JPS6018214B2 - Catalyst for gas purification - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a catalyst for gas purification for preventing air pollution, and particularly for cleaning harmful substances, oil smoke, etc. generated from various household combustion appliances and cooking appliances using oil, gas, briquettes, etc. as fuel. This invention relates to a catalyst body for purifying exhaust gas including odors.

The composition of exhaust gas from this type of household appliances is not uniform; for example, in combustion appliances, the main components of exhaust gas are unburned carbon monoxide and hydrocarbons, especially olefinic hydrocarbons; Mainly fatty acid hydrocarbons,
and aldehydes.

To explain in more detail, the temperature of the catalyst body of various household combustion appliances depending on the preferred installation position of the catalyst body is 600 oo or less (
Maximum temperature is 70,000 or less).

In view of the above, the present invention provides a pellet-shaped catalyst body with excellent resistance to scaling at a maximum temperature of 70,000°C. Recently, with the spread of aluminum sashes, houses have become more airtight, and apartments,
Due to the rise in the number of high-rise buildings such as apartments,
Ventilating indoor air under natural conditions is difficult.

Under these circumstances, there is a strong desire for safety of household combustion appliances and for making the exhaust gas during cooking bonito-free and odor-free.

The purpose of the present invention is to: When using household combustion equipment,
We provide a catalyst body that improves the safety and comfort of using the cooker not only during normal use but also during abnormal use.
The present invention provides a catalyst body for oxidizing and purifying the oil smoke and odor of exhaust gas.

Furthermore, technological innovations are being made in household combustion equipment to achieve higher performance and lower prices.

Due to such progress and marketability, a low-cost catalyst is essential, and the present invention provides a high-performance catalyst that is inexpensive and easy to manufacture. Hitherto, various catalyst bodies have been studied and industrialized as catalyst bodies that meet such purposes.

The main catalysts are noble metal catalysts and metal oxide catalysts. It has been said that platinum, palladium or platinum black catalysts are particularly suitable as noble metal catalysts. However, conventional platinum catalysts are expensive, and while metal oxide catalysts are cheaper, they are still too expensive for use in household combustion appliances. Platinum catalysts are expensive, not only because the platinum itself is expensive, but also because the alumina molded bodies and glass fibers used as supports are expensive, the manufacturing method (pretreatment) is complicated, and the method for supporting platinum is expensive. This is also due to the complexity of post-processing.

Furthermore, it is difficult to impregnate the catalyst into a carrier, making it difficult to obtain a homogeneous product, and the wear resistance due to vibration is poor, especially the spalling resistance at high temperatures is poor, and the life of the catalyst is therefore shortened. There was a drawback. The catalyst carrier is not limited to alumina; for example, as described in Japanese Patent Publication No. 47-50980, heat-resistant, chemically inert, and porous zircon, silimanite, and magnesium silicate can be used. , aluminosilicate, etc.

However, the mainstream of materials in practical use are those whose main component is alumina. Recently, carriers using porous metals such as foamed metals have also been commercialized. Materials used as carriers can be roughly classified into two types: ceramic carriers and metal carriers, and there are various proposals for manufacturing methods for these carriers.

However, each of these catalysts has advantages and disadvantages.
The catalyst obtained by either method is expensive and requires further improvement before it can be applied to household combustion equipment. The present invention eliminates the above-mentioned conventional drawbacks,
The present invention provides a high surface area catalyst that is inexpensive, has excellent catalytic activity, spalling resistance, abrasion resistance, and molding yield.

That is, the present invention uses a pellet-shaped molded body containing alumina cement as a main component, and contains alumina cement in the carrier composition, granular base aggregate to improve spalling resistance, and a carrier surface area. It is characterized in that powder aggregate is mixed in to increase the particle size, and a metal or metal oxide catalyst is supported on the non-dawn pellet-like carrier. The catalysts previously proposed by the present inventors include A: lime aluminate-manganese oxide catalyst; B: lime aluminate-manganese oxide catalyst;
Catalysts can be roughly divided into three types: manganese oxide-heat-resistant crushed aggregate-based catalysts, and catalysts supported on carriers containing C alumina cement.

