JP3769204B2 - Combustion treatment method of waste including organic waste - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for combusting waste containing high water content organic waste such as sludge, livestock dung, and garbage, and fermenting and drying the waste containing the high water content organic waste. The dry raw material is burned, and the combustion of the dry raw material is improved by making the combustion processing device more combustible so that the thermal energy can be used effectively. The present invention relates to a method for combustion treatment of waste including organic waste that can be highly deodorized.
[0002]
[Prior art]
When combusting general waste such as municipal waste, in general, auxiliary fuel is introduced into the combustion device, and the waste introduced by the combustion energy of this auxiliary fuel is combusted, and the waste energy is continuously input. The generated waste is burned, and the subsequent combustion cycle is continued. As a result, the combustion exhaust gas has a considerable amount of thermal energy as surplus energy, and measures are being taken to generate electricity using this thermal energy or to use it as various heat sources.
[0003]
In contrast, waste containing organic waste with high water content such as raw garbage, organic sludge, livestock manure, manure, food residues, and seafood residues (hereinafter referred to as raw materials) contains a large amount of water. When these raw materials are subjected to a combustion treatment, not only problems related to the combustion of organic substances but also a specific technical problem associated with the evaporation of a large amount of water occurs.
[0004]
FIG. 3 shows an example of a conventional combustion processing apparatus that treats general waste as a processing target. The raw material P is directly fed into the combustion processing apparatus C by the receiving supply apparatus B and burned. Further, the exhaust gas or water vapor G generated by burning the raw material P is purified by the subsequent exhaust gas treatment device D and then released into the atmosphere.
The combustion processing plant in FIG. 3 is intended to continue combustion by using the self-heat amount of the raw material P. However, when the raw material P has a high water content and a low calorific value, the combustion state is maintained by supplying the auxiliary fuel F to the combustion processing device C. In such a case, (1) the temperature of the combustion exhaust gas G decreases due to the latent heat of vaporization of the moisture, and it is difficult to recover heat from the exhaust gas G. (2) A constant amount of auxiliary combustion is required. There are many problems such as consumption.
[0005]
FIG. 4 shows an example of a combustion processing plant using a conventional melt type combustion processing apparatus C. The raw material P is supplied to the thermal decomposition apparatus C ₁ via the receiving supply apparatus B, and the thermal decomposition is performed. the resulting solid pyrolysis residue R pyrolysis gas E and combustible is burned in the melter C ₂ (molten) to residual heat utilization device I thermal energy H recovered from the hot combustion exhaust gas G from the melting apparatus C ₂ It introduces and uses the thermal energy.
[0006]
The combustion processing plant in FIG. 4 originally performs the melting process using the self-heat amount of the raw material P. However, when the raw material P has a high water content and a low calorific value, it cannot be melted by self-heating alone, or stable melting becomes difficult. Therefore, the auxiliary fuel F is supplied to the thermal decomposition apparatus C ₁ and the melting apparatus C ₂ . To maintain the melting temperature.
[0007]
As a result, since the temperature of the combustion exhaust gas G becomes high, heat recovery is also performed, but a large amount of auxiliary fuel F is consumed to maintain the melting temperature, and the running cost of the combustion treatment plant increases. There is a problem.
The same applies to the case of using the direct-melting combustion processing apparatus C without the thermal decomposition apparatus C ₁ , and the auxiliary fuel F is used for the melting (combustion) processing of the raw material P having a high water content and low calorific value. A large amount of coke is consumed, and there is a problem similar to the case of the combustion treatment plant in FIG.
[0008]
FIG. 5 shows an improved type of the combustion treatment plant of FIG. 3, which is an energy-saving plant in which the raw material P, which is difficult to self-combust, can be combusted with less consumption of the auxiliary fuel F. .
The raw material P is input to the drying device J through the receiving / supplying device B, and used as the dry material K in advance. This dry raw material K is input to the combustion treatment device C via the input device L, and the heat energy H of the generated combustion exhaust gas G is used as a heat source of the drying device J. The exhaust heat M from the drying device J is Returned to the combustion treatment apparatus C.
[0009]
In the combustion treatment plant of FIG. 5 described above, the combustibility of the raw material P can be enhanced without using the auxiliary fuel F, and it has excellent utility.
However, since the heat energy H of the exhaust gas G is used as a heat source for the drying device J, the surplus heat of the exhaust gas G cannot be used for power generation or the like. That is, in the combustion treatment plant of FIG. 5, the thermal energy H of the exhaust gas G is used only to dry the raw material P, and the raw material P is merely burned to release the exhaust gas G. There is a problem that it is impossible to generate electric power or generate hot water using the thermal energy H.
