JP2001241624A - Waste-incinerating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste-incinerating plant for effectively performing both material and energy cycles by obtaining power from waste and at the same time activated carbon. SOLUTION: A carbonization furnace 1 obtains primary carbon by carbonizing woody waste, an activation furnace 2 obtains activated carbon by activating primary carbon that is manufactured by the carbonization furnace 1, a waste heat boiler 3 generates steam with a carbonization gas that is generated from the carbonization furnace 1 and the activation furnace gas that is generated from the activation furnace 2 as fuel, and a turbine generator 4 allows a generator to generate power by the rotation of a turbine by steam from the waste heat boiler. The carbonization furnace 1 is connected to the activation furnace 2 via combustion equipment 5, and the generated carbonization gas is partially burnt and is sent to the activation furnace 2. The activation furnace 2 is connected to the carbonization furnace 1 via the combustion equipment 6, and the generated activation furnace gas is partially burnt and is sent to the carbonization furnace 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an effective recycling technique for woody wastes having a high calorific value such as construction waste materials and flammable bulky garbage, and also being an excellent raw material for activated carbon. More specifically, the present invention relates to a waste incineration plant capable of obtaining activated carbon and electric power from woody waste.

[0002]

2. Description of the Related Art Conventionally, there is a wood-based waste incineration plant as shown in FIG. In the conventional waste incineration plant shown in FIG. 7, when processing about 100 tons / day or more of waste, a continuous incinerator 81 is used, and the waste incinerated in the incinerator 81 is used. Waste heat is recovered by a waste heat boiler 82, and steam generated by the waste heat is sent to a steam turbine generator 83. Thereby, the steam turbine rotates and the generator generates power. When the lower calorific value of the waste is about 3200 kcal / kg, the output of the steam turbine generator 83 is 3130 kcal / kg.
kw. Further, the gas in the boiler 82 is discharged into the atmosphere from a chimney 85 via an exhaust gas treatment facility 84.

[0003] At this time, the entire amount of the combustible material is burned in the incinerator 81, and the incinerated ash is discarded at the final disposal site without containing any combustibles. Some incineration ash has been further melted, formed and otherwise used in road ground materials and other civil engineering applications.

[0004]

However, in the above-mentioned conventional waste incineration plant, since only electric power is recovered, material recycling of woody waste has not been sufficiently performed. In other words, woody waste such as construction waste has a high fixed carbon content,
In the past, they were only used as fuel and did not take advantage of their potential advantages. In addition, the reuse of incinerated ash requires a further high-temperature treatment step of melting, and it cannot be said that there is sufficient economic merit.

[0005] As described above, the conventional waste incineration plant is not sufficient in terms of material recycling and energy recycling, and can achieve both, and can effectively reuse resources. A plant was desired.

[0006] The present invention solves the above problems and provides a waste incineration plant capable of effectively performing both material recycling and energy recycling by obtaining activated carbon from waste. The purpose is to provide.

[0007]

Means for Solving the Problems By the way, construction waste and woody large garbage carried into an incineration plant have a high fuel value of about 20% moisture and a low calorific value of about 3000 to 4000 kcal / kg. In addition, the fixed carbon content therein is 20% or more, which is the best raw material for producing charcoal or activated carbon.

As a result of studying a method for producing activated carbon using such building waste as a raw material, the present inventors have found that activated carbon can be produced with little additional combustion. In addition, the amount of waste heat discharged as a result of the activated carbon production process is reduced only by the calorific value of the produced activated carbon (about 20%) as compared with a case where the entire amount is simply incinerated. There was no significant reduction in the amount of heat collected, and it was found that sufficient power recovery was possible while producing activated carbon.

Activated carbon accounts for 6% by weight of the raw material.
The yield can be expected to be about the same, and if this is converted into the market price of activated carbon, the profit from the sale will result in 3 per ton of building waste.
It was found that it could cover the processing cost of about ¥ 10,000, providing unexpected advantages from the viewpoint of waste disposal and resource recycling.

Further, in recent years, measures against dioxin in incineration plants are urgently required, but the powdered activated carbon obtained here can be widely used for removing dioxin from exhaust gas of incinerators.

