JPH11182835A - Method and device for treating exhaust gas at gasifying incinerating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of chemicals to remove a noxious material. SOLUTION: A cyclone 11 to collect carbonaceous residues from thermal decomposition gas is located in a thermal decomposition gas introduction line 2 connected to a gasifying melt furnace 3 from a gasifying incinerator 1. A carbonaceous residue line 17 running from the cyclone 11 is connected to an exhaust gas line 4 and introducing collected carbonaceous residues in exhaust gas and adsorbing a noxious material is arranged. A second filter 13 to collect a carbonaceous material after adsorption from exhaust gas is arranged in the exhaust line 4 situated downstream from the connection part of the carbonaceous feed line 17. Namely, carbonaceous residues having the same nature as that of activated coal are effectively utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasification and incineration plant for introducing a pyrolysis gas generated in a gasification and incineration furnace into a gasification and melting furnace to burn and melt ash accompanying the pyrolysis gas. The present invention relates to an exhaust gas treatment method and apparatus for removing harmful components of exhaust gas.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a dry type exhaust gas treatment apparatus in a gasification and incineration system uses a pyrolysis gas introduction line 2 to convert a pyrolysis gas generated in a fluidized bed type gasification and incinerator 1 into a gas. Then, it is introduced into the gasification melting furnace 3 and burned to melt ash contained in the pyrolysis gas (incineration ash discharged from the incinerator can also be melted). In the exhaust gas line 4 of the exhaust gas, after heat is recovered from the exhaust gas by the heat exchanger 5, a chemical such as slaked lime or activated carbon is blown into the exhaust gas by the chemical supply device 6, and the agglomerated substance that agglomerated harmful substances by the chemical is bag-filtered. Collect at 7. And the exhaust gas is reheated 8
After the heating, the gas was introduced into the denitration device 9, denitrated, and discharged from the chimney 10.

[0003]

However, the above configuration has a problem that the running cost due to the blowing of the chemical is high, and the cost is particularly increased due to activated carbon.

[0004] It is an object of the present invention to provide a method and an apparatus for treating exhaust gas in a gasification and incineration plant which can remove harmful substances in exhaust gas at low cost by solving the above problems.

[0005]

According to a first aspect of the present invention, there is provided a method for treating an exhaust gas, comprising: introducing a pyrolysis gas generated in a gasification incinerator into a gasification melting furnace; When treating the exhaust gas of the gasification incinerator that melts the ash, the carbonaceous residue is taken out of the pyrolysis gas generated in the gasification incinerator, and this carbon residue is blown into the exhaust gas discharged from the gasification and melting furnace. In this method, the harmful substances in the exhaust gas are adsorbed, and the carbon residue after the adsorption of the harmful substances is collected from the exhaust gas.

According to a fourth aspect of the present invention, there is provided an exhaust gas treatment apparatus for a gasification and incineration facility for introducing a pyrolysis gas generated in a gasification and incineration furnace into a gasification and melting furnace to burn and melt ash. The pyrolysis gas introduction line connected from the incinerator to the gasification and melting furnace is provided with a carbonaceous collection means for collecting carbonaceous residues from the pyrolysis gas, and is connected to the exhaust gas line from the carbonaceous capture means. A carbonaceous supply line for introducing the collected carbonaceous residue into the exhaust gas and adsorbing harmful substances is provided, and the carbonaceous material after the adsorption from the exhaust gas is provided in the exhaust gas line downstream of the carbonaceous supply line connection. It is provided with a carbonaceous material collecting means for collecting the residue.

[0007] According to each of the above constitutions, the harmful substances in the exhaust gas can be adsorbed and removed by effectively utilizing the carbonaceous residue in the pyrolysis gas, so that the exhaust gas can be satisfactorily treated and the running cost of using chemicals can be reduced. Can be.

According to a second aspect of the present invention, in addition to the method of the first aspect, a chemical is blown into the exhaust gas to cause a reaction, and the reaction aggregate is collected together with fly ash, and then the carbonaceous residue is contained in the exhaust gas. Is to blow in.

According to a fifth aspect of the present invention, in addition to the exhaust gas treating apparatus of the fourth aspect, a chemical is blown into the exhaust gas on the upstream side of the exhaust gas line upstream of the connection portion of the carbonaceous supply line to react harmful substances. The apparatus is provided with a medicine supply means for aggregating and a dust collecting means for catching the agglutinate on the downstream side.

According to each of the above-mentioned structures, after the reaction agglomerates are captured by the dust collecting means with the chemical on the upstream side of the exhaust gas line, the harmful substances are adsorbed and captured by the carbonaceous residue on the downstream side thereof. And the fly ash that is difficult to treat and the carbonaceous residue that can be incinerated after the adsorption of harmful substances can be separately collected without increasing the throughput of fly ash.

According to a third aspect of the present invention, in addition to the method of the second aspect, the carbonaceous residue collected from the exhaust gas after the adsorption of the harmful substance is introduced into a gasification melting furnace and burned together with the pyrolysis gas. It is.

