JP4081102B2 - Waste complex treatment facility - Google Patents

Description

  The present invention relates to a combined waste treatment facility that combines waste incineration and methane fermentation.

  Currently, incineration using an incinerator is generally used as a treatment method for reducing or detoxifying waste. However, the treatment target is food waste that contains food waste and organic waste with high water content such as sewage sludge. In this case, since a large amount of drying energy is required for incineration, not only the thermal energy efficiency of the incinerator is deteriorated, but also the fuel cost required for the auxiliary combustion device or the drying device provided for pretreatment is increased. It was easily bulky and an increase in operating costs was inevitable.

  For this reason, in the treatment of this garbage, sewage sludge, or other organic waste that is highly hydrous and suitable for fermentation with anaerobic microorganisms (hereinafter referred to as “fermentation-adapted product”), it is discarded. Methane fermentation facilities were often used for the purpose of reducing waste and using the energy of recovered methane.

  Here, FIG. 2 is an equipment flow diagram showing an example of a conventional methane fermentation facility, where methane fermentation is performed on the fermentation adaption to produce digestion gas containing about 60% of methane, and this gas is generated and supplied. The structure of the energy recovery equipment used for heat is shown.

  In FIG. 2, 1 is a methane fermentation facility, which receives a crushed garbage supplied to a crushing device (not shown), injects dilution water into a slurry, and slurries 50 to 60 ° C. The fermenter 12 in which the digestion gas containing methane is produced by the methane-fermenting bacteria while maintaining and stirring (in the case of high-temperature fermentation), and the fermentation residue after the fermentation is discharged, and the fermenter 12 The main body is composed of a desulfurizer 13 that removes a trace amount of sulfur contained in the digestion gas sent from and a gas holder 14 that stores the desulfurized digestion gas.

  The digestion gas once stored in the gas holder 14 is sent to a subsequent energy recovery facility 15 for energy recovery. Examples of the energy recovery facility 15 include various power generation devices such as a micro gas turbine, and heat recovery facilities such as a boiler, and these are configured singly or in combination. Furthermore, a part of the heat generated in the energy recovery facility 15 is used for heating the fermenter 12.

  In addition, in order to remove the carbon dioxide in the digestion gas to obtain a fuel gas with a high calorific value and to use it in the energy recovery facility 15 or to sell it directly, a gas purification facility may be provided separately. is there.

  On the other hand, the above-mentioned fermentation residue discharged from the fermenter 12 is separated into a solid residue and waste liquid by a dehydrator (not shown), and the residue is separately subjected to composting or the like. And is adjusted to meet a predetermined water quality standard through steps such as biological treatment and coagulation treatment, and is discharged or reused.

  By the way, for example, municipal waste, which includes not only food waste but also various wastes at the same time, a lot of waste that is not suitable for fermentation (hereinafter referred to as “fermentation unsuitable”) is also included. Yes. When receiving and processing such waste that contains a considerable amount of both fermented and unsuitable fermented materials, the waste processing system equipped with both methane fermentation facilities and incineration facilities for the purpose of improving processing efficiency. Facilities were sometimes established.

  FIG. 3 is an equipment flow diagram showing an example of a waste treatment facility provided with such a methane fermentation facility and an incineration facility, and is configured by adding an incineration facility to the methane fermentation facility shown in FIG. Although both facilities may be provided in the same site or may be provided separately in the vicinity, they are described here without any particular distinction because they differ only in the means for transferring the processed material. Also, the same reference numerals are assigned to the same substances and devices as those described in FIG. 2, and detailed description thereof is omitted.

  In FIG. 3, reference numeral 2 denotes a waste pretreatment facility, which includes a crushing device 21 for crushing waste (such as garbage) supplied from a receiving facility (not shown), a fermented product and a fermented product. For example, a sorting device 22 such as a grain size sorter is selected. The fermented product selected by the pretreatment facility 2 is sent to the methane fermentation facility 1 and subjected to methane fermentation as described above.

  3 is an incineration facility that incinerates the selected unsuitable fermentation material together with other incineration waste that is separately supplied. The incinerator 31, the waste heat boiler 32, the temperature reducing equipment 33, the bug An exhaust gas treatment facility 34 such as a filter, an induction fan (IDF) 35, a chimney 36, and other incidental facilities are included.