The performance of catalysts A and B differs significantly depending on the concentration of poisonous substances in the exhaust gas (especially S02 gas). In other words, for relatively low concentration S02 (less than loppm as S02), such as in oil stoves that burn kerosene,
Exhaust gas (C0, HC) purification performance is excellent, but S0
It was found that the purification performance of exhaust gas containing 2 concentrations of 50 ppm or more deteriorated significantly. - On the other hand, as mentioned above, a C catalyst was proposed for purifying exhaust gas containing a high concentration of S02, such as briquette combustion exhaust gas. The present invention is an improved version of this C catalyst, which further improves low-temperature activity, provides a catalyst with an excellent catalyst life, and limits the composition ratio of the carrier composition of the catalyst. The carrier composition of the present invention uses alumina cement as an inorganic binder, and is composed of powdered silica-based, alumina-based, silica-alumina-based Honemura, and further includes cordierite, fluorite, calcium carbonate, magnesium carbonate, etc. powdered aggregate,
Preferably, it is composed of porous powder aggregate (specific surface area of 5/more than bait), and C is further limited in composition. The catalyst of the present invention relates to a non-sintered pellet-shaped catalyst that is inexpensive and has excellent catalytic activity, heat resistance, wear resistance, and particularly spalling resistance.

The main component of the catalyst carrier used in the present invention is alumina cement, which is distinguished from Boltland cement.

Alumina cement is generally expressed as mA1203・nCa○, and Boltland cement is expressed as mSi02:n'
It is represented by CaO. Boltland cement is in high demand and is inexpensive, but it has drawbacks such as heat resistance, spalling resistance, and slow hardening speed, and is also susceptible to attack by sulfate ions. On the other hand, alumina cement has high heat resistance and a fast curing speed, and can be said to be a preferable cement from the viewpoint of catalyst production. The composition of alumina cement is as described above, and when the lime content exceeds 4% by weight, the mechanical strength of the damaged body increases, but the heat resistance decreases and it reacts with heavy metal oxides at high temperatures, such as aMn204 which forms manganese oxide at temperatures above 650°C
etc., resulting in thermal destruction of the catalyst.

If the lime content is less than 10,000, the heat resistance and bending will be improved, but the mechanical strength will be lowered, the curing time during molding will be longer, and the productivity will be worse. Furthermore, when the alumina content is less than 35% by weight, the heat resistance decreases. On the other hand, as the alumina content increases, heat resistance improves. When the amount of mixed iron oxide exceeds 2% by weight, the mechanical strength during heating decreases and the heat resistance decreases.

This iron oxide can be used for gas purification at temperatures of about 300 pm or higher.
For example, it has a catalytic ability to purify carbon monoxide. In order to exhibit such a promoter effect, it is preferable to contain iron oxide in an amount of 2% by weight or more. A preferred composition of the alumina cement is a lime content of 15 to 4% by weight, especially 30 to 4% by weight, alumina of 35 to 80% by weight, especially 40 to 6% by weight.
, an iron oxide content of 0.3 to 20% by weight, especially 2 to 1% by weight. Boltland cement is an example of this type of cement material, but it cannot withstand temperatures of 300 oo or higher and cannot be used for the purpose of purifying exhaust gas from household combustion appliances where the catalyst temperature is about 30,000 or higher.

Although alumina cement can sufficiently withstand temperatures of 30,000 degrees Celsius or more, high alumina cement is preferably used to withstand temperatures of about 70,000 degrees Celsius or more. Next, the granular base aggregates include silica base aggregate, silica alumina base aggregate, and alumina base aggregate, and as the mineral phase,
It is preferable to use silicate minerals such as mullite, corundum, sillimanite, P-alumina, magnesia, chromium, dolomite, tomage black, and chromag.

