JPH0824582A - Treatment of waste gas - Google Patents

Abstract

PURPOSE:To obtain a method for treating a waste gas with a durable catalyst having high desulfurizing and denitrating performance by granulating a porous carbon particle having a small specific surface and contg. transition metal along with a false boehmitestructure hydrous alumina, smectite, etc., and using the granulation product in desulfurizing and denitrating the waste gas. CONSTITUTION:A waste gas 5 contg. SOx and/or NOx is brought into contact with a catalyst 3 consisting of the granulated composition contg. a transition metal component and a sulfur component, contg. a porous carbon particle having 5-50m<2>/g BET specific surface and a false boehmite-structure hydrous alumina in (1:1.4) to (3:1) weight ratio and further contg. 10-30wt.%, based on the total weight, synthetic or natural smectite-group clay mineral or synthetic or natural zeolite. The catalyst has high desulfurizing and denitrating performance and excellent resistance to powdering and durability. Since this carbon is easily available, the catalyst cost is remarkably reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating exhaust gas containing sulfur oxides and / or nitrogen oxides, and more specifically to a catalyst composed of a granular formed body of specific porous carbon particles. The present invention relates to a method of removing each oxide in the above exhaust gas.

[0002]

2. Description of the Related Art Conventionally, it has long been known to use a carbonaceous adsorbent such as activated carbon to remove sulfur oxides, nitrogen oxides, etc. contained in combustion furnace exhaust gas. For example,
In JP-A-58-153523, exhaust gas containing sulfur oxides and nitrogen oxides is contacted with a carbonaceous adsorbent to adsorb and remove most of the sulfur oxides in the exhaust gas. It is described that the concentration of sulfur oxides and the concentration of nitrogen oxides are detected, ammonia gas equivalent to their chemical equivalents is supplied to the exhaust gas and mixed, and then the exhaust gas and the carbonaceous adsorbent are brought into contact with each other.

Further, according to a material issued by Project News Co., Ltd. in 1990, Mitsui Mining Co., Ltd. simultaneously desulfurizes, denitrates and dedusts by using a porous adsorbent "active coke" whose main raw material is coal. And completed a dry desulfurization and denitration device for recovering high-purity sulfur or concentrated sulfuric acid as a by-product, and in this device, the adsorption tower filled with active coke is a gravity type moving bed of two upper and lower layers, and exhaust gas is the lower layer. It has been reported that desulfurization is conducted by introducing it to the first layer, and exhaust gas from which sulfur oxides have been removed is injected with ammonia, and then it is introduced into the upper second layer to perform denitration.

[0004]

The activated carbon has a remarkably high specific surface area and exhibits a high adsorption performance, but it has a problem that it tends to be pulverized and its price is high. It is unavoidable that the surface activity gradually decreases.

The present inventors show high desulfurization performance and denitration performance even when the specific surface area is low, contrary to the conventional idea that the performance of desulfurization and denitration is enhanced by using activated carbon having a high specific surface area. As a result of searching for carbon, the inventors have found that porous carbon containing a transition metal component granulated with pseudo-boehmite-type hydrated alumina, smectite, etc. is suitable for this purpose, and arrived at the present invention. That is, an object of the present invention is to provide a catalyst having a high desulfurization performance and denitration performance while having a relatively small specific surface area and having resistance to pulverization tendency and activity reduction during long-term use. It is to provide a method of treating the used exhaust gas. Another object of the present invention is to provide a treatment method for desulfurization and / or denitration of exhaust gas which has a low catalyst cost and therefore a low operating cost.

[0006]

According to the present invention, porous carbon particles containing a transition metal component and a sulfur component and having a BET specific surface area in the range of 5 to 50 m ² / g, and pseudo-boehmite hydration. Granular molded article of a composition containing alumina in a weight ratio of 1: 1.4 to 3: 1 and containing 10 to 30% by weight of a synthetic or natural smectite group clay mineral or a synthetic or natural zeolite. There is provided a method for treating exhaust gas, which comprises contacting a catalyst consisting of (3) with exhaust gas containing sulfur oxides and / or nitrogen oxides.

