KR101917802B1 - Catalyst supporter for diesel particle filter and method for preparing the same - Google Patents

Abstract

The present invention relates to a honeycomb catalyst support having a specific porosity and pore size range and further having a specific cell density in a honeycomb structure and a shape of a cell which is a square cell or a hexagonal cell, The catalyst support according to the present invention has an advantage that it has a large specific surface area and the catalyst has a high mechanical activity while exhibiting a high catalytic activity by being treated to the inside of the structure, A filter, a catalyst for a VOC removing device, an SCR catalyst, and the like.

Description

[0001] The present invention relates to a catalyst support having improved catalytic performance, a process for producing the same, and a catalyst support prepared by the catalyst support,

The present invention provides a catalyst support capable of maximizing mechanical strength and catalytic activity, exhibiting improved catalyst performance while exhibiting a high mechanical strength, a catalyst containing the catalyst support, and a process for producing the same.

Diesel particulates contained in automobile exhaust gas are fine particles mainly composed of carbon. When an automobile engine rotates at a high speed, exhaust gas discharged from the automobile is comparatively high in temperature, so that diesel particles are naturally burned. However, When rotating at a low speed, the diesel particulates are not burned well and are released into the atmosphere together with the exhaust gas to pollute the atmosphere.

In recent years, the development of diesel engine manufacturing technology has led to an increase in the number of diesel vehicles worldwide. In addition, the emission of pollutants has been steadily decreasing due to the development of engine design and manufacturing technology. However, It is difficult to satisfy the regulation value.

As a method for reducing the exhaust gas of a diesel vehicle, a combustion mechanism such as a low-excess air combustion method, an exhaust gas recirculation method, and a low NOx burner utilization method and a burner technology are used to improve combustion conditions on the generation mechanism, There is a method of post-treating the discharged nitrogen oxides such as Selective Catalytic Reduction (SCR), Selective Non-Catalytic Reduction (SNCR), plasma method, and wet treatment method. The pretreatment method is fundamentally Although it is an ideal method for suppressing the formation of nitrogen oxides, most of the nitrogen oxide reduction systems are mainly used in the post-treatment system because the energy efficiency and the nitrogen oxide removal efficiency are very low compared with the post- Among them, reducing agents such as ammonia, urea and hydrocarbons A selective catalytic reduction method in which nitrogen oxide and a reducing agent are mixed at a relatively low temperature to reduce nitrogen oxides into harmless nitrogen and water vapor in the catalyst bed.

The catalyst used in this selective catalytic reduction technique can be classified into a honeycomb structural monolithic catalyst produced by an extrusion molding process, a metal plate catalyst manufactured using a metal plate, a pellet catalyst, and the like, depending on the form. Generally, Monolytic catalysts and plate catalysts are mainly used. Such a catalyst is a catalyst prepared by supporting one or more active metal oxides such as vanadium oxide, tungsten oxide, molybdenum oxide, and iron oxide in a titania, alumina, zirconia, silica, zeolite and the like which are large in specific surface area and chemically stable carrier raw materials Is prepared by using a catalyst raw material powder. Particularly, the honeycomb structure type monolithic catalyst is produced by extruding the clay made by adding various organic and inorganic additives to the above catalyst raw material, passing through a mold having a desired shape, extruding it into a honeycomb structure, drying it, and calcining it.

Generally, ceramic honeycomb structures are applied to catalyst support for purification of exhaust gas of automobiles. Typical examples are SCR catalyst, which is a key component of Selective Catalytic Reduction (SCR), which harmlessly converts nitrogen oxides generated during combustion of power plants, incinerators and marine engines, various harmful gases And a catalyst for removing various volatile organic compounds (VOC). In particular, Volatile Organic Compounds (VOCs) derived from materials used in petrochemical raw materials and buildings used in production plants are harmful to the human body as carcinogenic and toxic chemicals and strictly regulated by the indoor air quality control method and odor prevention method. Is a harmful substance. Odorous and volatile organic compounds such as hydrogen sulfide compounds and nitric acid compounds are present in a mixed gas form rather than a single compound.