Also, depending on the operating temperature of the catalyst, the temperature may vary from 300 to 700q.
In o), a general granular base aggregate is used, and the high temperature side (700℃
Above), it is preferable to use a heat-resistant granular base aggregate.
More specifically, examples of the silica-based aggregate include silica stone. These base bones have Si02 as a main component. Silica-alumina base aggregates include chamotte, waxite, high alumina, etc., and the main components are Si02-AI203. As alumina base aggregate, Q Ilsan 203,
There are P-AI203, y-AI203, p-yama203, etc. More commonly used main mineral phases include silicate minerals, mullite, corundum, sillimanite, and B-alumina. These base aggregates can be crushed to a certain extent, or commercially available base aggregates such as conical silica sand, alumina, and chamotte can be used.Generally, it is best to use commercially available silica sand or chamotte. It's convenient. Furthermore, magnesia, chromium, dolomite, magcro, and chromag-based skeletons can be used, but these are mainly used at very high temperatures (over 130,000 ℃) and are uneconomical to obtain a cheap catalyst support. be.

In general, it is sufficient that the material has excellent spalling resistance at temperatures of up to about 1000 oo, and a silica-based base aggregate is sufficient.

Furthermore, for temperatures up to about 60,000, it is convenient to use ordinary sand, beach sand, etc., which are inexpensive among silica-based base aggregates. Next, the grain size of the granular basal bone village will be explained.

The granular bone particles used in the present invention refer to those having a particle size of 200 mesh or more, preferably those having a particle size of 35 to 200 mesh at 9% by weight or more. This is because the pellet-shaped carrier has a smaller volume than the honeycomb type, and has less influence on the anti-spawning IJ properties such as thermal destruction (cracking). Therefore, it is preferable that the particle size of the granular base aggregate is smaller than that of the honeycomb type. The extrusion pressure molding method is generally used to manufacture pellet-shaped carriers, so if the aggregate particle size is large, the pressure applied during carrier molding will be uneven, resulting in a molded body with a uniform diameter or homogeneous shape. It becomes difficult to mold the product.

As a result of various studies carried out by the present inventors, we found that when granular base aggregate of 35 mesh or more is used in pellet molding of a size smaller than 100 mm, it becomes impossible to obtain a molded body (vellet) with a uniform diameter, and the molded body is The percentage is less than 70% (more than 30% becomes small lumps or powder), which causes problems in production. On the other hand, if a granular base bone village of 35 mesh or less is used, a homogeneous molded body with a uniform diameter (high mechanical strength) can be obtained. The particle size of the granular base aggregate used in the present invention is JIS-G590.
1 (1974) was used.
As mentioned above, the preferred particle size is 35-200 mesh (4
20 to 7 small), and according to the JIS standard, a range of No. 48 to No. 150 is good. Table 1 shows the results before and after firing (700 qo
The figure shows the yield after 2 hours of heat treatment).

The composition of the pellet-like carrier at this time was alumina cement (
Alumina content 47.1% by weight, lime content 36.0% by weight,
Main component is iron oxide 9.5% by weight) 6% by weight
and, as a granular base village, No. 14, No. 28, No. 48, No. 65
It is composed of 4% by weight of silica sand of seven types of particle sizes: No. 1, No. 10, No. 15, and No. 20.

Table 1 As shown in Table 1 above, when the grain size of the granular base aggregate becomes coarse, it becomes impossible to obtain the desired pellet diameter. That is, there are fewer pellets with an outer diameter of 5 skins, and there are more thin pellets with an outer diameter of about 4 to 2 skins. In addition, when the particle size becomes coarse, the molding pressure is insufficient, the mechanical strength before firing is low, and it is easy to break during high temperature treatment (700 oo for 2 hours), and there are many small lumps. 1st
The table shows alumina cement 6 and granular base aggregate 4, but the mixing ratios of alumina cement and granular base aggregate are (4:6), (5:5), (7:3), ( 8:2)
, (9:1), the results of changing the particle size of the granular base aggregate in the same way are not shown, but similar results can be obtained if the granular base aggregate has a particle size in the range of 35 to 200 mesh. Ta.

