JPH10180038A - Waste gas simultaneous treating device and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously remove soot, hydrogen chloride, sulfur oxide, nitrogen oxide, mercury and an organic chlorine compound, which are contained in a waste gas with a functional bag filter. SOLUTION: This waste gas simultaneous treating device is constituted of a waste gas cooling column 2 for cooling the waste gas from a fluidized bed type incineration furnace 1, a temp. reducing column 3 for further lowering the temp., a flue 4 for introducing the waste gas from the temp. reducing column 3, an alkali power storage tank 5 for blowing an alkali powder such as slaked lime and an ammonia storage tank 6 for blowing ammonia, which are connected to the flue 4, a bag house 7 connected to the flue 4 in the down stream and housing the bag filter 8 and a sucking blower 9 connected to the bag house 7 and for feeding the waste gas to a smoke stack 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for simultaneously treating a plurality of harmful components contained in exhaust gas from a municipal waste incinerator.

[0002]

2. Description of the Related Art In recent years, regulations on harmful components in exhaust gas from municipal waste incinerators have become stricter from the viewpoint of environmental protection. As the harmful components in the exhaust gas, there are dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organic chlorine compounds, and the treatment technology for each harmful component has been established. For the acidic hydrogen chloride and sulfur oxide, alkali such as slaked lime is injected into the flue upstream of the bag filter, and the reaction products are collected by the bag filter together with the dust. Regarding nitrogen oxides, there is a technology to reduce by injecting a reducing agent such as urea into the incinerator, and a technology to install a heat exchanger and a denitration catalyst tower downstream of the bag filter and raise the temperature of exhaust gas to the optimal temperature for denitration reaction to denitrate. is there. Further, a technique for carrying out denitration by carrying a denitration catalyst on a bag filter is disclosed in Japanese Patent Publication No. Hei 4-36729 and Japanese Patent Laid-Open No. Hei 5-84.
No. 411. For organic chlorine compounds such as polychlorinated dibenzoparadioxin and polychlorinated dibenzofuran, technology for collecting and collecting mist by lowering the temperature of the bag filter, technology for introducing activated carbon into the flue upstream of the bag filter and adsorbing it, Adsorption tower in the flue,
There is a technique of providing a catalyst tower and performing adsorption or decomposition. Techniques for oxidatively decomposing organic chlorine compounds into harmless substances using a catalyst are disclosed in JP-A-4-503772 and JP-A-2-39514. Mercury in the exhaust gas can be easily collected as mist by lowering the temperature of the bag filter using the difference in vapor pressure. Also, there is a technique in which activated carbon is adsorbed at a high removal rate and the activated carbon is injected into a flue upstream of the bag filter.

[0003]

