-containing catalyst, but due to the cost of the precious metal material is limited in general purpose applications. Recently, catalysts using transition metals, which are more economical than precious metals, have been mainly developed. Representatively, manganese oxides or copper-manganese oxides are used to remove harmful gases such as carbon monoxide, volatile organic compounds (VOCs), ammonia and hydrogen sulfide. A catalyst is being developed.

Such a catalyst may adhere to a filter media, collectively called a filter medium, to physically or chemically capture or remove various harmful microparticles. However, catalysts are generally manufactured in powder form, in which case it is difficult to control the reaction of the catalyst in the reactor, pressure loss is large, and catalyst powder may cause contamination of the reactor and other devices, so You have to mold. In recent years, the catalyst in powder form has been used in the form of pellets. However, when the pellet composition does not have sufficient mechanical strength, it breaks easily and generates a differential pressure in the reactor, which causes a decrease in activity and selectivity of the catalyst. Therefore, improving the strength of the pellet composition is a necessary requirement for industrial catalysts such as improving the performance of the catalyst. However, the conventional pellet composition does not have sufficient strength and is easily broken, and a phenomenon such as powder blowing occurs.

In addition, the pellet composition also has a limit on the adsorption capacity, it may cause plugging or poisoning phenomenon in the catalyst surface or pores when used for a long time, resulting in the pore volume and specific surface area of the pellet composition ( specific surface area is reduced. The pellet composition needs to be replaced at regular intervals, and the pellet composition at the end of its life is designated as a waste and is landfilled. However, landfilling pellet compositions containing expensive metals is not economical and may cause environmental problems.

 The present inventors have found that the strength of the pellets is significantly increased while maintaining the harmful gas removal performance when the pellets are manufactured by mixing two kinds of silica particles and clays having different particle sizes in the catalyst for removing harmful gases. A method for preparing a high strength pellet composition containing an optimized catalyst for removing harmful gases and a recycling method thereof have been developed.

Republic of Korea Patent Application Publication No. 10-2004-0097738 (Invention name: manganese oxide catalyst for ozone decomposition and its manufacturing method, Applicant: KOTECH Co., Publication Date: November 18, 2004) Republic of Korea Patent Publication No. 10-2017-0009429 (Invention name: copper-manganese composite catalyst oxide for removing noxious gases and a method for producing the same, Applicant: SSA, published date: January 25, 2017) Republic of Korea Patent Publication No. 10-2011-0117301 (Invention name: nanometer sized copper-based catalyst manufacturing method, Applicant: SK Innovation Co., Ltd., Publication Date: October 27, 2011)

An object of the present invention is to produce a pellet composition containing a catalyst for removing harmful gases, the strength is improved to prevent damage to the equipment by the powder in the molding process and easy to move and store.

Another object of the present invention is to provide a method for recovering and recycling a porous carrier including silica particles and the like by a simple process from a pellet composition containing the catalyst for removing harmful gases at the end of life.

The present invention (1 step) preparing a catalyst for removing harmful gas;

(Step 2) preparing a mixture by mixing the harmful gas removal catalyst, silica microparticles, silica nanoparticles and clay;

(Step 3) extruding the mixture to prepare a molding composition;

(4 step) heat-treating the molding composition to produce a pellet composition containing a catalyst for removing harmful gases; And

(5) recovering the silica carrier by immersing and stirring the pellet composition containing the catalyst for removing harmful gases in an acid aqueous solution; and a method for recycling the pellet composition containing the catalyst for removing harmful gases, comprising: to provide.

At this time, the catalyst for removing harmful gases in the first step is preferably a manganese oxide catalyst or a copper-manganese oxide catalyst.

More preferably, in the first step, the catalyst for removing the noxious gas may include (a) preparing an aqueous metal salt solution;

(b) adding a silicate aqueous solution to the metal salt aqueous solution and then stirring to prepare a mixed solution;

(c) separating the mixed solution into a precipitate and a solution and then washing the precipitate; And

(d step) drying and heat treating the precipitate washed in the above; characterized in that it is prepared.

At this time, the metal salt aqueous solution in step a is preferably an aqueous solution of manganese salt or a mixture of copper salt and manganese salt.

In the second step, the silica microparticles preferably have an average particle size of 20 to 40 μm.

The silica nanoparticles in the second step is preferably an average particle size of 10 ~ 20nm.

In the second step, the clay (montmorillonite), bentonite, bentonite, hectorite, heidelite (beidellite), nontronite, saponite, laponite ), Dolomite, talc, feldspar, vermiculite, kaolin, halosite, illite, green stone, brookite, vermicullite, synthetic mica, kanemite, magadiite and It is preferably one or more selected from the group consisting of kenyaite.

In the second step, the mixture is characterized in that 1 to 15 parts by weight of catalyst for removing harmful gases, 15 to 35 parts by weight of silica nanoparticles and 0.5 to 5 parts by weight of clay based on 100 parts by weight of silica microparticles.

