WO1996022827A1

WO1996022827A1 - Deodorant material, process for producing the same, and method of deodorization

Info

Publication number: WO1996022827A1
Application number: PCT/JP1996/000140
Authority: WO
Inventors: Shinya Kitaguchi; Koichi Yamamoto; Junichi Miyake
Original assignee: Nippon Shokubai Co., Ltd.
Priority date: 1995-01-27
Filing date: 1996-01-24
Publication date: 1996-08-01
Also published as: CN1145592A; KR970701583A; TW278042B

Abstract

A deodorant material comprising a deodorant component supported on a carrier material mainly comprising activated carbon, wherein the deodorant component comprises 0.5-10 parts by weight (in terms of CuO) of copper oxide, 1-20 parts by weight (in terms of MnO2) of manganese oxide and 1-20 parts by weight (in terms of AgNO3) of silver nitrate, and the total content of copper oxide, manganese oxide and silver nitrate accounts for 3-30 wt.% of the deodorant material as a whole. The material has an excellent performance of eliminating various malodorous components, such as a hydrogen sulfide, mercaptans, ammonia and amines, contained in gases.

Description

Description Name of Invention

Deodorizing material, its production method and deodorizing method

The present invention relates to a deodorizing material used for removing malodorous components from a gas containing various malodorous components such as hydrogen sulfide, various mercaptans, ammonia and amines, a production method thereof, and a deodorizing method. The deodorization method can be widely used for deodorization in refrigerators, toilets, animal breeding houses, sewage treatment plants, and the like. Conventional technology

Conventionally, for deodorizing toy refrigerators, etc., the adsorption method of adsorbing odorous components on adsorbents mainly composed of activated carbon and the method of oxidizing and decomposing odorous components using ozone and a catalyst have been mainly used. Have been. However, the former uses the adsorption action of activated carbon and has a limited adsorption capacity. When used for a long time or when the concentration of odorous components is high, the activated carbon must be replaced frequently. The latter uses the oxidizing power of ozone, and can be semi-permanently deodorized by proper combination with a catalyst, but requires special equipment such as an ozone generator and high-pressure transformer. It is pointed out that the cost and operating cost increase.

By the way, recently, a catalyst deodorization method capable of removing malodorous components at room temperature without adding ozone and without heating has been developed and is attracting attention. However, this method is effective for the removal of highly reactive malodorous components such as hydrogen sulfide-methyl mercaptan butane, but it produced by-product methyl disulfide, another malodorous component, from methyl mercaptan. Alternatively, malodorous components having low reactivity, such as methyl sulfide, ammonia, and amines, have insufficient deodorizing effects, and improvement in deodorizing performance is desired.

The present invention has been made in view of such problems of the prior art. The purpose of the present invention is to provide a direct reaction for a long period of time not only for malodorous components having high reactivity but also malodorous components having low reactivity. It is an object of the present invention to provide a deodorizing material which can stably maintain an excellent deodorizing effect, a production method thereof, and a deodorizing method.

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The deodorizing material of the present invention is characterized in that a deodorizing component comprising copper oxide, manganese oxide and silver nitrate is carried on a carrier material containing activated carbon. Copper oxide in the deodorizing material, preferable composition ratio of manganese oxide and silver nitrate, copper oxide:. 0 C u 0 Convert 5-1 0 part by weight, manganese oxide: M n 0 ₂ terms at 1-2 0 parts by weight , silver nitrate: a _g N 0 ₃ ranges from 1 to 2 0 parts by weight in terms, also copper oxide occupied in the deodorizing material, the total content of manganese oxide and silver nitrate ranges from 3 3 0 wt% Is preferred. Further, the deodorizing component consisting of copper oxide, manganese oxide and silver nitrate is carried on a carrier material containing activated carbon as a main component. The content of the activated carbon in the carrier material is 30 to 70% by weight. And the specific surface area as a deodorant is preferably 250 m ² / or more. If this deodorizing material is used to treat a gas containing malodorous components such as hydrogen sulfide, various mercaptans, ammonia, and amines, these malodorous components are removed and the deodorization can be performed efficiently.

