JP7367326B2 - Combustion catalyst molded body - Google Patents

Description

The present invention relates to a combustion catalyst molded article. More specifically, the present invention relates to a combustion catalyst molded article that not only has high catalytic activity but also has excellent handling properties and can suppress dust generation during handling.

Garbage including various plastic products and the like is usually disposed of in landfills or incinerated, but in recent years most of it has been incinerated due to the problem of a shortage of disposal facilities.

During the incineration process, heavy oil as a fuel and air as an oxidizing gas are supplied to burn the material to be incinerated. In order to reduce the cost of incineration, efforts are being made to improve combustion efficiency and reduce the amount of heavy oil used. In order to improve the combustion efficiency of materials to be incinerated, attempts have been made to utilize combustion catalysts that promote the combustion of materials to be incinerated, and iron oxide particles have been used as such combustion catalysts.

However, the iron oxide particles are not easy to handle, and in order to be used as a combustion catalyst during incineration, it is necessary to introduce a dedicated large-scale feeder and equipment, which increases the initial cost. In addition, when iron oxide particles are handled, including during supply, a significant amount of dust is generated, which can cause contamination at the site.

On the other hand, a technique has been proposed in which a type of iron oxide particles is blended as a pigment powder to produce a compressed granule to obtain a coloring material for building materials such as cement (Patent Documents 1 and 2). . Such coloring materials are obtained by compressing and granulating a mixture of iron oxide, which is pigment powder, and surfactants (Patent Document 1) and auxiliary substances that promote processability (Patent Document 2). It is something.

Japanese Patent Application Publication No. 07-089754 Japanese Patent Application Publication No. 10-060302

The coloring material has good dispersibility in building materials such as cement, is relatively easy to handle, and is useful for coloring building materials. However, although this coloring material is useful as a coloring agent for construction materials, it is compacted and difficult to disperse into materials to be incinerated for this purpose. Since it is not suitable for efficient contact with the material to be incinerated as a catalyst, it is very difficult to use and apply it as a combustion catalyst in incineration treatment.

In this way, it is possible to improve the combustion efficiency of incinerated materials, and it is also easy to handle, and moreover, it is possible to suppress the generation of dust during handling. No catalyst has yet been discovered.

The combustion catalyst molded article according to the present invention is
It is a molded composition containing iron oxide powder, and is characterized by an average crushing strength of 0.5N to 40.0N in accordance with the regulations of JIS Z8841.

The combustion catalyst molded body preferably includes:
Under the conditions of reaction pressure: 0.01 MPa, reaction temperature: 300 °C, and space velocity: 100000 h ^-1 , CO concentration: 5.0%, O ₂ concentration: 2.5%, and N ₂ concentration: 92.5. The following formula (1) when circulating % CO and air:
Conversion rate (%) = [ CO ₂ concentration / (CO concentration + CO ₂ concentration)] × 100 (1)
The conversion rate from CO to CO ₂ is 70% or more.

The combustion catalyst molded body preferably includes:
The content of the iron oxide powder in the composition is 85% by weight or more.

The combustion catalyst molded body preferably includes:
The molded article is a composition that further contains at least one carbon-containing additive selected from the group consisting of a binder and a dispersant, and the composition further contains at least one carbon-containing additive selected from the group consisting of a binder and a dispersant. The amount of residual carbon is 1.2% by weight or less.

The combustion catalyst molded article of the present invention has a high catalytic activity, so it not only has a great effect of promoting the combustion of materials to be incinerated, but also has excellent handling properties, and can be directly supplied to a garbage pit or garbage hopper, for example. Therefore, it is not necessary to introduce a large-sized feeder or equipment, and moreover, it is possible to suppress the generation of dust during handling such as during feeding.

A combustion catalyst molded body according to one embodiment of the present invention is a molded body of a composition containing iron oxide powder. Iron oxide has a catalytic activity that oxidizes (combusts) the other substance it comes into contact with, as expressed in the chemical reaction formula 3Fe ₂ O ₃ +CO → 2Fe ₃ O ₄ +CO ₂ , and has the effect of promoting combustion. Demonstrate. As a result, it is possible to reduce auxiliary combustion energy such as heavy oil, gas, kerosene, etc. during incineration processing, and to reduce costs.

