JPH0312221A - Waste refuse treatment method - Google Patents

Abstract

PURPOSE:To prevent generation of toxic organic chlorine compounds such as dioxin by introducing a combustion gas discharged from an incinerator into a waste refuse collecting part of an incinerator installation after treating the gas with a catalyst of a metal oxide in a specified composition. CONSTITUTION:A catalyst is obtained by molding >=1 of Ti, Si, and Zn and/or >=1 of their composite oxides with >=1 of Pt, Pd, Ru, Mn, Cu, Cr, Fe, and their oxides into a pellet, a plate, a cylinder, or a honeycomb shape. After a combustion gas containing toxic chlorine-type polymer compounds such as polychlorodibenzodioxin, polychlorodibenzofuran, etc., from an incinerator is treated with the catalyst, the gas is introduced into a waste refuse collecting part of an incinerator installation so as to prevent generation of toxic organic chlorine compounds.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for treating waste containing chlorinated polymer compounds, and in particular to a method for treating waste containing chlorinated polymer compounds, particularly for preventing the generation of toxic organic chlorine compounds such as polychlorinated dibenzodioxins and polychlorinated dibenzofurans. It concerns a waste disposal method that successfully prevents

[Conventional technology] Incineration facilities that process industrial waste, municipal waste, etc. can generate extremely toxic organic chlorine compounds such as dioxins, which are highly likely to cause environmental pollution problems. The substance called dioxin is a compound called polychlorinated dibenzodioxin, and it is known as dichloride, tetrachloride, pentachloride, hexachloride, etc. depending on the number of chlorine atoms. In addition, there are over 70 types of isomers,
In particular, dibenzodioxin tetrachloride (T4CDD) is known as the most toxic substance. Moreover, dioxin is a very stable substance that does not dissolve in water and its toxicity does not disappear semi-permanently, so combined with its strong toxicity, it has a significant impact on the environment.

Regarding the mechanism of dioxin generation in incineration facilities, it is thought that waste containing chlorinated polymer compounds is thermally decomposed in the incinerator and is generated through side reactions, but the generation mechanism has not been fully elucidated. The reality is that it is not.

[Problems to be Solved by the Invention] The present invention has been made in view of these circumstances, and is a waste treatment method that can prevent the generation of toxic organic chlorine compounds such as dioxins when incinerating various wastes. The purpose is to provide a method.

[Means for Solving the Problems] The method of the present invention, which has achieved the above-mentioned object, is a method for treating waste containing chlorinated polymer compounds in an incinerator equipped with an incinerator and an i-seat. The gist of this method is to prevent the generation of toxic organic chlorine compounds by treating the discharged exhaust gas using a catalyst and then introducing it into a dust collection section.

[Function] In order to prevent the release of toxic organic chlorine compounds (dioxins will be explained below as a specific example) from incineration facilities, we investigated the status of dioxin generation in incineration facilities and found that dioxin does not necessarily exist inside the incinerator. It has been found that there is a high possibility that dust is generated not only in the incinerator, but also in the dust collection section attached to the incinerator (generally equipped with an electrostatic precipitator). In other words, incineration facilities generally consist of an incinerator, a cooling duct, a dust collector, etc., and when measuring the dioxin concentration in the exhaust gas at the entrance and exit of each product, it was found that the concentration of dioxin was highest at the exit of the dust collector. It was found that it does not contain much dioxin. This is because the high heat conditions inside the incinerator are rather unfavorable conditions for the dioxin production reaction, and the temperature environment (around 300°C) that is cooled by the cooling duct and where the dioxin production reaction easily progresses is used for dust component removal. This is thought to be because the dioxin is introduced into the dust collection section, where the dioxin production reaction progresses.

Based on this knowledge, the inventors of the present invention decided that it would be better to decompose and remove the substances that cause dioxin formation before they are introduced into the dust collection section, and after repeated various studies, they found that the incinerator We have arrived at the configuration of the present invention, in which the exhaust gas discharged from the exhaust gas is passed through a catalyst and treated, and then introduced into the dust collection section.