The present invention has been made based on the above findings. A waste incineration plant according to the present invention comprises a carbonizing furnace for carbonizing woody waste to obtain temporary coal, and a primary furnace obtained by the carbonizing furnace. An activation furnace that activates charcoal to obtain activated carbon, a boiler that generates steam using the carbonization gas generated from the carbonization furnace and the activation furnace gas generated from the activation furnace as fuel, and a turbine that is rotated by the steam from the boiler to generate electricity And a turbine generator for generating electric power by the electric machine, so that activated carbon and electric power can be recovered from the woody waste.

In the waste incineration plant of the present invention,
Activated carbon is manufactured from the woody waste through a carbonization furnace and an activation furnace, and the carbonization gas generated from the carbonization furnace and the activation furnace gas generated from the activation furnace are burned in a boiler to obtain steam, and the steam is used to form a turbine. Rotate to generate electricity with a generator.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A waste incineration plant according to the present invention will be described with reference to a conceptual diagram shown in FIG.

In FIG. 1, 1 is a carbonizing furnace for carbonizing woody waste to obtain primary coal, 2 is an activation furnace for activating primary carbon produced in the carbonizing furnace 1 to obtain activated carbon, and 3 is a carbonizing furnace 1 Waste heat boiler, which generates steam using the dry distillation gas generated from the fuel and the activation furnace gas generated from the activation furnace 2 as a fuel, and 4 is a turbine generator in which a turbine is rotated by steam from the waste heat boiler and a generator generates power. . Further, the carbonization furnace 1 is connected to the activation furnace 2 through the activation furnace combustor 5, and a part of the generated carbonization gas is burned and sent to the activation furnace 2 as the activation gas. Numeral 2 is connected to the carbonization furnace 1 via the carbonization furnace combustor 6, and a portion of the generated activation furnace gas is burned to directly contact the woody waste to partially burn and carbonize (internal combustion type combustion gas). (In the case of an external combustion type carbonizing furnace) or as a heat source gas for heating the carbonizing furnace (in the case of an external combustion type carbonizing furnace). The activation furnace 2 is connected to a storage 8 via a cooler 7, and the waste heat boiler 3 is connected to a chimney 10 via an exhaust gas treatment facility 9. Further, a pure water device 11 is provided on a return path from the turbine generator 4 to the waste heat boiler 3.

In the above waste incineration plant, woody waste is supplied to the carbonization furnace 1. In the case of the internal heating type rotary kiln, in the carbonization furnace 1, the combustion gas of the partial combustion air and a part of the activation furnace gas (those not sent to the waste heat boiler) is supplied to partially remove the woody waste. Primary coal is obtained by burning and carbonizing, and the obtained temporary coal is sent to the activation furnace 2. In the case of an externally heated rotary kiln, a portion of the activation path gas is burned and the rotary kiln is heated as a heat source gas to carbonize the internal woody waste to obtain primary coal. In the activation furnace 2, the combustion gas and steam of a part of the carbonization gas (which has not been sent to the waste heat boiler) from the carbonization furnace 1 are supplied to activate the primary coal to obtain activated carbon.

The carbonization gas generated in the carbonization furnace 1 and the activation furnace gas generated in the activation furnace 2 are sent to the waste heat boiler 3 and burned, and steam is obtained by the heat. The obtained steam is sent to the turbine generator 4, which rotates the turbine to generate power.

As described above, in the waste incineration plant of the present invention, woody waste can be finally taken out as activated carbon for material recycling, and it can also be taken out as electric power for energy recycling. Can be.

[0018] The carbonization furnace may be a furnace type such as a rotary kiln type (both internal and external heat types are applicable), a fluidized bed type, a moving bed type, and the like. Either can be applied. Carbonization is generally carried out at an air ratio of 0.1
Partial combustion at about 0.3. The carbonization temperature is 300
Approximately 600 ° C. is used, and an auxiliary fuel and an auxiliary heat source can be appropriately charged.

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. In addition, an auxiliary fuel and an auxiliary heat source can be appropriately added.

As the waste heat boiler and the turbine generator, known techniques conventionally used can be used. Also, exhaust gas (HCl, NO
x, SOx, etc.) in the exhaust gas treatment equipment can use a conventionally known technique.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a waste incineration plant according to the present invention will be described with reference to FIGS.

FIG. 2 is a schematic view of a waste incineration plant, FIG. 3 is a cross-sectional view of a carbonization furnace used in the waste incineration plant cut in parallel with a kiln axis, and FIG. 4 is a cross-sectional view taken along line AA in FIG. FIG.