However, when the amount of alumina cement was small, the yield of finer granular skeletons was higher.

From the above, the grain size of the granular base aggregate used for the non-sintered pellet-like carrier is 35 to 200 mesh (JIS Standard 3 (4)
The range of No. 8 to No. 150) is preferable because the yield before and after firing is 70% or more.

However, since JIS standard No. 48 to 15 Pibata Medium contains 2 to 10% by weight of coarse and fine particles, 35 to 2
A preferable particle size distribution of the silica sand 3 used in the present invention is that the range of 00 mesh is 90% or more. Next, as the powder aggregate, silica-based, alumina-based, silica-alumina-based aggregate, etc., similar to the granular base aggregate, can be used.

In addition to these aggregates, porous powder aggregates such as fluorite, cordierite, calcium carbonate, and magnesium carbonate (
(specific surface area of 6〆/g or more) can also be used. The particle size of the powder aggregate of the present invention is 200 mesh or less.
Next, the present invention will be explained in more detail with reference to Examples. Second
The table shows the relationship between the composition of the pellet-shaped carrier and the spalling resistance (yield and wear resistance after pellet molding and firing) at a constant temperature5. Fig. 1, Fig. 2, and Fig. 3 are plotted in the three-component system composition diagram of single granular base aggregate-powder aggregate.

Figure 1 shows the claims of the present invention, Figure 2 shows the yield of non-defective products when the pellet-shaped carrier is heated at 70,000 for 2 hours, and Figure 3 shows the yield of non-defective products when the pellet-shaped carrier is heated at 700:00 for 2 hours. Shows the wear resistance when In these figures and tables, regarding the yield of non-defective products, the mark 0 indicates a yield of 90% or more, and the mark ○ indicates a yield of 70%.
~90%, ● indicates a yield of 70% or less. In addition, in terms of wear resistance, 0 marks indicate a wear rate of 2% or less, and 0 marks indicate a wear rate of 2% or less.
5%, ● indicates a wear rate of 5% or more. The pellet-shaped carrier used here was made of alumina cement (alumina content: 47.1
Weight%, lime content 36.0% by weight, iron oxide content 9.5% by weight
(remaining silicon oxide, titanium oxide, etc.), silica sand (JIS standard No. 10) as the granular base aggregate, and alumina (alpha type) as the powder aggregate.
were mixed in the proportions shown in Table 2, enough water was added to the mixture to form it, and the mixture was pressure-molded into pellets with an outer diameter of 5 willows using a granulator.After primary curing, the mixture was poured into boiling water. It was obtained by secondary curing and drying.

Table 2 These results clearly show the difference in spalling resistance at high temperatures (70,000).

That is, the yield of non-defective products decreases when the amount of alumina cement is small and when the amount of granular aggregate is large. Furthermore, the same applies to wear resistance; the less alumina cement and the more granular aggregate, the greater the degree of wear. On the other hand, when there is a large amount of alumina cement, both the yield of good products and the wear resistance are excellent. From the above results, the preferable composition is the range consisting of points C, D, E, F, G, 1, 1, and J in FIG. In this way, at the maximum operating temperature of 700°C for household combustion equipment, points B, C, D, E, F, G, day, 1, J
It is necessary to have a composition within the range enclosed by the lines connecting them.
Conventionally, many soot carrier materials have undergone a freezing process during molding, and in order to compensate for the low surface area, there are many cases in which activated alumina, etc., which is active and has a large surface area, is supported on the surface.
However, the characteristics of the present invention are that the carrier has high strength even without competitive bonding (non-competitive bonding) as described above, and also has a high surface area. It is.