Regarding a filter for removing diesel particulate matter, Korean Patent Registration No. 10-14191209 discloses an adsorption step of adsorbing a solvent in a porous filter base; A solidification step of solidifying the solvent absorbed in the inner pores of the porous filter base in the absorption step; A coating step of coating a catalyst slurry on the upper surface of the solidified solvent in the solidifying step to form a catalyst layer; And a treatment step of drying and removing the solvent from the porous filter base and treating the catalyst particles of the catalyst layer to be fixed on the upper surface of the porous filter base, and a manufacturing method of the filter for removing diesel particulate matter, Korean Patent Laid-Open Publication No. 10-2013-0114401 discloses a diesel particulate filter including a first impregnation step of impregnating a diesel particulate filter into a diesel oxidation catalyst mixture so as to apply a diesel oxidation catalyst mixture to an exhaust gas outlet line of the diesel particulate filter, A second impregnation step of impregnating the diesel particulate filter with the denitrated oxide catalyst mixture so as to apply the denitrification catalyst mixture to the exhaust gas inflow line of the diesel particulate filter, a drying step of drying the diesel particulate filter through the second impregnation step and And a firing step of firing the diesel particulate filter that has undergone the drying step. Production method of the NOx catalyst is a diesel particulate filter coated "it is is disclosed.

However, conventionally in the production of a catalyst support for a diesel particulate filter, the presence of an inactive catalyst support results in a reduction in performance of about 40% compared to making the catalyst support as a whole active. However, when a catalyst support having a catalytic activity as a whole is manufactured to avoid this problem, there is a problem that the mechanical and thermal strength of the catalyst support significantly decreases due to a low firing temperature for maintaining the catalyst performance. Particularly, this occurs more severely where the catalyst particles are eroded by the dust particles, where many dust particles occur, such as ships, power plants or factories. Accordingly, there has been a constant demand for development of a catalyst support capable of minimizing performance deterioration while having high mechanical strength.

Accordingly, a technical problem to be solved by the present invention is to provide a catalyst support having a high pore size and a high porosity, exhibiting improved catalytic performance through permeation of the catalyst into the interior of the support, and having high mechanical strength, and a method for producing the same. .

In order to accomplish the object of the present invention as described above, the present invention relates to a catalyst support which is produced by a specific composition and a manufacturing method and exhibits improved catalyst performance, but also has a high mechanical strength, a catalyst containing the same, .

Hereinafter, the present invention will be described in more detail.

In one aspect, the present invention provides a cordierite raw material composition comprising kaolin powder, calcined kaolin powder, talc powder, aluminum oxide powder, aluminum hydroxide powder and silica powder; Walnut shell; Binder composition; And a polyvinyl alcohol. The catalyst support has a honeycomb structure in which a plurality of cells extend to a predetermined length to form a fine tunnel and a plurality of pores are formed in an inner wall of the fine tunnel.

Preferably, the cordierite raw material component contained in the catalyst support for a filter according to the present invention contains 20 to 30 wt% of kaolin powder, 10 to 20 wt% of calcined kaolin powder, 30 to 50 wt% of talc powder, 10 to 20% by weight of aluminum oxide powder, 5 to 15% by weight of aluminum hydroxide powder and 5 to 15% by weight of silica powder. And further comprising 20 to 35 parts by weight of a walnut cell, 7 to 10 parts by weight of a binder composition and 1 to 2 parts by weight of polyvinyl alcohol based on 100 parts by weight of the cordierite raw material component. Has a median pore size of 5 to 30 μm and a porosity of 45 to 65% by volume. Due to the pore size and the porosity of the support, the catalyst support according to the present invention allows the catalyst component to permeate into the interior of the support, thereby not only maintaining the catalyst performance high, but also ensuring mechanical strength 1).