  In the incineration facility 3, the supplied waste is incinerated in the incinerator 31 to be incinerated, and the generated gas is cooled in a subsequent waste heat boiler 32 and then further controlled in a water injection type. After the temperature is reduced to about 200 ° C. or less by the temperature reducing equipment 33 using a tower or a heat exchanger tube heat exchanger, the exhaust gas treatment equipment 34 collects and treats dust and acidic harmful substances in the exhaust gas, and then the induction fan 35 Through the chimney 36 to the atmosphere.

  In the waste heat boiler 32, steam generated by heat exchange between the exhaust gas and the preheated feed water is sent to the steam turbine power generation device 37 and used for power generation, and various remaining heat is used. .

As a prior art document disclosing a methane production technique by methane fermentation, for example, there is Patent Document 1. Moreover, as an example of the prior literature which sorts waste into a fermentation suitable product and a fermentation unsuitable product and performs fermentation and incineration, respectively, there is Patent Document 2, in which digestion gas obtained by fermentation is modified. A gas purification technique is also disclosed.
JP 2004-237181 A JP 2003-221204 A

  However, in the conventional waste treatment facility shown in FIG. 3, the methane fermentation facility 1 and the incineration facility 3 are provided so that the received waste can be treated in a lump, and the waste that is suitable for the treatment method is selected and supplied. Because the heat loss during the treatment of high water content waste is improved, there is a certain cost reduction effect in the overall construction and operation of the facility compared to the case of installing an incinerator alone, but the facilities of each facility The configuration was not significantly different from the case of single installation.

  That is, although the conventional methane fermentation facility 1 was responsible for treating most of the highly water-containing waste, it still has expensive equipment that uses or treats digestion gas and fermentation residue produced by fermentation. In addition, since the incidental equipment has not been optimized in consideration of the economic efficiency of the entire facility, the effect of reducing the construction and operation costs of the facility is insufficient, and there is a cost merit when two treatment facilities are provided. There was a problem of few.

  Therefore, the present invention solves the above-described problems of the prior art and provides a combined waste disposal facility that is not only provided with a methane fermentation facility and an incineration facility, but is also optimized for cost effectiveness. The task is to do.

The waste combined treatment facility according to claim 1 of the present invention includes a methane fermentation facility for fermenting a fermentation-adapted product of waste to produce digestion gas and a fermentation residue, and an incineration for incinerating a fermentation inappropriate product of waste. An incineration facility with a furnace,
The incinerator of the incineration facility has a structure in which a combustion chamber for burning the unsuitable fermentation material and a combustion gas recombustion chamber provided downstream thereof are connected,
A first supply line for supplying the entire amount of digestion gas generated in the methane fermentation facility to the recombustion chamber of the incinerator for combustion treatment;
A second supply in which the entire amount of the fermentation residue composed of the solid matter and the liquid matter discharged from the methane fermentation facility is supplied to the combustion chamber of the incineration facility without being separated from the solid matter and the liquid matter, and incinerated or evaporated. And having a line.

The waste combined treatment facility according to claim 2 of the present invention includes a methane fermentation facility for fermenting waste fermentation-adapted material to produce digestion gas and fermentation residues, and incineration for incinerating waste unsuitable fermentation materials. A first supply line that is provided with an incineration facility having a furnace and supplies the entire amount of digestion gas generated in the methane fermentation facility to the incinerator for combustion treatment, and solids and liquids discharged from the methane fermentation facility A second supply line that supplies the entire amount of fermentation residue consisting of the following to the incineration facility for incineration or evaporation, and the methane fermentation facility includes a slurry hopper that slurries the fermentation adaption, In order to transfer the fermentation residue discharged from the fermentor, which stores and agitates the slurry-issued issuance product, ferments methane, and produces digestion gas and fermentation residue. An incinerator having a structure in which a combustion chamber for combusting the unsuitable fermentation material and a combustion gas recombustion chamber provided downstream thereof are connected to each other. And a waste heat boiler that recovers the sensible heat of the exhaust gas from the incinerator to generate steam, a water injection temperature control tower that further lowers the temperature of the exhaust gas from the waste heat boiler, and purifies the exhaust gas The first supply line is connected to a recombustion chamber of the incinerator, and the second supply line is a solid material transfer means and a liquid material separated by the solid-liquid separation means. The solid material transfer means is connected to the combustion chamber, and the liquid material transfer means is connected to the temperature control tower.

