JP3327099B2 - Method for treating gas containing organic halogen compound and catalyst for decomposing organic halogen compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for decomposing organic compounds containing halogen such as fluorine, chlorine and bromine such as chlorofluorocarbons (CFCs, for example, chlorofluorocarbons), trichloroethylene, methyl bromide and halon with high efficiency, and The present invention relates to a catalyst that maintains activity for a long time and a method for producing the same.

[0002]

2. Description of the Related Art Organic halogen compounds containing fluorine, chlorine, and bromine in organic compounds such as chlorofluorocarbon, trichloroethylene, methyl bromide, and halon are widely used as blowing agents, refrigerants, fire extinguishers, fumigants, and the like. Have been.
It has been pointed out that these compounds cause destruction of the ozone layer and have serious effects on the environment, such as the generation of carcinogens, and methods of recovering and decomposing organic halogen compounds that have been used so far have been studied. I have.

[0003] Since the recovered organic halogen compounds are relatively stable compounds having low reactivity, at present, there is no appropriate decomposition treatment technology. Further, the decomposition products contain corrosive halogen gas, which makes the decomposition processing technology more difficult. As the decomposition treatment method, there are mainly a combustion technique at a high temperature and a plasma technique. However, this method uses a large amount of fuel and electric power, has low energy efficiency, and has a problem that the generated halogen damages the furnace wall. In particular, in the plasma method, when the content of the organic halogen compound in the processing gas is low, the energy loss is large. On the other hand, a decomposition method using a catalyst is an efficient and excellent method that can be processed with low energy if the performance of the catalyst is sufficiently high.

A TiO ₂ -WO ₃ catalyst has been reported as a catalyst for decomposing an organic halogen compound in Japanese Patent Publication No. 6-59388. This catalyst has a W content of 0.1 to ₂₀ wt% of TiO _2.
(In terms of atomic ratio, Ti is at least 92 mol%
9.96Mol% or less, W is less 8 mol% or more 0.04 mol%), to process CCl ₄ order of ppm 3
A decomposition rate of 99% was maintained at 75 ° C. for 1500 hours. However, the effect as a catalyst poison in organic halogen compounds is C
Not only l but also F is larger. Therefore, Cl,
A halogen-resistant catalyst that does not easily react with both halogen elements of F is required.

[0005]

The present invention suppresses the reaction with F and Cl in an organic halogen compound, and
An object of the present invention is to provide a high-performance catalyst for decomposing an organic halogen compound capable of maintaining its performance, a production method, an apparatus, and a processing method.

[0006]

Means for Solving the Problems The present inventors have developed a high-performance catalyst which can decompose an organic halogen compound with high efficiency and which is hardly deteriorated by halogens, particularly F, contained in reactants and decomposition products. As a result of conducting the search in detail, the present invention was reached. That is, it contains titania, silica and tungsten oxide, contains 2 to 15 % by weight of silica with respect to titania, and the atomic ratio of Ti to W is such that Ti is 20 mol% or more and 95 mol%.
% Or less, W is 80 mol% or less, 5 mol% or more, a catalyst containing at least the surface of titania covered with one kind of porous layer of silica or tungsten oxide, and a gas containing an organic halogen compound not exceeding 10 vol%. Treating the organohalogen compound by contacting the stream with a catalyst, wherein the gas stream is maintained at a temperature not exceeding 500 ° C. and a total gas flow of 30 ° C.
The organic halogen compound is decomposed into carbon monoxide, carbon dioxide and hydrogen halide by contact in the presence of water vapor not exceeding vol%. When the catalyst has a porous layer of silica on the surface of titania particles, and further has a porous layer of tungsten oxide on the surface of the porous layer of silica, the catalyst exhibits excellent decomposition activity, particularly high durability. I found it. It has also been found that the same excellent decomposition activity is exhibited when a porous layer of tungsten oxide is provided on the surface of titania particles and a porous layer of silica is further provided on the surface of the porous layer of tungsten oxide. This catalyst contains silica, titanium and tungsten in the form of a mixture of oxides or a composite oxide.