[0012] Further, according to the invention of claim 6, in addition to the constitution of claim 5, the carbonaceous residue connected to the gasification and melting furnace from the carbonaceous recovery means burns the carbonaceous residue after the adsorption of harmful substances together with the pyrolysis gas. A quality processing line is provided.

According to each of the above structures, the carbonaceous residue after the adsorption of harmful substances is reused as fuel for the gasification and melting furnace.
The calorific value of the pyrolysis gas does not decrease.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of a gasification and incineration plant according to the present invention will be described with reference to FIG. The same members as those in the related art will be described with the same reference numerals.

The cyclone gas introduction line 2 is provided with a cyclone 11 as carbonaceous capturing means for capturing carbonaceous residues from the pyrolysis gas. Note that, as the carbonaceous capturing means, a capturing device of a collision plate type, a wire mesh type, a bag filter type, or the like can be employed instead of the cyclone 11.

In the exhaust gas line 4, a first bag filter 1 serving as an upstream dust collecting means is provided downstream of the heat exchanger 5.
2 and a second bag filter 13 as a carbonaceous recovery means on the downstream side, and the first bag filter 12
A coagulation drug from a drug supply device 14 which is a drug supply means,
For example, slaked lime is put into an exhaust gas, brought into contact with a chlorine gas, a sulfide gas, or the like, and reacted to generate a particulate aggregated compound and capture the aggregated particles of these compounds.

The fly ash caught by the first bag filter 12 is sent to a detoxification processing device 16 via a fly ash processing line 15, detoxified, transported to a landfill, and used for landfill. Or be offered to Yamamoto reduction. The yamamoto reduction refers to recovering valuable metals in the collected ash by chemical means or physical means.

From the cyclone 11 to the first bag filter 1
An exhaust gas line 4 between the second bag filter 13 and the second bag filter 13 is provided with a carbonaceous supply line 17 for pneumatically feeding the carbonaceous residue collected by the cyclone 11 and introducing the residue into the exhaust gas. The carbonaceous residue collected from the pyrolysis gas is composed of char (dry carbon content) and tar content, and reacts and binds with harmful substances such as heavy metals and sulfide gas, similar to activated carbon.
It can be adsorbed and collected. Therefore, by introducing this into the exhaust gas from the carbonaceous supply line 17, harmful substances are adsorbed similarly to the activated carbon, and the second bag filter 1
Exhaust gas can be detoxified by collecting and removing it in step 3. The amount of fly ash collected by the first bag filter 12 is reduced, and the amount of processing and landfill by the detoxification processing device 16 is reduced as compared with the case where slaked lime and activated carbon are simultaneously injected as in the related art. You.

Between the second bag filter 13 and the downstream side of the cyclone 11 of the pyrolysis gas introduction line 2, the collected carbonaceous residue after the adsorption of the harmful substances is fed to the gasification and melting furnace 3 for melting. Carbonaceous processing line 18 is connected. Accordingly, the carbonaceous residue and the adsorbed substance thereof can be heated and melted to reduce the volume and render the carbonaceous residue harmless.

In the above configuration, when refuse is supplied to the gasification incinerator 1, the refuse is dry-distilled in a high-temperature fluidized bed to generate a pyrolysis gas, and the pyrolysis gas is supplied to the pyrolysis gas introduction line 2.
Is introduced into the gasification and melting furnace 3 via the At this time, the pyrolysis gas is supplied to the cyclone 11 in the middle of the pyrolysis gas introduction line 2.
And the carbonaceous residue is captured. Gasification and melting furnace 3
In this method, combustion air is mixed at high speed and burned, and ash entrained by the pyrolysis gas is melted and discharged as molten slag.

The exhaust gas is discharged to an exhaust gas line 4 and recovered in a heat exchanger 5.
Slaked lime is blown into the exhaust gas by the sludge, and slaked lime causes reactive aggregates of chlorine gas and sulfide gas to flow into the first bag filter 1.
Collected at 2. Next, the carbonaceous residue is blown into the exhaust gas from the carbonaceous supply line 17 to be brought into contact with and adsorbed to harmful substances in the exhaust gas. The carbonaceous residue after the adsorption of these harmful substances is collected by the second bag filter 13. Thereafter, the exhaust gas is heated by the reheater 8, introduced into the denitration device 9, denitrated, and discharged from the chimney 10.

The carbonaceous residue collected by the second bag filter 13 after the adsorption of harmful substances is returned to the pyrolysis gas introduction line 2 downstream of the cyclone 4 by the carbonaceous recovery line 18 and merges with the pyrolysis gas. The gas is supplied to the melting furnace 3 and burned.

According to the above embodiment, the carbonaceous residue in the pyrolysis gas having the same properties as the activated carbon is taken out and used effectively, and the harmful substances in the exhaust gas are adsorbed and removed. Can be greatly reduced,
Exhaust gas can be satisfactorily treated, and running costs can be reduced.

Further, since the harmful substances are adsorbed and trapped by the carbonaceous residue downstream of the first bag filter 12 for trapping the aggregates due to the chemicals, the fly ash containing heavy metals trapped by the first bag filter 12 is removed. The amount can be reduced and fly ash can be easily treated.