In addition, in a preferred embodiment, the cells of the catalyst support honeycomb-type structure may be formed in the shape of a quadrangle, a triangle, or a hexagon, but may preferably be a quadrangle or a hexagon, more preferably a hexagon. Preferably, the cell density of the cell is 20 to 100 cpsi.

When the hexagonal shape of the cell is used, the specific surface area is increased, and the catalyst can be supported on the support as much as possible, so that the performance of the catalyst can be remarkably increased (at least 10% or more). However, the partition wall of the honeycomb support is thin There is a problem in that the strength of the support is lowered due to the load. As a result, there are problems such as canning operation before being used in the diesel particulate reduction apparatus, breakage or cracking in assembling the module. However, it has been confirmed that the catalyst support according to the present invention has an advantage that it is manufactured at a cell density in a range particularly selected from 20 to 100 cpsi and does not have such a problem of strength reduction.

The honeycomb structure is characterized in that the cell interval is within 1.5 to 7.5 mm and the cell wall thickness is 0.3 to 1.0 mm. In addition, the cell may have a shape of a square cell or a hexagonal cell, but is not limited thereto.

Further, the honeycomb structure may be formed in a rectangular, circular or elliptic shape.

Among the components included together with the cordierite component, the binder composition may include one or more kinds of binders selected from the group consisting of organic binders and inorganic binders, and additives.

In a specific embodiment, the organic binder is preferably a binder consisting of a cellulose-based component, more preferably the cellulose-based component is at least one selected from the group consisting of hydroxypropylmethylcellulose and methylcellulose, The cellulosic component exhibits excellent extrudability and exhibits excellent extrudability even at low pressure during extrusion molding of the diesel particulate filter. It is also effective for extruding diesel particulate filter components such as cordierite starting material, walnut, graphite, etc. It is also important that

The inorganic binder may be at least one selected from the group consisting of clay, feldspar, alumina, silica-alumina, silica, and magnesium aluminum-silicate.

As the additive, any additive that can be included in the binder composition may be used without limitation. For example, triethylene glycol, wax, and the like may be included.

In addition, in a preferred embodiment, the binder composition may contain the binder and the additive in a mixing ratio of 1: 2: 6 to 8 as a ratio of binder: additive.

Due to the above-mentioned composition and structural characteristics, the catalyst support according to the present invention has an advantage that it can penetrate the catalyst to the inside of the support, thereby exhibiting improved catalytic performance and high mechanical strength. The honeycomb catalyst exhibits excellent mechanical strength and catalytic activity.

The honeycomb catalyst according to the present invention can be produced by treating the catalyst support for the filter with a catalyst. Examples of such a catalyst include, but are not limited to, a diesel oxidation catalyst or a denitrogen oxide catalyst, and any of those used in an exhaust gas treatment device such as a known diesel particulate filter, a VOC gas treatment device, .

In another aspect, the present invention relates to a process for preparing the catalyst support comprising the steps of:

(a) preparing a raw material of cordierite including kaolin powder, calcined kaolin powder, talc powder, aluminum oxide powder, aluminum hydroxide powder and silica powder;

(b) mixing the raw material with a walnut shell, a binder composition and polyvinyl alcohol;

(c) shaping the mixture into a honeycomb structure and cutting the mixture to a predetermined length to form a honeycomb formed body;

(d) heating the honeycomb formed body; And

(e) firing the molded article heated in step (d).

According to one specific embodiment of the present invention, in the step of preparing the cordierite raw material, in order to produce a raw material which is formed by cordierite after firing, 20 to 30% by weight of kaolin powder, 10 to 20% by weight of powder, 30 to 50% by weight of talc powder, 10 to 20% by weight of aluminum oxide powder, 5 to 15% by weight of aluminum hydroxide powder and 5 to 15% by weight of silica powder were mixed.

