JPH07136509A - Catalyst for decomposition of oil - Google Patents

Abstract

PURPOSE:To provide a catalyst to oxidize, decompose, and remove org. matters such as oils produced in cooking apparatus such as a microwave oven and a fish roaster. CONSTITUTION:This catalyst essentially consists of manganese oxide and aluminum oxide with 10/90 to 90/10 weight ratio of manganese oxide/aluminum oxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst for oxidizing and removing organic substances such as fats and oils generated from cookers such as oven microwave ovens and fish roasters.

[0002]

2. Description of the Related Art In a heating cooker such as an oven microwave oven and a fish roaster, when cooking fish or meat, a large amount of oil smoke and odors are generated, and the kitchen is filled with smoke and odor, and the surroundings of the cooker. An unfavorable situation such as stains will occur. In order to prevent these, a gas purifying catalyst is provided in the exhaust passage of the cooker to allow oil fumes, etc., generated during cooking to pass through the catalyst and be naturally exhausted, and, if necessary, the cooker. An exhaust fan motor, etc. is installed outside the, and the fan motor is activated during cooking to force exhaustion. As the catalyst for this, platinum, precious metals such as palladium, or oxides such as manganese dioxide, copper oxide, iron oxide,
Alternatively, a perovskite-type composite oxide supported on a honeycomb ceramic carrier such as cordierite is used.

[0003]

However, it is hard to say that any of the above-mentioned conventional gas purification catalysts is a sufficiently satisfactory catalyst. That is, the noble metal-based catalyst is very high in cost even if it is satisfactory in performance, and it is difficult to say that it is practically appropriate. On the contrary, although the catalyst is relatively inexpensive in terms of performance, it cannot be said that the catalyst is satisfactory in terms of performance.

The present invention has been made in order to solve these problems that the conventional catalyst for oxidative decomposition of oils and fats for cooking appliances has, and its purpose is to compare with conventional catalysts. , Which is a catalyst that is low in cost and excellent in removal ability.

[0005]

A catalyst for oxidative decomposition of fats and oils according to the present invention for achieving the above object comprises manganese oxide and aluminum oxide as main components, and contains manganese oxide /
Aluminum oxide weight ratio 10/90 to 90/1
It is characterized by being in the range of 0, preferably 75/25 to 25/75.

Commercially available powders can be used for the manganese oxide and the aluminum oxide used in the catalyst of the present invention. These commercially available manganese oxides are electrolytic manganese dioxide (DE) manufactured by Mitsui Mining & Smelting Co., Ltd.
NMAN), TAD, TAM, TSV, TSM, TR
F, TKV, electrolytic manganese dioxide manufactured by Tosoh Corporation, H
MH, FV, etc. are also used as aluminum oxides such as activated alumina A-11, AC-11, A manufactured by Sumitomo Chemical Co., Ltd.
C-11K, AC-12, AF-115, TA-100
Examples include N, TA-200N, activated alumina T-101, M-200, and DN-1A manufactured by Mizusawa Chemical Co., Ltd., respectively.

The manganese oxide and aluminum oxide used in the catalyst of the present invention can be prepared by various methods in addition to the above commercial products. For example, manganese oxide powder contains salts such as carbonate at 200 ° C. to 60 ° C.
It can also be obtained by firing at 0 ° C. Further, the manganese oxide thus obtained and the above-mentioned commercially available manganese dioxide are slurried, and an aqueous solution of aluminum nitrate or aluminum sulfate is simultaneously neutralized with ammonia or the like to form a precipitate of aluminum hydroxide, followed by filtration.・ Repeated washing with water and repulsion
You may bake at 200 to 600 degreeC after drying. On the contrary, it is also possible to simultaneously neutralize an aqueous solution of manganese nitrate and manganese sulfate with the activated alumina slurry using ammonia or the like to form a precipitate of manganese hydroxide. Furthermore, it is also possible to neutralize a mixed solution of water-soluble salts such as manganese and aluminum as described above with ammonia or the like to form a coprecipitated hydroxide thereof.

The shape of the catalyst used in the present invention is
The shape is not particularly limited, and various shapes such as a honeycomb shape, a pellet shape, a column shape, a plate shape, and a pipe shape can be used. Among them, the most general shape is a honeycomb shape. These can be manufactured by a kneading method, an impregnation method, a wash coating method, or the like. In the case of extrusion molding, a molding aid may be added to impart shapeability, or a reinforcing agent such as an inorganic fiber or an organic binder may be appropriately added to improve mechanical strength and the like. The catalytically active component contained in these molded bodies is preferably 50 wt% or more, more preferably 80 wt%. When it is 50 wt% or less, the oxidative decomposition performance is significantly reduced. In addition, the catalyst of the present invention is preferably a coat type catalyst from the viewpoint of its reaction characteristics. It can be manufactured. At this time, the thickness of the coat is preferably 5 to 100 μ, more preferably 10 to 50 μ. If the coat thickness is 5 μm or less, the oxidative decomposition performance is deteriorated, and even if it is 100 μm or more, the decomposition activity is not improved to the extent commensurate with it, and only the pressure loss is increased.