The above prior art is regulated,
They are used in combination according to needs. Until now, no consideration has been given to simultaneously treating solid harmful components of dust and gaseous harmful components of hydrogen chloride, sulfur oxides, nitrogen oxides, mercury and organochlorine compounds. There is a problem with processing. In particular, with regard to the removal of mercury and organochlorine compounds, the technology that puts activated carbon into the flue and repairs it with a downstream bag filter uses activated carbon that has adsorbed those harmful components in dust generated in large quantities in a fluidized bed incinerator. And its separation is difficult. Further, the technology of decomposing nitrogen oxides and organochlorine compounds by providing a catalyst tower downstream of a bag filter requires new equipment, which not only increases the equipment cost of a refuse incinerator but also increases the installation area.
An object of the present invention is to reduce the amount of dust contained in exhaust gas, hydrogen chloride,
The simultaneous removal of sulfur oxides, nitrogen oxides, mercury and organochlorine compounds with a functional bag filter.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flue for introducing exhaust gas containing dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organochlorine compounds, and to treat the exhaust gas guided by the flue. This is achieved by having a functional bag filter carrying a catalyst and an adsorbent, a reducing agent supply means and a basic absorbent supply means connected to a flue upstream of the functional bag filter. The above-mentioned object is to decompose flue gas for introducing exhaust gas containing dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organochlorine compounds, and to decompose nitrogen oxides and organochlorine compounds in the exhaust gas guided by the flue gas. This is achieved by having a functional bag filter carrying a catalyst, an adsorbent for adsorbing organic chlorine compounds and heavy metals, a reducing agent supply means and a basic absorbent supply means connected to a flue upstream of the bag filter. The catalyst is a Ti, MO, V-based denitration catalyst, and the adsorbent is preferably activated carbon. The above objectives include dust, hydrogen chloride, sulfur oxides, nitrogen oxides,
This is achieved by blowing a reducing agent and a basic absorbent into an exhaust gas containing a heavy metal and an organochlorine compound, leading the exhaust gas to a functional bag filter carrying a catalyst and an adsorbent, and treating the exhaust gas. The purpose is dust, hydrogen chloride, sulfur oxide,
Blowing a reducing agent and a basic absorbent into an exhaust gas containing nitrogen oxides, heavy metals and organochlorine compounds, leading it to a functional bag filter carrying a catalyst and an adsorbent, and treating the exhaust gas at a temperature of 200 to 220 ° C. Is achieved by According to the above configuration, the acidic hydrogen chloride and sulfur oxide contained in the exhaust gas react with the basic absorbent blown upstream of the functional bag filter, and the reaction product is collected together with the dust by the functional bag filter. Is done. Nitrogen oxides are reduced to harmless nitrogen by performing a reducing reaction in a functional bag filter carrying a denitration catalyst with ammonia as a reducing agent blown upstream of the functional bag filter. Mercury is adsorbed by a functional bag filter carrying activated carbon as an adsorbent. Organochlorine compounds are oxidized and decomposed into carbon dioxide, moisture, and hydrogen chloride by a functional bag filter carrying a catalyst, and the decomposed hydrogen chloride reacts with the basic absorbent collected by the functional bag filter. At the same time as the organic chlorine compound alone is adsorbed on the adsorbent, thereby improving the removal efficiency. In this way, a plurality of harmful components in the exhaust gas can be simultaneously removed by the functional bag filter.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. The apparatus according to the present embodiment has an incineration amount of 4
Test plant with T / D capability. FIG. 1 is a flowchart showing the configuration of the embodiment of the present invention.
As shown in the figure, the exhaust gas from a fluidized bed incinerator 1 is cooled by an exhaust gas cooling tower 2, and the temperature is further reduced by a cooling tower 3. A flue 4 for introducing exhaust gas from the cooling tower 3 is connected to an alkali powder storage tank 5 for blowing alkali powder such as slaked lime and an ammonia storage tank 6 for blowing ammonia. A baghouse 7 containing a functional bag filter 8 is connected to the stack 4, and the exhaust gas is discharged to the chimney 10 to the baghouse 7.
The air blower 9 to send to the air is connected.

Embodiment 1 A functional bag filter 8 has a diameter of 15 cm and a length of 1.
Ti, MO, V type (90.5-5-4.5 wt.), In which 2 wt.
%) And a denitration catalyst having a particle size of 1 μm or less occupying 72% by weight of activated carbon were mixed at a weight ratio of 6: 4, and the supported amount was 38%.
What was carried at a rate of 0 g / m ² was used. ZnI ₂ may be used instead of activated carbon. An exhaust gas simultaneous treatment test was performed using the apparatus shown in FIG. 1 under the following conditions. Harmful component concentration in exhaust gas Dust 4.5 to 12 g / Nm ³ Hydrogen chloride 400 to 600 ppm Sulfur oxide 30 to 40 ppm Nitrogen oxide 100 to 120 ppm Mercury 0.2 to 0.5 mg / Nm ³ Organochlorine compound 18 to 68 ng TEQ / Nm ³ blowing conditions Slaked lime ratio 3.5 Ca / (Cl + 1 / 2S) Slaked lime particle size 3 μm Slaked lime specific surface area 35 m ² / g NH ₃ / NO 1.0 Bag filter condition Temperature 180-240 ° C. Exhaust gas passing flow rate 1 m / min Test result Above Table 1 shows the results of the exhaust gas simultaneous treatment test under the conditions.

[0007]

[Table 1]

Embodiment 2 The functional bag filter 8 has a diameter of 15 cm and a length of 1.
67% by weight of 1m or less particle size in 2m polyimide nonwoven fabric
Ti, MO, V system (90.5-5-4.5 wt
%) And an adsorbent in which 10 wt% of ZnI ₂ is supported on diatomaceous earth having a particle diameter of 1 μm or less occupying 48 wt% at a ratio of 4 to 6 by weight, and the supporting amount is 520 g / m ² . What was carried was used. Test Results Table 2 shows the results of the exhaust gas simultaneous treatment test performed under the above conditions.

