JPH08308917A - Deodorizing apparatus - Google Patents

Abstract

PURPOSE: To enable controlling of desorption speed during heating of an adsorbent by depositing a metal carbonate and hydroxide inside and outside a fine hole of a metal ion exchange zeolite. CONSTITUTION: A pentasil type zeolite SZM-5 undergoes an ion exchange by a metal salt solution so excessive as to bring the ion exchange rate to 100% as compared with a quantum value to deposite a metal carbonate, basic carbonate and hydroxide in a fine hole and on the external surface of the ZSM-5. The metal ion exchange ZSM-5 modified by the metal salt thus obtained is contained in a deodorizing body to allow the suppressing of desorption of odor during heating or oxidizing decomposition after the adsorption of the odor thereby enabling quick deodorizing. The ion exchange metal and the metal salt herein used are selected from among metals of 1A, 2A, 1B and 2B groups in the periodic table. A deodorizing body is also usable having a catalyst layer comprising at least five components of alumina, noble metal, copper oxide, zeolite and silica formed on a base material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing device used in combustion, hot water supply, drying, cooking, refrigerating, air conditioning equipment and the like.

[0002]

2. Description of the Related Art Heretofore, a method of arranging an adsorbent such as activated carbon or zeolite in a deodorizer to adsorb gaseous malodorous substances to deodorize has been mainly used. In addition, a device that has an ozone generation function is placed in the deodorizing device to oxidize and decompose the malodorous components with ozone gas, or an oxidative decomposition catalyst such as a noble metal is installed near the heat source such as a flame or a heating element to improve the catalyst. A method of deodorizing by heating and activating and oxidizing and decomposing odorous substances is also adopted.

Further, in recent years, by installing a deodorizer having an inorganic adsorbent and an oxidative decomposition catalyst such as a noble metal near a heat source such as a heating element, and adsorbing an odorous substance by the adsorbent when the heating element is not energized. Deodorization is performed.When the heating element is energized, the catalyst is heated and activated to oxidize and decompose the odorous substances that come into contact with the deodorant, and at the same time, oxidatively decompose the odorous substances adsorbed on the adsorbent to regenerate the adsorbent. It is being appreciated.

[0004]

However, the conventional deodorizing method using a deodorizing body composed of an inorganic adsorbent and an oxidative decomposition catalyst has the following problems.

In the conventional catalyst deodorization, deodorization has been performed by repeating adsorption at room temperature and oxidative decomposition during heating. During heating after adsorption in the deodorizing process (oxidative decomposition process)
In the above, there was a problem that odor molecules were significantly desorbed from the catalyst by heat in a short time, and the odor concentration in the deodorizing space became higher than that before heating. Such a phenomenon is considered to occur when the rate of desorption of odorous molecules from the adsorbent during heating exceeds the rate of oxidative decomposition of odorous molecules. Development was urgent.

The present invention has been made in view of the above problems of the conventional deodorizing apparatus, and an object of the present invention is to provide a deodorizing apparatus using an adsorbent capable of controlling the desorption rate during heating.

[0007]

The present invention is characterized in that it comprises a metal ion-exchanged zeolite having at least one metal carbonate or hydroxide salt deposited inside or outside the pores thereof. It is a deodorizing device.

The present invention also relates to a pentasil type zeolite Z.
It is characterized by precipitating carbonates, basic carbonates and hydroxides of the above-mentioned metals by ion-exchanging SM-5 with a metal salt solution in excess of a stoichiometric value such that the ion exchange rate is 100%. It is a deodorizing device.

Further, the present invention relates to an ion exchange metal and a metal to be deposited on the inside and outside surfaces of zeolite pores.
The deodorizing device is a metal belonging to the A, 2A, 1B, and 2B groups, and is Cu among the metals.

Further, the present invention comprises a deodorant body in which a catalyst layer comprising at least five components of alumina, a noble metal, copper oxide, zeolite and silica is formed on a substrate, and a heating means for intermittently heating the deodorant body. It is a deodorizing device characterized by having.