The pellet composition of a catalyst for the removal of harmful gases contained in the above step 4 is preferred to have more than 5.0kg / m ² intensity, and more specifically, is characterized by having a strength of 5.0 ~ 6.5kg / m ^2.

In addition, the pellet composition containing the catalyst for removing harmful gases preferably has a specific surface area of 200 m ² / g or more, and more specifically, has a specific surface area of 200 to 240 m ² / g. In addition, it has a mesopore volume of 0.65ml / g or more.

The acid solution in step 5 is characterized in that the acid containing 30 to 70 parts by weight based on 100 parts by weight of purified water, preferably the acid is hydrogen chloride (HCl), acetic acid (CH ₃ COOH), phosphoric acid (H ₃ PO ₄ ), Sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ) and hydrogen bromide (HBr) may be one or more selected from the group consisting of.

In the fifth step, the stirring temperature is 15 to 65 ℃, the stirring speed is 300 to 500rpm, the stirring is preferably 12 to 48 hours.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention provides a method for preparing a pellet composition containing a catalyst for removing harmful gases and a recycling method thereof, and more particularly, the present invention provides a method for preparing a catalyst for removing harmful gases;

(Step 2) preparing a mixture by mixing the harmful gas removal catalyst, silica microparticles, silica nanoparticles and clay;

(Step 3) extruding the mixture to prepare a molding composition;

(4 step) heat-treating the molding composition to produce a pellet composition containing a catalyst for removing harmful gases; And

(Step 5) recovering the silica carrier by immersing and stirring the pellet composition containing the catalyst for removing harmful gases in an acid aqueous solution.

At this time, the harmful gas removal catalyst in the first step is preferably a manganese oxide catalyst or a copper-manganese oxide catalyst, more preferably the manganese oxide catalyst is a manganese / silicon composite metal oxide catalyst, the copper-manganese oxide catalyst May be a copper-manganese / silicon composite metal oxide catalyst.

The catalyst for removing harmful gases is (a step) preparing a metal salt aqueous solution;

(b) adding a silicate aqueous solution to the metal salt aqueous solution and then stirring to prepare a mixed solution;

(c) separating the mixed solution into a precipitate and a solution and then washing the precipitate; And

(d step) drying and heat treating the precipitate washed in the above; characterized in that it is prepared.

In this case, the aqueous metal salt solution in step a may be an aqueous solution of manganese salt or a mixed solution of copper salt and manganese salt. It is preferable that it is at least one selected from the group, and the copper salt is preferably at least one selected from the group consisting of copper acetate, copper nitrate, copper chloride, copper iodide, copper bromide, and copper sulfate.

When the harmful gas removal catalyst is a manganese oxide catalyst, the metal salt aqueous solution is an aqueous solution of manganese salt in step a, and the aqueous solution of manganese salt is preferably prepared by mixing 5 to 20 parts by weight of manganese salt based on 100 parts by weight of purified water. If the amount of manganese salt is less than 5 parts by weight based on 100 parts by weight of purified water, the amount of wastewater is increased, and if it exceeds 20 parts by weight, it is not preferable because it is not sufficiently dissolved or economical efficiency is lowered.

When the harmful gas removal catalyst is a copper-manganese oxide catalyst, in step a, the metal salt aqueous solution is prepared by (a-1) preparing a manganese salt aqueous solution; And (a-2) adding a copper salt and a manganese salt mixed aqueous solution to the aqueous manganese salt solution to prepare a metal salt aqueous solution.

In the step a-1, the manganese salt solution is preferably prepared by mixing 1 to 10 parts by weight of manganese salt based on 100 parts by weight of purified water. When the amount of manganese salt is less than 1 part by weight based on 100 parts by weight of purified water, the amount of wastewater is increased, and when it exceeds 10 parts by weight, it is not preferable because it is not sufficiently dissolved or economical efficiency is lowered.

In step a-2, the mixed copper salt and manganese salt solution is more preferably mixed with 1 to 10 parts by weight of copper salt and 5 to 20 parts by weight of manganese salt based on 100 parts by weight of purified water. When the content of copper salt and manganese salt is less than the above range based on 100 parts by weight of purified water, the amount of wastewater is increased, and if it exceeds the above range, it is not preferable because it is not sufficiently dissolved or economical efficiency is lowered.

In addition, the manganese of step a-1 or step a-2 may be the same or different types.

In the b step, the silicate aqueous solution is preferably mixed with a silicate concentration of 15 to 30% (w / v). If the concentration of the silicate is less than 15% (w / v) is not produced a catalyst for removing harmful gas is not sufficient, if it exceeds 30% (w / v) it is undesirable because the catalyst properties may be lowered.

At this time, the silicate is to improve the reactivity when preparing the catalyst for removing harmful gases, to improve the porosity of the catalyst for removing harmful gases, sodium metasilicate (Na ₂ SiO ₃ ), potassium metasilicate (K ₂ SiO ₃ ) and It is preferably one kind selected from the group consisting of lithium metasilicate (Li ₂ SiO ₃ ).