In the present invention, when the exhaust gas is a sulfur oxide-containing gas, the exhaust gas and the catalyst are mixed at 100 to 250 ° C.
When the exhaust gas is a nitrogen oxide-containing gas, it is advisable to contact the exhaust gas with the catalyst at a temperature of 150 to 300 ° C. together with ammonia. When the exhaust gas is a gas containing sulfur oxides and nitrogen oxides, the exhaust gas or a mixed gas of exhaust gas and ammonia is brought into contact with the first layer of the catalyst at a temperature of 80 to 150 ° C. The sulfur oxides therein are removed, and when the gas after contact does not contain ammonia, the gas after contact is mixed with ammonia, and the mixed gas is mixed with the second layer of the catalyst at 200 to 300 ° C. It is preferable to remove the nitrogen oxides in the exhaust gas by contacting at the temperature of.

The porous carbon used in the catalyst of the present invention preferably contains 1 to 30% by weight of a transition metal component and 5 to 15% by weight of a sulfur component, and the transition metal component is iron, nickel, cobalt and vanadium. It preferably comprises at least one metal component selected from the group consisting of: The porous carbon from which the catalyst of the present invention is based is not limited to this, but is easily available as crude oil and heavy oil-fired thermal power generation soot dust.

[0009]

The catalyst used in the present invention comprises (a) porous carbon particles, (b) pseudo-boehmite-type hydrated alumina and (c) granular molded products of smectite group clay mineral or zeolite. is (1) a transition metal component and contain a sulfur component, and (2) BET specific surface area of 5 to 50 m ² / g, especially 10 to 50 m ² /
g and the carbon adsorbent are in an exceptionally low range, which is a remarkable feature. The following "Table 1" compares the specific surface area of activated carbon or activated coke widely used for desulfurization and denitration with the porous carbon used in the present invention, which is incomparable to that of the conventional one. Shows a small specific surface area.

[0010]

[Table 1]

According to the present invention, the specific porous carbon is combined with a pseudo-boehmite-type hydrated alumina and a smectite group clay mineral or zeolite in a predetermined quantitative ratio and granulated to mechanically (pressure resistance) of the granular material. ) Not only the strength and abrasion resistance are remarkably improved, but also the desulfurization performance and the denitration performance are remarkably improved.

[0012] "Fig. 1" is a catalyst prepared by granulating together with pseudo-boehmite-type hydrated alumina and smectite using Tokyo Electric Power Co., Inc. Oi crude oil ash and Shinagawa crude oil ash as porous carbon (Example 1 described later in detail). Through 7), S
The relationship between the temperature, the desulfurization rate, and the denitrification rate when a mixture of O ₂ and NO is mixed with ammonia is shown.
According to this result, a desulfurization rate of 90% or more and 97.9% at 120 ° C. was obtained at a temperature lower than 200 ° C., particularly at a temperature lower than 150 ° C., while a high temperature of 200 ° C. or higher was obtained. On the other hand, especially on the high temperature side of 225 ° C. or higher, it can be seen that a denitrification rate of 65% or more and up to 91.5% at 250 ° C. can be obtained.

Further, "Fig. 2" is for the one showing a high desulfurization rate in the test of "Fig. 1" (using Oi crude oil ash).
The relationship between the gas passing time at 0 ° C. and the average desulfurization rate is plotted, and the surprising result that the desulfurization rate of 100% is maintained over 10 hours becomes clear. The above-mentioned porous carbon used in the present invention is, as crude oil soot, heavy oil soot, etc., discharged in large amounts from a combustion device that uses a fuel such as crude oil or heavy oil, so it can be obtained at extremely low cost, and the problem of environmental pollution due to disposal It has the advantage that it can be reused for desulfurization or denitration purposes. In the present invention, as the granulation medium, when using pseudo-boehmite-type hydrated alumina and synthetic or natural smectite-type clay mineral or synthetic or natural zeolite, in terms of physical properties of the granular material,
It has been found that significant advantages are achieved in terms of desulfurization and denitration.