Possible techniques for decomposing and removing the above-mentioned substances that cause dioxin formation include the so-called direct combustion treatment method that performs high-temperature combustion, the adsorption method using activated carbon, etc., and the cleaning method using chemicals. It is necessary to maintain the temperature at a temperature of .degree. C., which requires a large amount of fuel cost, and since the concentration of the substance to be treated in the exhaust gas is low, the treatment efficiency inevitably becomes low. Next, the adsorption method requires regeneration treatment of the waste activated carbon, and the cleaning method requires secondary treatment of the waste liquid, and these secondary treatment methods are extremely troublesome, so they cannot be considered a practical decomposition removal technology. .

In contrast, in the present invention, a catalyst is activated in a high temperature state before reaching the dust collecting section to decompose and remove the substances that cause dioxin formation in the exhaust gas. Therefore, by going through this process, the reaction temperature decreases to a temperature suitable for supplying to the dust collection section, so the processing cost is low, the processing efficiency is high, and the burden for secondary processing etc. is extremely light. .

In particular, in the present invention, the decomposition and removal treatment using the catalyst is applied to the exhaust gas immediately after it is discharged from the incinerator, and at this point, in addition to the dioxin itself, as is clear from the above findings, the substances that cause dioxin formation are removed. will also be disassembled and removed. In other words, substances that cause dioxin formation, including thermal decomposition substances of chlorinated polymer compounds, are decomposed into COz, H20, Clx, HC1, etc. by passing through a catalyst, and even when these decomposition products are introduced into the dust collection section, they are no longer converted to dioxin. It does not lead to the generation of

Furthermore, even if a small amount of dioxins are present in the waste or are generated in the incinerator, they can be decomposed by passing the exhaust gas from the incinerator through a catalyst. Furthermore, in the present invention, exhaust gas can be cooled by passing it through a catalyst,
The cooling process required for supplying the dust to the dust collecting section can be simplified or omitted, and the equipment cost and the energy cost required for cooling can be reduced.

Although there are no particular restrictions on the catalyst that can be applied to the present invention, Ti may be used as the A component.

At least one metal selected from the group consisting of St and Zr alone or one or more selected from composite multi-element oxides, and Pt as the B component.

Oxidation catalysts comprising a catalyst composition comprising at least one metal selected from the group consisting of Pd, Ru, Mn, Cu, Cr and Fe or an oxide thereof are particularly effective; It is particularly preferred as a catalyst that efficiently decomposes and removes the dioxin generation-causing substances and toxic organic chlorine compounds such as dioxin in an environment where NOx, SOx, HCI, halogen gas, Co, etc. are present over a long period of time. The oxidation catalyst consisting of component A and component B is more preferably Tie, -5i02 or 7i.
02-Zr02 binary composite oxide or Tie, -
S'i0. -Using a ternary complex oxide of Zr02 as a base,
pt for this.

Examples include those on which at least one metal selected from the group consisting of Pd, Ru, Mn, Cu, Cr, and Fe or an oxide thereof is supported.

TiO2-5in, or T i O2-S i O2-Z
Due to their unique physical properties, rO2 can provide favorable physical properties to the finished catalyst and at the same time play the role of a support.

Tie, -5iO□ in the present invention is, for example, described by Kozo Tabe [J, Catal, Vol. 35.225-23
1 (1974)], it is a so-called solid acid that exhibits remarkable acidity not found in the individual constituent oxides, and also has a large surface area. That is, TiO
2-5i0 be. Tie2-
ZrO2 and Tie2-3in2-ZrO, also Tie2-
It is similar to 3iO2, and when titanium, silicon, and zirconium form a binary or ternary composite oxide, it exhibits favorable physical properties.