[0010]
[Problems to be solved by the invention]
The present invention has the above-described problems in the combustion treatment of wastes including organic wastes with high water content, that is, (1) a large amount of auxiliary fuel is required, and combustion treatment costs cannot be reduced; (2) The temperature of the combustion exhaust gas is relatively low, and it is difficult to recover the stored thermal energy. (3) The recovered thermal energy is spent on drying the raw materials, and it is difficult to use surplus energy. Waste containing high water content organic waste can be combusted with high efficiency, and at the same time, the surplus energy held in the combustion exhaust gas is actively used for power generation and heat sources, etc. The present invention provides a method for burning waste including organic waste that can contribute to the environment.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, an object to be treated including organic waste having a high water content is fermented and dried in a fermentation drying apparatus equipped with an air supply fan, and a dry raw material having a reduced moisture content is supplied to the combustion processing apparatus. Supplying and performing combustion treatment, and deodorizing the exhaust air from the fermentation drying device by a deodorization device, and further operating the refrigeration device using the heat of the combustion exhaust gas from the combustion treatment device as a driving source and from the refrigeration device The basic structure of the present invention is to cool the exhaust air before the deodorization device with a refrigerant to dehumidify and deodorize the exhaust air.
[0012]
The invention according to claim 2 is the invention according to claim 1, wherein an intake fan is provided on the air outlet side of the fermentation treatment device, and a part of the exhausted air after dehumidification is branched from the discharge side of the intake fan. The air is recirculated to the air inlet side.
[0013]
The invention of claim 3 is the invention of claim 1, wherein a mixing device is provided upstream of the workpiece input port of the fermentation processing device, and a part of the dry raw material is returned to the mixing device and mixed with the workpiece. By doing this, the moisture content of the workpiece to be put into the fermentation treatment apparatus is adjusted.
[0014]
The invention of claim 4 is the invention of claim 1, wherein the combustion treatment device is an incineration combustion treatment device or a melt combustion treatment device.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block configuration diagram of an incineration combustion treatment plant to which the first embodiment of the present invention is applied, in which P is an object to be treated (raw material), P ₁ is a dry material, A is air, A ₁ is exhaust air, G is combustion exhaust gas, S is steam, Q is a low-temperature refrigerant, 1 is a receiving and supplying device, 2 is a mixing device, 3 is a fermentation drying device, 4 is a charging device, 5 is a combustion treatment device, and 6 is Exhaust gas treatment device, 7 is an air supply fan, 8 is an intake fan, 9 is a deodorization device, 10 is a residual heat recovery device, 11 is a refrigeration device, and all the equipment and devices constituting the combustion treatment plant are known. Detailed description thereof is omitted here.
[0016]
Referring to FIG. 1, an object to be treated (hereinafter referred to as a raw material) P containing organic waste with high water content such as garbage, organic sludge, and food residue is fed from an incoming supply device 1 through a mixing device 2. The product is introduced into the fermenter / dryer 3 from the treated product inlet 3c.
In the fermentation drying apparatus 3, the fermentation decomposition of microorganisms is promoted by the air A that is forcibly supplied by the air supply fan 7 and the biodegradable organic matter contained in the raw material P, and heat of fermentation is generated.
[0017]
Due to the forced aeration of the air A by the fermentation heat and the air supply fan 7, the raw material P is dried without using an external heat source. The rate of 80% is reduced to 30 to 50% at the outlet moisture content.
In addition, although the said fermentation drying apparatus 3 is normally equipped with the stirring apparatus, if the structure can maintain the air permeability of the raw material P, the stirring apparatus may not be installed. The fermentation drying apparatus 3 may have any structure, and in this embodiment, a rotary drum type fermentation drying apparatus 3 is used.
[0018]
The exhaust air A ₁ from the fermentation drying device 3 is introduced into the deodorization device 9 where the raw material P and malodorous components generated in the fermentation process are removed and then led out to the outside.
In the present embodiment, an intake fan 8 is installed on the side of the air outlet 3b of the fermentation drying apparatus 3, and the exhaust air A ₁ is introduced into the dehumidifying condenser 14 by using the intake fan 8 to perform dehumidification. A part is circulated through the circulation passage 12 to the air inlet 3a side of the fermentation drying apparatus 3 so that malodorous components are decomposed by microorganisms in the fermentation drying apparatus 3. In this way, by circulating a part of the exhaust air A ₁ , the load on the deodorizing device 9 is reduced, and the miniaturization thereof becomes possible.
[0019]
Most of the dry raw material P ₁ having a moisture content of 30 to 50% dried by the fermentation drying device 3 is supplied to the combustion processing device 5 via the charging device 4 and incinerated here.