That is, the hydrated alumina or the like not only serves as a granulation medium having excellent workability for forming porous carbon particles into granules having a predetermined size and a predetermined shape, but also the formed granules. It exerts a highly convenient action to enhance the compressive strength and abrasion resistance, and also the water resistance (wet strength). Moreover, the combination of the hydrated alumina and smectite or zeolite has an auxiliary effect of increasing the specific surface area of the granular molded product, increasing the adsorption capacity, and also increasing the desulfurization or denitration performance. That is, in this composite catalyst used in the present invention, sulfur oxides and nitrogen oxides are first adsorbed on the alumina surface, and then on the porous carbon the formula (1) 2SO ₂ + O ₂ + 2H ₂ O → 2H ₂ SO ₄ ... ( It was confirmed that the reaction of 1) and the reaction of formula (2) and (2 ') 4NO + 4NH ₃ + O ₂ → 4N ₂ + 6H ₂ O (2) 6NO + 4NH ₃ → 5N ₂ + 6H ₂ O (2') proceed. To be Of course, smectite and zeolite added to the catalyst also contribute to their adsorption and reaction.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Porous Carbon The porous carbon particles used in the present invention include a transition metal component,
In particular, components such as iron, cobalt, nickel and vanadium are generally contained in the form of oxides in an amount of 1 to 30% by weight, particularly 3 to 26% by weight, based on the particles. This transition metal component acts as a catalyst for the reactions of the above formula (1) and formulas (2) and (2 ′). It also effectively acts on the chemisorption of acid. Also,
The carbon particles contain a sulfur component in an amount of 5 to 15% by weight, and particularly 6 to 14% by weight. These sulfur components exist in the form of elements or various oxides and are considered to act effectively for denitration.

The porous carbon particles further include Na,
It contains an alkali metal component such as K and an alkaline earth metal component such as calcium and magnesium, and the amount thereof is generally in the range of 0.1 to 2.0% by weight based on the particles.
The following “Table 2” shows the composition analysis results of an example of typical porous carbon particles.

[0017]

[Table 2]

The porous carbon particles used in the present invention preferably contain carbon having a calorific value of 3000 kcal / kg or more. A scanning electron micrograph (300 magnification) of the porous carbon used in the present invention is shown in FIG.
Shown in From this figure, it is understood that the porous carbon of the present invention has so-called pumice-like macropores. BET
The specific surface area determined by the method is 5 to 50 m ² / g, especially 10
To 50 m ² / g, which is surprisingly small, and the pore volume determined by the N ₂ adsorption method is 0.01 to 0.07 ml / g, especially 0.01
It is as small as 5 to 0.035 ml / g, and the pore size is generally 2
It is in the range of 0 to 70Å.

The particle diameter of the porous carbon is 0.05 to 50 μm, especially 0.5 to 30 μm in terms of median diameter by Coulter counter method. This porous carbon is obtained by sufficiently drying crude oil soot, heavy oil soot, etc. discharged from a power plant, etc., and removing iron rust using a 70-80 mesh screen, but it has the above composition and characteristics. If it is a thing, of course, it is not limited to this.

Catalyst In the present invention, carbon particles and pseudo-boehmite-type hydrated alumina are mixed in a ratio of 1: 1.4 to 3: 1, particularly 17: 1 to 2.
Used in a weight ratio of 5: 1. Furthermore, 10 to 30 per whole
%, Especially 15 to 25% by weight of synthetic or natural smectite clay mineral or synthetic or natural zeolite is used in combination.

The hydrated alumina used in the present invention is generally 5
particle size of less than μm, especially less than 3 μm and 200 to 400 m
BET specific surface area of ² / g and 0.3 to 0.6 ml / g
Those having a pore volume of Pseudo-boehmite hydrated alumina is generally produced by reacting sodium aluminate with a mineral acid such as sulfuric acid or by reacting an aluminum salt such as aluminum sulfate with an alkali such as caustic soda. Even the hydrated alumina produced by the general production method of 1) which satisfies the above requirements can be used for the purpose of the present invention. Hydrated alumina which is advantageously used for the purpose of the present invention is disclosed in Japanese Examined Patent Publication No. 56-1.
It is manufactured by the method described in Japanese Patent No. 3652 and described in the same publication. The hydrated alumina used as the raw material has the formula (3) Al ₂ O ₃ .xH ₂ O (3) where x is 1.0 to 2.0, and particularly 1.4 to 1.8. And a pseudo-boehmite type hydrated alumina is particularly preferred among the hydrated alumina.