TiO□-5toz and TiO2-5if2-ZrO
Another advantage of using 2 is that because the catalyst itself is acidic, it exhibits remarkable acid resistance, is completely unaffected by sulfur compounds and halogen compounds contained in the process gas, and is stable over a long period of time. The point is that it shows excellent decomposition and removal performance. Furthermore, the catalyst according to the present invention can be used for TiO2-3i02 or Tie2
Because S i 02-Z r 02 is used, its ability to oxidize SO□ present in the process gas to SO3 is extremely low, and it is a substance that causes dioxin generation. The low oxidizing ability of SO2, which exhibits the property of selectively oxidizing toxic organic chlorine compounds such as dioxins, is industrially important in terms of economic efficiency of heat exchange and inhibition of material corrosion, as mentioned above. It will be extremely advantageous. Further, as another feature, the catalyst according to the present invention has a large surface area of Tie2-3i02 and TiO2-3i.
Because O2-Z r O2 is used, it exhibits high activity even at low temperatures and good decomposition and removal performance even at high space velocities, as shown in Examples below.

Another feature of the catalyst according to the present invention is that it is easy to prepare. Therefore, the catalyst shapes are pellet-like, plate-like, two-cylindrical, and lattice-like.

It is possible to form it into any shape such as a honeycomb shape. Further, the catalyst according to the present invention has extremely excellent mechanical properties and physical properties, such as crushing strength, abrasion resistance, and drop strength, and can stably withstand long-term use.

Catalysts with excellent physical properties as mentioned above are even more advantageous when treating exhaust gas that contains a lot of dust. is common. Therefore, the catalyst is required to have the above-mentioned extremely excellent physical properties, especially durability, and the catalyst according to the present invention has sufficient durability.

In the present invention, in addition to the multi-component composite oxide, TiO2-based
Single oxides such as 2-based and ZrO2-based oxides can also be used, but Ti
O□-stow binary composite oxide and TiO2-3i0
The ternary composite oxide of 2-Zr02 has improved activity of the finished catalyst, durability of the catalyst activity due to acid resistance, and mechanical and physical properties related to catalyst preparation, compared to a mixed oxide that simply mixes each oxide. It is extremely advantageous in that the binary composite oxide of T i O2S i O2 used in the present invention and Ti
The ternary composite oxide of e2-Sio and -ZrO2 exhibits particularly excellent properties. Therefore, the above-mentioned catalyst that satisfies these various requirements can be said to be an extremely advantageous catalyst from an industrial perspective.

Preferably, the catalyst according to the present invention is a decomposition and removal catalyst containing a catalytically active substance consisting of the above-mentioned components A and B, but it also has a characteristic feature of having a large specific surface area, which is extremely effective. A particularly preferable specific surface area is 10 to 450 m2/g. In addition, Tie, -5in, and T i O2- used in the catalyst of the present invention
S I O2 Zr02 etc. preferably have a specific surface area of 10 2 / g or more, and TiO2 is 5 to 95 mol % in terms of oxide, sio, alone or Si
Particularly preferred is one in which the sum of O and ZrO is in the range of 5 to 95 mol% (all based on TlO2+5i02+ZrO2=100 mol%).

T i O2-S i Ox or TiO2-5i02-Z
Although it is possible to obtain r02 outside the above range, the mechanical strength of the catalyst becomes slightly weaker in its use, which is not very preferable.

In order to prepare the carrier such as TiO2-3loz used in the present invention, a Ti source is first selected from inorganic titanium compounds such as titanium chlorides and titanium sulfate, and organic titanium compounds such as titanium oxalate and tetraisopropyl titanate. The Si source is colloidal silica and water glass.

It can be selected from inorganic silicon compounds such as silicon tetrachloride and silica gel, and organic silicon compounds such as tetraethyl silicate. Some of these raw materials may contain trace amounts of impurities or contaminants, but this does not pose a problem as long as they do not significantly affect the physical properties of the obtained Tie2-Sin2.

A preferred method for preparing TiO2-3LO2 includes the following method.

■Impregnating titanium tetrachloride into silica gel, 150 to 650
Tie was decomposed by heat treatment at ℃.

- A method for forming 5lo2.

(2) A method in which titanium tetrachloride is mixed with silica gel, ammonia is added to form a precipitate, the precipitate is washed, dried, and then calcined at 150 to 650°C.

■ Add sodium silicate aqueous solution to titanium tetrachloride and react to form a precipitate, which is washed and dried for 150 min.
A method of firing at ~650°C.