Further, in step (b), as a step of mixing walnut cell, binder composition and polyvinyl alcohol with cordierite as a main component. Specifically, 20 to 35 parts by weight of a walnut cell, 7 to 10 parts by weight of a binder composition and 1 to 2 parts by weight of polyvinyl alcohol are mixed with 100 parts by weight of a cordierite raw material.

 In the step (c), the mixture of step (b) is formed into a honeycomb structure and cut to form a honeycomb formed body, the step of molding the mixed mixture through the step of preparing the mixture, The honeycomb structure is formed by mixing the mixed mixture through the honeycomb structure. The honeycomb structure can be adjusted according to the cell density and the shape of the cell mentioned in the support for the filter. In the molding step, the molding of the mixed mixture into the honeycomb structure through the mixing step is not limited to a molding method or a molding apparatus, but a known molding method and molding apparatus can be used.

Further, in the step (d), the honeycomb formed body is heated to oxidize the pore material to form pores. According to one specific embodiment of the present invention, in the heating step, the temperature raising rate is controlled at 0.05 to 3 ° C / min And the heating temperature is maintained at 500 to 700 ° C to uniformize the micropores formed by the raw materials mixed in the mixture preparation step and the macropores formed by the pore forming agent Walnut.

Preferably, the heating step comprises a furnace selected from the group consisting of an electric furnace, a brick furnace, and a gas furnace.

The firing step may be a step of firing a molded product through the heating step, and the molded product having been subjected to the firing step may be preferably performed at a firing temperature of 1350 to 1450 캜 for 2 to 24 hours. The above-described firing temperature and time are sufficient to achieve the object of the present invention.

The catalyst support according to the present invention has a specific porosity and a pore size range and further has a specific cell density and cell shape in the honeycomb structure and thus has a large specific surface area and the catalyst is treated to the inside of the structure to exhibit high catalytic activity It has an advantage of having a remarkably increased mechanical strength, and exhibits an excellent effect of providing excellent diesel particle filter, filter for VOC removing device, SCR filter and the like.

1 is a view for explaining technical features of the present invention.

Hereinafter, the structure of the present invention will be described in more detail with reference to specific examples. However, it is apparent to those skilled in the art that the scope of the present invention is not limited by the descriptions of the embodiments.

One. Example  1 and Comparative Example  Preparation of catalyst support for filter according to

As shown in the following Table 1, 100 parts by weight of a raw material composed of 18.56% by weight of kaolin, 10.83% by weight of calcined kaolin, 40.28% by weight of talc, 15.35% by weight of aluminum oxide, 7.38% by weight of aluminum hydroxide and 7.6% And 5 parts by weight of an organic binder, 1 part by weight of an inorganic binder, 1 part by weight of triethyleneglycol (TEG) and 1 part by weight of wax were mixed and kneaded using a Sigma mixer.

Then, extrusion molding was performed using an extrusion die of 200 cpsi, dried using a high frequency dryer, and then processed to 50 x 160 mm.

Then, the workpiece was fired at a temperature of 1410 DEG C for 6 hours to prepare a diesel particulate filter of Example 1. [

Comparative Example 1 was carried out in the same manner as in Example 1, except that no walnut cell was added as shown in Table 1 below.

Comparative Example 1 Example 2 Kaolin (Polyplate-P01) 18.56 18.56 Caldined kaolin (GXL) 10.83 10.83 Talc (Hon-50) 40.28 40.28 Aluminum oxide (A152SG) 15.35 15.35 Aluminum hydroxide (H-42M) 7.38 7.38 Silica (KS-1000) 7.60 7.60 Raw material system 100.00 100.00 WalnutShell 0.00 25.00 Organic binder (A4M) 5.00 5.00 The inorganic binder (Actigel) 1.00 1.00 TEG 1.00 1.00 WAX 1.00 1.00

2. Test Example : Example  1 and Comparative Example  Comparison of physical properties of 1

The density, porosity, water absorption, apparent specific gravity, compressive strength, intrusion volume and median pore size of the catalyst support prepared in Example 1 and Comparative Example 1 were measured and shown in Table 2 below. The measurement method of each property is as follows.