A part of the dry raw material P ₁ is returned to the mixing device 2 through the return path 13 and mixed into the raw material P. Thereby, the moisture content of the to-be-processed object (raw raw material) P supplied to the fermentation drying apparatus 3 is adjusted to the moisture content (for example, about 60 to 80%) suitable for fermentation.
[0020]
Incidentally, fermented drying device drying material P ₁ taken out of 3 is dried to a self-combustion is possible moisture content as described above (approximately 30-50%), it has increased its heat value. As a result, the dry raw material P ₁ can be sufficiently combusted without using auxiliary fuel or even in a state where the amount of use is greatly reduced.
The combustion treatment apparatus 5 may be of any type such as a stoker furnace or a fluidized bed furnace. In this embodiment, a stoker type incinerator is used as the combustion treatment apparatus 5.
[0021]
The combustion exhaust gas G generated by the combustion of the dry raw material P ₁ is recovered by the residual heat recovery device 10 and then discharged to the outside through the exhaust gas processing device 6.
In this embodiment, a so-called waste heat recovery boiler is used as the residual heat recovery device 10, but it is also possible to use a type of waste heat recovery device that directly converts heat into electric energy by a thermoelectric element or the like.
[0022]
Part of the heat recovered by the residual heat recovery device 10 is sent to the refrigeration device 11 in the form of steam S and used as a drive source. Also, low-temperature refrigerant Q formed in the refrigeration apparatus 11 is sent to the dehumidifying condenser 14 to cool the exhaust air A _1. Thus, deodorization of the deodorizing device 9 of condensed off and wake moisture in the exhaust air A ₁ is performed more efficiently.
In the present embodiment, an absorption refrigerator using ammonia as a refrigerant, an absorption refrigerator using lithium bromide as a refrigerant, or the like is used as the refrigeration apparatus 11.
Of course, the surplus heat recovered by the residual heat recovery device 10 is used for power generation and hot water generation.
[0023]
FIG. 2 is a block diagram of a melt combustion processing plant to which the second embodiment of the present invention is applied.
In the second embodiment, a so-called thermal decomposition apparatus 5a and a melting combustion apparatus 5b are used as the combustion processing apparatus 5, and other plant configurations excluding the combustion processing apparatus 5 are used. Is substantially the same as the case of FIG. 1, and the description thereof is omitted here.
[0024]
The melting combustion processing apparatus 5 directly melts the workpiece P using an apparatus composed of a combination of the thermal decomposition apparatus 5a and the melting combustion apparatus 5b employed in the present embodiment and an auxiliary fuel such as coke. Of course, the present invention can be applied to any type of melt combustion processing apparatus.
[0025]
With reference to FIG. 2, the dry raw material P ₁ supplied from the charging device 4 into the pyrolysis device 5a is so-called dry distillation / pyrolysis, and is converted into pyrolysis gas and pyrolysis residue. The pyrolysis gas and the combustible solid (fixed carbon) in the pyrolysis residue are continuously sent into the melt combustion apparatus 5b, where they are so-called melt combustion. In addition, since the structure and operation | movement itself of the fusion | melting type combustion processing apparatus 5 are well-known, detailed description is abbreviate | omitted here.
[0026]
A heat source for the pyrolysis device 5a is the combustion heat of the combustion exhaust gas and the pyrolysis gases from the melt combustion apparatus 5b is commonly used, is reduced moisture content of the dried material P ₁ is up to 30-50% Therefore, the auxiliary fuel used for the operation of the thermal decomposition apparatus 5a can be greatly reduced or eliminated.
Further, the pyrolysis gas and the combustible solid (fixed carbon) supplied to the melt combustion apparatus 5b each have a high calorific value. Therefore, the melting combustion apparatus 5b can cover the heat required for melting without using auxiliary fuel (or in a state where the amount used is greatly reduced), and in the case of a direct melting type melting combustion apparatus using coke. The amount of coke used can be greatly reduced.
Furthermore, the retained heat of the high-temperature combustion exhaust gas G of about 800 to 900 ° C. generated by the melting combustion device 5b is recovered by the residual heat recovery device 10 and used for the driving heat source, power generation, hot water generation, etc. of the refrigeration device 11.
[0027]
【The invention's effect】
In the present invention, the raw material P is first dried using self-generated heat from fermentation, and then the dried raw material P ₁ having a low water content is combusted. As a result, the dry raw material P ₁ can be combusted without requiring auxiliary fuel in the combustion processing device 5 (or in a state where the use of auxiliary fuel is greatly reduced), and the processing cost is greatly reduced. It becomes possible.
Further, since the dry raw material P ₁ having a low moisture content and a high calorific value is combusted, the combustibility in the combustor 5 is improved. As a result, the generation of unburned gas and unburned gas due to incomplete combustion of the object to be processed is greatly reduced, and it becomes possible to reduce the size of the exhaust gas treatment device 6 and prevent environmental pollution.