[0007] Titania has a high activity against the decomposition of organic halogen compounds. However, if F is present in the reaction gas, it forms a compound called TiOF _{2 and} is desorbed from the catalyst, resulting in a decrease in active sites. It was found that the activity gradually decreased. On the other hand, it has been found that silica alone does not exhibit high activity against decomposition of organic halogen compounds, but exceeds the activity of titania alone due to an increase in strong acid sites when combined with titania.

Therefore, it is necessary to provide a long life without impairing the high activity of titania. As a result of searching for a metal oxide which has low reactivity with F, that is, a metal oxide which is difficult to form F, it was found that tungsten oxide hardly reacts with F. Therefore, it is desirable that only tungsten oxide exhibit high activity, but only tungsten oxide has a small specific surface area and low activity. As a method of increasing the specific surface area of the tungsten oxide, there is a method of dispersing it on titania, tungsten oxide, zeolite, or the like. In particular, when silica or tungsten oxide is mixed with titania, the amount of active sites (particularly strong acid sites) is increased. increased. These acid sites are hardly deteriorated with respect to the decomposition products HF and HCl, and maintain high activity. Therefore, it has been considered that the catalyst life can be extended without impairing the activity of titania by forming a porous layer of tungsten oxide on the surface of the particles in which titania and silica are mixed or formed into a complex oxide.

Further, it was considered that the activity of titania particles was not impaired even when a porous layer of silica was formed on the surfaces of particles in which titania and tungsten oxide were mixed or formed into a composite oxide, and that the catalyst life could be extended.

As a method for forming a silica or tungsten oxide porous layer on the surface of titania particles, an impregnation method in which a solution containing silica or a solution containing W is impregnated into titania particles and fired is used. When silica or tungsten oxide is in excess, the surface of the titania granulated particles formed by assembling fine titania particles one by one can also be coated with excess silica or W ions. Further, it can be prepared by applying a solution containing silica or W to the titania particles or by a vapor deposition method.

In order to cover the surface of the titania particles with silica or tungsten oxide, an appropriate amount of silica or tungsten oxide is required. Titania particles having a particle size of 0.5 to 1 mm are impregnated with a porous layer of tungsten oxide by impregnation. Is formed, the atomic percentage of W to Ti is 10%.
Otherwise, it was found that the surface of the titania particles could not be completely covered. If the titania cannot be completely covered, TiOF ₂ will be generated at that part. On the other hand, silica has a particle size of 0.5.
When a porous layer of silica was formed by impregnating ニ ア 1 mm of titania particles, it was found that the surface of the titania particles could be completely covered if the silica was 2% by weight or more based on the titania. However, it was found that when the amount of silica exceeds 15 % by weight with respect to titania, the activity characteristics of silica alone gradually approached. That is, silica is 15 to titania.
If the content is more than 10% by weight, a decrease in the activity is observed as compared with the activity of the catalyst alone in which titania is impregnated with tungsten oxide.

In the case of the impregnation, when the organic halogen compound is a molecule having 1 carbon atom, the atomic ratio between Ti and W is Ti
Is preferably 40 mol% or more and 90 mol% or less, and W is preferably 60 mol% or less and 10 mol% or more. In the case of a molecule having 2 carbon atoms, the number of halogen elements contained in the molecule increases, so that the atomic ratio of Ti to W is set to 20 mol% or more and 85 mol% or less, and W is set to 80 mol% or less and 15 mol% or more. It is preferable that the porous surface of the titania particles is thickly laminated. In any case, the silica is desirably in the range of 2 to 15 % by weight with respect to titania.

The granular titania in the present invention is most effectively formed by the rolling granulation method. In this case, the amount of pores inside the catalyst can be easily adjusted.