Examples of the iron oxide having catalytic activity, which is a raw material for the iron oxide powder used in the present invention, include goethite (α-FeO(OH)), achagenite (β-FeO(OH)), lepidocrocite (γ Hydrous iron oxides (FeO(OH)) such as -FeO(OH)), iron oxides such as hematite (α-Fe ₂ O ₃ ), magnetite (Fe ₃ O ₄ ), and maghemite (γ-Fe ₂ O ₃ ) can be mentioned. Among these, when hydrated iron oxide (FeO(OH)) undergoes a dehydration reaction and changes to Fe ₂ O ₃ , countless pores are generated and its specific surface area increases significantly. The increase in the specific surface area increases the probability of contact with the other substance and tends to improve the catalytic activity. It is preferable that hydrated iron oxides such as , achagenite, and lepidocrocite are included, and it is preferable to use these goethite, achagenite, and lepidocrocite alone or in a mixture of two or more types.

Iron oxide powder can be obtained by subjecting the iron oxide to pulverization using a general pulverizer such as an atomizer, pin mill, or Henschel mixer.

The iron oxide powder used in the present invention has an iron oxide purity of about 75%, which is determined by dissolving a sample in acid and analyzing it using a plasma emission spectrometer (SPS4000, manufactured by Seiko Electronics Co., Ltd.). % to 95%, more preferably about 80% to 95%, and may also contain moisture and inorganic oxides derived from raw materials.

In addition, the iron oxide powder used in the present invention is
B. with nitrogen. E. T. The BET specific surface area measured by the method is about 3 m ² /g to 320 m ² /g, more preferably about 5 m ² /g to 320 m ² /g,
The particle diameter (median diameter D50) measured by a laser diffraction scattering particle size distribution analyzer (SK Laser Micronsizer LMS-2000e, manufactured by Seishin Enterprise Co., Ltd.) is approximately 0.5 μm to 22.0 μm, and more preferably approximately 1.0 μm. Must be 0 μm to 20.0 μm,
The bulk density measured in accordance with JIS K5101-12-1 is approximately 0.2 g/cm ³ to 1.2 g/cm ³ , more preferably approximately 0.3 g/cm ³ to 1.0 g/cm ³ , and a photograph was taken using an electron microscope, and the major axis diameter and minor axis diameter of the 80 particles shown therein were measured, and the average aspect ratio was approximately 1.0 to 5. 2, more preferably about 1.0 to 5.0. Note that the shape of the iron oxide particles used is not particularly limited, and may be, for example, needle-like, plate-like, spindle-like, or the like.

Normally, when obtaining a molded body using mineral oxide powder, a considerable amount of a binder is often added to the mineral oxide powder in order to maintain the shape of the molded body. However, since the combustion catalyst molded article of the present invention is a combustion catalyst for incinerating materials to be incinerated such as garbage, the shape as a molded object is maintained until it comes into contact with the material to be incinerated, as will be described later. , and it is preferable that the material be easily powdered when it comes into contact with the material to be incinerated. By pulverizing, the material to be incinerated and the iron oxide of the combustion catalyst molded body come into contact with each other efficiently, and efficient catalytic activity is exhibited. Considering the balance between maintaining the shape of the molded article and easy powdering, the combustion catalyst molded article of the present invention is required to have appropriate strength. Therefore, in order to impart appropriate strength to the combustion catalyst molded article of the present invention, the content of the iron oxide powder in the composition is preferably 85% by weight or more, more preferably 90% by weight. % or more, more preferably 95% or more, particularly preferably 99% or more by weight, and the composition does not contain additives such as a binder other than the iron oxide powder, that is, the oxidized The content of iron powder may be 100% by weight.

As described above, the composition for obtaining the combustion catalyst molded body of the present invention may be composed only of the iron oxide powder, but may also contain additives other than the iron oxide powder. Examples of such additives include carbon-containing additives such as binders and dispersants, and other additives such as forming aids.

As the binder, for example, fatty acids, cellulose, polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, maltose, carboxymethylcellulose, etc. are preferably used. As the dispersant, for example, stearic acid, oleic acid, lauric acid, rosin amine, lauryl amine, oleyl amine, etc. are preferably used. Examples of the forming aid include non-hydratable alumina, α-alumina, aluminum salt, silica, clay, talc, bentonite, zeolite, cordierite, titania alkali metal salt, alkaline earth metal salt, rare earth metal salt. , zirconia, mullite, sepiolite, montmorillonite, hallosite, saporite, stevensite, hectorite, silica alumina, etc. are preferably used. These dispersants can be used alone or in combination of two or more.