Another feature of the present invention is that the catalyst carrier is heated to a high temperature (300q
o or more) and have catalytic ability.

The features of the present invention are as follows. '11
Because we used a mixture of alumina cement, granular aggregate, and powdered aggregate as a catalyst carrier, the price was low, and the bonding strength of alumina cement itself was used without going through processes such as consolidation. It can be molded into the desired shape. ■
The catalyst carrier itself has the ability to purify carbon monoxide at high temperatures (300 to 500 q0), and also has the ability to adsorb and remove acidic gases such as dioxide ions due to the lime content in the alumina cement.

{3' The surface hardness of the catalyst carrier is high, the surface area is quite large, and it plays a sufficient role as a loss body.

'41 High adhesion efficiency (including adhesion strength) of the catalyst to the catalyst prisoner. That is, the wetting phenomenon of the catalyst salt such as water or alcohol with the solvent is large, and the catalyst can be supported in an effective homogeneous dispersion. {5- Compared to commercially available alumina supports, it has higher abrasion strength, less attrition loss during use, and is stable as a catalyst for a long period of time.

'61 Since the catalyst can be reactivated using the Ajijo carrier, when using precious metal catalysts such as Rt, Pd, Ru, Rh, etc., the supported amount of the catalyst is extremely small, resulting in high performance and long life. A catalyst body with a long life can be obtained.

For example, platinum group metal catalyst with sulfur dioxide gas.

2 Pt10S.

211 Pt-S.

C in alumina cement when inactivated as in 3.
It is reactivated by a0·H20 as follows.

Pt・S03 Cao・QO → Pt+CaS04・String ○ In addition, the case of metal oxide M0× is reactivated as follows.

. 2 M.

X+S. 2--MS.

4 MS040 Ca○・Ratio 0 → M(OH)X+CaS04 M(OH) It is not necessary and can be molded at room temperature, and compared to Akatsuki compact, the cement particles are finer and the surface area is larger.

Furthermore, the sintered body undergoes thermal shrinkage of about 10 to 30% compared to the original mold, making it difficult to maintain uniform mold precision of the molded body (carrier). On the other hand, when alumina cement is used (it is a sintered body), it is possible to reduce the mold accuracy to 2% or less. '8) The surface of conventional sintered bodies is sintered and has a small surface area. For this reason, performance cannot be obtained unless the amount of catalyst supported is large, but since the molded body of the present invention is unsintered, the supporting surface is an aggregate of fine particles, and the surface area is large, and the amount of soot supported Since only a small amount is required and it can be homogeneously dispersed, a high-performance catalyst can be obtained even with a small amount of support. '9) Since alumina cement is used as a catalyst support, the solution in which noble metal salts are dissolved is made alkali (for example, Pt
Therefore, the catalyst is generated near the surface of the carrier and does not reach deep inside the pores of the carrier.

Therefore, the concentration distribution of the catalytic metal is concentrated on the surface of the bile body and does not diffuse into the interior of the carrier. Therefore, the catalytic metal is uniformly dispersed, and the amount of the catalytic metal supported is only required on the surface, which is smaller than that of conventional methods. The catalyst body of the present invention is mainly used for the purpose of purifying exhaust gas from household combustion equipment and cookers, and is preferably used at a relatively low temperature of 70,000 ℃ or less. The method is not limited to those described above, but is also effective for oxidation purification of exhaust gas from various plants.

Furthermore, it is not only effective for carbon monoxide and hydrocarbons, but also for adsorption and removal of sulfur dioxide, for converting NO into NO2 for nitrogen oxide removal equipment, or for NO and C○,
It is also effective as a catalyst for the reaction between NO and N (platinum group catalyst). Next, the method of supporting the catalyst will be explained.