[0009]

[Table 2]

In the simultaneous exhaust gas treatment by the functional bag filter 8 carrying a catalyst and an adsorbent, as shown in Table 1, the removal rate of the organic chlorine compound is high regardless of the temperature because the decomposition by the catalyst and the adsorption by the activated carbon This is due to the synergistic effect of The concentration of harmful components at a temperature of 200 ° C. at the outlet of the functional bag filter 8 is as follows: dust 0.006 g / Nm ³ or less Hydrogen chloride 20 ppm or less Sulfur oxide 10 ppm or less Nitrogen oxide 30 ppm or less Mercury 0.02 mg / Nm ³ or less Organochlorine compound 0 .1 ng TEQ / Nm ³ or less, and advanced treatment of exhaust gas was sufficiently achieved. In particular, the organic chlorine compounds are rendered harmless, and mercury is stored in the functional bag filter 8.

In the operating conditions of the functional bag filter 8, the upper limit of the temperature depends on the heat resistance of the material, but can be in the range of 160 to 240 ° C., and the range of 200 to 220 ° C. is desirable in consideration of the removal rate of harmful components. The rate at which the catalyst and the adsorbent are loaded on the functional bag filter 8 is 200 to 600 g / m ^2.
And the range of 300 to 400 g / m ² is desirable, at which time the exhaust gas passage velocity is 1.4 to 1.5 m / m ^2.
Even if it is increased to min, a high removal rate can be obtained. As described above, the embodiment has the following effects. 1. The facility cost and installation area of the refuse incinerator can be reduced without requiring a new processing device downstream of the bag house. 2. Even if the temperature is low under the operating conditions of the functional bag filter, the removal rate of nitrogen oxides, mercury, and organic chlorine compounds among the harmful components is good, and especially the organic chlorine compound removal rate is excellent. 3. Mercury and organochlorine compounds are accumulated in the adsorbent collected by the functional bag filter and are not mixed with a large amount of fly ash as in the prior art, so that subsequent processing is easy. 4. The amount of catalyst and adsorbent carried on the functional bag filter is extremely small as compared with the prior art, and the operating cost can be reduced.

[0012]

According to the present invention, a basic absorbent and a reducing agent are blown into the upstream of a functional bag filter to decompose and adsorb harmful components in exhaust gas by a catalyst and an adsorbent carried on the functional bag filter. In addition, an effect of simultaneously removing a plurality of harmful components in the exhaust gas with the functional bag filter can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a configuration of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Incinerator 2 Exhaust gas cooling tower 3 Cooling tower 4 Flue 5 Alkaline powder storage tank 6 Ammonia storage tank 7 Bag house 8 Functional bag filter 9 Induction blower 10 Chimney

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B01D 53/64 B01D 53/36 G 53/86 Z ZAB ZABD 53/94 102D F23J 15/00 F23J 15/00 AB HJ

Claims (5)

[Claims] 1. A flue for introducing exhaust gas containing dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organochlorine compounds, and a function of carrying a catalyst and an adsorbent for treating the exhaust gas guided by the flue. An exhaust gas simultaneous treatment device comprising: a functional bag filter; a reducing agent supply unit and a basic absorbent supply unit connected to a flue upstream of the functional bag filter. 2. A flue for introducing exhaust gas containing dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organochlorine compounds, and decomposes nitrogen oxides and organochlorine compounds in the exhaust gas led by the flue. A functional bag filter carrying an adsorbent for adsorbing an organic chlorine compound and heavy metals, and a reducing agent supply means and a basic absorbent supply means connected to a flue upstream of the functional bag filter. Exhaust gas simultaneous treatment device. 3. The exhaust gas simultaneous treatment apparatus according to claim 1, wherein the catalyst is a Ti, MO, V-based denitration catalyst, and the adsorbent is activated carbon. 4. A reducing agent and a basic absorbent are blown into an exhaust gas containing dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organochlorine compounds, and are guided to a functional bag filter carrying a catalyst and an adsorbent. Treating the exhaust gas simultaneously. 5. An exhaust gas containing dust, hydrogen chloride, sulfur oxides, nitrogen oxides, heavy metals and organochlorine compounds is blown with a reducing agent and a basic absorbent, and guided to a functional bag filter carrying a catalyst and an adsorbent. Exhaust gas treatment at a temperature of from 200 to 220C.