JP2001220119A - Method for manufacturing activated carbon from waste and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing activated carbon with the heat supplied from the outside minimized at the time of continuously carbonizing and activating waste as a raw material. SOLUTION: Scrap wood 30 as the raw material is continuously charged into a rotary kiln 11. The scrap wood 30 is partially burned in an aeration part 12 since hot air is supplied from a wind box 19 and further transported in a non-aeration part 13 to promote carbonization. The obtained primary carbon is sent to an activation furnace 2. The dry-distillation gas generated in a carbonization furnace 1 is sucked by a steam ejector 7, sent to a combustor 6, burned and then sent to the activation furnace 2. The primary carbon is activated by the activating gas to obtain activated carbon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing activated carbon used for gas treatment, water treatment and other purposes, and more particularly to an activated carbon which can be efficiently produced from waste. The present invention relates to a manufacturing method and a manufacturing apparatus. Also, the present invention relates to an environmental protection technology applicable as a system for dioxin countermeasures such as a waste incinerator.

[0002]

2. Description of the Related Art Conventionally, various techniques have been proposed for a method for producing activated carbon from waste materials. In most of the techniques, activation treatment is performed offline using primary coal obtained by some method as a raw material.
In addition, regardless of the activated carbon production system using waste as raw material, procured palm shell coal or coal, etc., which are locally produced in Japan and around the world at low cost, and activated using these as raw materials to produce activated carbon There is a manufacturing method, and it is the substance that only such a method for manufacturing activated carbon is industrially movable. This is because conventionally, in the production of activated carbon, the only purpose was to produce activated carbon, and the main focus was only on how cheaply activated carbon could be produced.

[0003] Therefore, an attempt to continuously produce activated carbon starting from waste and by consistent carbonization and activation operations has not been put to practical use in the past and can be said to be new.

[0004] By the way, even if any kind of waste is supplied with heat from the outside, carbonization and activation steps are respectively carried out based on each conventional technique, and if these steps are combined, continuous processing is possible. Thus, an apparatus for obtaining activated carbon can be obtained. FIG. 7 shows an example of an apparatus for producing activated carbon that can be considered in this way.

[0005] The activated carbon manufacturing apparatus shown in FIG.
%, A plant that obtains activated carbon from construction waste wood having a low calorific value of about 3200 kcal / kg. In this activated carbon manufacturing apparatus, the hopper 51
Is fed into the carbonization furnace 53 by the feed mechanism by the feed mechanism 52, and hot air is sent to partially burn and carbonize the waste material. At this time, the amount of waste material sent is 16
At 4.7 kg / h, 30.86 kg / h primary coal is obtained.

[0006] The primary coal is discharged and crushed by a crusher 54.
After being crushed by the above, it is sent to the activation furnace 55. Then, 6 Nm ³ / h of LPG fuel and 30 kg / h of steam are supplied to the combustor 56.
The activated gas is produced by supplying the degree and burning, and the activated gas is supplied to the activation furnace 55 to produce activated carbon from primary coal. At this time, 10.8 kg / h of activated carbon is obtained. Further, the dry distillation gas discharged from the carbonization furnace 53 and the activation furnace gas discharged from the activation furnace 55 are sent to the secondary combustor 57 and are discharged after being burned. The activated carbon is cooled by the cooler 58 and then stored in the storage. It is sent to 59.

[0007]

In the method for producing activated carbon as described above, it is necessary to supply a large amount of heat from the outside in order to obtain activated carbon. Cost was a big problem.

An object of the present invention is to solve the above problems and to provide a method and an apparatus for producing activated carbon from waste, wherein the amount of heat supplied from the outside can be eliminated or reduced.

[0009]

As described above, the production of activated carbon is carried out in the order of the carbonization step and the activation step. In the activated carbon production step composed of such steps, the heat energy consumption is activated. Occurs in the process.

The process in which the primary coal produced in the carbonization process is activated in the activation process is described by burning of carbon by an oxidation reaction with water vapor and CO ₂ as shown in the following formulas (1) and (2). You. This reaction is an endothermic reaction,
External heating is required to carry out the reaction. C + H ₂ O → CO + H ₂ +28178 kcal / Kmol (1) C + CO ₂ → 2CO + 37960 kcal / Kmol (2)

The activation step is a reaction at a high temperature of 800 to 1000 ° C., and the fuel is consumed in addition to the reaction heat for preheating the primary coal, raising the temperature of the combustion gas to 900 ° C., and the like. On the other hand, about 70% of primary coal is consumed by oxidation, CO,
It is discharged as a combustible gas such as H ₂ out of the furnace.