The supporting methods mainly include coprecipitation, deposition, impregnation, and coating methods, and the impregnation method is used for honeycomb-shaped platinum catalysts using alumina as a carrier. Although this impregnation method is relatively simple to manufacture, it may be subject to restrictions on the amount of catalyst supported, wear out the surface of the carrier, and reduce the surface area and pores.
It has drawbacks such as low activity in some cases. In the examples of the present invention, an impregnation method and a coating method were mainly adopted.

The next supported catalyst is mainly a platinum group metal, including platinum, palladium, ruthenium, rhodium, and iridium, and chlorides are preferred as their salts. Tetrachloroplatinic acid day 2Ptc〆4, hexachloroplatinic acid day 2
P Niso 6, platinum diaminodinitrite Pt (NH3)
Representative examples include 2(N02)2, palladium chloride Pdcso2, ruthenium chloride Ruc〆3, and rhodium chloride. These metal salts are used after being dissolved in a solvent such as water or alcohol. The concentration varies depending on the amount deposited and the supporting method, but if the solution is too concentrated, the dispersibility of the catalyst particles will deteriorate, so the optimum concentration is determined depending on the purpose of use, shape, etc. In particular, when a platinum group metal is used, a catalyst body with a supported amount of platinum of 0.001 to 0.1% by weight compared to conventional platinum catalysts can be obtained with higher performance in both initial performance and lifetime performance.

That is, conventional platinum catalysts use supports such as alumina and cordierite, and the supported amount of platinum is 0.5 to 0.1% by weight, and when the supported amount is 0.1% by weight or less, the life performance is particularly deteriorated. is large, and the amount supported is common knowledge. On the other hand, when the catalyst carrier of the present invention is used, high performance can be achieved even if the amount of platinum supported is small. As described above, when the catalyst carrier of the present invention is used, a high-performance catalyst body with a reasonable amount of supported platinum or the like can be obtained.

This is because part of the lime aluminate in the carrier absorbs water, A〆2QnCa0 is partially dissolved, part of Ca◯ is liberated, and the solution exhibits alkalinity. On the other hand, most of the raw materials for noble metal catalysts are chlorides, including RuCso3, Rh
C evening 3, PdC so 2, day 2P ni so 4, Philippine PtC evening 6
It is indicated by. For example, in the case of chloroplatinic acid, when dissolved in water, some of the PtC ions (Ca
○) is eluted and shows alkalinity, so P is 6(OH
) to form. This salt PtC〆6(OH) is generated near the surface of the carrier and does not reach deep inside the pongee pores. Therefore, the concentration distribution of the catalyst metal of the present invention is concentrated on the surface and does not diffuse into the interior of the carrier. That is, as described above, the catalytic metal ions turn into hydroxides on the surface of the constant body and adhere as they are. Furthermore, since the carrier is alkaline, the catalyst metal cations and a portion of the carrier surface form a compound, which is firmly attached to the carrier. In this way, since it is possible to support only the surface layer, a high-performance catalyst can be obtained even if the supported amount is small. In addition, iron group elements iron, cobalt, and nickel, chromium group elements chromium and molybdenum, carbon group elements tin and lead, manganese group elements manganese, steel group elements copper and silver, rare elements lanthanum, Oxides of zinc and cadmium, which are zinc group elements, and vanadium, which is a vanadium group element, can also be supported.

Among these, Pt, Pd, Mn,
A metal or oxide selected from Fe, C and Ag is preferred. There is a large relationship between the amount of supported catalyst and performance, and normally, as the amount of supported catalyst increases, the performance will improve accordingly, but if it is too large, problems such as catalyst falling off and catalyst dispersion will occur.

Furthermore, in addition to the amount of catalyst, by supporting two or more types of various metals or metal oxides, the purpose of use, shape, low-temperature activity, life span, etc. can be improved. FIG. 4 shows the results of measuring the specific surface area by the BET method when pellet molded bodies made of alumina cement having a diameter of 5 kites and a length of about 3 skins were heat treated at various temperatures for 1 hour.