As the natural or synthetic smectite type clay mineral, dioctahedral type smectites such as montmorillonite, beidellite and nontronite, and trioctahedral type smectites such as saponite, hectorite, sauconite and stevensite can be used. These smectite group clay minerals have adsorbability themselves, and also have an action as an inorganic binder to improve the mechanical strength and abrasion resistance of the molded product. Particularly preferred are acid clay or activated clay belonging to montmorillonite, synthetic layered magnesium phyllosilicate described in JP-A-61-10020, JP-A-61-100.
21. Synthetic fly pontite described in JP-A No. 21-63, JP-A-63-
Active bentonite described in Japanese Patent No. 50310, Japanese Patent Application No. 62-62
The synthetic stevensite of JP-A-20476 and the like can be mentioned. These clay minerals generally have a particle size of 10 μm or less, particularly 3 μm or less, and 200 to 600 m ² /
It is preferable to have a BET specific surface area of g, especially 200 to 500 m ² / g. Synthetic stevensite, in particular, formula (4) MgxNaySi ₄ O ₁₀ (OH) ₂ · Na ₂ (4) In the formula, x and y are numbers of 2 or more and y is 0 to 0 under the condition that x + y <3. It is preferable that the chemical composition is a number of 0.1 and z is a number of 0 to 1.0. On the other hand, as synthetic or natural zeolites, A-type zeolite, Y-type zeolite, X-type zeolite, P-type zeolite, HY-type zeolite, mordenite, clinoptilolite and the like can be used.

The composition containing the porous carbon can be granulated by a method known per se such as an extrusion granulation method, a tableting granulation method, a tumbling granulation method and the like. As a typical example, porous carbon, a granulating medium, other auxiliaries and the like are mixed, and this mixture is kneaded for homogenization in the presence of water and then molded into a predetermined shape. A kneader, a super mixer, a single-screw or twin-screw extruder, etc. can be used for the kneading operation, and a vacuum-type kneader can be used if necessary. For molding the granules, various molding machines known per se, for example, an extrusion molding machine, a tableting machine, a rolling granulator and the like can be used. Generally, the kneading and molding is preferably carried out by an extruder, and the kneading is preferably carried out in at least one stage, preferably in multiple stages. In multi-stage kneading and molding, the particle size of extrusion molding can be gradually reduced.

The granular compact is subjected to a drying treatment at a temperature of 100 to 120 ° C. and then calcined at a temperature of 200 to 400 ° C. Drying at the above temperature prior to calcination is important for obtaining a dense and excellent composite adsorbent, and at a temperature lower than the above range, water is not sufficiently removed. There is a tendency for foaming during calcination, and at temperatures higher than the above range, there is a tendency for foaming during drying due to rapid removal of water. The purpose of calcination is to make the composition densified and strengthened by baking, and at the same time to convert quasi-boehmite hydrated alumina into highly active alumina. In addition, in the composite adsorbent of the present invention, the pseudo-boehmite type structure is preserved even after the conversion to high activity alumina. When the temperature of the heat treatment is lower than the above range, the densification due to quenching is insufficient, the conversion into highly active alumina is insufficient, and the durability becomes poor. On the other hand, when the heat treatment temperature is higher than the above range, the surface activity of the adsorbent tends to decrease. The calcination process is generally performed for 60 to 360 minutes, particularly 120 to 240 minutes.
It can be performed by heating for a minute.

The granular molded product used in the present invention may have any shape such as a columnar shape (pellet shape), a tablet shape, a spherical shape, etc., and the particle size thereof is 1 to 10 mm, especially 2
It is preferably in the range of 5 mm to 5 mm. Suitable catalysts for use in the present invention are generally 100 to 250 m ² /
It has a BET specific surface property of g, particularly 120 to 200 m ² / g, and a pore volume of 0.1 to 0.35 ml / g, especially 0.15 to 0.3 ml / g. In the present invention, the catalyst having particularly enhanced desulfurization or denitration performance can be obtained by irradiating the porous carbon particles with microwaves at any stage of the particle size before granulation. As microwave, frequency 1 that is generally used for microwave heating
Or good in the range of 3GH _Z, the irradiation energy may have a range of 1kg per 0.8 to 3W, irradiation time may be short time of about 10 to 50 seconds.