Further, a feature of the method for producing a deodorizing material according to the present invention is that after a carrier material containing activated carbon is formed into a predetermined shape, copper oxide and manganese oxide are added thereto. And a solution containing silver nitrate or their precursors are applied or impregnated, and calcined in a non-oxidizing atmosphere at a temperature lower than the decomposition temperature of silver nitrate. Deodorizing material can be obtained. A more preferable method for producing a deodorizing material is to add a solution containing copper oxide, manganese oxide, silver nitrate or a precursor thereof to citric acid in an amount of 1 to 3 mol with respect to silver nitrate to form an activated carbon-containing carrier. It is preferable to adopt a method of applying or impregnating and firing in a non-oxidizing atmosphere at a temperature lower than the decomposition temperature of silver nitrate, because a more excellent deodorizing material can be obtained more reliably. BEST MODE FOR CARRYING OUT THE INVENTION

Under the above-mentioned conventional technology, the present inventors have developed a method of converting not only highly reactive malodor components but also less reactive malodor components without using costly ozone or the like and without requiring heat treatment. On the other hand, various researches have been conducted with the aim of developing a deodorizing material that can stably maintain an excellent deodorizing effect over a long period of time.

As a result, if the three components of copper oxide, manganese oxide, and silver nitrate are used in combination as the main deodorizing active components, and activated carbon is used as the main carrier material for holding or supporting them, a deodorizing material with excellent performance can be obtained. I knew that it could be done. Especially, the composition ratio of the three components to be contained in the main deodorizing component in the deodorizing material, copper oxide:. 0 5-1 0 weight parts C u O terms, manganese oxide: 1 in M n 0 ₂ conversion 2 0 parts by weight, of silver nitrate: a g N 0 ₃ set in the range of 1 to 2 0 parts by weight in terms of, 3 to 3 the total content of these three components occupied in or deodorant 0 wt% range Further, if the activated carbon content of the carrier material supporting the deodorizing component is 30 to 70% by weight, excellent deodorizing performance meeting the object of the present invention is exhibited. I found to do. Of the above components, copper oxide has a large amount of surface oxygen and exerts the effect of oxidizing and decomposing hydrogen sulfide / methyl mercaptan at room temperature.The oxygen consumed in this oxidative decomposition reaction is Since it is gradually supplemented by the oxygen contained in the air, its deodorizing effect is maintained for a long time.

In addition, manganese oxide effectively exerts the deodorizing effect on the above-mentioned various odorous gases, but in particular, suppresses the conversion of methyl mercaptan into methyl disulfide caused by the copper oxide. It works effectively in doing so. To effectively exhibit such effects, arbitrariness preferred that the weight ratio of M n 0 ₂ / C u 0 and 2 or more blending ratio against copper oxide.

Next, silver nitrate is the most characteristic component in the present invention, and its strong oxidizing ability makes it difficult to remove by conventional techniques. It is a low-reactive-odor component, especially ammonia, trimethylamine, methyl sulfide. Decomposition and removal of acetoaldehyde and the like are possible.

It is already known that silver or silver oxide is used as one of the deodorizing components, but these have a property that they tend to become large particles of metallic silver by heat treatment during the preparation of the deodorizing material. Inactive against odorous gas. Therefore, there have been proposed several methods of supporting silver as a composite oxide, wet oxidation with a peroxide or the like, and supporting silver as a silver oxide on a carrier. In addition, it is difficult to disperse and support in a fine particle state, and a satisfactory deodorizing effect has not been obtained. However, in the present invention, instead of utilizing silver as silver oxide as in the past, silver was utilized in the form of silver nitrate, thereby maximizing the effective use of silver as a deodorizing component. However, it has a great feature.

