JP2002153838A - Method for treating activated carbon with dioxins adsorbed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method effective for burning the DXN(dioxin)-adsorbed activated carbon completely when the DXN-adsorbed activated carbon obtained by treating with powdery activated carbon the DXN-containing exhaust gas generated when waste is incinerated or melted is burned. SOLUTION: Powdery activated carbon is blown into the DXN-containing exhaust gas generated when waste is incinerated or melted on the upstream side of a duct collector to adsorb/remove DXN from the exhaust gas, the DXN- adsorbed activated carbon collected at the duct collector is mixed with liquid fuel and the obtained mixture of a slurry state is sent to an incinerator, a melting furnace, an afterburning chamber or the high temperature part of the flue of each of these facilities to burn it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a DXN (hereinafter referred to as D
XN) is blown into a waste incineration exhaust gas or a waste molten exhaust gas containing activated carbon powder upstream of a dust collecting apparatus, and DXN is adsorbed and removed from the exhaust gas.

[0002]

2. Description of the Related Art In recent years, DXN emission regulations for exhaust gas typified by waste incinerators have been tightened, and the incineration capacity is 4 t / h.
Emission standards 0.1ng-TEQ / Nm ³ is defined in the above new furnace. In addition, residents around the facility are demanding emission at a lower concentration than the regulated value. DX like this
One of the methods for responding to the demand for a high level of N reduction is the adsorption removal method using activated carbon, that is, 50
A method has been developed in which powder activated carbon of 100 mg / Nm ³ or more is blown to form an activated carbon layer on a filter cloth to adsorb and remove DXN.

[0003] DXN removal method using activated carbon includes DXN.
There is a problem with the treatment of activated carbon that has adsorbed water. When this is discharged outside the facility, the treatment standards for dust and soot related to the waste incinerator (3
When DXN of ng-TEQ / g or more is adsorbed on activated carbon, it is necessary to perform a decomposition treatment of DXN. For this reason, as a method of treating the DXN-adsorbed activated carbon, a method of injecting it into an incinerator and incinerating it has been considered.

When employing this incineration method, it is necessary to completely burn the activated carbon. If the combustion does not proceed sufficiently, DXN adsorbed on the activated carbon will not be decomposed, but will be scattered again in the exhaust gas, and densified from the activated carbon.
DXN is generated by ovo synthesis, which causes the concentration of DXN in exhaust gas to be increased.

[0005]

An object of the present invention is to provide a DX.
It is an object of the present invention to provide an effective method for completely burning the activated carbon adsorbed by DXN when incinerating the produced DXN-adsorbed activated carbon by using powdered activated carbon for treating waste incineration exhaust gas or waste molten exhaust gas containing N. .

[0006]

According to a first treatment method of the present invention, activated carbon powder is blown into a waste incineration exhaust gas or a waste molten exhaust gas containing DXN in front of a dust collector,
In the method for adsorbing and removing DXN from exhaust gas, DXN-adsorbed activated carbon collected in a dust collector is mixed with a liquid fuel,
This is a method for treating DXN-adsorbed activated carbon, which comprises sending the obtained mixture in a slurry state to an incinerator, a melting furnace, a reburning chamber or a high-temperature portion of a facility flue for incineration treatment.

[0007] In the first treatment method, the dust collector is preferably an electric dust collector or a bag filter. The activated carbon is preferably a powdered activated carbon having a particle diameter of 500 μm or less.
The liquid fuel is preferably gasoline, kerosene, light oil or heavy oil. The mixing ratio between the DXN-adsorbed activated carbon and the liquid fuel is preferably in the range of 1: 1 to 1: 1,000,000 by weight.
Prior to incineration, DXN-adsorbed activated carbon can be separated from the mixture slurry by solid-liquid separation and then incinerated. DX
It is preferable that the mixture of the N-adsorbed activated carbon and the liquid fuel be incinerated by a burner provided in a high temperature portion of the facility flue where the exhaust gas temperature is 800 ° C. or higher. Solid-liquid separation is preferably 1 to 50 μm
Perform on a mesh screen. The liquid fuel separated from the slurry can be used again as a liquid fuel for mixing DXN-adsorbed activated carbon collected in the dust collector.

In a second treatment method according to the present invention, activated carbon powder is blown into a waste incineration exhaust gas or a waste molten exhaust gas containing DXN in front of a dust collector, and DXN is discharged from the exhaust gas.
In the method of adsorbing and removing D, the D
XN adsorption activated carbon is mixed with catalyst, waste incineration fly ash or waste melting fly ash, and the resulting mixture is supplied to an incinerator, a melting furnace, a reburning room or a high temperature section of a facility flue for incineration. This is a method for treating DXN-adsorbed activated carbon.