The silicate aqueous solution in step b is preferably added so that the pH of the mixed solution is 6.5 ~ 7.5. If the pH is less than 6.5, the catalyst for removing the harmful gas is not sufficiently generated, and if the pH exceeds 7.5, the performance of the generated catalyst for removing the harmful gas deteriorates rapidly, which is not preferable.

In step c, the mixed solution may be separated into a precipitate and a solution through, for example, centrifugation, sedimentation, and bag filtration, but is not limited thereto.

In step d, the heat treatment temperature is 200 to 300 ° C., and the heat treatment time is preferably 1 to 24 hours. If the heat treatment temperature and time is less than the above range, it is difficult to produce a catalyst, and if it exceeds the above range, the density increases as the liquid phase sintering by the silicate proceeds, and thus the catalyst property may be deteriorated, which is not preferable.

In the second step, the mixture is preferably mixed with 1 to 15 parts by weight of catalyst for removing harmful gases, 15 to 35 parts by weight of silica nanoparticles and 0.5 to 5 parts by weight of clay based on 100 parts by weight of silica microparticles.

That is, the present invention is characterized in that a high-strength pellet composition is prepared by mixing two kinds of silica particles and clays having different sizes in a catalyst for removing harmful gases.

At this time, the harmful gas removal catalyst is preferably included 1 to 15 parts by weight based on 100 parts by weight of silica microparticles. If the amount of the catalyst for removing the harmful gas is less than 1 part by weight based on 100 parts by weight of the silica microparticles, the effect of removing the harmful gas may not be sufficient. If the amount is more than 15 parts by weight, the excessive catalyst may deteriorate the harmful gas removal performance. It is not desirable.

The silica microparticles preferably have an average particle size of 20 ~ 40㎛. When the average particle size of the silica microparticles is less than 20 μm, the viscosity of the pellet composition becomes high, and thus, it is difficult to prepare a pellet composition of uniform physical properties due to poor mixing dispersibility when preparing the pellets, and when the thickness exceeds 40 μm, the strength of the pellet composition decreases. It may be undesirable.

In addition, the silica microparticles more preferably have a specific surface area of 210 ~ 270m ² / g. If the specific surface area is less than 210m ² / g is not preferable because the harmful gas adsorption capacity of the pellet composition may be lowered. The larger the specific surface area of the silica microparticles, the better the catalyst performance, but sufficient strength and catalyst performance may be satisfied just by satisfying the above range.

In addition, the silica microparticles more preferably have a void volume of 0.6 ~ 0.9ml / g. If the void volume is out of the above range, the strength improvement effect is insignificant, which is not preferable.

The silica nanoparticles are preferably an average particle size of 10 ~ 20nm. When the average particle size of the silica nanoparticles is less than 10 nm, the dispersibility is poor due to agglomeration of crystals with each other, and when the average particle size exceeds 20 nm, the final specific surface area of the pellet composition may be lowered, which is not preferable.

In this case, the silica nanoparticles are more preferably colloidal silica in which 25 to 32 wt% of ultrafine silicon dioxide particles are dispersed in a solvent, and the solvent is selected from the group consisting of water or methyl ethyl ketone, methyl isobutyl ketone, methanol, and isopropanol. It may be one kind of organic solvent.

In addition, the viscosity of the silica nanoparticles is more preferably less than 13cps at 25 ℃. When the viscosity of the silica nanoparticles exceeds 13 cps, the mixing dispersibility is poor when mixed with the catalyst for removing harmful gases, which makes it difficult to prepare a pellet composition having a uniform physical property.

In addition, the silica nanoparticles are preferably included 15 to 35 parts by weight based on 100 parts by weight of silica microparticles. When the content of the silica nanoparticles is less than 15 parts by weight based on 100 parts by weight of the silica microparticles, the effect of improving the strength of the pellet composition is not sufficient, and when the content of the silica nanoparticles exceeds 35 parts by weight, it is difficult to produce a pellet composition having a uniform physical property. Not.

The clay (montmorillonite), bentonite (bentonite), hectorite, heidite (beidellite), nontronite (satronite), saponite, laponite, laponite, dolomite, Talc, feldspar, vermiculite, kaolin, halosite, illite, chlorite, brookite, vermicullite, synthetic mica, canemite, magadiite and kenyaite It is preferably one or more selected from the group consisting of.

The clay preferably contains 0.5 to 5 parts by weight based on 100 parts by weight of the silica microparticles. If the content of clay is less than 0.5 parts by weight with respect to 100 parts by weight of the silica microparticles, there is a problem in controlling the physical properties of the catalyst, and if it exceeds 5 parts by weight, the catalyst activity may decrease, which is not preferable.

In the step 2, the catalyst for removing harmful gases, silica microparticles, silica nanoparticles and clay are preferably mixed by stirring for 0.5 to 5 hours. If the stirring time is less than 0.5 hours, each component is not sufficiently mixed, if it is more than 5 hours is not economical is not preferable.

In the third step, the mixture may be extruded through an extruder, and the extruder may be used without limitation as long as it is in the form of an extruder for molding a slurry or dough, for example, a screw extruder may be used.