The catalyst according to the present invention is used in a heating cooker such as an oven microwave oven or a fish roaster.
A suitable temperature required for contacting oils and fats and efficiently oxidatively decomposing them is 200 ° C to 400 ° C or higher. 20
If the temperature is 0 ° C or lower, the decomposition activity may decrease, and a large amount of unreacted fats and oils may be exhausted. The contact between the catalyst and the reaction gas is 5 to 25 in area velocity (AV: area velocity).
It is preferable that the process is performed in the "city". This is because if the area velocity is less than 5, a large amount of catalyst is required, and if the area velocity exceeds 25, the efficiency is low and a predetermined decomposition rate cannot be obtained. Here, the areal velocity is the space velocity (1
/ Hr) is the gas contact area per unit volume (m ² /
It is the value divided by m ³ ).

[0010]

EXAMPLES The present invention will be described in detail below based on examples. However, the present invention is not limited to the following examples. A. Preparation of catalyst Example 1 Electrolytic manganese dioxide TAD manufactured by Mitsui Mining & Smelting Co., Ltd., 2
0g and activated alumina AF-11 manufactured by Sumitomo Chemical Co., Ltd.
Add water and glass beads to 5,180g and
The mixture was stirred and mixed for 1 minute to obtain a wash coat slurry.
Water was further added to this slurry to dilute it, and then the cordierite honeycomb (420 cells / inch) prepared in advance was diluted.
² ) is immersed, the excess slurry is removed and dried, and the washcoat is repeated until the dried washcoat layer becomes 0.2 g / cc-honeycomb substrate, and MnO ₂ -Al is added.
_{A two-} way catalyst carrying ₂ O ₃ (weight ratio 10:90) with a coat thickness of 39 μ was obtained. The coat thickness was measured by XMA line analysis.

Example 2 In Example 1, 50 g was used instead of 20 g of electrolytic manganese dioxide TAD manufactured by Mitsui Mining and Smelting Co., Ltd., and 150 g was used instead of 180 g of activated alumina AF-115 manufactured by Sumitomo Chemical Co., Ltd. MnO in the same manner as in Example 1 except that
Coating with _2- Al ₂ O ₃ (weight ratio 25:75) 45
A two-way catalyst supported by μ was obtained.

Example 3 In Example 1, 100 g instead of 20 g of electrolytic manganese dioxide TAD from Mitsui Mining & Smelting Co., Ltd., and 100 g instead of 180 g of activated alumina AF-115 from Sumitomo Chemical Co., Ltd. Mn in the same manner as in Example 1 except that
O ₂ -Al ₂ O ₃ (weight ratio 50:50) was coated thickness 4
A binary catalyst supported by 3 μm was obtained.

Example 4 In Example 1, the electrolytic manganese dioxide of Mitsui Mining & Smelting Co., Ltd. was replaced with 20 g of TAD to be 150 g, and the activated alumina AF-115 made by Sumitomo Chemical Co., Ltd. was changed to 180 g, to be 50 g. MnO is the same as in Example 1 except for the above.
Coating with _2- Al ₂ O ₃ (weight ratio 75:25) 38
A two-way catalyst supported by μ was obtained.

Example 5 In Example 1, the electrolytic manganese dioxide of Mitsui Mining & Smelting Co., Ltd. was replaced with 20 g of TAD to 180 g, and the activated alumina AF-115 of Sumitomo Chemical Co., Ltd. was replaced with 180 g to 20 g. MnO is the same as in Example 1 except for the above.
Coating with _2- Al ₂ O ₃ (weight ratio 90:10) 35
A two-way catalyst supported by μ was obtained.

Example 6 In Example 4, except that electrolytic manganese dioxide TAD manufactured by Mitsui Mining & Smelting Co., Ltd. was replaced by manganese carbonate manufactured by Shodo Kagaku Co., Ltd., which was calcined at 300 ° C. for 5 hours. Was obtained in the same manner as in Example 4 to obtain a two-way catalyst in which MnO _x —Al ₂ O ₃ (weight ratio 75:25) was supported with a coating thickness of 38 μ.

Example 7 500 g of manganese carbonate manufactured by Shodo Kagaku Co., Ltd. was used for 2500 m.
and Riparubu of water l, a slurry, as _Al 2 _{O 3} while stirring the slurry 60g / l Al (N
O ₃₎ and 2000ml of ₃ · 9H ₂ O aqueous solution, the pH of the slurry was simultaneously added dropwise a 25% aqueous _NH 4 OH 6
Simultaneous neutralization while maintaining ~ 7 allowed the formation of aluminum hydroxide precipitate. This slurry was repeatedly filtered, washed with water, and re-pulped, dried, calcined at 350 ° C. for 5 hours, and then pulverized with a sample mill to obtain MnO _x —Al 2 O 3 (weight ratio 76:24) powder. Using these powders 200 g, in the same manner as the following Example _1, MnO x _-Al 2 O
A two-way catalyst carrying ₃ (weight ratio 76:24) with a coat thickness of 42 μm was obtained.