In the second treatment method, the dust collector is preferably an electric dust collector or a bag filter. The activated carbon is preferably a powdered activated carbon having a particle diameter of 500 μm or less.
The catalyst is preferably Na, K, Mg, Ca, Zn, Ni,
Pb, Ti, Cu, Fe, Sn, Mn, Al, V, W or Mo, or an oxide or salt thereof. Since the smoke wastewater discharged from the smoke tower contains alkali metals such as Na and alkaline earth metals such as Mg and Ca, the wastewater is sprayed onto the DXN-adsorbed activated carbon to mix the DXN-adsorbed activated carbon with the catalyst. You can also. Mixing catalyst, waste incineration fly ash or waste molten fly ash with DXN adsorption activated carbon, adding DXN adsorption activated carbon to an aqueous solution of catalyst, waste incineration fly ash or waste molten fly ash, or DXN adsorption activated carbon Then, it is preferable to spray an aqueous solution of a catalyst, waste incineration fly ash or waste melting fly ash to contain DXN-adsorbed activated carbon, a catalyst, waste incineration fly ash or waste melting fly ash. Using nitric oxide or nitrogen dioxide or sulfur dioxide as a catalyst and contacting it with DXN-adsorbed activated carbon, or using an aqueous nitric acid solution or sulfuric acid solution as a catalyst and adding DXN-adsorbed activated carbon to it or subjecting it to DXN adsorption Spray on activated carbon, DX
The N-adsorbed activated carbon may contain a catalyst. It is preferable that the DXN-adsorbed activated carbon is dried to a water content of 30% or less by weight before being supplied to the incineration position. DXN
The mixing ratio of the adsorbed activated carbon to the catalyst, waste incineration fly ash or waste melt fly ash is preferably 100: 0.1 to 10 by weight.
0: 1000 range. A combination of two or more of catalyst, waste incineration fly ash and waste molten fly ash can also be mixed with DXN-adsorbed activated carbon. Preferably, the mixture is incinerated by a burner provided in a high temperature section of the facility flue where the exhaust gas temperature is 800 ° C. or higher. The incineration of the mixture is preferably carried out using a pulverized coal burner.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be specifically described based on embodiments.

Embodiment 1 FIGS. 1 and 2 show a method in which powdered activated carbon is blown into a DXN-containing exhaust gas upstream of a dust collector, and DXN is adsorbed and removed from the exhaust gas.

In a system in which fly ash hardly exists in exhaust gas, as shown in FIG. 1, DXN-adsorbed activated carbon is recovered from a dust collector. In a system where fly ash is present in the exhaust gas, as shown in FIG. 2, a bag filter is provided downstream of the dust collector, and the DXN-adsorbed activated carbon is collected by the bag filter.

As shown in FIG. 3, DXN-adsorbed activated carbon collected in a dust collector is mixed with kerosene, and the obtained mixture is sent to an incinerator in a slurry state, and fuel is supplied to a burner provided on the wall of the incinerator. And incinerated by complete combustion. In FIG. 3, (1) is an incinerator, (2) is its burner, and (3) is a boiler.

Example 2 As shown in FIG. 4, DXN-adsorbed activated carbon collected in a dust collector was mixed with kerosene, and the resulting mixture was sent to a filtration tank (4) in a slurry state to be filtered to a 10 μm mesh. Screen (5)
And filtered. The separated DXN-adsorbed activated carbon is put into the front side of the incinerator, and the DXN-adsorbed activated carbon is incinerated by complete combustion. The kerosene separated from the slurry is used again for mixing the DXN-adsorbed activated carbon collected in the dust collector. In FIG. 4, (1) is an incinerator and (3) is a boiler.

Example 3 As shown in FIG. 5, a catalyst or waste incineration fly ash was mixed with DXN-adsorbed activated carbon collected by a dust collector, and the resulting mixture was sent to an incinerator, and the incinerator wall was removed. The fuel is blown into the pulverized coal burner provided in the above, and incinerated by complete combustion. In FIG. 5, (1) is an incinerator, (2) is a pulverized coal burner,
(3) is a boiler.

Example 4 As shown in FIG. 6, DXN-adsorbed activated carbon was mixed with a catalyst by spraying smoke-washing wastewater from a smoke-washing tower onto DXN-adsorbed activated carbon collected in a dust collector. The mixture is introduced into the front side of the incinerator, and the DXN-adsorbed activated carbon is incinerated by complete combustion. In FIG. 6, (1) is an incinerator and (3) is a boiler.

Differential thermal analysis (DTA) New activated carbon, activated carbon with NO ₂ attached to new activated carbon,
FIG. 5 shows the measurement results of differential thermal analysis under an air atmosphere for three types of activated carbons carrying KOH.