It has also been found that a catalyst to which at least one of sulfur, phosphorus, molybdenum and vanadium is added as a fourth component has improved catalyst durability.
In other words, it has been found that the effect is great if the catalyst composed of titania, silica and tungsten oxide further contains S, Mo, and V as the fourth component in an amount of 0.001 to 10 mol% with respect to the titanium atom.

The catalyst according to the present invention can be used as it is in the form of granules, pellets, honeycombs or the like. As the molding method, an arbitrary method such as an extrusion molding method, a tablet molding method, and a tumbling granulation method can be adopted according to the purpose. In this case, alumina cement, calcium-sodium cement, other ceramics and organic components can be mixed for the purpose of improving the strength and increasing the specific surface area.
Needless to say, the catalyst component can be supported on a particulate carrier such as alumina or silica by impregnation or the like. Also,
It can also be used by coating on ceramics or metal honeycombs or plates.

As the titanium raw material for preparing the catalyst of the present invention, titanium oxide, various titanic acids that generate titanium oxide by heating, titanium sulfate, titanium chloride, organic titanium compounds, and the like can be used.

These titanium raw materials are converted to water, ammonia water,
It is also a preferable method to form a precipitate of hydroxide with an alkali solution or the like and to form an oxide by final baking.

A silica sol or the like can be used as a silica raw material.

Further, as the tungsten raw material, tungsten oxide, tungstic acid, ammonium paratungstate and the like are preferable. A raw material containing both phosphorus and tungsten, such as ammonium phosphotungstate, can also be used.

The catalyst of the present invention is less susceptible to deterioration as the active sites in the catalyst are more acidic, and it is also effective that the catalyst contains a component such as S or P which enhances the catalytic acidity. S exists in the form of oxide ions such as sulfate ions.

The organic halogen compounds to be used in the present invention are compounds containing fluorine, chlorine and bromine in the organic compounds, such as various chlorofluorocarbons (fluorocarbons), trichloroethylene and methyl bromide.

Taking Freon 113 and methyl bromide as examples, the following reactions are typical.

CCl ₂ F—CCIF ₂ + 3H ₂ O → CO
+ CO ₂ + 3HCl + 3HF CH ₃ Br + 3 / 2O ₂ → CO + HBr + H ₂ O In order to carry out the decomposition reaction of the organic halogen compound having 2 carbon atoms, the gas to be treated contains water vapor at least three times the number of moles of the organic halogen compound. Adjust so that
By performing the reaction in such an atmosphere, an improvement in the decomposition efficiency can be expected. It also has the advantage that the decomposition products are obtained in a form of hydrogen halide which is easy to work up. If it is less than three times, these effects are not sufficient.

It is preferable that the concentration of the organic halogen compound in the reaction gas does not exceed 10 vol%. If the concentration is higher than 10 vol%, the activity of the catalyst having a porous layer of tungsten oxide is apt to decrease. Further, when the treatment concentration increases, the amount of HF and HCl generated increases.
Problems such as corrosion of the device material also occur. Conversely, when the processing density is 10
If the concentration is as low as 00 ppm or less, the energy required for decomposition is smaller than other treatment methods, but energy loss occurs. Depending on the amount of the halogen element contained in the molecule, the concentration of the organic halogen compound is preferably 0.1 to 10 vol% when the organic halogen compound having 1 carbon atom is treated, and 0 when the organic halogen compound has 2 carbon atoms. .1 to 6 vol% is preferred.

It is preferable that the temperature at which the catalyst is brought into contact with the catalyst does not exceed 500 ° C. When the catalyst temperature is 500 ° C. or higher, the reaction between the catalyst and F tends to proceed, and the performance of the catalyst tends to decrease. In particular, when treating an organic halogen compound having 1 carbon atom, the temperature is preferably from 250 to 450 ° C. In the case of an organic halogen compound having 2 carbon atoms, the halogen element in the molecule may increase, and the temperature is preferably 300 to 500 ° C. When an organic halogen compound is treated at a temperature exceeding 500 ° C., high-temperature gases of HF and HCl, which are decomposition products, flow in the apparatus, and the reaction tubes and pipes of the organic halogen compound processing apparatus are rapidly corroded. Progressed,
Costs such as maintenance are required.