As is clear from the figure, the bound water in the alumina cement of the brood medium carrier is dehydrated, and the specific surface area of the mortar rapidly increases around 25,000.

When the specific surface area of currently commercially available Q-alumina carriers is measured, it is 5 to 15〆/g, which is 1
Although it is smaller than 00 to 300 force/g, a platinum catalyst using aluminum alumina has excellent low-temperature activity, so it is possible that a catalyst carrier using alumina cement has sufficient functionality. Recognize. Figure 5 shows the weight percent of alumina cement 5 with various compositions shown in Figure 3, silica sand (
This graph shows the carbon monoxide purification rate of a 50% by weight composition formed into a pellet similar to the above and heat-treated at 350qo for 1 hour.
These are Pi0 and 600qo.

Note that the conditions for measuring the purification rate are the same as in Example 1, which will be described later.
As is clear from the figure, the greater the iron oxide content in the catalyst carrier (alumina cement), the greater the carbon monoxide purification ability.

Table 3, Figure 6 shows that pellet A, which is made of 50 parts by weight of alumina cement and 5 parts by weight of silica sand (No. 15) having the composition shown in Table 3 and 8, and pellet B, which is made of commercially available Q-alumina, were 3 more
The carbon monoxide purification rate is compared for samples heat-treated at a temperature of 00qC for 1 hour.

As is clear from the figure, the catalyst carrier of the present invention has considerable catalytic ability at high temperatures, but commercially available catalyst carriers have almost no purification capacity even at high temperatures.

The present invention will be explained below with reference to Examples. (Example 1) Alumina cement having a diameter of 5 and consisting of 10 parts by weight of the composition shown in Table 3 and 10 parts by weight of silica sand (No. 15 Pi)
Leg pellets were prepared, and after adjusting the particle size to the average length on three sides (2 to 4 skins), the pellets were heat-treated at 300 qo for 1 hour, and used as a catalyst carrier.

An aqueous solution in which hexachloroplatinic acid was dissolved at a ratio of 1 g to
1,0.05 Impregnate the mortar to a concentration of 0.1% by weight,
After drying at 80°C for 1 hour, it was heat-treated in an electric furnace at 500 pm for 1 hour. The amount of catalyst supported in this way was 0.001,
0.01, 0.05, 0.1% by weight of the catalyst, respectively a,
Let them be b, c, and d. In addition, a catalyst body in which 0.5% by weight of platinum was supported on commercially available Q-alumina was used. Na. Approximately 42 cc of these catalyst bodies were loaded into a quartz tube on the inner diameter 35 side, and air containing approximately 20 pm of carbon monoxide CO was heated at a space velocity of 10,000 ml.
The Cq purification rate was determined by passing through the catalyst layer in the KARI-1 and measuring the CQ degree on the inlet and outlet sides.

The results are shown in FIG. Catalysts a to d of the present invention are slightly inferior to commercially available platinum catalyst e, but have improved activity at low temperatures compared to manganese oxide catalyst c. (Example
2) The catalyst body of Example 1 was installed above a kerosene stove as shown in FIG. 8, and a life test of the catalyst was conducted by continuously burning the catalyst. The results are shown in FIG. 9.

In Fig. 8, 1 is the kerosene stove body, 2 is the husband plate, 3 is the combustion wick upper and lower knobs, and 4 is the reflector.
A chimney 5 is provided in front of the.

6 is a catalyst tank installed in the upper part of the combustion section, and this catalyst tank has 1
Catalyst layer 7 was formed by providing two stages of 0-mesh wire mesh, and loading 25 female catalyst pellets in each stage, 50 female catalyst pellets in total, on the wire mesh.
is provided.

The catalyst tank 6 is a cylindrical body with an inner diameter of 160 ribs, and is suspended by a hanging fitting 8 fixed to the top plate 2. During combustion, the temperature of the lower catalyst layer is maintained within the range of 600±2000℃,
The space velocity of exhaust gas passing through the catalyst layer is approximately 2000 Hr.
It is l/1 stage.