Further, since the dry raw material P ₁ is combusted, the moisture in the combustion exhaust gas G decreases, the amount of exhaust gas decreases, and the temperature of the exhaust gas G becomes high. As a result, it is possible to reduce the size of the residual heat recovery device 10 and improve the heat recovery efficiency.
In addition, since the raw material P is dried by self-generated heat, it is not necessary to use the heat of the combustion exhaust gas G as a heat source for drying the raw material P. As a result, a large amount of surplus is generated by the thermal energy recovered by the residual heat recovery device 10, and it can be used for power generation, air conditioning, hot water generation, and the like.
[0028]
Further, in the present invention, an absorption refrigeration apparatus 11 using the heat recovered by the residual heat recovery apparatus 10 as a drive source is provided, and the exhaust air A ₁ is cooled by the dehumidifying condenser 14 using the low-temperature refrigerant Q. Yes. As a result, it is possible to efficiently perform the condensation and separation of moisture in the exhaust air A ₁ and the removal of odor components, and a more advanced deodorization treatment of the exhaust air A ₁ is possible.
[0029]
According to the second aspect of the present invention, a part of the exhaust air A _{1 at} the outlet of the dehumidifying condenser 14 is circulated to the air inlet 3 a side of the fermentation drying apparatus 3 by the intake fan 8. As a result, the air-drying property in the fermentation drying device 3 is further improved, and the odor component itself is effectively re-decomposed in the fermentation drying device 3, and the deodorizing device 9 for treating the exhausted air A ₁ is downsized. Is possible.
[0030]
In the invention of claim 3, the portion of the dried material P ₁ were mixed to the raw material P, it is configured to adjust the optimum value of water content of the material to be dried is supplied to the fermentation drying device 3. As a result, the fermentation drying apparatus 3 is always operated under optimum fermentation conditions, and the raw material P can be stably dried.
The present invention has excellent practical utility as described above.
[Brief description of the drawings]
FIG. 1 is a block diagram of an incineration combustion processing plant to which a first embodiment of the present invention is applied.
FIG. 2 is a block configuration diagram of a melt combustion processing plant to which a second embodiment of the present invention is applied.
FIG. 3 is a block diagram showing an example of a conventional incineration combustion processing plant.
FIG. 4 is a block diagram showing an example of a conventional melt combustion processing plant.
FIG. 5 is a block diagram showing another example of a conventional incineration combustion processing plant.
[Explanation of symbols]
P is an object to be treated (raw raw material), P ₁ is a dry raw material, A is air, A ₁ is exhaust air, G is combustion exhaust gas, S is steam, Q is a low-temperature refrigerant, 1 is an incoming supply device, 2 is a mixing device 3 is a fermentation and drying device, 3a is an air inlet, 3b is an air outlet, 3c is a workpiece input port, 4 is a charging device, 5 is a combustion treatment device, 5a is a thermal decomposition device, 5b is a melt combustion device, and 6 is An exhaust gas treatment device, 7 is an air supply fan, 8 is an intake fan, 9 is a deodorizing device, 10 is a residual heat recovery device, 11 is a refrigeration device, 12 is a circulation passage, 13 is a return passage, and 14 is a dehumidifying condenser.

Claims (4)

  A material to be treated containing organic waste with a high water content is fermented and dried in a fermentation drying device equipped with an air supply fan, and a dry raw material with a reduced water content is supplied to the combustion processing device for combustion treatment. The exhaust air from the fermentation drying device is deodorized by a deodorizing device, and the refrigeration device is operated using the heat of the combustion exhaust gas from the combustion processing device as a drive source and before the deodorizing device by the refrigerant from the refrigeration device. A combustion treatment method for waste containing organic waste, characterized in that the exhaust air is cooled to dehumidify and deodorize the exhaust air.   2. The structure according to claim 1, wherein an intake fan is provided on the air outlet side of the fermentation treatment apparatus, and a part of the exhausted air after dehumidification is branched from the discharge side of the intake fan and is returned to the air inlet side of the fermentation treatment apparatus. A method for combusting waste containing organic waste. Moisture of the workpiece to be fed into the fermentation processing device by providing a mixing device upstream of the workpiece input port of the fermentation processing device and returning a part of the dry raw material to the mixing device and mixing it with the workpiece. The method for combustion treatment of waste containing organic waste according to claim 1, wherein the content rate is adjusted.   The combustion processing method of the waste containing the organic waste of Claim 1 which used the combustion processing apparatus as the incineration type combustion processing apparatus or the fusion type combustion processing apparatus.

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