In addition, the particle size of the mixture extruded in step 3 is not particularly limited, but is preferably molded to a size capable of minimizing pressure loss and maximizing the removal efficiency of contaminants. It is preferable that it is 20 mm. For example, if it is columnar pellet, the thing of about 0.5-10 mm in diameter and 0.5-15 mm in length can be easily obtained.

In the step 4, the heat treatment temperature is 200 to 300 ° C, and the heat treatment time is preferably 1 to 24 hours. If the heat treatment temperature and time is less than the above range, the strength of the pellet composition is not sufficient, and if it exceeds the above range, it is not economical and is not preferable.

The pellet composition of a noxious gas removing catalyst prepared in the above step 4 contained is desirable to have more than 5.0kg / m ² intensity, and more specifically, is characterized by having a strength of 5.0 ~ 6.5kg / m ^2.

In addition, the pellet composition containing the catalyst for removing harmful gases preferably has a specific surface area of 200 m ² / g or more, and more specifically, has a specific surface area of 200 to 240 m ² / g. In addition, it has a mesopore volume of 0.65ml / g or more.

The acid aqueous solution in step 5 is preferably contained 30 to 70 parts by weight of acid based on 100 parts by weight of purified water. If the acid content is less than 30 parts by weight based on 100 parts by weight of purified water, it is difficult to reuse the porous carrier containing silica particles due to insufficient effect of removing harmful substances, and if it exceeds 70 parts by weight, the risk of high concentration acid, It is undesirable because there may be secondary disadvantages and economic disadvantages due to the use of excess acid.

The acid is at least one selected from the group consisting of hydrogen chloride (HCl), acetic acid (CH ₃ COOH), phosphoric acid (H ₃ PO ₄ ), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ) and hydrogen bromide (HBr). More preferred.

In the fifth step, the stirring temperature during stirring is 15 to 65 ° C, the stirring speed is 300 to 500rpm, and the stirring time is preferably 12 to 48 hours.

If the stirring conditions are less than the above range, it is difficult to reuse the porous carrier including silica particles due to insufficient effect of removing the harmful substances from the pellet composition, and if it exceeds the above range, it is not preferable in terms of economics.

Pellet composition for removing harmful gases provided by the present invention is excellent in strength and significantly reduced the generation of fine dust when mounted or detached in the air purification system device, mechanical impact during the movement, storage, regeneration process, The generation of breakdown and fine dust can be fundamentally improved.

In addition, through the recycling method of the pellet containing the catalyst for removing harmful gases provided by the present invention, it is possible to selectively recover expensive metal components in the pellet by a simple process, and also to recover a porous carrier including silica particles and the like. It is economical because it can be used again as a filter media for removing odors, especially ammonia, or the recovered silica can be used as a porous carrier when preparing new pellets.

Hereinafter, a preferred embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, it is provided to fully convey the spirit of the present invention to those skilled in the art so that the contents introduced herein are thoroughly and completely.

Preparation Examples 1 and 2. Preparation of Catalysts for Removing Hazardous Gases

Preparation Example 1 Preparation of Manganese Oxide Catalyst

63.85 g of potassium permanganate (KMnO ₄ ) and 643.67 g of manganese acetate tetrahydrate (Mn (CH ₃ COO) _{2 ·} 4H ₂ O) were added to 6 kg of purified water to prepare a mixed solution. Subsequently, precipitation of manganese dioxide (MnO ₂ ) was induced by a redox precipitation reaction while stirring at 16.9 ° C. for 4 hours. At this time, the pH of the solution was 5.02. Thereafter, an aqueous sodium metasilicate solution (Na ₂ SiO ₃ , 23.5 w / v%) was added to the pH solution of manganese dioxide and stirred at 17.4 ° C. for 4 hours. After the reaction was completed, the precipitate and the solution were separated using a centrifuge, and the precipitate was washed three times with distilled water to remove impurities. Subsequently, the precipitate was dried at 120 ° C. for 1 hour and then heat-treated at 250 ° C. for 4 hours to prepare manganese oxide (IV) manganese oxide (II) catalyst (Mn ₃ O ₄ catalyst), and the components of the catalyst were analyzed by X-ray fluorescence. As a result of analysis, it was confirmed that the chemical formula of (Mn ₃ O ₄ ) _0.183 (SiO ₂ ) _0.817 .