An example of the amount and composition of the exhaust gas at the outlet of the carbonization furnace and the activation furnace in the activated carbon production apparatus shown in FIG. 7 is shown below.

[0013] carbonization furnace; temperature 450 ° C. carbonization gas flow 231 nm ³ / h average calorific value 1015kcal / Nm ³ (lower) Gas Composition _{H 2: 0.86%, CO:} 2.1% methane, ethane, ethylene and the like hydrocarbons : Total 1.5% Tar content: 2-3% Others: oxygen, nitrogen, CO ₂

[0014] activating furnace; temperature 900 ° C. activating oven gas flow rate 241 nm ³ / h average calorific value 817kcal / Nm ³ (lower) Gas Composition _{H 2: 10%, CO:} 18.6% Others: steam, nitrogen, CO ₂

The carbonization gas discharged from the carbonization furnace is self-combustible, and its calorific value depends on the amount of L consumed in the activation furnace.
It was larger than the total calorific value of PG. The present invention
The present invention has been made based on the above-mentioned knowledge, and is capable of reducing the amount of heat required to be supplied from the outside by effectively utilizing a carbonization gas generated from a carbonization furnace.

That is, the method for producing activated carbon from waste according to the present invention is a method for producing activated carbon by continuously performing a carbonization step and an activation step using waste as a raw material to obtain activated carbon, which is generated from the carbonization step. The combustible carbonization gas is burned and supplied as an activation gas in the activation step.

In the method for producing activated carbon from waste according to the present invention, the carbonization gas generated from the carbonization step is once burned, supplied to the activation step as an activation gas at an elevated temperature, and sent from the carbonization step. Activate primary coal.

An apparatus for producing activated carbon from waste according to the present invention is an apparatus for producing activated carbon having a carbonizing furnace for producing primary carbon and an activation furnace for producing activated carbon by activating primary coal produced in the carbonizing furnace. The carbonization furnace and the activation furnace are connected by a dry distillation gas ventilation pipe, and a combustor is provided in the dry distillation gas ventilation pipe.

In the apparatus for producing activated carbon from waste according to the present invention, the carbonization gas generated in the carbonization furnace is sent to the activation furnace through the carbonization gas ventilation pipe. The heated and heated state is supplied to the activation furnace and used as an activation gas.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing activated carbon from waste according to the present invention, the carbonization gas supplied from the carbonization step to the activation step can be a carbonization gas generated in the carbonization step if the amount required for the activation step is satisfied. It does not need to be the whole amount, but may be a part thereof.

As the carbonization furnace, a furnace type such as a rotary kiln type, a fluidized bed type, a moving bed type and the like are used.
Any of a batch type and a continuous type can be applied. Carbonization is
Generally, partial combustion is performed at an air ratio of about 0.1 to 0.3. A carbonization temperature of about 300 to 600 ° C. is used.

As the activation furnace, various types such as a rotary kiln, a fluidized-bed furnace, a fixed-bed furnace, a moving-bed furnace, a moving-bed furnace, and the like can be applied. Both batch furnaces can be applied. In this activation process, steam, air, carbon dioxide,
Combustion gas or the like is used. Among these, activation by steam is considered to be the best in terms of the performance of the obtained activated carbon. As the steam, steam generated by a waste heat boiler can be used, or steam generated by using various kinds of heat generated in an incinerator can be used.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the apparatus for producing activated carbon from waste according to the present invention will be described with reference to FIGS.

FIG. 1 is a schematic view of an activated carbon production apparatus, FIG. 2 is a cross-sectional view of a carbonization furnace used for the activated carbon production apparatus cut in parallel with the axis of the kiln, and FIG. is there.

In FIG. 1, 1 is a carbonization furnace for producing primary coal from waste, 2 is a fluidized bed type activation furnace for producing activated carbon by activating primary coal sent from the carbonization furnace 1, and 3 is a carbonization furnace. A secondary combustor for burning the gas discharged from the furnace and the activation furnace 20, a cooler for cooling the activated carbon produced by the activation furnace, a storage for storing the activated carbon cooled by the cooler 4, and a storage for 6. A combustor 7 for producing an activation gas to be supplied to the activation furnace 2 is a steam ejector 7 for feeding steam and a carbonization gas to the combustor 6. The outlet side (right side in the figure) of the carbonization furnace 1 is connected to the activation furnace 2 via a primary coal discharge feeder and crusher 8, and the primary coal produced in the carbonization furnace 1 is directly supplied to the activation furnace 2. It has become so. Further, the vicinity of the exit side of the carbonization furnace 1 is activated by the dry distillation gas ventilation pipe 9.
The vaporized gas vent pipe 9 is provided with the steam ejector 7 and the combustor 6 so that the carbonized gas generated in the carbonization furnace 1 can be burned and then supplied to the activation furnace 2. . The outlet side of the carbonization furnace 1 is connected to the secondary combustor 3.