Treatment of Exhaust Gas The present invention relates to various exhaust gases containing sulfur oxides and / or nitrogen oxides, for example, thermal power plant exhaust gas, boiler exhaust gas, petroleum refining exhaust gas, chemical industrial process exhaust gas, heating furnace exhaust gas, incinerator exhaust gas. It is useful for treating metal refining exhaust gas, sintering furnace exhaust gas, glass melting furnace exhaust gas, and the like.

For the treatment of exhaust gas, a catalyst is used in the form of a fixed bed, a moving bed or a fluidized bed, and desulfurization or denitration operation is carried out by contacting in one or more stages. In order to remove the sulfur oxides, it is preferable to bring them into contact with each other at a temperature of 80 to 200 ° C., particularly 100 to 150 ° C. As shown in the above formula (1), the sulfur oxides should be mixed with SO ₃ or H ₂ SO _{2. In} order to oxidize into ₄ , it is preferable that 4 to 5% by weight of oxygen and 2 to 10% by weight, especially 3 to 5% by weight of water coexist in the exhaust gas.

In order to remove nitrogen oxides, exhaust gas and ammonia are mixed in a substantially stoichiometric ratio, and contact between the two is performed.
It is preferable to carry out at a temperature of 0 to 300 ° C., particularly 225 to 275 ° C. In the present invention, desulfurization and denitration can be performed at the same time by using a single or multi-stage catalyst packed column, but it is desirable to perform desulfurization and denitration in separate catalyst layers because their optimum temperatures are different. .

Generally, exhaust gas or a mixed gas of exhaust gas and ammonia is mixed with the first layer of the catalyst at 100 to 150 ° C.
To remove the sulfur oxides in the exhaust gas,
When the gas after contact does not contain ammonia, after mixing the gas after contact with ammonia, the mixed gas is brought into contact with the second layer of the catalyst at a temperature of 200 to 300 ° C. It is better to remove nitrogen oxides. In FIG. 4 showing an example of an apparatus used for this method, a desulfurization tower 1 and a denitration tower 2 are arranged, and these towers 1 and 2 are filled with the above-mentioned granular molded article catalyst 3. Has been done. In this specific example, the catalyst 3 in each tower is a moving bed, the catalyst 3 discharged from the denitration tower 2 is sent to the desulfurization tower 1, and the catalyst discharged from the desulfurization tower 1 is supplied to the desorption tank 4. To be done.

The exhaust gas 5 is cooled to a temperature suitable for desulfurization, for example, 100 to 150 ° C. through the heat exchanger 6, and is supplied to the desulfurization tower 1, where the sulfur oxides are oxidized and adsorbed. The exhaust gas 7 from which the sulfur oxides have been removed is heated by the heat exchanger 6 to a temperature suitable for denitration, for example, 200 to 250 ° C., and supplied to the denitration tower 2. Ammonia gas 8 is also simultaneously supplied to the denitration tower 2, is brought into contact with the catalyst 3 to be reduced to nitrogen, and the treated gas 9 is released into the atmosphere.

On the other hand, the catalyst 3'having adsorbed sulfuric acid from the desulfurization tower 1 is sent to the desorption tank 4 and comes into contact with steam or spray water 10 to release sulfuric acid 11, while the catalyst 3 is regenerated in the regeneration tower 1.
2, is regenerated by drying, sieving, etc., and is again sent to the denitration tower 2. The catalyst used in the present invention is significantly cheaper than conventional activated carbon and the like, and therefore can be used as a one-way catalyst. In this case, the catalyst from the desorption tank 4 is discarded.

Further, the desulfurization catalyst and the denitration catalyst may be different from each other. For example, as described with reference to FIG. 1, there are transition metal-containing porous carbons suitable for desulfurization and those suitable for denitration. Therefore, a desulfurization catalyst is used exclusively for desulfurization, and a denitration catalyst is used. It can be used exclusively for denitration. The invention is illustrated by the following example.