In FIG. 2, 20 is a carbonization furnace for producing primary coal from waste, 31 is a horizontal multistage activation furnace for activating primary carbon sent from the carbonization furnace 20 to produce activated carbon,
32 is a carbonization gas generated from the carbonization furnace 20 and an activation furnace 31.
A waste heat boiler that generates steam by burning the activation furnace gas generated from the furnace, 33 is a turbine generator that rotates a turbine with steam from the waste heat boiler 32 to generate electricity by a generator, and 34 is manufactured by an activation furnace A cooler for cooling the activated carbon, a storage 35 for storing the activated carbon cooled by the cooler 34, and an activation furnace combustor 36 for burning the carbonization gas supplied to the activation furnace 31 to produce an activation gas. The outlet side (right side in the figure) of the carbonization furnace 20 is connected to the activation furnace 31 via a primary coal discharge feeder / crusher 37, and the primary coal produced in the carbonization furnace 20 is directly supplied to the activation furnace 31. It has become. The waste heat boiler 32 is connected to an exhaust gas treatment facility 38 and a chimney 39, and a recirculation path from the turbine generator 33 to the waste heat boiler 32 is provided with a pure water device 40.

As shown in FIGS. 3 and 4, the carbonizing furnace 20 has a ventilation section 22 having a large number of ventilation holes except for the vicinity of both ends of the rotary kiln 21. End plates 23, 23 are provided at both ends of the rotary kiln 21, and the rotary kiln 21 is slidably supported by these end plates 23, 23 so as to be rotatable. A drive mechanism 24 including a gear and a motor is provided on the outlet side (right side in the figure) of the rotary kiln 21 so as to rotate in a fixed direction.

A cylindrical outer shell 25 is provided on the outer periphery of the ventilation section 22 of the rotary kiln 21 with a small gap therebetween. On the lower side of the outer shell 25, air or combustion gas is supplied to the rotary kiln. Air supply wind box 26 for introduction into 21
Is provided, and on the upper surface side of the outer shell 25, an exhaust wind box 27 for discharging the carbonized gas is provided.
The air supply wind box 26 is provided with an air supply port 28 connected to a supply source (not shown) such as air.
7 is provided with an exhaust port 29, and this exhaust port 29 is connected to the waste heat boiler 32 and the combustor 36 for the activation furnace. Further, inside the rotary kiln 21, a screw 30 that conveys the raw material by the rotation of the rotary kiln 21 is provided.

In order to operate the above waste incineration plant, building waste as woody waste is continuously charged into the carbonization furnace 20. The injected building waste is conveyed to the outlet side by the screw 30 with the rotation of the rotary kiln 21, but the hot air is supplied from the air supply wind box 26 in the ventilation part 22, so that it is partially burned and carbonized. Carbonization gas is generated. This carbonization gas is 845 kcal / N
It has a calorific value of m ³ and is capable of self-combustion. The carbonization furnace is operated at 450 ° C. The primary coal obtained in the carbonization furnace 20 is sent to the activation furnace 31 in a state of being crushed to about several mm by the discharge feeder / crusher 37. On the other hand, the carbonized gas generated in the carbonization furnace 20 is supplied to the waste heat boiler 32 and supplied to the combustor 36 for combustion.
It is supplied to the activation furnace 31 as an activation gas together with steam.
At this time, LPG is used for auxiliary combustion.

In the activation furnace 31, the temporary coal sent from the carbonization furnace 20 is activated by the mixed gas of the combustion gas of the carbonization gas and the steam sent from the waste heat boiler 32, as described above. Activated carbon can be obtained. At this time, the activation furnace 31 is operated at 900 ° C. The obtained activated carbon is stored in the storage 35 after being cooled by the cooler 34.
An activation furnace gas containing hydrogen and carbon monoxide is generated from the activation furnace 31, and the activation furnace gas is sent to a waste heat boiler 32,
Burned together with the carbonization gas sent from the carbonization furnace 20,
Collected as steam. At this time, the steam is 12.1 t
on / h. Most of the steam in the waste heat boiler 32 is sent to the turbine generator 33, which turns the turbine to generate power. Part of the steam is supplied to the activation furnace 31 as described above. Further, replenishment of steam is performed by the pure water device 40. The exhaust gas from the waste heat boiler 32 is sent to an exhaust gas treatment facility 38 where it is treated, and then discharged from a chimney 39 into the atmosphere. The temperature of the exhaust gas at the outlet of the waste heat boiler 32 was 200 ° C.