Effectively exerts the effects of copper oxide, manganese oxide and silver nitrate To achieve this, the composition ratio of these three components in the deodorizing material is determined as follows: copper oxide: 0.5 to 100 parts by weight (more preferably 1 to 5 parts by weight) in terms of CuO, manganese oxide: M n 0 ₂ terms at 1-2 0 parts by weight (more preferably rather is 2-1 0 part by weight), silver nitrate: 1-2 0 parts by weight A _g n 0 ₃ conversion (more preferably 2-1 0 weight If the amount of copper oxide is less than 0.5 part by weight, the amount of manganese oxide is less than 1 part by weight, and the amount of silver nitrate is less than 1 part by weight, the respective effects become insufficient and the odor components are reduced. The decomposition effect is not sufficiently exhibited, and it is difficult to obtain a satisfactory deodorizing effect.

However, when the composition ratio of copper oxide exceeds 10 parts by weight, the amount of conversion from the malodorous component methyl mercaptan to the other malodorous component methyl disulfide increases, and the deodorizing effect is not effectively exerted. It becomes. Further, even if the composition ratio of manganese oxide exceeds 20 parts by weight or the composition ratio of silver nitrate exceeds 10 parts by weight, no further improvement in the deodorizing effect is observed, and the activated carbon adsorption site This tends to reduce the effect of deodorization on the contrary, which is undesirable.

In order to effectively exhibit the deodorizing effect of the combination of these three components, the total content of these three components in the deodorizing material should be 3 to 30% by weight, more preferably 5 to 20% by weight. If the content is less than 2% by weight, the absolute amount as an active ingredient for deodorization tends to be insufficient and the deodorization performance is insufficient, and is particularly satisfactory when applied to a gas having a high concentration of malodorous components. If the deodorizing effect becomes difficult to obtain, and if the total content of the above three components exceeds 30% by weight and becomes excessively large, the absolute amount of activated carbon acting as a carrier component tends to be insufficient, and as described below, the odor is bad. The adsorption site of the components tends to be short, and it is difficult to obtain satisfactory deodorizing performance.

The starting materials for copper oxide include copper nitrate, copper sulfate and copper oxide. As a starting material for manganese oxide, manganese nitrate, manganese sulfate, activated manganese dioxide and the like are exemplified as preferable ones.

The deodorizing active component used in the present invention essentially contains the above three components. However, depending on the type of the malodorous component contained in the gas to be treated, if necessary, nickel may be used as another deodorizing active component. It is also possible to contain metal oxides such as iron, cobalt, chromium, zinc, and vanadium, and platinum group metals in appropriate amounts. In addition, metallic silver, silver oxide, copper, or a composite oxide of manganese and silver may coexist. However, the amounts thereof are desirably suppressed to about 5% by weight or less, more preferably about 2% by weight or less in the deodorizing material so as not to dilute the effects of the three components.

The carrier material for holding or supporting the active ingredient for deodorization contains activated carbon as an essential ingredient, preferably 30 to 70% by weight, more preferably 40 to 60% by weight. % Is selected.

Here, the reason for choosing activated carbon is as follows. That is, the malodorous component is composed of a mixture of various gases, but in order to decompose and remove the malodorous component, it is necessary to first adsorb and trap the malodorous component on the deodorizing material. For example, ammonia, which is a basic gas, is easily adsorbed on a carrier such as silica or titania ash with high acidity, but hydrogen sulfide, which is an acid gas, is not easily adsorbed. The opposite is true. Almost no neutral gas, such as methyl sulfide, is adsorbed on acidic or basic carriers. In addition, zeolite has the effect of adsorbing gas into the pores, but has a poor effect of trapping malodorous components having a small molecular size with small pore size, and the adsorption trap performance is deteriorated by humidity. There is a disadvantage. Activated carbon, on the other hand, is neutral in its own right, but has a very large specific surface area and numerous micropores, making it resistant to any acidic, basic, or neutral odorous gas. Also exhibits excellent adsorption trap effect. Such an excellent adsorption trapping effect of the activated carbon is effectively exhibited as an adsorption site for the deodorizing component and the malodorous component. The adsorption site efficiently adsorbs and holds the malodorous component, and simultaneously carries the malodorous component on the adsorption site. It is considered that the malodorous component is promptly decomposed by the action of the deodorizing active component and the deodorization proceeds efficiently.