[0011]

By performing ion exchange of ZSM-5 with a metal salt solution in excess of a stoichiometric value such that the ion exchange rate becomes 100%, carbonates of the above metal are formed in the pores and the outer surface of ZSM-5. Precipitate basic carbonate and hydroxide. By including the metal ion-exchange ZSM-5 modified with such a metal salt in the deodorant body, it is possible to suppress the desorption of the odor during heating after odor adsorption and oxidative decomposition, and to enable rapid deodorization. . Such an effect is small with only the metal ion exchange ZSM-5, and the one modified with a metal salt has a remarkable effect.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

In the conventional catalytic deodorization in which adsorption and oxidative decomposition are repeated, odor molecules are significantly desorbed from the catalyst by heat during heating after adsorption (oxidative decomposition process), and the odor concentration in the deodorizing space is higher than that before heating. It also had the problem of becoming higher. Therefore, in the present invention, it was found that the metal ion-exchanged ZSM-5 modified with a metal salt is remarkably effective in suppressing the desorption of odors from the catalyst during heating. Also, the ion exchange metal and modified metal salt of zeolite are 1A, 2A, 1
Metals of Group B and 2B are suitable, and Cu among them has the most excellent odor desorption suppressing effect.

The pentasil-type zeolite of the present invention is ZS
M-5, various metallosilicates and the like can be used.

The alumina of the present invention comprises β-, γ-, δ-, θ-, η
Metastable alumina such as-, ρ-, χ-alumina. Further, the activity can be further improved by supporting a promoter such as a rare earth oxide on the surface of alumina. Further, it is desirable to add barium to the activated alumina because the thermal stability of the alumina can be improved.

The noble metal of the present invention is preferably Pt or Pd, and more preferably both Pt and Pd. This is because the oxidative decomposition power of Pt and Pd is higher than that of Rh and Ir, and the higher activity is obtained by using both Pt and Pd. Further, when Ru is used, Ru is volatilized and becomes a harmful substance when used at high temperature, which is not preferable.

In the metal ion-exchange ZSM-5 of the present invention, nitrates, sulfates, acetates, chlorides and the like can be used as raw materials for various ion-exchange metals. The ion exchange treatment of zeolite was performed by heating and stirring the zeolite in a metal ion solution at a temperature from room temperature to 98 ° C.

The copper oxide of the present invention can be used by thermally decomposing copper chloride, copper nitrate, copper acetate, copper sulfate or the like as a raw material thereof.

The silica of the present invention is silicon dioxide, but the use of silicic acid, which becomes silicon dioxide by thermal decomposition, instead provides stronger adhesion of the catalyst layer.

A typical embodiment of the deodorizing apparatus of the present invention is shown in FIG. In FIG. 1, 1 is a nichrome wire, 2 is a quartz tube, 3 is a catalyst coating, and 4 is an insulator. Further, 5 is an air flow.

A more specific embodiment will be described below.

<Example 1> In order to investigate the physical properties of the metal ion-exchanged zeolite modified with a metal salt, the following studies were carried out.

The metal salt-modified metal ion-exchanged zeolite was prepared by using H-ZSM-5, which is a zeolite, and various metal salt (nitrate, acetate, sulfate, chloride) aqueous solutions. The preparation method was as follows: H-ZSM-5 was added with 5 times the stoichiometric amount (ion exchange rate 100%) of metal salt and H-ZSM-5.
Add 0 times the amount of deionized water, and add 2 at room temperature to 98 ° C.
The mixture was heated and stirred for 4 hours or more. The ion exchange rate is defined as ZSM-5 if the ion exchange metal is a monovalent metal.
The state in which the same amount of metal as the amount of Al contained in the zeolite is contained in the zeolite is defined as 100%, and if the ion exchange metal is a divalent metal, it is 1/1 of the amount of Al contained in ZSM-5.
The state in which two metals are contained in zeolite is defined as 100%.

Then, it was washed with ion-exchanged water and dried. The above treatment is performed for Na, Ca, Sr, Mn, Fe, Co, Ni, Pt, Cu, Ag, Zn, L
It carried out about 13 types of metal of a and Ce.

Atomic absorption spectrometry was carried out on the prepared sample to examine the ion exchange rate and the amount of metal contained in the sample. The analysis results are shown in (Table 1).

[0026]

[Table 1]

As shown in (Table 1), Na, Ca, S
For 5 kinds of r, Cu, Ag and Zn, the amount of metal exceeding the stoichiometry (ion exchange rate 100%) was detected. When these samples were analyzed by XRD or the like, it was found that carbonates, basic carbonates, hydroxides of ion-exchange metal species were precipitated on the zeolite. Therefore, when the zeolite is ion-exchanged with excess metal salt of the 1A, 1B, 2A, and 2B groups, carbonate is formed inside and outside the pores of the metal ion-exchanged zeolite.
It is possible to obtain a product in which basic carbonate, hydroxide, etc. are deposited.