In addition, the CO purification rate was determined to be 350 when the lower catalyst was removed.
After drying at qo for 1 hour and storing in a desiccator for 1 day, it was determined in the same manner as in Example 1.

However, the purification rate is when the catalyst layer temperature is 200°C. (Example 3) A pellet with a diameter of 5 sides and a length of 3 skins was formed using the same carrier material as in Example 1, and heat treated at 30,000 for 1 hour.

This carrier was impregnated with an aqueous solution of copper nitrate and thermally decomposed at 300°C to produce Cu◯. This supported amount is 0.05% by weight
It is. After the above thermal decomposition, it was slowly cooled in a desiccator, and then an aqueous solution of hexachloroplatinic acid was added to the solution with a platinum loading of 0.
．． The mixture was mixed to a concentration of 0.01% by weight, dried at 8000° C. for 1 hour, and then heated in an electric furnace at 500° C. for 1 hour. The CO purification rate of this catalyst body at 150:00 was 98%. (Example 4) Oxidized steel and manganese oxide were prepared in the same manner as in Example 3, except that an aqueous solution containing the same amounts of copper nitrate and manganese nitrate was used instead of the aqueous solution of nitrate steel in Example 3. % by weight, and 0.01% by weight of platinum.

The Cq purification rate of this catalyst body at 150 qo was 99%. Also, at a temperature of 250℃, toluene 200p
When brought into contact with air containing m (in terms of methane), the oxidation purification rate was 98%. As described above, the present invention provides a high-performance, low-cost catalyst for gas purification.

In addition, oxides such as manganese steel, nickel, iron, vanadium, cobalt, lead, silver, chromium, etc. may be added in a range of 5 parts (5% by weight) or less out of 100 parts of powder aggregate added. It is also possible to use it depending on the purpose and use.

Furthermore, in order to improve the spalling resistance, a fibrous inorganic material such as asbestos, glass fiber, etc. is added to the carrier composition 100.
It is also possible to add at a rate of 1 part by weight or less per part by weight.

[Brief explanation of the drawing]

FIG. 1 shows a three-component system composition diagram in the present invention, and the second
The figure shows the yield of good products when heated at 700°C in carrier production, Figure 3 shows the spalling resistance (wear resistance), and Figure 4 shows the results when the carrier made of alumina cement was treated at various temperatures. Figure 5 is a diagram showing the specific surface area by the BET method. Figure 5 is a diagram showing the relationship between the CO purification rate of a carrier made of alumina cement and silica sand and the amount of iron oxide in the alumina cement.
Figure 7 is a diagram comparing the temperature of the carrier and CO purification rate, Figure 7 is a diagram comparing the CO purification rate of various catalysts, and Figure 8 is a diagram showing a kerosene stove using a catalyst according to an embodiment of the present invention. The strategy diagram, Figure 9, is a diagram comparing the lives of various catalysts. Figure 1 Figure 2 Figure 3 Figure 4 Figure 9 Figure 5 Figure 6 Figure 7, Figure 8

Claims (1)

[Claims] 1 Alumina cement as an inorganic binder, and at least one particle size 35 selected from the group consisting of silica-based, alumina-based, and silica-alumina-based aggregates mixed in the binder.
It consists of granular base aggregate of ~200 mesh and powdered aggregate with a particle size of 200 mesh or less obtained by pulverizing the base aggregate, and the amount of alumina cement, the amount of granular base aggregate, and the amount of powder aggregate are shown in Figure 1. In the ternary composition diagram shown in , C. D, E, F,
It is characterized by being composed of a non-sintered pellet-like carrier within the range surrounded by lines connecting G, H, I, and J, and a catalyst made of a metal or metal oxide supported on this carrier. Catalyst for gas purification.