Further, the carbonaceous residue after the adsorption of harmful substances is
After collection by bag filter 13, carbonaceous processing line 1
Since the fuel is sent to the gasification and melting furnace 3 and reused as fuel by the method 8, the calorific value of the pyrolysis gas does not decrease.

FIG. 2 shows a modification of the above embodiment.
The first bag filter 12 is changed to an electric dust collector 21,
The same effect can be obtained by providing the wet smoke washer 22 for removing dioxin on the downstream side of the second bag filter 13.

[0027]

As described above, according to the first and fourth aspects of the present invention, the harmful substances in the exhaust gas can be adsorbed and removed by effectively utilizing the carbonaceous residue in the pyrolysis gas. Can be satisfactorily treated, and the running cost of using a drug can be reduced.

According to the second and fifth aspects of the present invention, after the reaction agglomerates are trapped by the chemicals on the upstream side of the exhaust gas line with the chemical, the harmful substances are adsorbed and trapped by the carbonaceous residues on the downstream side. Therefore, it is possible to separately collect fly ash which contains heavy metals and is difficult to treat, and carbonaceous residue after adsorption of harmful substances which can be incinerated, without increasing the throughput of fly ash.

Further, according to the third and sixth aspects, the carbonaceous residue after the adsorption of harmful substances is reused as fuel for the gasification and melting furnace, so that the calorific value of the pyrolysis gas does not decrease.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a gasification and incineration facility according to the present invention.

FIG. 2 is a configuration diagram showing a modification of the gasification and incineration facility.

FIG. 3 is a configuration diagram showing a modification of the conventional gasification and incineration facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gasification incinerator 2 Pyrolysis gas introduction line 3 Gasification and melting furnace 4 Exhaust gas line 11 Cyclone (carbonaceous collecting means) 12 First bag filter (dust collecting means) 13 Second bag filter (carbonaceous collecting means) 14 Chemical supply device 16 Detoxification device 17 Carbonaceous supply line 18 Carbonaceous treatment line

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23G 5/02 ZAB F23G 5/14 ZABE 5/027 ZAB F23J 1/00 B 5/14 ZAB B01D 53/34 B F23J 1/00 F23J 15 / 00Z (72) Inventor Yoshimasa Miura 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Hideo Shimotani 1-7-89 Minami-Kohoku, Suminoe-ku, Osaka-shi, Osaka Hitachi Zosen Corporation (72) Inventor Daisuke Fujita 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Hitachi Zosen Corporation

Claims (6)

[Claims] Claims 1. A pyrolysis gas generated in a gasification incinerator,
When processing exhaust gas from a gasification incinerator that melts ash by introducing it into a gasification and melting furnace, it removes carbonaceous residues from the pyrolysis gas generated by the gasification and incineration furnace, and gasifies and melts the carbon residues. A method for treating exhaust gas in a gasification and incineration plant, comprising blowing into exhaust gas discharged from a furnace to adsorb harmful substances in the exhaust gas, and collecting carbon residues after the adsorption of the harmful substance from the exhaust gas. 2. A reaction is performed by blowing a chemical into exhaust gas.
2. The method for treating exhaust gas in a gasification and incineration plant according to claim 1, wherein a carbonaceous residue is blown into the exhaust gas after collecting the reaction aggregate together with fly ash. 3. The exhaust gas treatment in a gasification and incineration plant according to claim 2, wherein the carbonaceous residue collected from the exhaust gas after the adsorption of harmful substances is introduced into a gasification melting furnace and burned together with a pyrolysis gas. Method. 4. An exhaust gas treatment apparatus for a gasification and incineration facility for introducing a pyrolysis gas generated in a gasification and incineration furnace into a gasification and melting furnace to burn and melt ash, wherein a gasification and incineration furnace is provided. In the pyrolysis gas introduction line connected to, a carbonaceous material collecting means for collecting carbonaceous residues from the pyrolysis gas is interposed, and the collected carbonaceous material is connected to the exhaust gas line from the carbonaceous capturing means. Providing a carbonaceous supply line for adsorbing harmful substances by introducing the residue into the exhaust gas, in the exhaust gas line downstream of the carbonaceous supply line connection,
An exhaust gas treatment apparatus for a gasification and incineration plant, comprising a carbonaceous recovery means for collecting carbonaceous residues after harmful substance adsorption from exhaust gas. 5. A chemical supply means for injecting a chemical into an exhaust gas on an upstream side of an exhaust gas line upstream of a connection portion of a carbonaceous supply line to react and coagulate harmful substances, and a dust collecting means for capturing an agglomerated substance on a downstream side. The exhaust gas treatment device for a gasification and incineration plant according to claim 4, further comprising: 6. A carbonaceous treatment line connected to the gasification and melting furnace from the carbonaceous recovery means and configured to burn the carbonaceous residue after adsorption of the harmful substance together with the pyrolysis gas. Exhaust gas treatment equipment for gasification and incineration equipment.