The processing gas is applied on the catalyst at a space velocity of 50%.
It is preferably used at 0 to 100,000 / hour. When treating an organic halogen compound having 1 carbon atom, the space velocity is preferably 1,000 to 50,000 / hour, and the space velocity is preferably 2 to 50,000 / hour.
When treating an organic halogen compound of
A space velocity of 0000 / hr is preferred.

As the shape of the reactor for carrying out the present invention, a conventional fixed bed, moving bed or fluidized bed type reactor can be basically used, but hydrogen fluoride, hydrogen chloride or the like can be used as a decomposition product gas. Since a corrosive gas is generated, a reactor which removes an acid component by contacting the decomposition product gas with an alkali solution immediately after passing through the catalyst layer is preferable.

The treatment device comprises at least an organic halogen compound gas supply device, a water vapor supply device, an air supply device, a reactor for filling the catalyst, a heating source for heating the catalyst, a catalyst, and a cleaning tank for the decomposition product gas. The apparatus size and the amount of catalyst used can be adjusted according to the halogen compound concentration.
When the organic halogen compound to be treated is liquid at room temperature,
It is gasified in advance and introduced into the catalyst layer. As a method for heating the catalyst, the catalyst may be heated by an electric furnace or the like, or an organic halogen compound gas or water vapor may be mixed with a combustion gas such as propane, kerosene or city gas and introduced into the catalyst layer. As a material of the reactor filled with the catalyst, a corrosion-resistant material such as Inconel or Hastelloy is preferable. As for the structure of the decomposition gas cleaning tank, the efficiency of cleaning by the spray tower is high, and the clogging of pipes due to crystal precipitation and the like is unlikely to occur. A method of bubbling a decomposition product gas in an alkaline solution and a washing method using a packed tower are also preferable methods. Further, the entirety of these devices is loaded on a 2t truck or the like, and moved to a collection place for discarded refrigerators, automobiles, or the like, or to a place where an organic halogen compound packed cylinder is stored, and the contained organic halogen compounds are removed. Extraction and direct processing are also possible. Further, a circulation pump for circulating the cleaning liquid in the decomposition product gas cleaning tank and an exhaust gas adsorption tank for adsorbing carbon monoxide and the like in the exhaust gas may be simultaneously mounted. Further, a generator, a cylinder filled with fuel such as propane, kerosene, city gas or the like serving as a heating source may be simultaneously mounted.

Since the catalyst of the present invention has a porous layer of silica holding strong acid sites and a porous layer of tungsten oxide hardly generating fluoride on the titania surface, it exhibits high activity against organic halogen compounds. It can suppress fluorination (formation of TiOF ₂ ) of titania and shows high durability. Tungsten oxide works to improve the durability because it hardly generates fluoride, and titania and silica work to improve the decomposition rate.
Since this catalyst does not immediately deteriorate in catalytic performance unlike the conventional catalyst, an operation such as catalyst replacement is not required, and the cost of the CFC decomposition process can be reduced.

The catalyst is preferably prepared by an impregnation method.
When the impregnation method is used, a porous layer of silica or tungsten oxide is formed on the surface of porous titania particles or titania particles formed by granulation, and silica and tungsten oxide are uniformly formed inside the titania particles. One or more of these can be dispersed, and even when silica or tungsten oxide on the surface of the titania particles is peeled off, the titania particles have low reactivity with F, exhibit high activity and high durability. By using the catalyst of the present invention, an organic halogen compound gas having a high concentration not exceeding 10 vol% can be efficiently treated.

Further, even if Mo and V are added as a third component to a catalyst containing titania, silica and tungsten oxide, molybdenum oxide and vanadium oxide cover the surface of titanium oxide exposed by the separation of tungsten oxide. And the durability is improved.