Moreover, the present inventors have confirmed that, in relation to the deodorizing active ingredient containing the three components selected above, an excellent effect exceeding the above-mentioned effect derived from the excellent adsorption trapping effect of activated carbon is obtained. It has been confirmed that a deodorizing effect can be obtained, and it is considered that some interaction between the specified deodorizing active ingredient and activated carbon acts to further enhance the deodorizing effect. However, the reason has not yet been elucidated.

In order to effectively exert such an effect of activated carbon, the content of activated carbon in the carrier material is preferably set in the range of 30 to 70% by weight, more preferably 40 to 60% by weight. When the content of the activated carbon is less than 30% by weight, the above-mentioned effects provided by the activated carbon become insufficient, and it becomes difficult to exhibit satisfactory deodorizing performance. On the other hand, if the content of activated carbon exceeds 70% by weight, the amount of one component of the binder tends to be relatively short, and the physical strength of the carrier is reduced, causing problems such as breakage and powder peeling during use. Come.

For a carrier material containing activated carbon, a predetermined amount of activated carbon powder is uniformly mixed with a ceramic-based binder such as silica-alumina, silica, alumina, titania, zeolite, titania silica composite oxide, etc. , Plate, honeycomb, etc. Alternatively, it can be obtained by firing under heating in a non-oxidizing atmosphere.

The deodorizing material of the present invention is produced by supporting a deodorizing component essentially containing the above-mentioned three components on the above-mentioned carrier by a method as described below. To make the deodorizing effect more effective, deodorizing material is used. It is desirable that the specific surface area of the material be at least 250 m ² Zg, more preferably at least 350 m ² Zg. As described above, it is considered that the deodorization of the offensive odor component is, first, that the offensive odor component is adsorbed and trapped on the adsorption site of the deodorant, and is decomposed into the odorless component by the action of the deodorant component in the adsorption site. In order to enhance the deodorizing effect, it is effective to increase the number of adsorption sites as much as possible. For that purpose, it is effective to increase the specific surface area of the deodorizing material as much as possible. In addition, if a carrier mainly composed of activated carbon is used, the specific surface area of activated carbon is very large, so that a specific surface area of 250 m ² Zg or more can be easily secured.

As a method for producing the deodorizing material, a method of kneading copper oxide, manganese oxide, silver nitrate, or a precursor thereof and a carrier material containing a predetermined amount of activated carbon to form the pellet, or using a carrier material to pelletize as described above. After forming into a honeycomb shape or the like, a method of supporting the deodorizing active component or a precursor thereof can be adopted, but the latter method is preferred, specifically, a carrier material containing activated carbon. Is formed into an arbitrary shape by a conventional method, and then coated or impregnated with a mixed solution of a water-soluble salt containing a precursor of a deodorizing active ingredient, and dried or fired.

If this method is adopted, the aforementioned deodorizing active component will be carried on the adsorption site wall surface of the activated carbon-based carrier. In the deodorizing treatment step, the deodorizing active component will be deodorized to the malodor component adsorbed and trapped on the adsorption site. This is because the components act quickly.

In carrying out the above-mentioned production method, among the deodorizing active ingredients, In order to effectively extract the activity of silver acid, when the carrier is coated with or impregnated with a solution containing the above three components or their precursors including silver nitrate and then calcined, the treatment atmosphere is changed to a non-nitrogen atmosphere. In addition to the oxidizing atmosphere, it is necessary to control the sintering temperature below the decomposition temperature of silver nitrate, preferably in the range of 200 to 400 *.

If the firing is performed in an oxidizing atmosphere, or the firing temperature exceeds 400 and exceeds the decomposition temperature of silver nitrate, the oxidation or decomposition of silver nitrate occurs and the effect of the present invention cannot be exhibited effectively. From. Although the lower limit of the firing temperature is not particularly defined, the firing temperature is desirably set to 20 O'C or more from the viewpoint of more securely activating and supporting the deodorizing active component including silver nitrate.