As shown in FIGS. 2 and 3, about half of the inlet side of the rotary kiln 11 is a ventilation section 12 having a large number of ventilation holes, and the exit side is a non-venting section 1 as shown in FIGS.
It is 3. End plates 1 at both ends of rotary kiln 11
4 and 14 are provided, and the rotary kiln 11 is slidably supported by these end plates 14 and 14 so as to be rotatable. A gear 15 is provided on the outer periphery of the rotary kiln 11, and the gear 15 is connected to the motor 1 via a gear 16.
The rotary kiln 11 is rotated in a fixed direction by the driving of the motor 17.

A cylindrical outer shell 18 is provided on the outer periphery of the ventilation section 12 of the rotary kiln 11 with a small gap, and air or combustion gas is supplied to the lower surface of the outer shell 18 by a rotary kiln. Supply air box 19 for feeding into 11
The air supply wind box 19 is provided with an air supply port 20 through which air or the like is sent. An exhaust port 21 for exhausting the carbonized gas is provided on the outlet side of the rotary kiln 11.
Are connected to the secondary combustor 3.

A screw 22 is provided inside the rotary kiln 11 for transferring the raw material by rotation of the rotary kiln 11, and a hopper 23 and the raw material are fed to the inlet side (left side in the figure) of the rotary kiln 11. Feeding mechanism 24 is provided.

In order to produce activated carbon with the above-described activated carbon production apparatus, waste wood 30 as a raw material is cut into 20 to 30 mm.
After the chips are made into the same degree, they are continuously fed into the rotary kiln 11 from the hopper 23 by the feeding mechanism 24.
The introduced waste wood 30 is conveyed to the outlet side by the screw 22 with the rotation of the rotary kiln 11, but the hot air is supplied from the air supply wind box 19 in the ventilation part 12, so that it is partially burned and carbonized. Carbonization is promoted while being transported through the non-ventilated portion 13. At this time, an air ratio of about 0.2 is appropriate, and at a carbonization furnace temperature of 450 ° C., the amount of waste wood introduced is 164.7 kg / h and the amount is 30.86 kg / h.
Of primary coal was obtained.

The primary coal obtained in the carbonization furnace 1 is sent to the activation furnace 2 in a state of being crushed to about several meters by the discharge feeder / crusher 8. On the other hand, the carbonization gas generated in the carbonization furnace 1 is:
The water is sucked by the steam ejector 7 and sent to the combustor 6. The calorific value of the carbonization gas at this point is 1015 kca
1 / Nm ³ and is self-combustible. The burnt carbonization gas is sent to the activation furnace 2 to activate the primary coal while fluidizing it. The gas composition at the entrance of the activation furnace 2 is: CO ₂ : 14%,
Water vapor: 30%, oxygen: 1.2%, nitrogen: 54.8%.

The activation furnace 2 is operated at 900 ° C. The carbonization gas of the carbonization furnace 1 consumed for this purpose is about 73% of the total carbonization furnace gas, and the entire amount of heat required in the activation furnace 2 is covered by the carbonization gas from the carbonization furnace 1. In the activation furnace 2, 65% of the input primary coal is burned and the remaining 3
5% is obtained as activated carbon, and the obtained activated carbon is sent to the storage 5 after being cooled in a cooler. The surplus carbonization gas and the activation furnace gas are sent to the secondary combustor 3 and are discharged after being burned.

In this embodiment, the lower heating value 320
The waste wood of 0 kcal / kg could be recycled as activated carbon at a yield of about 6.5% by weight without introducing fuel from the outside.

Although a steam ejector is used in this embodiment, the invention is not limited to this, and a normal blower may be used. However, by using a steam ejector, steam required as an activation gas can be used as a power source for gas circulation, so that the activated carbon production apparatus can be simplified and the power can be reduced. Fluidized bed activation furnaces have the advantage that they can be designed to be small,
Since the supply gas needs to be pressurized to about 500 mmH ₂ O, a steam ejector is an effective means for this.