Preparation Example 2 Preparation of Copper-Manganese Oxide Catalyst

An aqueous potassium permanganate solution was prepared by dissolving 153.24 g of potassium permanganate (KMnO ₄ ) in 3 kg of purified water. Then copper acetate monohydrate to purified water to _{3kg (Cu (CH 3 COO)} 2 · H 2 O) 121.09g , and manganese acetate tetrahydrate _{(Mn (CH 3 COO) 2} · 4H 2 O) was dissolved in 356.49g copper-manganese acetate An aqueous solution was prepared and the copper-manganese acetate aqueous solution was added to the aqueous potassium permanganate solution and mixed. After stirring at 17.5 ° C. for 4 hours, precipitation of CuO: MnO ₂ was induced by a redox precipitation reaction. The pH of the solution was 4.38. Next, an aqueous sodium metasilicate solution (Na ₂ SiO ₃ , 23.5 w / v%) was added to the CuO: MnO ₂ precipitation solution so as to have a pH of 7.0, and stirred at 19.8 ° C. for 4 hours. After the reaction was completed, the precipitate and the solution were separated using a centrifuge, and the precipitate was washed three times with distilled water to remove impurities. The precipitate was then dried for one hour at 120 ℃, copper and heat-treated at 250 ℃ 4 hours - After a manganese oxide catalysts were prepared through the X- ray fluorescence spectrometry analysis of the components of the catalyst (K ₂ O) _0.020 (Na ₂ O) _0.013 (CuO) _0.099 (MnO ₂ ) _0.327 (SiO ₂ ) It was confirmed to have a chemical formula of _0.572 .

Examples 1 to 4 and Comparative Examples 1 to 14. Preparation of a pellet composition comprising a catalyst for removing harmful gases

Example 1 Preparation of a Pellet Composition Comprising a Manganese Oxide Catalyst

2.0 kg of manganese oxide catalyst dispersion (19 wt%) prepared in Preparation Example 1, silica powder (average particle diameter 35 μm, specific surface area 217 m ² / g, pore volume 0.8 ml / g) 5.0 kg, colloidal silica (solid content 30.2 wt%) %, Particle size 12nm, 4.0kg of viscosity 9.17cps (@ 25 ℃) and 4.0kg of montmorillonite dispersion (2wt%) in a kneader and mixed for 1 hour. Subsequently, the mixture mixed above was extruded into pellet granules having a diameter of 3.5 mm and a length of about 10 mm using an extrusion type pellet granulation apparatus. Thereafter, hot air dried at 70 ° C. for 20 hours, and then heat treated at 250 ° C. for 4 hours to prepare a pellet composition including a manganese oxide catalyst.

Examples 2 to 3. Preparation of pellet composition comprising manganese oxide catalyst

To prepare a pellet composition in the same manner as in Example 1, the weight of each composition was referred to the values in Table 1 below.

Example 4 Preparation of a Pellet Composition Comprising a Copper-Manganese Oxide Catalyst

2.0 kg of copper-manganese oxide catalyst dispersion (16 wt%) prepared in Preparation Example 2, silica powder (average particle diameter 35 μm, specific surface area 217 m ² / g, pore volume 0.8 ml / g) 5.0 kg, colloidal silica (solid content) 30.2 wt%, particle size 12 nm, viscosity of 9.17 cps (@ 25 ° C.) 4.0 kg and 4.0 kg of montmorillonite dispersion (2 wt%) were added to a kneader and mixed for 1 hour. Subsequently, the mixture mixed above was extruded into pellet granules having a diameter of 3.5 mm and a length of about 10 mm using an extrusion type pellet granulation apparatus. After hot air drying at 70 ° C. for 20 hours, heat treatment was performed at 250 ° C. for 4 hours to finally prepare a pellet composition including a copper-manganese oxide catalyst.

Comparative Example 1. Preparation of pellet composition using silica powder having an average particle diameter of less than 20 mu m

A pellet composition was prepared in the same manner as in Example 1, but was prepared using silica powder having an average particle diameter of 18 μm and a specific surface area of 220 m ² / g.

Comparative Example 2. Preparation of Pellet Composition Using Silica Powder with an Average Particle Size Over 40 µm

A pellet composition was prepared in the same manner as in Example 1, except that silica powder having an average particle diameter of 45 μm and a specific surface area of 261 m ² / g was used.

Comparative Example 3. 210 m specific surface area ² pellet composition using silica powder less than / g

A pellet composition was prepared in the same manner as in Example 1, except that silica powder having an average particle diameter of 35 μm and a specific surface area of 204 m ² / g was used.

Comparative Example 4. Preparation of the pellet composition using colloidal silica having a particle size of less than 10 nm

A pellet composition was prepared in the same manner as in Example 1, except that colloidal silica having a particle size of 8 nm was used.

Comparative Example 5. Preparation of Pellet Composition Using Colloidal Silica with Viscosity> 13 cps (@ 25 ° C)

A pellet composition was prepared in the same manner as in Example 1, but using colloidal silica having a viscosity of 15 cps (@ 25 ° C.).

Comparative Examples 6 to 11. Preparation of pellet composition by varying the weight of each composition

To prepare a pellet composition in the same manner as in Example 1, the weight of each composition was referred to the values in Table 1 below.

Comparative example  12 to 14. Preparation of Pellet Compositions by Different Weights of Each Composition

To prepare a pellet composition in the same manner as in Example 4, the weight of each composition was referenced to the values in Table 1.