In addition, the presence of SO ₄ ions increases the acidity of the reaction site in the catalyst. Strong acid sites are hardly deteriorated by HF and HCl, which are strong acids in the decomposition product, which is effective for improving decomposition activity and durability.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 In this example, the activity of a catalyst in which the surface of titania was covered with a porous layer of tungsten oxide and then further covered with a porous layer of silica was examined.

Granular titanium oxide (CS-224S, manufactured by Sakai Chemical Co., Ltd.) having a diameter of 2 to 3 mm was pulverized, sieved to 0.5 to 1 mm, and dried at 120 ° C. for 2 hours. For 100 g of the dried titanium oxide, ammonium paratungstate 82.
2 g of a dissolved hydrogen peroxide solution was impregnated. After impregnation, dried again at 120 ° C. for 2 hours, baked at 500 ° C. for 2 hours,
Catalyst A was prepared. Next, an aqueous sol solution B obtained by adding 50 g of distilled water to 25 g of a silica sol having a content of 20% by weight.
Is prepared. The sol aqueous solution B was impregnated with the catalyst A, and the whole was dried in the air at 120 ° C. for 2 hours, and then calcined at 500 ° C. for 2 hours to prepare a catalyst C. Catalyst C has a silica content of 5% by weight with respect to titania. For Catalyst D containing 10% by weight of silica based on titania, a sol aqueous solution E was prepared by adding 24 g of distilled water to 51 g of a silica sol having a content of 20% by weight. The sol aqueous solution E is impregnated with the catalyst A, and the whole is dried at 120 ° C. for 2 hours in the air, and then 500 ° C.
For 2 hours. In addition, a catalyst was prepared in which the silica concentration was changed with respect to the titania content, and the relationship with the decomposition activity was determined.

The configuration of the apparatus used in the experiment is as follows. The reaction tube is an Inconel reaction tube having an inner diameter of 16 mm, and has a catalyst layer at the center of the reaction tube. It has a thermocouple protection tube made of Inconel with an outer diameter of 3 mm inside. The reaction tube is heated in an electric furnace, and the temperature of the catalyst is measured with a thermocouple. The amount of water vapor was adjusted by supplying a predetermined amount of pure water to the upper part of the reaction tube by a pump and evaporating the same. Organic halogen compounds are C
FC12 was used. The supplied processing gas has the following composition.

CFC12 5% Water vapor 25% Oxygen 10-20% Nitrogen balance Gas of this composition was passed through the catalyst layer at a catalyst temperature of 400-440 ° C. at a space velocity of 20,000 per hour. The decomposition product gas that has passed through the catalyst layer is bubbled in an alkaline aqueous solution,
The concentration of CFC12 in the gas passed through the alkaline aqueous solution is
The analysis was performed by an ID gas chromatograph. The decomposition rate of the organic halogen compound was determined by the following equation.

[0038]

(Equation 1)

FIG. 1 shows the relationship between the decomposition rate of CFC12 and the concentration of silica relative to titania 5 hours after the start of the reaction.

In the United Nations Environment Program (UNEP), CF
It is said that the CFC decomposition rate recognized as a C treatment method is 99%.

Example 2 FIG. 2 shows the results of a continuous cracking test of the catalysts C and D of the present invention at a catalyst temperature of 440 ° C. for 100 hours. The test conditions are the same as in Example 1.

(Embodiment 3) This embodiment is an example of an apparatus for decomposing an organic halogen compound when the organic halogen compound to be treated is a liquid at room temperature. The disassembly device is shown in FIG.