The new activated carbon starts burning at 520 ° C., whereas the activated carbon in which NO ₂ is adsorbed on the new activated carbon is 4%.
It can be seen that 90 ° C. and 250 ° C. for KOH-supported activated carbon have lower combustion start temperatures, respectively. That is, by adopting the second processing method according to the present invention, DX
The activated carbon to which N is adsorbed can be ignited at an early stage, and can be easily completely burned.

[0019]

According to the first processing method of the present invention,
The following effects can be obtained.

Since the transport form of the DXN-adsorbed activated carbon is a slurry, the operation is easier than that of a powdered object of the DXN-adsorbed activated carbon alone, and there is no danger of dust explosion in the transport pipe.

Activated carbon is produced by activating the raw material at a temperature close to 1000 ° C., so it contains almost no volatile matter and hardly starts burning. However, by mixing kerosene with activated carbon, it becomes a combustion promoter, and DXN adsorbed activated carbon is used. Can be completely burned.

Mixing kerosene with the DXN-adsorbed activated carbon makes the DXN-adsorbed activated carbon heavier. As a result, the DXN-adsorbed activated carbon that has not been sufficiently burned is scattered along with the combustion gas flow and flows out into the flue. Can be prevented.

According to the second processing method of the present invention, D
Activated carbon adsorbed by XN can be ignited early,
It can be completely burned easily.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a method in which powdered activated carbon is blown into DXN-containing exhaust gas in front of a dust collector in a system in which fly ash is hardly present in exhaust gas, and DXN is adsorbed and removed from the exhaust gas by activated carbon. is there.

FIG. 2 is a diagram showing a system in which fly ash is present in exhaust gas, in which powdered activated carbon is blown into DXN-containing exhaust gas in front of a dust collector;
It is a flow sheet which shows the method of making DXN adsorb and remove from exhaust gas.

FIG. 3 is a flow sheet showing a method of mixing DXN-adsorbed activated carbon with kerosene and sending the mixture to an incinerator in a slurry state for incineration.

FIG. 4 is a diagram showing a mixture of DXN-adsorbed activated carbon and kerosene, and sending the mixture in a slurry state to a filtration tank where the mixture is filtered and separated.
It is a flow sheet which shows the method of incinerating XN adsorption activated carbon in an incinerator.

FIG. 5 is a flow sheet showing a method of mixing catalyst or waste incineration fly ash with DXN-adsorbed activated carbon and incinerating the mixture with a pulverized coal burner in an incinerator.

FIG. 6 is a flow sheet showing a method of mixing DXN-adsorbed activated carbon with a catalyst by spraying smoke washing wastewater onto DXN-adsorbed activated carbon, and incinerating the mixture in an incinerator.

FIG. 7 shows differential thermal analysis (DT) of three types of activated carbon, a new activated carbon, an activated carbon obtained by adhering NO _{2 to} a new activated carbon, and an activated carbon carrying KOH, in an air atmosphere.
It is a graph which shows the measurement result of A) in FIG.

[Explanation of symbols]

 (1): Incinerator (2): Burner (3): Boiler (4): Filtration tank (5): Screen

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 7/00 ZAB B09B 3/00 ZAB F23J 15/00 F23J 15/00 JH (72) Inventor Osamu Hamano 1-7-89 Minami Kohoku, Suminoe-ku, Osaka Nichi Tate Shipbuilding Co., Ltd. (72) Inventor Kenichi Nagai 1-7-89 Minami Kohoku, Suminoe-ku, Osaka Nichi Tate Shipbuilding Co., Ltd. F-term (reference) 3K070 DA01 DA03 DA05 DA24 DA25 DA30 DA32 DA37 4D002 AA21 AC04 BA04 CA11 DA41 4D004 AA37 AA47 AA50 AB07 AC05 BA03 CA13 CA15 CA28 CA42 CB34 CC09 DA03 DA09 DA10 DA20 4D048 AA11 BA01Y BA03Y BA05Y BA14Y BA15Y BA21 BAY BAYY CC38 CD03 CD05 EA04 4G066 AA05A AA05B BA09 CA33 DA02 EA20

Claims (20)