■ Add ethyl silicate [(Cz Hs O) 4 Sil to a water-alcohol solution of titanium tetrachloride to cause a hydrolysis reaction to form a precipitate, which is washed and dried for 150~
A method of firing at 650℃.

(2) A method in which ammonia is added to a water-alcohol solution of titanium oxide chloride (TiOCl2) and ethyl silicate to form a precipitate, which is washed, dried, and then calcined at 150 to 650°C.

Among the methods described above, method (■) is particularly preferred;
Specifically, this method is carried out as follows. That is,
The above Ti source and Si source compounds are T i O2 and S
i The molar ratio of O2 is taken as a predetermined amount, and the concentration of titanium and silicon in terms of oxides is 0.01-1.0 g/i in an acidic aqueous solution state or sol state.
Aqueous ammonia was added dropwise as a neutralizing agent into the solution while stirring, and a coprecipitated compound consisting of titanium and silicon was formed at pH 2 to 10 for 10 minutes to 3 hours. After being filtered and washed thoroughly, Tie can be obtained by drying at ~140°C for 1-10 hours and baking at 150-650°C for 1-10 hours.
, -3in, can be obtained. Alternatively, the above-described silicon source compound and a sufficient amount of ammonia water for neutralization are mixed, and the specified titanium source compound is added dropwise under stirring to produce a coprecipitated compound, and the above method is followed. TiO2-5i02 can also be obtained in the same manner.

Moreover, Ti02-ZrO2 and Tie.

sio2-ZrO2 is prepared in the same manner as TiO2Sin2, and the Zr source can be selected from inorganic Zr compounds and organic Zr compounds.

That is, by treating the Zr compound together with the Si compound in the same manner as in the above method, TiO2-5i O2-Z r
O2 can be easily prepared. The amount of Zr present as an oxide is preferably in the range of up to 30% by weight based on the total amount of TiO, +SiO□+ZrO2.

T i O2-S i Ox and T
The finished catalyst is obtained by the following catalyst preparation method using ie, -5in2-ZrO,. - To give an example, an appropriate molding aid is added to and mixed with the obtained TiO2-3in2 or TiO2-5iO2-ZrO2, an appropriate amount of water is added, and the mixture is well kneaded, then molded into a cylindrical shape using an extruder, then dried, Baked and T
ie2StO2 or T i O2-S i O2-Z r
A molded product of O2 is obtained.

As a molding aid, microcrystalline cellulose, methyl cellulose, polyethylene glycol, polyvinyl alcohol,
Known organic substances, such as polyacrylamide, polyvinyl acetate, starch, etc., which are decomposed and oxidized and scattered during baking can be added as appropriate. Acids may also be used to make molding easier. The acid can be appropriately selected and added from mineral acids such as sulfuric acid and nitric acid, and organic acids such as formic acid, acetic acid and oxalic acid. In addition, glass fiber, glass powder, etc. can be added to increase the catalyst strength. In addition, TiO2-5iO□, Tie, -S to2-Zr
It is also possible to use 02 mixed with a powder commonly used as a carrier. For example, alumina, silica, silica-alumina, bentonite, diatomaceous earth, titania.

Zirconia, titanium phosphate, magnesia, barium oxide, zinc oxide, tin oxide, etc. can be used.

The shape of the molded product can be arbitrarily selected such as a pellet shape, a plate shape, a honeycomb shape, a donut shape, a ribbon shape, a corrugated plate shape, etc., and is usually extruded using an extrusion molding machine.

It is also possible to spray TiO2-5i02 or TiO2-3i02-ZrOz in the form of a slurry onto the above-mentioned ordinary carrier and treat it in the same manner as the above-mentioned molded product. The molded product is dried at 10 to 140°C for 1 to 48 hours, and then fired. Firing is usually carried out in an air atmosphere or under air circulation at a temperature of 1 to 100°C or less, preferably 200 to 900°C.
It will be held for 10 hours.