The concentration of the CFC 12 gas 1 to be treated is measured by an analyzer 3 such as a FID gas chromatograph, and diluted with air 2 to a Freon concentration of about 3%. After adding water vapor 4 in an amount 5 times the number of moles of Freon to the diluted Freon gas, Example 1 is introduced into the catalyst layer 5 filled with the catalyst. The space velocity at this time is 3,000 per hour (space velocity = gas flow rate (ml / h) / catalyst amount (ml)). The catalyst layer was heated in an electric furnace 6 from the outside, and the catalyst temperature was set to 440 ° C. In addition, as a method of raising the temperature of the catalyst, a method of flowing a high-temperature gas obtained by burning propane gas or the like can also be used. The decomposition product gas is bubbled into the alkali absorption tank 8 while being in contact with the aqueous sodium hydroxide solution sprayed from the spray nozzle 7. The gas that has passed through the alkali absorption tank 8 passes through an adsorption tank 9 filled with activated carbon or the like, and is then released to the atmosphere. The liquid sprayed from the spray nozzle 7 may be simple water or a slurry liquid such as calcium carbonate.
Alkaline aqueous solution 10 as waste liquid in alkali absorption tank 8
Can be taken out periodically and a new alkaline aqueous solution 11 can be replaced. The alkali solution sprayed from the spray nozzle circulates the solution in the alkali absorption tank 8 by the pump 12.

(Embodiment 4) This embodiment is an example of an apparatus for decomposing an organic halogen compound when the organic halogen compound to be treated is a liquid at room temperature. The device is shown in FIG.

This is an example in which a preheater 14 is provided in the organic halogen compound decomposing apparatus of the third embodiment. Here, only the differences from the third embodiment will be described. When the organic halogen compound to be treated is a liquid at room temperature, such as CFC113 liquid 13, the preheater 14
Then, the concentration is measured by an analyzer 3 such as an FID gas chromatograph and the like, and diluted with air 2 to a Freon concentration of about 3%. The diluted Freon gas is treated in the same manner as in Example 3 below.

[0046]

According to the present invention, chlorofluorocarbons (CFCs), trichloroethylene, methyl bromide,
Organic compounds containing halogen such as fluorine, chlorine and bromine such as halon can be decomposed with high efficiency and the activity can be maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the concentration of silica relative to titania and the decomposition activity of CFC12 5 hours after the start of the reaction in the catalyst of the present invention.

FIG. 2 shows the results of a continuous cracking test of the catalyst of the present invention at a catalyst temperature of 440 ° C. for 100 hours.

FIG. 3 is a diagram illustrating a configuration of an organic halogen compound decomposing apparatus according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an organic halogen compound decomposing apparatus according to Example 4 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CFC12 gas, 2 ... Air, 3 ... FID gas chromatograph, 4 ... Steam, 5 ... Catalyst layer, 6 ... Electric furnace, 7 ...
Spray nozzle, 8 ... Alkaline absorption tank, 9 ... Adsorption tank, 1
0: Waste liquid, 11: New alkaline aqueous solution, 12: Pump, 1
3 ... CFC113 liquid, 14 ... Remaining heater.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Arato 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Hisao Yamashita 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd., Hitachi Research Laboratories (72) Inventor Shigeru Shozuhata 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd., Hitachi Research Laboratory (72) Inventor Shin Tamada 3-chome, Sachimachi, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Hitachi Plant (56) References JP-A-1-111443 (JP, A) WO 92/19366 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B01D 53/86 B01J 21/00-37/36

Claims (9)