When using the additives, the content of the additives in the composition may be adjusted as appropriate within the remaining amount of the iron oxide powder so that the effects of each additive are exhibited, for example: The amount of the additive is preferably about 1.3 parts by weight or less, more preferably about 1.2 parts by weight or less, based on 100 parts by weight of the iron oxide powder. Among the additives, especially when using the above-mentioned carbon-containing additive together with iron oxide powder, as described above, it is necessary to impart appropriate strength to the combustion catalyst molded article of the present invention and to avoid an increase in cost. It is preferable to take this into consideration so that it does not occur. For example, in the case of a molded body using a binder as a carbon-containing additive, the amount of residual carbon derived from the binder in the molded body is 1.2% by weight or less, further 1.1% by weight or less, particularly It is preferably 0.7% by weight or less. For example, in the case of a molded body using a dispersant as a carbon-containing additive, the amount of residual carbon derived from the dispersant in the molded body is 1.2% by weight or less, further 1.1% by weight or less. It is preferable. In addition, when the molded object is molded from a composition that further contains at least one carbon-containing additive selected from the group consisting of a binder and a dispersant, the carbon-containing additive in the molded object The amount of residual carbon derived from the agent is preferably 1.2% by weight or less, more preferably 1.1% by weight or less.

The residual carbon amount was determined from the following formula (2) using the carbon amount, molecular weight, and addition amount (content in the composition (weight %)) of each carbon-containing additive.
Amount of residual carbon (weight%) = (amount of carbon/molecular weight) x amount added (2)
Further, the amount of residual carbon can also be determined using a carbon analyzer or the like.

The composition is prepared by adjusting and blending the iron oxide powder and, if necessary, the additives so that the content of each in the composition is, for example, within the above range, and then mixing using a rotary mixer or an agitating mixer. It can be prepared by dry mixing using a machine, high-speed mixer, etc.

The combustion catalyst molded article of the present invention is obtained by molding the composition prepared as described above, and by adding, for example, water and/or alcohol as a dispersion medium to the composition, a clay-like kneaded product is formed. It can also be shaped afterwards. When using such a dispersion medium, it is preferable to mix about 20 to 50 parts by weight of the dispersion medium to 100 parts by weight of the composition to form a clay-like kneaded product.

There are no particular limitations on the molding method, and for example, methods such as compression molding, press molding, and tablet molding can be employed. Furthermore, there are no particular limitations on the molding conditions for each molding method, and it is preferable to adjust them as appropriate so that a desired molded article can be produced.

For example, the molded product obtained by the above-mentioned molding method may be passed through a sieve having a specified opening, if necessary, and then dried by a method such as natural drying, hot air drying, or vacuum drying. A combustion catalyst molded body can be manufactured. Moreover, the shrinkage rate before and after drying is 5% or less, and the shape of the molded article and the shape of the combustion catalyst molded article almost match. When using the sieve, the opening of the sieve may be appropriately selected in consideration of the desired size of the combustion catalyst molded body. Furthermore, the drying conditions in these drying methods are not particularly limited as long as the desired combustion catalyst molded body is produced. Note that, for example, it is possible to further heat-treat the combustion catalyst molded body dried by such a drying method, but there is a risk that the pores of the molded body will be crushed and the catalytic activity will decrease, and the manufacturing cost will be increased. Since this tends to increase the temperature, such heat treatment is usually not necessary.

The combustion catalyst molded article of the present invention thus produced has an average crushing strength of 0.5N to 40.0N in accordance with the regulations of JIS Z8841. As mentioned above, the combustion catalyst molded article of the present invention is a combustion catalyst for incinerating materials to be incinerated such as garbage, and therefore, until it comes into contact with materials to be incinerated, it is difficult to improve handleability and suppress dust generation. Therefore, it is preferable that the shape of the molded body is maintained and that when it comes into contact with the material to be incinerated, it is easily pulverized from the viewpoint of improving the catalytic activity by increasing the contact area. Considering the balance between maintaining the shape of the molded article and easy powdering, the combustion catalyst molded article of the present invention is required to have appropriate strength. Therefore, the combustion catalyst molded article of the present invention has an average crushing strength of 0.5N or more, preferably 1.0N or more, more preferably 1.5N or more, and 40.0N or less, according to the regulations of JIS Z8841. Preferably it is 39.5N or less, more preferably 39.0N or less. If the average crushing strength is less than 0.5N, the desired catalytic activity can be obtained, but the generation of dust cannot be sufficiently suppressed. Moreover, when the average crushing strength exceeds 40.0 N, although the generation of dust can be sufficiently suppressed, the desired catalytic activity cannot be obtained.