Tio,
Other catalyst components B used together with -3in, Tie, -5i02-Zr, O, i.e., noble metal catalyst materials such as Pt, Pd, Ru, Mn, Cu, Cr, Fe, etc. as metals, or oxides thereof. A completed catalyst is obtained. As these catalyst components B, especially
Among them, Pt, Pd, R
U is preferable. As starting materials for catalyst component B, chlorides, nitrates, organic acid salts, chlorinated noble metal acids, copper compounds, etc. are preferable. Catalyst component B is T i O2- in terms of metal amount.
0.05 to 20 g, preferably o, i to 5 g per molded product 11 of S i O2, Tie, -5i02-Zr02
, more preferably 0.3 to 3 g.

In the method for preparing the catalyst of the present invention, the use of a polyoxyethylene nonionic surfactant is extremely useful for supporting catalyst components. The presence of a polyoxyethylene nonionic surfactant generates appropriate foaming, which facilitates mutual contact between the aqueous catalyst component solution, carrier particles, and the wall of the preparation container, resulting in uniform reproducibility when supporting the catalyst component. In the case of supporting component B, due to the low permeability of the surfactant, effective dispersion is carried out on the surface and surface layer of the catalyst, and the desired level can be achieved with the minimum amount of support. A catalyst having the following performance can be obtained. These advantages are particularly advantageous when preparing a large amount of catalyst. Examples of the surfactants used in the method of the present invention are as follows.

Polyethylene glycol NO (CH2CH2). 0)
+ (n: 11-900), polyoxyethylene glycol alkyl ether RO(C)12CH20) n
H (R is an alkyl group having 6 to 30 carbon atoms, and n = 3 to 1
20), polyoxyethylene-polyoxypropylene-
Polyoxyethylene glycol l(O(CH2CH20
).

(CH2CH2CH20)b (CH2CH2)6H(
as bs C is 1 or more and a+b+c=20~40
0), "Tetronic type nitrogen-containing nonionic surfactant (x+ ~ x4 * yr ~ y4 is 1 or more, XI
+x2 +x, +x4+y+ +y2+y.

+3/4-20 to 500), polyoxyprolene is an alkyl group having 6 to 12 carbon atoms and n=3 to 120), polyoxyethylene alkyl varnish 7 R-COO (C2H4
0) nH or R-Coo (C2H40).

C1hCHzCOO-R (R is an alkyl group having 6 to 24 carbon atoms and n=3 to 120), polyoxyethylene alkylamine\(C2)140). 2 days (R is an alkyl group having 6 to 30 carbon atoms and n, nl and n2 are 3 to 120), polyoxyethylene alkylamide R-CONH (C2) 140) nH or (C
2) 140). , ■ / is a kill group, and n, n, and n2 are 3 to 120)
, polyoxyethylene sorbitan fatty acid ester 0 (C2H40), IH (R is an alkyl group having 6 to 24 carbon atoms, and n is 3 to 60
) Among these polyoxyethylene nonionic surfactants, those with an average molecular weight of 500 or more are preferable, especially those with an average molecular weight of 500 or more.
That's all. This is because if the average molecular weight is less than 500, the permeability will increase, and the catalyst component (especially the noble metal component) will be uniformly supported and distributed inside the carrier, making it necessary to increase the amount supported. This surfactant is a carrier! ! 0.1-50g, preferably 0.2-20g per
g used and 0.01 when added to the catalyst component aqueous solution.
~101! It is used in an amount of %, preferably in a range of 0.02 to 5Ii %.

Thus, the composition carrying platinum, palladium, and rhodium compounds can be heated at temperatures of 30 to 200°C, preferably 70 to 170°C.
and then calcined in air at 300-700°C, preferably 400-60°C, or with hydrogen gas,
150-600℃ in hydrogen-nitrogen gas, preferably 250℃
Reduction treatment at ~500°C. In addition, these air heating treatments.

Instead of hydrogen gas or hydrogen-nitrogen gas treatment, a completed catalyst can also be obtained by treatment and activation with exhaust gas to be treated.

The catalyst according to the present invention has an exhaust gas temperature of 250 to 50
It works particularly effectively at 0° C., particularly in the range of 300 to 450'e, and in the space velocity (SV) range of 3,000 to 50,000 hr-' (STP). There is no particular limitation on the pressure, but it is 0.01
A range of ~10 kg/cm' is preferred.