[0033]

According to the present invention, the specific surface area is 5 to 50.
Porous carbon particles having a small m ² / g and containing a transition metal are granulated together with pseudo-boehmite-type hydrated alumina, smectite, etc., and are used for desulfurization or denitration of exhaust gas to obtain high desulfurization performance or It has the advantage that denitration performance can be achieved, and that it is also excellent in dust resistance and durability. Also, since this carbon is easily available as heavy oil soot, crude oil soot,
There is an advantage that the catalyst cost is extremely low and the operating cost as a whole can be reduced.

[0034]

EXAMPLES The evaluation test in the present invention was carried out by the following method. 1. BET specific surface area automatic BET specific surface area measuring device (CORLO-ERBA Corp. Sorptomatic Series 180
0) was used to determine the nitrogen gas adsorption amount V _m [cc / g] to be adsorbed by the monomolecular layer on the test surface, and the specific surface area was determined by the following formula (5). Specific surface area SA = 4.35 × V _m [m ² / g] (5) 2. Pore volume Automatic N ₂ made by CARLO-ERBA
Adsorption device (Sorptomatic Series 1
After 2hr degassed at 10 ^-2 mmHg, 250 ° C. with 800), temperature of liquid nitrogen, N ₂ in N ₂ pressure 735mmHg
The standard state N ₂ adsorption amount (V1) was calculated from the adsorption amount, and the pore volume was calculated from the following formula (6).

Pore volume (PV) = V1 × 1.555 × 10 ⁻³ (ml / g) (6) 3. Average Pore Radius (r) The average pore radius [(r), Å] was calculated from the following formula (7) assuming that the pores are cylindrical. Average pore radius (r) = 2 × pore volume (PV) × 10 ⁴ / BET specific surface area (SA) (7) 4. Particle Strength Using a Kiya type hardness meter (10 Kg meter), the crush strength of 20 samples dried at 250 ° C. for 2 hours was measured, and the average value thereof was taken as the particle strength.

5. Average particle size Coulter Count method
er, Model TA-2 type), the particle size obtained from the 50% volume distribution point of the cumulative particle size curve was taken as the average particle size. 6. Desulfurization test The desulfurization test was performed by continuously aerating 100 ppm of SO ₂ through a sample packed column and measuring the concentration of SO ₂ by a non-dispersive infrared absorption method (manufactured by Nippon Thermo Electron 711p). 7. Denitration test In the denitration test, 130 ppm of NH ₃ was added to 130 ppm of NO, and this was continuously ventilated through a sample packed column to determine the NO concentration under reduced pressure chemiluminescence method (Japan Thermo Electron 512PL.
Manufactured).

(Examples 1 to 7) Porous carbon [Oi crude oil ash (A-1) or Shinagawa crude oil ash (A-2)] and a composite oxide containing pseudo-boehmite hydrated aluminum (B) and MgO, Alternatively, the compositions (C-1) to (C- shown in "Table 3")
After mixing the zeolite etc. (C) of 4) in the compounding amounts shown in "Table 5", open the kneader and adjust the humidity to obtain a water content of 50.
The mixture was homogeneously kneaded to give a content of 60% by weight. Then, the kneaded product was extruded and granulated (EXD-60 manufactured by Fuji Paudal).
After molding, it was granulated into a cylindrical material having a particle size of 0.5 to 1.5 mm, and then sintered and molded at 300 ° C. The molded product was further irradiated with microwaves for 30 to 50 seconds using a household microwave oven at a predetermined temperature,
Desulfurization and denitration tests were conducted. The results are shown in "Table 5". Further, the denitration rate and the desulfurization rate according to the temperature changes in Example 1 and Example 2 are shown in "Fig. 1". The test conditions are shown in "Table 4".