In addition, in this specification, the average crushing strength of a molded object is the average value of 100 values measured using a tension/compression type load cell and evaluated in accordance with the method specified in JIS Z8841. say.

Further, the combustion catalyst molded article of the present invention was produced under the conditions of reaction pressure: 0.01 MPa, reaction temperature: 300°C, and space velocity: 100000 h ^-1 , CO concentration: 5.0%, O ₂ concentration: 2. 5% and _N2 concentration: 92.5% when CO and air are circulated, the conversion rate from CO to _CO2 is preferably 70% or more, more preferably 72% or more, particularly preferably It is 75% or more. If the conversion rate is less than 70%, the catalytic activity of the combustion catalyst molded body is insufficient, and there is a risk that the effect of promoting the combustion of incineration materials such as garbage may not be sufficiently exhibited when incinerating materials to be incinerated such as garbage. There is. Further, from the viewpoint of obtaining high catalytic activity, the higher the conversion rate, the better, but the conversion rate based on the above conditions is usually about 90% or less.

Note that the catalytic activity of the combustion catalyst molded body is determined by calculating the conversion rate from CO to CO ₂ . Catalytic activity evaluation was carried out by flowing CO and air having the above composition under the above conditions through a catalyst tube filled with molded bodies. The conversion rate from CO to CO ₂ was determined from the following formula (1) by measuring the CO concentration and CO ₂ concentration in the gas after the reaction.
Conversion rate (%) = [ CO ₂ concentration / (CO concentration + CO ₂ concentration)] × 100 (1)

There is no particular limitation on the shape of the combustion catalyst molded body, and any shape that can be adopted as a normal combustion catalyst may be used. Examples of the shape include a spherical shape, a cylindrical shape, a hollow cylindrical shape, a pellet shape, and the like.

There is no particular limitation on the size of the combustion catalyst molded body, and it may be any size that can be adopted as a normal combustion catalyst. For example, in the case of a spherical combustion catalyst molded body, the diameter is usually preferably 0.5 mm to 10 mm, more preferably 0.5 mm to 5 mm. For example, in the case of a cylindrical combustion catalyst molded body, the height (long axis) is usually preferably 1 mm to 10 mm, more preferably 1 mm to 8 mm, and the diameter (short axis) is preferably 1 mm to 2 mm, More preferably, it is 1 mm to 1.8 mm.

Since the combustion catalyst molded body of the present invention has high catalytic activity, it is of course highly effective in promoting the combustion of incinerated materials such as garbage, and unlike conventional powder combustion catalysts, it is a molded body. Therefore, it has excellent handling properties, and can be directly supplied to a garbage pit or garbage hopper, for example, so there is no need to introduce a special large-scale feeder or equipment, and the initial cost can be significantly reduced. Moreover, since it is possible to suppress the generation of dust during handling such as during supply, there is no need to introduce pollution control equipment, which not only improves work efficiency but also significantly reduces costs. can.

EXAMPLES Below, the combustion catalyst molded article of the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

First, combustion catalyst molded bodies were produced in Examples 1 to 6 and Comparative Examples 1 to 3 below.

<Example 1>
Goethite (α-FeO(OH)) having the following properties and shape was prepared.
FeO(OH) purity: 87.0%
BET specific surface area: 73.5m ² /g
Particle size (median diameter D50): 14.3 μm
Bulk density: 0.52g/ ^cm3
Aspect ratio: 3.5
Particle shape: spindle shape

528 g of the goethite was pulverized using an atomizer to obtain goethite powder. This goethite powder was mixed with 147 g of water and kneaded to obtain a clay-like kneaded product. From 675 g of the obtained clay-like kneaded material, a molded product with a diameter of about 1.0 to 1.5 mm was obtained using a round making machine (PT-6015A, manufactured by Freund Turbo). The obtained molded product was passed through a standard sieve (mesh opening: 1.41 mm) specified in JIS Z8801, and then dried at 80° C. for 360 minutes to obtain a spherical combustion catalyst molded product.