In this embodiment, the amount of construction waste material input is 100 ton / day (4147 kg / h), and 257 k
Assuming that activated carbon of g / h is obtained and activated carbon is 500,000 yen / ton, a profit of sale of about 30,000 yen per ton of construction waste material can be obtained, which can cover most of waste disposal costs. Also,
The amount of power generation is 2590 kW, which is only reduced by about 20% as compared with the conventional technology (total incineration), and can not only cover all power in the plant but also sell the surplus power.

A second embodiment of the waste incineration plant according to the present invention will be described with reference to FIGS.

FIG. 5 is a schematic view of a waste incineration plant, and FIG. 6 is a cross-sectional view of a carbonization furnace used in the waste incineration plant cut in parallel with the axis of the kiln.

The second embodiment shown in FIG. 5 uses an externally heated rotary kiln for the carbonization furnace, and the other components are the same as those of the first embodiment.
The configuration is substantially the same as that of the embodiment. That is, in FIG. 4, reference numeral 50 denotes a carbonization furnace, which uses an externally heated rotary kiln, and includes an activation furnace 61, a waste heat boiler 62, a turbine generator 63, a cooler 64, and a storage 6.
5. Activation furnace combustor 66, discharge feeder and crusher 6
7. Exhaust gas treatment equipment 68, chimney 69 and pure water equipment 70
Is the same as in the first embodiment, but in this embodiment, the carbonization furnace 50 and the activation furnace 61 are connected via the carbonization furnace combustor 71, and after the activation furnace gas is burned, It can be supplied to the carbonization furnace 50 as a heat source gas.

As shown in FIG. 6, the carbonizing furnace 50 is provided with a rotary kiln 51, and a double-pipe heat exchanger 52 is provided on the outer periphery of the rotary kiln 51 over substantially the entire length. At the lower end of the double-pipe heat exchanger 52, an air supply port 53 is provided, and at the upper end, an exhaust port 54 is provided. Bowl 71
, And the exhaust port 54 is connected to the waste heat boiler 62. An outlet 55 for the dry distillation gas is provided on the outlet side of the rotary kiln 51, and this outlet 55 is also connected to the waste heat boiler 62 and the activation furnace combustor 66.

In order to operate the above waste incineration plant, construction waste and combustible bulky waste as woody waste are crushed to 15 to 30 mm and put into the rotary kiln 51. The input construction waste is a rotary kiln 51
The inside of the rotary kiln 5
In No. 1, since the heat source gas obtained by burning the activation furnace gas in the combustor for carbonization furnace 71 is introduced into the double-pipe heat exchanger 52 and heated, carbonization occurs, and at the same time, carbonization gas is generated. This carbonized gas has a calorific value of 2600 kcal / Nm ³ and burns without any auxiliary combustion. The carbonization gas is supplied from the exhaust port 55 to the waste heat boiler 62 and is also supplied to the activation furnace combustor 66 and burned, and then supplied to the activation furnace 61 together with water vapor as an activation gas. The heat source gas introduced into the double tube heat exchanger 52 is sent from the exhaust port 54 to the waste heat boiler 62.
The carbonization furnace 50 is operated at 450 ° C.

The primary coal obtained in the carbonization furnace 50 is sent to the activation furnace 61 in a state of being crushed to about several mm by the discharge feeder / crusher 67. In the activation furnace 61, primary coal is activated by a mixed gas of the combustion gas and steam to obtain activated carbon. At this time, the activation furnace 31 is operated at 900 ° C. The obtained activated carbon is stored in the storage 65 after being cooled by the cooler 64.