By the way, silver nitrate is a compound having a high oxidizing property, and is easily passed in the presence of a substance that is easily reduced. When a solution containing silver nitrate is impregnated with a carrier containing activated carbon, precipitation of metallic silver is observed on the surface of the carrier. It is easily understood from the above description that such a phenomenon is not preferable for the present invention.However, the solution containing the three components is mixed with citric acid in an amount of 1Z3 to 1Z2 mol based on silver nitrate. It was confirmed that when contained, the precipitation of metallic silver was remarkably suppressed, and loading as silver nitrate was more reliably performed. Although the reason has not been clearly clarified, it has been confirmed that citric acid effectively acts as a competitive adsorbent when the platinum group metal is supported on the carrier. We believe it plays a role in protecting the reaction site with silver nitrate. rnm

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. It is also possible to implement the present invention with appropriate modifications within a range that can conform to the gist of the description, and all of them are included in the technical scope of the present invention. Example 1

Coconut shell activated carbon powder (specific surface area ^{1 5 0 0 m 2 / g} ) of the clay mineral-based inorganic by Nda (composition: A 1 ₂ 0 a 4 0 wt%, S i 0 ₂ 6 0 by weight%) and cellulose based organic It was kneaded with a binder, extruded, dried and fired to produce a honeycomb-shaped carrier having an activated carbon content of 45% by weight. The resulting honeycomb carrier, copper nitrate, C u O shown manganese nitrate, silver in Tables 1: M n 0 _2:. While contained in A g N 0 3 conversion ratio, 0 for silver nitrate 4 Impregnated with a mixed aqueous solution in which double molar amount of citric acid was dissolved, the excess liquid was removed by air blow, then dried by ventilation at 100, and calcined in nitrogen atmosphere at 300 * 0 for 2 hours. A deodorant was obtained. Table 1 shows the composition of the obtained deodorizing material.

Examples 2 to 5, Reference example 1

A deodorizing material was produced in the same manner as in Example 1 except that the blended amount of the activated carbon and the content ratio of the deodorizing active component were changed as shown in Table 1.

(Comparative Examples 1 to 3)

A comparative deodorizing material was produced in the same manner as in Example 1 except that some of the essential components were omitted as shown in Table 1.

(Comparative Example 4)

The 82 cam-shaped carrier produced using activated alumina was impregnated with a mixed aqueous solution of manganese nitrate and silver nitrate, dried, and calcined at 500 C for 2 hours in the air to obtain a comparative deodorizing material. Table 1 shows the composition of the obtained deodorant.

(Reference example 2)

Example 1 was the same as Example 1 except that citrate was not added. Similarly, a reference deodorant was obtained.

(Reference example 3)

A reference deodorant was obtained in the same manner as in Example 1 except that the firing temperature in a nitrogen atmosphere was changed to 150 at 2 hours.

(Reference example 4)

A reference deodorizing material was obtained in the same manner as in Example 1, except that the firing temperature in a nitrogen atmosphere was changed to 500 ° C. for 2 hours.

[Evaluation as a deodorant]

The deodorization performance was measured using a flow-through reactor, collecting gas at the inlet and outlet of the packed bed filled with each deodorant, measuring the odor of each odorous component gas by gas chromatography, and The removal efficiency of the components was determined. Three types of malodorous gases were selected: methyl mercaptan, methyl sulfide, and trimethylamine, with an inlet concentration of lO ppm and a space velocity of 50, 0 at 25 ° C, 50% humidity and 50% RH. Evaluation was made under the condition of 0 0 H r. For methyl mercaptan, the gas concentration of methyl disulfide detected at the outlet of the packed bed was also measured. Table 2 shows the measurement results of the deodorizing materials of Examples, Comparative Examples, and Reference Examples 2 hours after the start of gas flow.