<Example 2>
In Example 1, a molded product with a diameter of approximately 2.4 to 2.8 mm was obtained using the same round-making machine as in Example 1, and then the molded product was passed through a standard sieve (mesh opening: 2.8 mm) specified in JIS Z8801. A spherical combustion catalyst molded body was obtained in the same manner as in Example 1, except that the molded body was heated to a diameter of 83 mm).

<Example 3>
724 g of the goethite was pulverized using an atomizer to obtain goethite powder. This goethite powder was mixed with 212 g of water and 8.4 g of methylcellulose (approximately 1.16 parts by weight per 100 parts by weight of the goethite powder) and kneaded to obtain a clay-like kneaded product. From 944.4 g of the obtained clay-like kneaded material, a molded product with a diameter of about 3.4 to 4.2 mm was obtained using the same round machine as in Example 1. The obtained molded product was passed through a standard sieve (mesh opening: 4.00 mm) specified in JIS Z8801, and then dried at 60° C. for 720 minutes to obtain a spherical combustion catalyst molded product.

<Example 4>
1000 g of the same goethite powder used in Example 1 and 270 g of water were kneaded using an HBN-10D double-arm batch kneader (manufactured by Honda Iron Works Co., Ltd.) to obtain a clay-like kneaded product. 1270 g of the obtained clay-like kneaded material was molded and dried using a PV-5S/11-200 type fine disc pelleter (manufactured by Dalton, opening: 1 mm) to obtain a cylindrical combustion catalyst molded body. .

<Example 5>
A cylindrical combustion catalyst molded body was obtained in the same manner as in Example 4, except that the amount of water as a dispersion medium was changed to 330 g and 1330 g of clay-like kneaded material was used.

<Example 6>
A cylindrical combustion catalyst molded body was obtained in the same manner as in Example 4, except that the amount of water as a dispersion medium was changed to 500 g, and 1500 g of clay-like kneaded material was used.

<Comparative example 1>
25 g of the same goethite powder used in Example 1 was pressurized and molded using a powder molding machine (HANDTAB-200, manufactured by Ichihashi Seiki Co., Ltd.) under a molding load of 5.2 kN to obtain a molded product. Ta. The obtained molded product was passed through a standard sieve (mesh opening: 3.36 mm) specified in JIS Z8801, and then air-dried at room temperature for 60 minutes to obtain a spherical combustion catalyst molded product.

<Comparative example 2>
845 g of the same goethite powder used in Example 1 and 65 g of carboxymethyl cellulose (approximately 7.69 parts by weight per 100 parts by weight of the goethite powder) were dry mixed using a high-speed mixer. This was mixed with 211 g of water and kneaded to obtain a clay-like kneaded product. A spherical combustion catalyst molded body was obtained in the same manner as in Example 1, except that 1121 g of the obtained clay-like kneaded material was used.

<Comparative example 3>
1000 g of the same goethite powder used in Example 1 and 15 g of polyvinyl alcohol (1.5 parts by weight per 100 parts by weight of goethite powder) dissolved in 330 g of water in advance were added to the same powder as in Example 4. The mixture was kneaded using a batch kneader to obtain a clay-like kneaded product. 1345 g of the obtained clay-like kneaded material was molded and dried using the same fine disc pelleter as in Example 4 to obtain a cylindrical combustion catalyst molded body.

Next, in Test Examples 1 to 3 below, the combustion catalyst molded bodies produced in Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated. These results are shown in Table 1 below, along with the content of goethite powder in the composition constituting the combustion catalyst molded body, the amount of residual carbon derived from the binder in the combustion catalyst molded body, and the shape and size of the molded body. Shown below.

<Test Example 1: Measurement of average crushing strength>
Values measured using a tension/compression type load cell DPU-500N and a vertical electric measuring stand EMX-1000N (manufactured by Imada Co., Ltd.) were evaluated in accordance with the method specified in JIS Z8841. The average value was determined from the 100 values obtained and was defined as the average crushing strength (N).