Silica microparticles
(kg) Catalyst Dispersion
(Catalyst content in dispersion)
(kg) Colloidal silica
(Silica nanoparticle content)
(kg) Clay dispersion
(Clay content in dispersion)
(kg) Remarks Manganese Composite Oxide Catalyst Copper-Manganese Composite Oxide Catalysts Example 1 5 2 (0.38) 4 (1.21) 4 (0.08) Example 2 5 3.5 (0.67) 4 (1.21) 3.5 (0.07) Example 3 5 2 (0.38) 5.5 (1.66) 2.5 (0.05) Example 4 5 2 (0.32) 4 (1.21) 4 (0.08) Comparative Example 1 5 2 (0.38) 4 (1.21) 4 (0.08) Silica Microparticles Below Average Particle Size Comparative Example 2 5 2 (0.38) 4 (1.21) 4 (0.08) Silica Microparticles Above Average Particle Size Comparative Example 3 5 2 (0.38) 4 (1.21) 4 (0.08) Less than silica microparticle specific surface area Comparative Example 4 5 2 (0.38) 4 (1.21) 4 (0.08) Silica Nanoparticles Below Average Particle Size Comparative Example 5 5 2 (0.38) 4 (1.21) 4 (0.08) Silica Nanoparticle Viscosity Exceeded Comparative Example 6 - 3.5 (0.67) 5.5 (1.66) 6 (0.12) Comparative Example 7 5 3.5 (0.67) - 6.5 (0.13) Comparative Example 8 5 5 (0.95) 5 (1.51) - Comparative Example 9 5 5 (0.95) 3 (0.91) 2 (0.04) Comparative Example 10 5 2 (0.38) 6 (1.81) 2 (0.04) Comparative Example 11 5 2 (0.38) 4 (1.21) 15 (0.3) Comparative Example 12 - 4.5 (0.72) 5.5 (1.66) 5 (0.1) Comparative Example 13 5 4.5 (0.72) - 5.5 (0.11) Comparative Example 14 5 4.5 (0.72) 5.5 (1.66) -

Evaluation Example 1 Evaluation of Characteristics of Pellet Composition Containing Catalyst for Removing Noxious Gas

Evaluation Example 1-1. Determination of strength, specific surface area and pore volume of pellet composition

The intensity of the pellet composition including the catalyst for removing harmful gases was measured through Examples 1 to 4 and Comparative Examples 1 to 14 using a strength tablet (Campbell Tablet).

In addition, the specific surface area and pore volume were measured through nitrogen adsorption-desorption isotherm analysis of the pellet compositions obtained through Examples 1 to 4 and Comparative Examples 1 to 14, and BJH (Barrett-Joyner- Halenda) pore diameter was calculated by the pore size model, and the results are shown in Table 2 below.

burglar
(kg / m ² ) Filling density (g / ml) Specific surface area (S _BET )
(m ² / g) Pore volume Pore diameter (BJH)
(nm) V _total
(ml / g) V _meso
(ml / g) Example 1 5.2 0.408 232.2 0.781 0.757 45.4 Example 2 5.2 0.407 232.0 0.781 0.755 45.5 Example 3 5.4 0.413 232.6 0.784 0.759 45.1 Example 4 6.2 0.388 200.9 0.676 0.655 49.6 Comparative Example 1 3.7 0.327 231.9 0.772 0.750 46.9 Comparative Example 2 3.1 0.316 231.5 0.770 0.749 46.8 Comparative Example 3 4.5 0.344 232.1 0.779 0.755 45.5 Comparative Example 4 3.4 0.321 231.8 0.770 0.747 46.9 Comparative Example 5 3.6 0.324 220.0 0.775 0.751 45.7 Comparative Example 6 2.1 0.278 251.4 0.809 0.781 41.3 Comparative Example 7 2.5 0.284 222.1 0.778 0.755 50.5 Comparative Example 8 2.7 0.297 215.3 0.765 0.741 51.2 Comparative Example 9 3.0 0.302 211.8 0.764 0.739 52.6 Comparative Example 10 4.8 0.390 231.9 0.773 0.750 46.9 Comparative Example 11 4.9 0.394 231.7 0.768 0.754 47.0 Comparative Example 12 3.4 0.206 228.6 0.728 0.721 32.4 Comparative Example 13 3.7 0.213 181.2 0.624 0.619 50.8 Comparative Example 14 3.6 0.210 204.4 0.679 0.653 44.7

Referring to Table 2, it was confirmed that the pellet compositions of Examples 1 to 4 have improved strength compared to Comparative Examples 1, 2, 4 to 9 and 12 to 14.

Evaluation Example 1-2. Ammonia (NH ₃ ) Removal efficiency evaluation

The ammonia removal efficiency of the pellet composition obtained through Examples 1 to 4 and Comparative Examples 1 to 14 was evaluated.

First, 1 g of the pellet composition of Examples 1 to 4 and Comparative Examples 1 to 14 was pretreated at 120 ° C. for 1 hour. Subsequently, it was encapsulated in a 10L Tedlar bag, vacuumed, a 52 ppm ammonia standard gas was injected, and a change in concentration of ammonia over time was measured using a test tube, and the results are shown in Table 3 below. It was.