[Claims] 1. A method for blowing powdered activated carbon into a waste incineration exhaust gas or a waste molten exhaust gas containing dioxins in front of a dust collector to adsorb and remove dioxins from the exhaust gas, wherein the dust is collected by a dust collector. The activated carbon adsorbed with dioxins is mixed with liquid fuel, and the resulting mixture is incinerated in a slurry state.
A method for treating dioxin-adsorbed activated carbon, wherein the activated carbon is sent to a melting furnace, a reburning chamber or a high-temperature portion of a facility flue for incineration. 2. The method according to claim 1, wherein the dust collector is an electric dust collector or a bag filter. 3. The method according to claim 1, wherein the activated carbon is a powdered activated carbon having a particle diameter of 500 μm or less. 4. The method according to claim 1, wherein the liquid fuel is gasoline, kerosene, light oil or heavy oil. 5. The method according to claim 1, wherein the mixing ratio between the dioxin-adsorbed activated carbon and the liquid fuel is 1: 1 to 1 by weight.
1: A method for treating dioxins-adsorbed activated carbon, which is in the range of 1,000,000. 6. The method according to claim 1, wherein the dioxin-adsorbed activated carbon is separated from the mixture slurry by solid-liquid separation before incineration, and the resulting mixture is incinerated. 7. The method according to claim 1, wherein a mixture of the dioxin-adsorbed activated carbon and the liquid fuel is incinerated by a burner provided in a high temperature section of the facility flue where the exhaust gas temperature is 800 ° C. or higher. Treatment method for activated carbon. 8. The method according to claim 6, wherein the solid-liquid separation is performed on a screen having a mesh of 1 to 50 μm. 9. The method according to claim 6, wherein
A method for treating dioxin-absorbed activated carbon, wherein the liquid fuel separated from the slurry is used again as a liquid fuel for mixing the dioxin-absorbed activated carbon collected in the dust collector. 10. A method for blowing powdered activated carbon into a waste incineration exhaust gas or a waste molten exhaust gas containing dioxins in front of a dust collecting device to adsorb and remove dioxins from the exhaust gas. The catalyst, waste incineration fly ash or waste melting fly ash is mixed with the activated dioxin-adsorbed activated carbon or sprayed with smoke washing wastewater, and the smoked wastewater is sprayed, and the resulting mixture is used in incinerators, melting furnaces, reburning rooms or facility flue. A method for treating dioxins-adsorbed activated carbon, wherein the activated carbon is supplied to a high-temperature section and incinerated. 11. The method according to claim 10, wherein the dust collecting device is an electric dust collector or a bag filter. 12. The method according to claim 10, wherein the activated carbon is a powdered activated carbon having a particle diameter of 500 μm or less. 13. The method according to claim 10, wherein the catalyst is Na, K, Mg, Ca, Zn, Ni, Pb, Ti, C.
A method for treating dioxin-adsorbed activated carbon, which is u, Fe, Sn, Mn, Al, V, W, or Mo, or an oxide or a salt thereof. 14. The method according to claim 10, wherein the catalyst, waste incineration fly ash or waste molten fly ash is mixed with DXN-adsorbed activated carbon or an aqueous solution of the catalyst, waste incinerated fly ash or waste molten fly ash. Put dioxin-adsorbed activated carbon into the dioxin-containing activated carbon, or spray an aqueous solution of catalyst, waste incineration fly ash or waste molten fly ash onto the dioxin-adsorbed activated carbon, and dioxin-adsorbed activated carbon, catalyst, waste incineration fly ash or A method for treating activated carbon adsorbing dioxins, characterized by including waste molten fly ash. 15. The method according to claim 10, wherein nitric oxide, nitrogen dioxide, or sulfur dioxide is used as a catalyst and brought into contact with activated carbon adsorbing dioxins, or an aqueous nitric acid solution or an aqueous sulfuric acid solution is used as a catalyst. A method for treating dioxin-adsorbed activated carbon, which comprises adding a catalyst to the dioxin-adsorbed activated carbon by adding dioxin-adsorbed activated carbon to the dioxin-adsorbed activated carbon, or spraying the dioxin-adsorbed activated carbon on the dioxin-adsorbed activated carbon. 16. The dioxin-adsorbed activated carbon according to claim 14, wherein the water content in the dioxin-adsorbed activated carbon is dried to 30% or less by weight before being supplied to the incineration position. Processing method. 17. The method according to claim 10, wherein the mixing ratio of the activated carbon adsorbed with dioxins and the catalyst, waste incineration fly ash or waste molten fly ash is 100: 0.1 to 10 by weight.
A method for treating dioxins-adsorbed activated carbon, wherein the ratio is in the range of 0: 1000. 18. The method according to claim 10, wherein a combination of two or more of catalyst, waste incineration fly ash, and waste molten fly ash is mixed with the dioxin-adsorbed activated carbon. Method. 19. The method according to claim 10, wherein the mixture is incinerated by a burner provided in a high-temperature section of the facility flue at an exhaust gas temperature of 800 ° C. or higher. 20. The method according to claim 10, wherein the incineration of the mixture is performed using a pulverized coal burner.