An activation furnace gas containing hydrogen and carbon monoxide is generated from the activation furnace 61, and the activation furnace gas is supplied to the waste heat boiler 6.
2 and, after being burned in the combustor for carbonization furnace 71, sent to the carbonization furnace 50. Therefore, in the waste heat boiler 62, the dry distillation gas sent from the carbonization furnace 50 and the activation furnace gas sent from the activation furnace 61 are burned and sent from the double-pipe heat exchanger 52. Water vapor is generated by the incoming heat source gas. At this time, steam is generated at 10.8 ton / h. Most of the steam in the waste heat boiler 62 is sent to the turbine generator 63, which turns the turbine to generate power. Part of the steam is supplied to the activation furnace 61 as described above. Further, replenishment of steam is performed by the pure water device 40. The exhaust gas from the waste heat boiler 62 is supplied to an exhaust gas treatment facility 6.
After being sent to 8 and processed, it is released from the chimney 69 to the atmosphere. The temperature of the exhaust gas at the outlet of the waste heat boiler 62 was 200 ° C.

In this embodiment, the amount of building waste material input is 100 ton / day (4147 kg / h) and 334 k
g / h of activated carbon is obtained, and about 4 tons of building waste
It is a gain of 10,000 yen. In addition, the amount of power generation is 2220 kw, which is only reduced by about 30% as compared with the conventional technology.
Not only can the entire site be covered, but the surplus can be sold.

[0037]

The present invention has the following effects by adopting the above structure. (1) A large amount of activated carbon can be recovered without a significant reduction in power generation. As a result, woody waste such as construction waste, which conventionally required a large amount of cost for the treatment, can be treated at a low cost. (2) Since a gas-fired boiler can be used as a boiler, combustion can be performed at a relatively low air ratio, the amount of exhaust gas can be reduced, and the exhaust gas treatment facility can be simplified.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a waste incineration plant according to the present invention.

FIG. 2 is a schematic view of a first embodiment of a waste incineration plant according to the present invention.

FIG. 3 is a cross-sectional view of the carbonization furnace used in the first embodiment of the waste incineration plant according to the present invention, cut in parallel to the axis of the kiln.

4 is a sectional view of the AA ship in FIG.

FIG. 5 is a schematic view of a second embodiment of the waste incineration plant according to the present invention.

FIG. 6 is a cross-sectional view of the carbonization furnace used in the second embodiment of the waste incineration plant according to the present invention, cut in parallel to the axis of the kiln.

FIG. 7 is a schematic view of a conventional waste incineration plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Carbonization furnace 2 ... Activation furnace 3 ... Waste heat boiler 4 ... Turbine generator 5 ... Activation furnace combustor 6 ... Carbonization furnace combustor 20 ... Carbonization furnace 31 ... Activation furnace 32 ... Waste heat boiler 33 ... Turbine generator 36 ... Activator Furnace Combustor 50 ... Carburizing Furnace 61 ... Activator Furnace 62 ... Waste Heat Boiler 63 ... Turbine Generator 66 ... Activator Furnace Combustor 71 ... Carburizing Furnace Combustor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/46 ZAB F23G 5/46 ZABB 4G046 F term (Reference) 3G081 BA02 BC07 BD00 DA14 3K061 AA24 AB02 AC17 CA01 FA07 FA21 3K065 AA24 AB02 AC17 JA01 JA18 3K078 BA03 CA02 CA11 CA21 4D004 AA12 AC05 BA03 BA10 CA26 CA50 4G046 CA00 CC01 HA09 HC09 HC26

Claims (5)

[Claims] 1. A carbonization furnace for carbonizing woody waste to obtain temporary coal, an activation furnace for activating primary carbon obtained in the carbonization furnace to obtain activated carbon, a carbonization gas generated from the carbonization furnace and activation It has a boiler that generates steam using the activated furnace gas generated from the furnace as a fuel, and a turbine generator that rotates a turbine with the steam from the boiler to generate power using a generator. Waste incineration plant characterized by the ability to collect waste. 2. A part of the carbonization gas generated from the carbonization furnace is burned and supplied to the activation furnace as an activation gas.
Waste incineration plant according to 1. 3. The carbonization furnace is an internal heating type carbonization furnace,
The waste incineration plant according to claim 1 or 2, wherein a part of the activation furnace gas generated from the activation furnace is burned and supplied as a combustion gas to the carbonization furnace. 4. The carbonization furnace is an external heat type carbonization furnace,
The waste incineration plant according to claim 1 or 2, wherein a part of the activation furnace gas generated from the activation furnace is burned and supplied as a heat source gas to the carbonization furnace. 5. The waste incineration plant according to claim 4, wherein the heat source gas supplied to the carbonization furnace is supplied to a boiler.