NH ₃ Concentration (ppm) / removal rate (%) 30 minutes 60 minutes Example 1 20/62 12/77 Example 2 19/64 10/81 Example 3 21/60 12/77 Example 4 17/67 9/83 Comparative Example 1 32/39 19/64 Comparative Example 2 27/48 17/67 Comparative Example 3 41/21 35/33 Comparative Example 4 37/29 23/56 Comparative Example 5 34/35 24/54 Comparative Example 6 30/42 25/52 Comparative Example 7 35/33 30/42 Comparative Example 8 34/35 30/42 Comparative Example 9 40/23 35/33 Comparative Example 10 40/23 34/35 Comparative Example 11 43/17 38/27 Comparative Example 12 34/35 23/56 Comparative Example 13 33/37 19/64 Comparative Example 14 33/37 20/62

Referring to Table 3, the pellet composition of Examples 1 to 4 was excellent in the ammonia removal effect. On the other hand, in the case of Comparative Examples 3, 10 and 11, although the strength of the pellet composition is excellent, the catalyst performance is significantly reduced compared to Examples 1 to 4, which is not suitable for practical use.

Evaluation example  1-3. Acetaldehyde ( CH ₃ CHO ) Removal efficiency evaluation

Acetaldehyde removal efficiency of the pellet compositions obtained through Examples 1 to 4 and Comparative Examples 1 to 14 was evaluated.

First, 1 g of the pellet composition of Examples 1 to 4 and Comparative Examples 1 to 14 was pretreated at 120 ° C. for 1 hour. Subsequently, it was encapsulated in a 10L tedala bag, vacuumed, 50 ppm concentration of acetaldehyde standard gas was injected, and the concentration of acetaldehyde was measured with a test tube using a test tube. Shown in

CH ₃ CHO Concentration (ppm) / removal rate (%) 30 minutes 60 minutes Example 1 27/46 20/60 Example 2 25/50 19/62 Example 3 28/44 21/58 Example 4 24/52 19/62 Comparative Example 1 33/34 24/52 Comparative Example 2 31/38 23/54 Comparative Example 3 39/22 33/34 Comparative Example 4 32/36 26/48 Comparative Example 5 33/34 25/50 Comparative Example 6 38/32 30/40 Comparative Example 7 41/18 31/38 Comparative Example 8 40/20 31/38 Comparative Example 9 45/10 38/24 Comparative Example 10 45/10 39/22 Comparative Example 11 48/4 40/20 Comparative Example 12 31/38 22/56 Comparative Example 13 33/34 25/50 Comparative Example 14 34/32 26/48

Referring to Table 4, the pellet composition of Examples 1 to 4 was excellent in acetaldehyde removal effect. On the other hand, in the case of Comparative Examples 3, 10 and 11, although the strength of the pellet composition is excellent, the catalyst performance is significantly reduced compared to Examples 1 to 4, which is not suitable for practical use.

Therefore, the present invention can satisfy both excellent strength and catalyst performance by limiting the properties and content of each component when preparing a pellet composition containing a catalyst for removing harmful gases.

Experimental Examples 1 to 3. Recycling the Pellet Composition Containing a Catalyst for Removing Hazardous Gases

In order to confirm the results according to the recycling method of the pellet composition of the present invention, the pellet composition prepared in Examples 1 and 4 was fixed to the filter for removing harmful gases and used for about 4000 hours, and then used waste pellets were collected. After the waste pellet was recycled in the following manner.

Experimental Example 1

5 g of the spent pellets of Example 1 were put in a beaker containing 95 g of a 50% (w / v) HCl aqueous solution and stirred at a speed of 400 rpm at 60 ° C. for 20 hours to regenerate the pellet composition.

Experimental Example 2

Recycling the waste pellet in the same manner as in Experimental Example 1, but using the waste pellet of Example 4.

Experimental Example 3

Waste pellets were recycled in the same manner as in Experimental Example 1, but 70% (w / v) acetic acid aqueous solution was used.

Evaluation Example 2 Evaluation of Characteristics of Recycled Pellet Composition

Evaluation example 2-1. Determination of strength, specific surface area and pore volume of recycled pellet composition

Specific surface area and pore volume were measured through nitrogen adsorption-desorption isotherm analysis of the pellet composition recycled through Experimental Examples 1 to 3, and the pore size of BJH (Barrett-Joyner-Halenda) was also measured. The pore diameter was calculated by the model, and the results are shown in Table 5.

In addition, in order to prepare for the evaluation of the characteristics of the waste pellet was not rehabilitation was prepared.

Specific surface area (S _BET )
(m ² / g) Pore volume Pore diameter (BJH) (nm) V _total
(cm ³ / g) V _meso
(cm ³ / g) Waste pellets 220.2 0.722 0.710 25.2 Experimental Example 1 240.5 0.789 0.772 28.0 Experimental Example 2 236.8 0.774 0.761 27.4 Experimental Example 3 228.4 0.751 0.739 26.5

Referring to Table 5, it can be seen that the specific surface area and pore diameter of the pellet composition recycled through the recycling method of the present invention was increased in comparison with the waste pellet not rehabilitated, thereby confirming that the harmful substances in the pellet surface were removed. Could.