Density, Porosity, Absorption Rate: Measured using Archimedes method using electronic balance and hot plate

Compressive strength: Measured using UTM (Universal Material Testing Machine)

intrusion volume, median pore size: Measured using Mercury porosimeter (mercury porosimeter)

Comparative Example 1 Example 1 Density (g / cm3) 1.38 1.10 Porosity 45.37% 56.49% Absorption rate 32.82% 51.28% Apparent Specific Gravity (g / ㎤) 0.516 0.404 Compressive strength (Mpa) 18.96 10.91 Intrusion Volume (mL / g) 0.269 0.460 Median Pore Size (占 퐉) 3.23 12.17

As shown in Table 2 above, the catalyst support prepared according to Example 1 had a remarkably high porosity and a high water absorption, and in the case of the ceramic filter produced by treating the catalyst support with such catalyst support, excellent mechanical performance and catalyst performance .

Claims (13)

Cordierite raw material components including kaolin powder, calcined kaolin powder, talc powder, aluminum oxide powder, aluminum hydroxide powder and silica powder; Walnut shell; Binder composition; And polyvinyl alcohol,
20 to 30 wt% of kaolin powder, 10 to 20 wt% of calcined kaolin powder, 30 to 50 wt% of talc powder, 10 to 20 wt% of aluminum oxide powder, 5 to 15 wt% of aluminum hydroxide powder based on the total weight of the cordierite raw material component, By weight, and 5 to 15% by weight of a silica powder,
20 to 35 parts by weight of a walnut cell, 7 to 10 parts by weight of a binder composition and 1 to 2 parts by weight of a polyvinyl alcohol based on 100 parts by weight of the cordierite raw material component,
Wherein the honeycomb structure has a structure in which a plurality of cells extend to a predetermined length to form a fine tunnel and a plurality of pores are formed in an inner wall of the fine tunnel. The method according to claim 1,
Wherein the support has a pore size of 5 to 30 탆 and a porosity of 45 to 65% by volume. The method according to claim 1,
Wherein the cells are formed in a square or hexagonal shape. The method according to claim 1,
Wherein the cell density of the cell is between 20 and 100 cpsi. delete delete The method according to claim 1,
Wherein the binder composition comprises at least one binder selected from the group consisting of an organic binder and an inorganic binder, and an additive. 8. The method of claim 7,
Wherein the organic binder is a binder containing a cellulose-based component and the inorganic binder is at least one selected from the group consisting of clay, feldspar, alumina, silica-alumina, silica and magnesium aluminum- Catalyst support. A catalyst for purification of noxious gas of a honeycomb structure comprising the catalyst support of any one of claims 1 to 4 or 7 to 8. delete (a) 20 to 30% by weight of kaolin powder, 10 to 20% by weight of calcined kaolin powder, 30 to 50% by weight of talc powder, 10 to 20% by weight of aluminum oxide powder, 5 to 20% by weight of aluminum hydroxide powder 5 To 15% by weight of a silica powder and 5 to 15% by weight of a silica powder;
(b) mixing 20 to 35 parts by weight of a walnut cell, 7 to 10 parts by weight of a binder composition and 1 to 2 parts by weight of polyvinyl alcohol with respect to 100 parts by weight of the cordierite raw material;
(c) shaping the mixture into a honeycomb structure and cutting the mixture to a predetermined length to form a honeycomb formed body;
(d) heating the honeycomb formed body; And
(e) firing the shaped article heated in the step (d). The method according to claim 11, wherein the heating temperature in step (d) is 500 to 700 占 폚. The method according to claim 11, wherein the baking temperature of step (e) is 1350 to 1450 ° C.

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