A second embodiment of the apparatus for producing activated carbon from waste according to the present invention will be described with reference to FIG.

FIG. 4 is a diagram schematically showing an apparatus for producing activated carbon from waste. The second embodiment shown in FIG. 4 has the same configuration as the first embodiment except that a rotary kiln type is used as the activation furnace, and the mass and heat balance is the same as that of the first embodiment. It is. That is, in FIG.
Is an activation furnace. The activation furnace 30 is of a rotary kiln type. The carbonization furnace 31, the secondary combustor 32, the cooler 33, and the storage 34 are the same as in the first embodiment. The outlet of 31 is connected to the inlet of the activation furnace 30 by a dry distillation gas vent pipe 35, and a combustor 36 is provided in the dry distillation gas vent pipe 35.

In this embodiment, since gas is easily sent to the activation furnace, gas circulation equipment is not required. Therefore, compared with the first embodiment, it is advantageous in terms of downsizing of facilities and construction cost of a plant.

5 and 6 show another example of a carbonization furnace that can be used in the apparatus for producing activated carbon from waste according to the present invention. FIG. 5 is a cross-sectional view cut parallel to the axis of the rotary kiln. FIG. 6 is a sectional view taken along line BB in FIG.

The carbonization furnace shown in FIGS. 5 and 6 has a rotary kiln 41 in which a ventilation section 42 is formed substantially all over, and an outer casing 43 has an exhaust wind box 44 and an exhaust port 45 provided on the upper surface side thereof. A dry distillation gas ventilation pipe is connected to the exhaust port 45. In addition, the air supply air box 46, the hopper 47, the feeding mechanism 48, and the like are the same as those in the carbonization furnace shown in FIGS.

[0039]

The present invention has the following effects by adopting the above structure. (1) By using the carbonization gas generated in the carbonization furnace as the heat source of the activation furnace, the heat consumption in the integrated factory can be significantly reduced. With waste wood with a lower calorific value of 3200 kcal / kg, it is possible to construct a process capable of self-sufficient supply of heat in the factory. (2) As a result, waste can be effectively recycled.

[Brief description of the drawings]

FIG. 1 is a schematic view of a first embodiment of an apparatus for producing activated carbon from waste according to the present invention.

FIG. 2 is a cross-sectional view of the carbonization furnace used in the first embodiment of the apparatus for producing activated carbon from waste according to the present invention, cut in parallel to the axis of the rotary kiln.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a schematic view of a second embodiment of the apparatus for producing activated carbon from waste according to the present invention.

FIG. 5 is a cross-sectional view of another example of a carbonization furnace that can be used in the apparatus for producing activated carbon from wastes according to the present invention, which is cut parallel to a shaft ship of a rotary kiln.

6 is a sectional view taken along line BB in FIG.

FIG. 7 is a schematic diagram of an activated carbon production device that can be considered from the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Carbonization furnace 2 ... Activation furnace 3 ... Secondary combustor 4 ... Cooler 5 ... Storage 6 ... Combustor 7 ... Steam ejector 8 ... Discharge feeder and crusher 9 ... Carbonization gas vent pipe 30 ... Activation furnace 31 ... Carbonization furnace 35: Dry distillation gas vent pipe 36: Combustor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F23G 5/14 ZAB B09B 3/00 ZAB F term (reference) 3K061 AA07 AB02 AC17 BA04 BA05 FA21 3K078 AA04 AA05 BA07 CA02 4D004 AA12 AC05 BA10 CA26 CA27 CA28 CB02 CB09 CC01 CC02 DA01 DA02 DA06 DA11 DA12 DA20 4G046 HA02 HA09 HC09 HC21 4H012 HA06

Claims (2)

[Claims] 1. A method for producing activated carbon by continuously performing a carbonization step and an activation step using waste as a raw material to obtain activated carbon, wherein a dry distillation gas generated from the carbonization step is burned to be used as an activation gas in the activation step. A method for producing activated carbon from waste, characterized in that it is supplied. 2. An activated carbon production apparatus comprising: a carbonization furnace for producing primary carbon; and an activation furnace for activating primary carbon produced by the carbonization furnace to produce activated carbon, comprising: a carbonization furnace; an activation furnace; Are connected by a carbonized gas vent pipe, and a combustor is provided in the carbonized gas vent pipe.