[0017]

Comparative Example 1 Example 1 was repeated except that the electrolytic manganese dioxide TAD manufactured by Mitsui Mining & Smelting Co., Ltd. was not added and the activated alumina AF-115 manufactured by Sumitomo Chemical Co., Ltd. was 200 g. In the same manner as above, a one-way catalyst supporting Al ₂ O ₃ with a coat thickness of 43 μm was obtained.

[0018]

[Comparative Example 2] In Example 1, except that activated alumina AF-115 manufactured by Sumitomo Chemical Co., Ltd. was not added, and 20 g of electrolytic manganese dioxide TAD manufactured by Mitsui Mining and Smelting Co., Ltd. was used instead of 200 g. MnO as in Example 1
Thus, a one-way catalyst carrying ₂ with a coat thickness of 39μ was obtained.

[0019]

[Comparative Example 3] An aqueous solution of cerium nitrate, copper nitrate and manganese nitrate having a molar ratio of Ce / Cu / Mn =
Form a mixed solution so that it becomes 10/4/6, and stir 7
It heated up at 0 degreeC, NaOH aqueous solution was added, and the hydrate was made to coprecipitate at pH 9-10. These are repeatedly filtered, washed with water, and re-pulped to remove the alkali content, dried, baked at 450 ° C. for 5 hours, crushed in a mortar, and then CeCu _0.4 Mn _0.6 O _y
Of fine powder was obtained. In the same manner as in Example 1 using 200 g of these powders, a perovskite-type composite oxide catalyst supporting CeCu _0.4 Mn _0.6 O _y with a coat thickness of 39 μ was obtained.

B. Catalytic activity test A simple sectional view of a commercially available fish roaster to which the catalyst of the present invention is applied is shown in FIG. In the figure,
Reference numeral 1 is a cooked product, 2 is a grill, and 3 is a honeycomb catalyst body. Oils and fats generated during cooking come into contact with the catalyst body 3 before passing through the exhaust holes 4 by natural exhaust gas to form carbon dioxide gas and water. Be disassembled. 5 and 6 are an upper heater and a lower heater,
Not only for cooking, but also for heating the catalytic body 3. These upper and lower heaters are appropriately selected by a heater changeover switch mounted on the outside of the roaster and a timer, in two types of cooking modes of double-sided grilling and top grilling, and cooking time according to the type and amount of food to be cooked. It is like this. In the case of over-baking, only the upper heater operates for a set time, and in the case of double-sided baking, the upper and lower heaters are alternately switched to operate.

The catalyst activity test was carried out using this fish roaster and a test apparatus whose flow sheet is shown in FIG. Reference numeral 7 in the figure is a fish roaster body, and a cover 8 for preventing dilution of the naturally exhausted gas is provided above the exhaust hole 4, and the sample gas is collected from this through a Teflon tube 9. .
The sample gas collected has its water content removed by the cold trap 10, and H. C (hydrocarbon) meter 11
In T. H. Used for C measurement. In addition, a thermocouple 12 is inserted just below the honeycomb catalyst in the fish roaster, and these data are shown every 30 seconds.
The computer 13 reads the floppy disk once.

When an actual fish grilling test is conducted with these test devices in the double-sided grilling mode and the cooking time is 20 minutes, the data shown in FIG. 3 is obtained. The curve 14 shows the change with time of the temperature immediately below the catalyst body, and it can be seen that the temperature raising / lowering is repeated in the range of about 200 ° C. to 400 ° C. depending on the operating state of the upper and lower heaters. Curve 15 represents the catalytic body
Curve 16 shows the T.I. after passing only the catalyst support which does not carry the active ingredient. H. The change over time of C is shown. The H. The C decomposition rate (%) is calculated by the following equation using the values S ′ ₁₅ and S ′ ₁₆ obtained by dividing the integrated areas S ₁₅ and S ₁₆ of the curves 15 and ₁₆ by the weight reduction of the respective cooked products. The test results are shown in Table 1.

As is clear from the above table, Examples 1-7
All the catalysts obtained in Example 1 had higher H.V. than those obtained in Comparative Examples 1 to 3. It has a C resolution.

[0024]

The catalyst for decomposing oils and fats according to the present invention has an excellent effect that the oils and fats etc generated from the heating cooker can be efficiently removed.

[0025]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a commercially available fish roaster.

FIG. 2 is a flow sheet of a catalyst performance test.

FIG. 3 is data obtained as a result of a catalyst performance test.

[Explanation of symbols]

 1. Cooking 2. Grill 3. Honeycomb catalyst 4. Exhaust hole 5. Upper heater 6. Lower heater 7. Fish roaster body 8. Cover 9. Teflon tube 10. Cold trap 11. H. C meter 12. Thermocouple 13. Computer 14. Temperature curve 15. H. C time course curve 16. H. C time change curve

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Joji Ikeda 5-1-1 Ebishima-cho, Sakai City, Osaka Prefecture Sakai Chemical Industry Co., Ltd. Central Research Laboratory

Claims (1)

[Claims] 1. Manganese oxide and aluminum oxide are the main components, and the manganese oxide / aluminum oxide weight ratio is 1
A catalyst for decomposing oils and fats, which is in the range of 0/90 to 90/10.