Example 2 With respect to the metal ion-exchanged zeolite, the metal salt-modified metal ion-exchanged zeolite and the proton ion-exchanged zeolite prepared in Example 1, the effect of suppressing odor desorption during catalytic oxidative decomposition was examined.

An aqueous solution of chloroplatinic acid, an aqueous solution of copper nitrate and alumina were thoroughly mixed using a ball mill, and then calcined and pulverized at 500 ° C. to prepare alumina carrying Pt and CuO. 160 g of alumina that carries Pt and CuO
And a colloidal silica aqueous solution containing 20 wt% of silica 4
A slurry was prepared by thoroughly mixing 00 g, 200 g of water and 160 g of zeolite with a ball mill.
On the other hand, the outer peripheral surface of the quartz tube 2 having an outer diameter of 10 mm, an inner diameter of 9 mm and a length of 344 mm is degreased and washed, and both sides 33 of the quartz tube 2 are cleaned.
After coating the slurry on the outer peripheral surface of the central portion excluding mm by a spray method, the slurry was dried at 100 ° C. for 2 hours and baked at 500 ° C. for 1 hour to prepare a quartz tube 2 having a catalyst coating 3. The coating weight is 1.0 g, the Pt content is 25 mg, and C
The uO content is 30 mg.

A 40 Ω coil-shaped nichrome wire 1 was built in this quartz tube 2, and both sides of the quartz tube 2 were insulated and held by an insulator 4 to produce a heating element. A heating element was prepared by using the metal ion-exchanged zeolite, the metal salt-modified metal ion-exchanged zeolite and the proton ion-exchanged zeolite prepared in Example 1 as zeolite in the above slurry.

An acetaldehyde purification test was conducted on these heating elements. In the purification test, the heating element was placed in a 250 l cubic container made of fluorine resin and the concentration was 15 pp.
The acetaldehyde was injected into the container so that the concentration became m, and 90 minutes later, the acetaldehyde concentration was examined. Furthermore, after 90 minutes, the heating element was heated to examine the acetaldehyde concentration after 100 minutes and 120 minutes. The measurement was performed by a gas chromatograph. The test results are shown in (Table 2).

[0032]

[Table 2]

As is clear from (Table 2), the metal ion-exchanged zeolite modified with carbonates, basic carbonates, hydroxides and the like of the 1A, 1B, 2A and 2B groups of the periodic table is unmodified. Compared with zeolite, desorption of odor during heating tends to be suppressed. Among them, Cu-zeolite modified with a Cu salt is most excellent in suppressing odor desorption.

Example 3 In order to investigate the relationship between the type of zeolite in the metal salt-modified metal ion-exchanged zeolite, the adsorption characteristics of odor, and the effect of suppressing the desorption of odor during catalytic oxidative decomposition, the following studies were conducted.

In preparing the metal salt-modified metal ion-exchanged zeolite of Example 1, pentasil type, A type, X type, Y type and mordenite were respectively prepared as zeolite species. Na and Cu were used as metal species at this time. At the same time, a heating element was produced.

An acetaldehyde purification test was conducted on these heating elements. The acetaldehyde purification test was performed in the same manner as in Example 2. The results of the purification test are shown in (Table 3).

[0037]

[Table 3]

As shown in (Table 3), the pentasil-type zeolite is superior to other zeolites (A, X, Y, mordenite) in both of the adsorption characteristics and the effect of suppressing odor desorption during oxidative decomposition. I understand.

Example 4 To investigate the adsorption characteristics of acetaldehyde and the effect of various pentasil-type zeolites,
The following studies were conducted.

A heating element was prepared in the same manner as in Example 1, except that the following pentasil-type zeolite was used as the metal salt-modified metal ion exchange zeolite in the slurry of Example 2. The zeolite used is Al-silicate ZSM-
5, Ga-silicate, Ti-silicate, Fe-silicate, Mn-silicate. Cu was used as the ion exchange metal and the metal salt. Next, in the same manner as in Example 2, an acetaldehyde purification test was performed on these heating elements, and the adsorbing property of acetaldehyde and the effect of suppressing odor desorption during oxidative decomposition were examined. The results are shown in (Table 4).

[0041]

[Table 4]

As shown in (Table 4), ZSM-5, which is an Al-silicate, has the best adsorption property and the effect of suppressing odor desorption during oxidative decomposition is also excellent. It is considered that the high activity of ZSM-5 in the odor adsorption property is due to the strong acid property of Al-silicate.

Example 5 The following experiment was conducted to examine the optimum composition of the catalyst.