(Comparative Example 1) A porous carbon (Oi crude oil ash) was used, which was irradiated with microwaves in the same manner as in Examples 1 to 7, and the same procedure was performed. The results are shown in "Table 5". (Comparative Example 2) The procedure of Examples 1 to 7 was repeated except that porous carbon (Oi crude oil ash) and pseudo-boehmite hydrated aluminum were mixed in the amounts shown in "Table 4". The results are shown in "Table 5". (Comparative Example 3) The same procedure as in Comparative Example 1 was repeated except that the amount of the compound was not irradiated with microwaves. The results are shown in "Table 5".

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

Example 8 The same sample as in Example 1 was used to measure the desulfurization rate with time at 100 ° C.
The test conditions at that time are shown in "Table 6", and the results are shown in "Table 7" and "Fig. 2".

[0043]

[Table 6]

(Example 9) The results obtained in the same manner as in Example 8 except that the sample of Example 2 was used are shown in "Table 7" and "Fig. 2".

[0045]

[Table 7]

[Brief description of drawings]

FIG. 1 is a graph showing the denitration rate and the deflux rate of porous carbon due to temperature changes.

FIG. 2 is a graph showing the results of measuring the outflow rate of porous carbon over time at temperatures of 100 ° and 200 ° C.

FIG. 3 is an electron micrograph showing a particle structure of porous carbon used in the present invention.

FIG. 4 shows an example of an apparatus for using the method of the invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location B01J 29/072 ZAB A 29/076 ZAB A 29/14 ZAB A 29/16 ZAB A 35/10 301 B (72) Inventor Kiyohiko Imai 4-1-21, Nihombashi Muromachi, Chuo-ku, Tokyo Mizusawa Chemical Industry Co., Ltd.

Claims (12)

[Claims] 1. A porous carbon particle containing a transition metal component and a sulfur component and having a BET specific surface area in the range of 5 to 50 m ² / g, and pseudo-boehmite hydrated alumina in a ratio of 1: 1.4 to 3 : 1 in a weight ratio and 1 in total
Contacting a catalyst comprising a granular molded product of a composition containing 0 to 30% by weight of a synthetic or natural smectite group clay mineral or a synthetic or natural zeolite with exhaust gas containing sulfur oxides and / or nitrogen oxides A method for treating exhaust gas, which comprises: 2. The transition metal component is at least one selected from the group consisting of iron, nickel, cobalt and vanadium.
The method of claim 1 wherein the metal component is a seed. 3. The transition metal component is contained in the porous carbon particles in an amount of 1 to 20% by weight.
Described processing method. 4. The treatment method according to claim 1, wherein the sulfur component is contained in the porous carbon particles in an amount of 5 to 15% by weight. 5. The porous carbon particles contain an alkali metal component and / or an alkaline earth metal component in an amount of 0.1 per total particle.
2. The processing method according to claim 1, wherein the content is from 2.0 to 2.0% by weight. 6. The porous carbon particles are 0.07 to 50.
The processing method according to claim 1, which has a median diameter of μm. 7. The porous carbon particles are 0.01 to 0.
The processing method according to claim 1, which has a pore volume of 07 ml / g. 8. The processing method according to claim 1, wherein the porous carbon particles are crude oil soot or heavy oil soot. 9. The catalyst as a whole is 100 to 250.
BET specific surface area of m ² / g and 0.1 to 0.35 ml /
The process according to claim 1, having a pore volume of g. 10. The exhaust gas is a sulfur oxide-containing gas,
The treatment method according to claim 1, wherein the exhaust gas and the catalyst are contacted at a temperature of 100 to 250 ° C. 11. The exhaust gas is a nitrogen oxide-containing gas,
The treatment method according to claim 1, wherein the exhaust gas is brought into contact with the catalyst together with ammonia at a temperature of 150 to 300 ° C. 12. The exhaust gas is a gas containing sulfur oxides and nitrogen oxides, and the exhaust gas or a mixed gas of exhaust gas and ammonia is mixed with the first layer of the catalyst in an amount of 80 to 15.
After contacting at a temperature of 0 ° C., the sulfur oxides in the exhaust gas are removed, and when the gas after contact does not contain ammonia gas, the gas after contact is mixed with ammonia, and then this mixed gas is used as the catalyst. 2. The treatment method according to claim 1, wherein the nitrogen oxide in the exhaust gas is removed by contacting the second layer with a temperature of 200 to 300 ° C.