Deodorizing pirate content during deodorization Deodorizing material carrier base material (wt%) Specific surface area

CuO Μηθ2 A NOa Substring 1 Active marrow (content 45%) 2 10 4 380

2 Same as above 4 8 4 375

3 Same as above 8 4 4 380

Λ 2 4 2 uUU o c 2 4 8 lU Reference example 1 Active (content 10%) 2 4 6 150 Comparative example 1 Active marrow (content 45%) 12 0 4 380

2 Same as above 0 12 4 370

3 Same as above 10 2 0 375

4 Activated alumina 0 12 4 160

Methyl mercaptan win and win

Deodorization efficiency Deodorization efficiency Outlet disulfide

No Jll iM f¾tf innUmU) (%) (%) 卖 ^^ Hli example l 1 9 8 0.

2 9 9 0.05 or less 9 5 9 7 r> Q A Q C O 9 9 0.08

4 99 0.05 or less 95 98

5 9 7 0. 0 5 or less 97 98 Reference example 1 9 6 0.12 88 9 0 Comparative example 1 y y U. O Z 90 8 5

2 8 2 0. 0 5 or less 9 3 94

3 9 9 0.09 65 7 3

4 78 1 .60 3 1 4 9 Reference example 2 98 0.34 68 7 2

3 7 5 0.2 2 70 6 3

4 9 5 0. 4 5 78 7 5

As is clear from Tables 1 and 2, the deodorizing materials of Examples that satisfy all the requirements of the present invention have higher deodorizing performance against various odorous gases than the deodorizing materials of Comparative Examples. It can be confirmed that excellent deodorizing performance is exhibited by optimizing the mixing ratio of the carrier material and the deodorizing active ingredient. Further, the reference example adopts a production method which deviates from the requirements recommended as preferable conditions in the present invention, and the deodorizing activity of the obtained deodorizing material varies depending on the content of activated carbon in the carrier material and the production conditions. Can be confirmed. The invention's effect

The present invention is constituted as described above, and is used not only for malodorous components having high reactivity such as hydrogen sulfide / methyl mercaptan, but also for malodorous components having low reactivity such as methyl sulfide, ammonia and amines. Also has an excellent deodorizing effect, and can efficiently decompose and remove malodorous components without producing by-products other methyl sulfide, methyl disulfide, from methyl mercaptan, so refrigerators, toilets, animal breeding houses, and sewage It can be widely used for deodorization in treatment plants and others.

Claims

The scope of the claims

1. A deodorizing material characterized in that a carrier material containing activated carbon is loaded with a deodorizing component comprising copper oxide, manganese oxide and silver nitrate.

2. copper oxide in the deodorizer, the composition ratio of manganese oxide and silver nitrate, copper oxide: 0.5 to 1 0 weight parts C upsilon 0 terms, manganese oxide: Micromax eta 0 ₂ terms at 1-2 0 parts by weight , silver nitrate: a g N 0 ₃ deodorizing material according to 1 to claim 1 which is 20 parts by weight basis.

3. The deodorizing material according to claim 1, wherein the total content of copper oxide, manganese oxide, and silver nitrate in the deodorizing material is 3 to 30% by weight.

4. The deodorizing material according to any one of claims 1 to 3, wherein the carrier material contains 30 to 70% by weight of activated carbon.

5. deodorizing material according to any one of claims 1 to 4 specific surface area of the deodorizing material is 2 50 m ² g or more.

6. After shaping the carrier material containing activated carbon into a prescribed shape, apply or impregnate a solution containing copper oxide, manganese oxide, silver nitrate or their precursors, and decompose the silver nitrate under a non-oxidizing atmosphere. A method for producing deodorants characterized by firing at lower temperatures.

7. The method according to claim 6, wherein a solution containing copper oxide, manganese oxide, silver nitrate or a precursor thereof and citrate in an amount of 1 Z3 to 1 Z2 mol based on silver nitrate is used.

8. A deodorizing method comprising treating an odorous component-containing gas using the deodorizing material according to any one of claims 1 to 5.