<Test Example 2: Evaluation of catalyst activity>
A catalyst tube was prepared by filling a stainless steel reaction tube with a diameter of 10 mm with 1 g to 20 g of the combustion catalyst molded body. In this catalyst tube, CO concentration: 5.0%, O ₂ concentration: 2.5%, and N ₂ were added under the conditions of reaction pressure: 0.01 MPa, reaction temperature: 300°C, and space velocity: 100000 ^{h -1} . CO oxidation reaction was carried out by circulating CO with a concentration of 92.5% and air. Using the values of the obtained CO concentration and CO ₂ concentration, the conversion rate (%) from CO to CO ₂ was determined from the following formula (1).
Conversion rate (%) = [ CO ₂ concentration / (CO concentration + CO ₂ concentration)] × 100 (1)

<Test Example 3: Evaluation of suppression of dust generation>
A circular Petri dish with an outer diameter of approximately 80 mm and a depth of approximately 15 mm was prepared, and a test stand was provided at a height of 50 cm from the bottom of the Petri dish. A 30 g combustion catalyst molded body was allowed to naturally fall vertically from this test stand toward the bottom of the Petri dish in a windless state, and the amount of the combustion catalyst molded body that fell into the Petri dish was measured. This natural fall test was performed five times, the average value of the measured values was determined, and the evaluation was made based on the following evaluation criteria.
(Evaluation criteria)
Good: 29.4 g (98%) or more of the combustion catalyst molded body was accommodated in the petri dish.
Δ: 27.9 g (93%) or more but less than 29.4 g (98%) of the combustion catalyst molded body was accommodated in the petri dish.
×: Only less than 27.9 g (93%) of the combustion catalyst molded body was accommodated in the petri dish.

As shown in Table 1, the combustion catalyst molded body obtained in Comparative Example 1 had a low average crushing strength of less than 0.5N. Therefore, the combustion catalyst molded body obtained in Comparative Example 1 has a conversion rate of CO to CO ₂ of over 80% when the reaction temperature is 300°C, and has high catalytic activity. When it is allowed to fall naturally from a height of 50 cm, the impact of the fall causes it to turn into powder, resulting in more than 7% of the material being unrecovered, and a significant amount of dust is generated during handling.

Furthermore, the combustion catalyst molded bodies obtained in Comparative Examples 2 and 3 all had high average crushing strengths exceeding 40.0N. Therefore, even when the combustion catalyst molded bodies obtained in Comparative Examples 2 and 3 are allowed to fall naturally from a height of 50 cm, close to 100% of the molded bodies can be recovered, and there is no dust during handling. Although generation is suppressed, the effective area of the catalyst surface is reduced due to compaction during molding, so the conversion rate from CO to CO ₂ reaches 60% when the reaction temperature is 300°C. catalytic activity is very low.

On the other hand, the combustion catalyst molded bodies obtained in Examples 1 to 6 all have an average crushing strength in the range of 0.5N to 40.0N. Therefore, the combustion catalyst molded bodies obtained in Examples 1 to 6 all have a conversion rate of CO to CO ₂ of over 80% when the reaction temperature is 300°C, and exhibit extremely high catalytic activity. have. Furthermore, even when the combustion catalyst molded bodies obtained in Examples 1 to 6 are allowed to fall naturally from a height of 50 cm, nearly 100% of the molded bodies can be recovered, and dust is removed during handling. The occurrence can be sufficiently suppressed.

The combustion catalyst molded article of the present invention is very useful as a combustion catalyst in the incineration treatment of materials to be incinerated such as garbage including various plastic products.

Claims (3)

A composition containing iron oxide powder is molded, and has an average crushing strength of 0.5N to 40.0N in accordance with the provisions of JIS Z8841,
A combustion catalyst molded article, wherein the content of the iron oxide powder in the composition is 90% by weight or more . Under the conditions of reaction pressure: 0.01 MPa, reaction temperature: 300 °C, and space velocity: 100000 h ^-1 , CO concentration: 5.0%, O ₂ concentration: 2.5%, and N ₂ concentration: 92.5. The following formula (1) when circulating % CO and air:
Conversion rate (%) = [CO ₂ concentration / (CO concentration + CO ₂ concentration)] × 100 (1)
The combustion catalyst molded article according to claim 1, which has a conversion rate of CO to _CO2 of 70% or more. The molded article is a composition that further contains at least one carbon-containing additive selected from the group consisting of a binder and a dispersant, and the composition further contains at least one carbon-containing additive selected from the group consisting of a binder and a dispersant. The combustion catalyst molded article according to claim 1 or 2 , wherein the amount of residual carbon is 1.2% by weight or less.