(57) [Claims] 1. A method comprising: containing titania, silica and tungsten oxide; containing silica in a concentration of 2 to 15 % by weight of titania;
mol% or less, W is 80 mol% or less and 5 mol% or more,
A catalyst in which at least the surface of titania is covered with at least one porous layer of silica and tungsten oxide,
A gas flow containing an organic halogen compound not exceeding 10 vol%, and a temperature of not more than 500 ° C. and a total gas flow of 30 vol%
% By contacting the organic halogen compound in the presence of water vapor that does not exceed 0.1% to decompose the organic halogen compound into carbon monoxide, carbon dioxide and hydrogen halide. 2. The composition contains titania, silica and tungsten oxide, contains silica in a concentration of 2 to 15 % by weight of titania, and has an atomic ratio of Ti to W of at least 20 mol% to 95 mol%.
Hereinafter, it is assumed that W is 80 mol% or less and 5 mol% or more, at least the surface of titania is covered with a porous layer of silica, and the surface of the silica porous layer is covered with a porous layer of tungsten oxide. Characteristic catalyst for decomposition of organic halogen compounds. 3. A composition comprising titania, silica and tungsten oxide, containing silica in a concentration of 2 to 15 % by weight with respect to titania, wherein the atomic ratio of Ti to W is at least 20 mol% and 95 m
ol% or less and W is 80 mol% or less and 5 mol% or more, at least the surface of titania is covered with a porous layer of tungsten oxide, and the surface of the porous layer of tungsten oxide is further covered with a porous layer of silica. A catalyst for decomposing an organic halogen compound. 4. The catalyst according to claim 2, wherein the fourth component contains at least one element of S, Mo, and V, and the ratio of each metal element is 0.0 with respect to Ti atom.
A catalyst for decomposing an organic halogen compound, which is present in an amount of from 0.01 to 10 mol%. 5. Impregnating titania particles with a solution containing a W component.
Baking, and then impregnating and baking with silica sol .
Containing titania, silica and tungsten oxide
Containing silica in a concentration of 2 to 15% by weight with respect to near,
The atomic ratio of Ti to W is 20 mol% or more and 95 mol% or less.
Below, a catalyst was prepared in which W is less than 80 mol% and more than 5 mol%.
Preparation of organic halogen compound-decomposing catalyst, characterized by manufacturing. 6. Impregnation of a solution containing a Si component into titania particles.
Baking, and further impregnating and baking with a solution containing W component.
Contains titania, silica and tungsten oxide
And silica at a concentration of 2 to 15% by weight with respect to titania
The atomic ratio of Ti to W is at least 95% by mol
mol% or less, W is less than 80mol% or more than 5mol%
A method for producing an organic halogen compound decomposition catalyst, which comprises producing a catalyst. 7. The method of the organic halogen compound-decomposing catalyst according to claim 5, immersed containing hydrogen peroxide solution containing the W component titania particles, calcining, further impregnated shea Rikazoru, and firing Production method of organic halogen compound decomposition catalyst. 8. An apparatus for treating an organic halogen compound, comprising at least a catalyst according to any one of claims 2 to 4 , a reactor filled with the catalyst, a heating source for heating the catalyst, has an organic halogen compound and a gas supply device and the steam supply device, an air supply device, a decomposition product gas cleaning tank,
The organic halogen compound supplied by organic halogen compound gas supply unit, and diluted with air delivered from the air supply device, the addition of water vapor from the water vapor supply apparatus to the diluent gas this is heated by the pressurized heat source An apparatus for decomposing an organic halogen compound, wherein the gas is introduced into the catalyst layer in the reactor, and the gas that has passed through the catalyst layer is introduced into the decomposition product gas washing tank for detoxification. 9. An apparatus for treating an organic halogen compound, comprising at least a catalyst according to any one of claims 2 to 4 , a reactor charged with the catalyst, a heating source for heating the catalyst, an organic halogen compound gas supply unit and the steam supply device, spray of the air supply device, water or an aqueous alkaline solution
And Renozuru, the decomposition product gas cleaning tank, the exhaust gas adsorption vessel
A supply of the organic halogen compound gas supply unit
Organohalogen compounds, and diluted with air delivered from the air supply device, adding steam to the diluent gas this from water vapor supplying device, to the catalyst layer in the reactor heated by the pressurized heat source Introduced and sprayed on the gas passing through the catalyst layer.
By spraying with water or an alkaline aqueous solution from Nozuru, then,
An organic halogen compound decomposition treatment apparatus characterized in that it is detoxified by being introduced into the decomposition product gas washing tank, exhaust gas passing through the decomposition product gas cleaning tank is introduced into the exhaust gas adsorption tank, and then released to the atmosphere. .