Although there are no particular limitations on the type of reactor, common reactors such as fixed bed, moving bed, and fluidized bed can be used.

Incidentally, since there is a large amount of dust in the incineration exhaust gas and there is a high risk of clogging, a honeycomb shape is particularly preferable as the shape of the molded product because the opening can be easily adjusted depending on the amount of dust.

In other words, if the exhaust gas contains a lot of dust, even if the catalyst shape is granular or honeycomb, if the through holes are small, the pressure loss will be large, and the height of the packed bed will actually be limited. be done.

Furthermore, if the through holes are small even if they are granular or honeycomb shaped, the catalyst is likely to be clogged due to accumulation or fusion of dust in the gas.

On the other hand, honeycomb-shaped catalysts have smaller pressure loss than granular catalysts, and if the size and opening ratio of the through holes are appropriately selected, it is possible to prevent the accumulation of dust in the exhaust gas and blockage due to fusion. .

In other words, in the present invention, the equivalent diameter (equivalent diameter - hole cross-sectional area x 4/hole inner diameter) and opening ratio of the through-hole made of the honeycomb structure are limited, and the pressure loss is small, and the through-hole is prevented from being blocked by dust. It has been discovered that this method prevents the decomposition of toxic organic chlorine compounds such as dioxins, and decomposes and removes them. In that case, the equivalent diameter is 2 or more and the aperture ratio is 50
A honeycomb catalyst made of a honeycomb structure that satisfies the conditions of % or more exhibits excellent removal performance over a long period of time in exhaust gas containing dust such as incinerator exhaust gas.

Note that if the equivalent diameter is less than 21, clogging by dust will easily occur and it will not be suitable for practical use.Also, although there is no upper limit on the equivalent diameter, if the equivalent diameter is less than
When it is around 0 mm, it becomes impossible to satisfy the gas amount per 1 square of catalyst surface area of 250 m'/hr (at temp,) or less, resulting in extremely low removal performance.
Next, if the open area ratio is less than 50%, pressure loss will increase, dust clogging will easily occur, and the advantages of the honeycomb structure cannot be utilized. Further, although there is no particular upper limit to the aperture ratio, in order to increase the aperture ratio to 90% or more, it is necessary to make the partition walls of the honeycomb structure thinner, which may impose restrictions on the strength of the structure.

The present invention will be explained in more detail below using Examples and Comparative Examples, but the present invention is not limited to these Examples.

[Example] Analysis of PCDD ■ Exhaust gas sample collection method For exhaust gas samples, insert a sample collection tube into the sampling point, collect the dust with a thimble filter, and then use an ice-cooled inbinger (2 bottles of 100o1 water, diethylene glycol) 10
0ml + 1 bottle containing 100ml of glass beads, 1 empty bottle) and adsorbent (Amberlite XAD-2) using the method of introducing it into the layer.54! A sample of 5001 L was collected at a flow rate of /sin.

■ Combine the extraction drain, diethylene glycol solution, methanol washing solution, and benzene washing solution and perform benzene extraction.

The filter paper thimble is placed in 2N-HC1 (100+sl), and after permeation, it is heated in a boiling water bath for 1 hour, and the treated tube is extracted with benzene. After the residue is air-dried, benzene is added and Soxhlet extraction is performed for 24 hours.

The XAD-2 resin is Soxhlet extracted twice with acetone and twice with benzene for 30 minutes each, the acetone and benzene extracts are combined, water is added, and the benzene layer is separated. The aqueous layer is extracted with benzene.

All the benzene extracts were combined, an internal standard was added, and alkaline washing (0,1N-NaOH) and acid treatment (c
onc, H2SO4), washed with water, dehydrated, concentrated and n-
Add hexane to bring the volume to 51, and use it for subsequent column clean napping.

(2) Prepare a column clean nappy alumina column and fractionate the sample obtained in (2). After removing impurities using n-hexane 120+1, PCDD and PCDF fractions are obtained with 70 ml of n-hexane-dichloromethane (1:1). The eluate is concentrated and cleaned using HPLC (high performance liquid chromatography).