Evaluation example 2-2. Evaluation of Noxious Gas Removal Rate of Recycled Pellet Composition

Experimental Examples 1 to 3 evaluated the carbon monoxide, ammonia and acetaldehyde removal efficiency for the recycled pellet composition.

First, 1 g of pellets regenerated through Experiments 1 to 3 were pretreated at 120 ° C. for 1 hour. Subsequently, it was encapsulated in a 10L Tetra bag and vacuum-treated, and 50 ppm carbon monoxide, ammonia, or acetaldehyde standard gas was injected, and a change in harmful gas concentration was measured after 60 minutes using a test tube. It is shown in Table 6 below.

In addition, to prepare a pellet composition of Example 1 not used in order to prepare for the removal efficiency evaluation was performed.

% Removal CO NH ₃ CH ₃ CHO Pellet Composition of Example 1 65 77 60 Experimental Example 1 16 84 54 Experimental Example 2 14 81 52 Experimental Example 3 16 83 55

Referring to Table 6, compared with the pellet composition of Example 1, it can be seen that the pellet compositions recycled through Examples 1 to 3 have similar ammonia and acetaldehyde removal efficiencies, in particular, odor removal efficiencies such as ammonia It can be seen to be very good. Therefore, the harmful gas can be sufficiently removed from the surface of the pellet composition through the recycling method of the present invention, and thus, a porous carrier including silica particles and the like can be used again as a filter media for removing odors.

On the other hand, the removal efficiency of carbon monoxide is significantly reduced because the transition metal is dissolved in the aqueous acid solution through the recycling method, the dissolved transition metal can be reused by eluting in the aqueous acid solution.

Claims (10)

(Step 1) preparing a catalyst for removing harmful gas;
(Step 2) preparing a mixture by mixing the harmful gas removal catalyst, silica microparticles, silica nanoparticles and clay;
(Step 3) extruding the mixture to prepare a molding composition;
(4 step) heat-treating the molding composition to produce a pellet composition containing a catalyst for removing harmful gases; And
(5 step) recovering the silica carrier by immersing and stirring the pellet composition containing the catalyst for removing harmful gases in an acid aqueous solution; recycling method of the pellet composition containing the catalyst for removing harmful gases, characterized in that it comprises a. The method of claim 1,
The hazardous gas removal catalyst in the first step is a manganese oxide catalyst or a copper-manganese oxide catalyst, the method for recycling the pellet composition containing the catalyst for removing harmful gases. The method of claim 1,
The catalyst for removing harmful gases in step 1 includes the steps of (a) preparing an aqueous metal salt solution;
(b) adding a silicate aqueous solution to the metal salt aqueous solution and then stirring to prepare a mixed solution;
(c) separating the mixed solution into a precipitate and a solution and then washing the precipitate; And
(d) drying and heat-treating the washed precipitates; method for recycling the pellet composition containing the catalyst for removing harmful gases, characterized in that it is prepared. The method of claim 3,
The metal salt aqueous solution in step a is a method for recycling the pellet composition containing the catalyst for removing harmful gases, characterized in that the aqueous solution of manganese salt or a mixture of copper salt and manganese salt. The method of claim 1,
In the second step, the silica microparticles have an average particle size of 20 to 40 μm, and the silica nanoparticles have an average particle size of 10 to 20 nm. The method of claim 1,
The clay is montmorillonite, bentonite, hectorite, baydelite, nontronite, saponite, laponite, dolomite, talc, leadstone, vermiculite, kaolin, halosite, illite, green stone, brookite, vermiculite, synthetic A method for recycling a pellet composition containing a catalyst for removing toxic gases, characterized in that at least one selected from the group consisting of mica, canemate, margotite and kenyanite. The method of claim 1,
In the second step, the mixture includes 1 to 15 parts by weight of catalyst for removing harmful gases, 15 to 35 parts by weight of silica nanoparticles, and 0.5 to 5 parts by weight of clay, based on 100 parts by weight of silica microparticles. Process for recycling a pellet composition containing a catalyst. The method of claim 1,
The acid solution in step 5 is a method for recycling the pellet composition containing the catalyst for removing harmful gases, characterized in that 30 to 70 parts by weight of acid based on 100 parts by weight of purified water. The method of claim 8,
The acid is at least one selected from the group consisting of hydrogen chloride (HCl), acetic acid (CH ₃ COOH), phosphoric acid (H ₃ PO ₄ ), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ) and hydrogen bromide (HBr). A method for recycling a pellet composition containing a catalyst for removing harmful gases. The method of claim 1,
In the fifth step, the stirring temperature is 15 ~ 65 ℃, the stirring speed is 300 ~ 500rpm, the stirring time is 12 to 48 hours, recycling method of the pellet composition containing the catalyst for removing harmful gases, characterized in that.