In a predetermined amount of the slurry of Example 2, noble metal, copper oxide, alumina, zeolite (Cu salt modified Cu
-ZSM-5) and 5 components of colloidal silica were combined to prepare 6 kinds of slurries by the combination of (Table 5) below, and at the same time, a heating element was also prepared.

Further, in order to see the effect of heat deterioration of the catalyst, the above heating element was heated at 700 ° C. for 24 hours, and then a methyl mercaptan purification test was conducted. Purification test is 250l
The heating element was placed in a cubic resin container made of fluorine resin, the methyl mercaptan was injected into the container so that the concentration became 15 ppm, and 90 minutes later, the methyl mercaptan concentration was examined. The heating element was not heated, and the measurement was performed by gas chromatography. Further, these heating elements were subjected to the same acetaldehyde purification test as the methyl mercaptan purification test. The test method was the same as the methyl mercaptan purification test.

[0046]

[Table 5]

As shown in (Table 5), at least five components of noble metal, copper oxide, alumina, zeolite and colloidal silica are required for activation of the catalyst in the above-mentioned purification test in consideration of heat resistance of the catalyst. Is.

<Example 6> In the slurry prepared in Example 2, the colloidal silica in the slurry was replaced with various inorganic binders so that the final binder contained the same amount of the inorganic binder. Was prepared, and a heating element similar to that in Example 2 was prepared. In order to investigate the film hardness of these catalyst coating layers, JISG-33
20 pencil hardness tests were performed. Further, an acetaldehyde purification test was performed on each heating element in the same manner as in Example 5. The results are shown in (Table 6).

[0049]

[Table 6]

As shown in (Table 6), when alumina sol or bentonite was used, the binding strength was weak and the coating layer hardness was improved, but a porous coating layer could not be formed and the catalytic activity was lowered. On the other hand, when colloidal silica is used as the inorganic binder, a strong coating layer can be formed without lowering the catalytic activity, which is most desirable.

Further, the following examination was conducted in order to examine the adhesion between the base material and the catalyst coating.

A quartz plate, an iron plate, an aluminum plate, and a stainless plate having a width of 100 mm × 90 mm and a thickness of 1 mm were degreased and washed. The slurry of Example 2 was applied to one surface of each of these base materials and baked at 400 ° C. to prepare a coating film having a weight of 1.0 g.

For these, an underwater quenching test in which the material was heated at 400 ° C. and immediately dropped in water at room temperature was repeated 5 times, and the presence or absence of peeling of the coating film was examined. The results are shown in (Table 7).

[0054]

[Table 7]

As described above, quartz is the most excellent in terms of adhesiveness, and the adhesiveness is low with respect to materials such as aluminum that have a remarkable thermal expansion. Thus, the adhesion between the catalyst coating and the substrate can be improved by selecting quartz or a metal having a relatively small thermal expansion as the substrate.

[0056]

As described above, by using the deodorant product of the present invention, desorption of odorous molecules from the catalyst during oxidative decomposition can be suppressed. Further, by forming the deodorant body as a film on the outer surface of the electric resistor or the base material incorporating the electric resistor by using an inorganic binder, the deodorant body excellent in thermal shock resistance can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a heating element using an embodiment of the present invention.

[Explanation of symbols]

 1 Nichrome wire 2 Quartz tube 3 Catalyst coating 4 Insulator 5 Air flow

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location B01J 29/42 ZAB B01J 29/76 ZABA 29/76 ZAB B01D 53/36 ZABH (72) Inventor Wakita Hidenobu 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A deodorizing device comprising a metal ion-exchanged zeolite containing at least one metal carbonate or hydroxide salt deposited inside or outside the pores thereof. 2. The deodorizing device according to claim 1, wherein the ion exchange metal and the metal salt are selected from metals of the 1A, 2A, 1B and 2B groups of the periodic table. 3. The deodorizing device according to claim 1, wherein the ion exchange metal and the metal salt are Cu. 4. The deodorizing device according to claim 1, wherein the zeolite is a pentasil type zeolite. 5. The deodorizing device according to claim 4, wherein the pentasil-type zeolite is ZSM-5. 6. At least alumina, noble metal, copper oxide,
A deodorizing device, which is a deodorizing body in which a catalyst layer composed of five components of zeolite and silica is formed on a substrate. 7. A deodorizing device comprising a heating means for intermittently heating a deodorized body, wherein adsorption is carried out by zeolite when not heated, and oxidative decomposition is carried out by a noble metal or copper oxide when heated, wherein the heating means is a base material. A deodorizing device, characterized in that it is built in the inside, or as a heating means, the base material itself serves as an electric resistor to generate heat when energized.