■PCDD obtained by HPLC column chromatography
After the CDD fraction, it is dissolved in chloroform and injected into a reverse phase column to obtain both fractions from T4CDD to 0♂CDD.

The eluate is extracted with n-hexane and concentrated. If further cleanup is required, fractions from T4CDD to 0 and CDD are obtained by HPLC using a normal phase column. The eluate is concentrated and then subjected to GC/MS analysis.

A similar treatment is performed on the PCDF fraction.

Example I Formed by supporting Pt (2 g/catalyst IJZ) on a honeycomb molded body with an opening of 2.0 mm, which is made of a composite oxide with T i : S i =8.5 : 1.5 (molar ratio). A preliminary test was conducted using the completed catalyst to decompose a gas containing polychlorinated dibenzodioxin (PCDD) under the following conditions, and the results shown in Table 1 were obtained.

(Conditions) Gas composition PCDD 1100n/Nm' empty
Air remaining 20,000hs” 350℃, 400℃.

450°C Space Velocity (SV) Temperature Table 1 Table 2 Example 2 Comprising a composite oxide of Ti:Zr-7:3 (molar ratio),
Example 1 using a honeycomb molded body with a mesh size of 2.0
When a preliminary test similar to the above was conducted, the results shown in Table 2 were obtained.

Example 3 Ti:Si:Zr=7:1.5:1.5
A preliminary test similar to that in Example 1 was conducted using a honeycomb molded body having a mesh opening of 2.0 square meters made of a composite oxide of (molar ratio), and the results shown in Table 3 were obtained.

Table 3 Example 4 A honeycomb molded body with a mesh opening of 2.01 made of a composite oxide with T i :S i =8.5 + 1.5 (mole ratio) was charged with 2.0 (g/catalyst tIl). A case in which a complete catalyst formed by supporting PT was installed in the part leading from the incinerator to the cooling duct of a municipal waste incinerator (the position before entering the electrostatic precipitator) (example) and a case in which it was not installed (comparative example) ), PC regarding exhaust gas on the exit side of the electrostatic precipitator
When the DDs concentration was measured, the results shown in Table 4 were obtained.

(Conditions) Space velocity (SV) 10000 hr −'Temperature
Degree 400℃ Table 4 Example 5 Exhaust gas is sucked from the part of the municipal waste incinerator leading from the incinerator to the cooling duct (the position before entering the electrostatic precipitator), and the equivalent diameter and opening of the through-hole of the honeycomb structure are change the rate,
When the change in pressure loss over time was investigated, the results shown in Table 5 were obtained. As shown in Table 5, the equivalent diameter of the through hole is 21 or more.

It was confirmed that if the opening ratio was set to 50% or more, it was possible to prevent blockage due to dust in the exhaust gas and a sudden increase in pressure loss.

Table 1 [Effects of the Invention] The present invention is configured as described above, and can prevent the generation of toxic organic chlorine compounds such as dioxins in the dust collection section, thereby preventing toxic organic chlorine compounds from being generated from incineration facilities. can effectively prevent the release of

It also cools the exhaust gas from the incinerator to the dust collection section. Therefore, cooling costs and equipment costs can be reduced.

Claims (3)

[Claims] (1) When waste containing chlorinated polymer compounds is processed by an incinerator equipped with an incinerator and a dust collection section, the exhaust gas discharged from the incinerator is treated with a catalyst, and then the dust collection section A waste treatment method characterized by preventing the generation of toxic organic chlorine compounds by introducing them into (2) The catalyst comprises, as the A component, at least one metal selected from the group consisting of Ti, Si, and Zr, alone or at least one selected from the group of composite multi-element oxides, and as the B component, Pt, The waste treatment method according to claim 1, wherein the catalyst composition comprises at least one metal selected from the group consisting of Pd, Ru, Mn, Cu, Cr, and Fe or an oxide thereof. (3) The waste treatment method according to claim (1) or (2), wherein the catalyst is a honeycomb catalyst made of a honeycomb structure in which the equivalent diameter of the through holes is 2 mm or more and the aperture ratio is 50% or more.