  According to the waste combined treatment facility according to the present invention, a waste methane fermentation facility and an incineration facility are provided, and by selectively supplying waste suitable for treatment for each facility, a highly hydrous waste Since no incineration is required, energy recovery efficiency can be improved and fuel costs can be reduced.

  In addition, there is no need to provide energy recovery equipment in the methane fermentation facility by providing a first supply line that supplies the digestion gas generated in the fermentor of the methane fermentation facility to the incinerator and burning it as it is in the incinerator. Cost can be reduced. In addition, when digestion gas is supplied to the recombustion chamber through the first supply line, the recombustion chamber can be stably maintained at a high temperature without using auxiliary fuel, and dioxins can be reliably prevented from being re-synthesized. In addition, since the exhaust gas sent to the subsequent waste heat boiler has a high calorific value, the amount of steam generated can be increased and the amount of energy recovered can be increased.

  Furthermore, by providing a second supply line that incinerates or evaporates the fermentation residue discharged from the fermenter in the combustion chamber of the incinerator, methane fermentation facilities do not require expensive wastewater treatment equipment, and equipment costs With the optimized equipment configuration, it is possible to achieve an excellent reduction effect on the construction and operation costs of the facility.

  Hereinafter, an embodiment of the waste combined treatment facility of the present invention will be described in detail.

  FIG. 1 is an equipment flow diagram showing an embodiment of a combined waste treatment facility of the present invention. In addition, the same code | symbol is attached | subjected to the same thing as the substance and apparatus demonstrated in FIG.2 and FIG.3, and detailed description is abbreviate | omitted.

  In FIG. 1, a methane fermentation facility 1 which is one main facility of the combined waste treatment facility includes a slurry hopper 11, a fermenter 12, a desulfurizer 13 and a gas holder 14 as in FIG. 3 described in the prior art. However, it is configured without providing energy recovery equipment for digestion gas produced by methane fermentation and wastewater treatment equipment for fermentation residues.

  On the other hand, the incineration facility 3 includes an incinerator 31, a waste heat boiler 32, a temperature reduction facility 33, an exhaust gas treatment facility 34, an induction fan (IDF) 35, and a chimney 36, as in FIG. A device 37 is attached. The interior of the incinerator 31 includes a combustion chamber 31a for burning the waste charged in the furnace, and a recombustion chamber 31b provided downstream thereof for completely burning the combustion gas generated by the combustion at approximately 850 ° C. or more. Are provided on the wall surface of the incineration chamber 31a, and an auxiliary combustion burner (not shown) used for starting up and down the furnace is provided on the wall surface of the recombustion chamber 31b. A reburn burner (not shown) for maintaining the temperature is provided.

  Further, near the outlet of the combustion chamber 31a, one or a plurality of secondary air inlet pipes 31c for feeding secondary air for burning unburned gas contained in the combustion gas (illustrated) 1) are arranged.

  Between the methane fermentation facility 1 and the incineration facility 3, there are provided two systems of transfer paths composed of a first supply line 41 and a second supply line 42, which will be described later. Fermentation residue) can be transferred to the incineration facility 3 for processing.

  The first supply line 41 is a transfer pipe that connects the gas holder 14 that stores the digested gas generated in the fermenter 12 of the methane fermentation facility 1 after desulfurization and the wall surface of the recombustion chamber 31b on the incineration facility 3 side. There is a flow control valve (not shown).

  The second supply line 42 is disposed between the fermentation tank 12 of the methane fermentation facility 1 and the combustion chamber 31a on the incineration facility 3 side, and is a transfer path for transferring the fermentation residue discharged from the fermentation tank 12. For example, a pipe provided with a sludge pump and an on-off valve is connected to a charging port (not shown) of the combustion chamber 31a.

  The type of the incinerator 31 is not particularly limited. In addition to typical furnace types such as a stoker type, a fluidized bed type, and a rotary type, a vertical type fixed bed type, a rotary furnace and a stoker, etc. A combination type may be used, or a treatment method using a gasification furnace or a melting furnace may be used.

  Next, a waste processing method in the composite waste processing facility configured as described above will be described with reference to FIG.

  Of the collected waste brought to the waste combined treatment facility, the separated garbage is supplied to the pretreatment facility 2 from the receiving supply facility (not shown), broken and crushed by the crushing device 21, and mixed. After the unsuitable fermentation materials such as resin and metals are removed by the sorting device 22, they are sent to the slurry hopper 11 of the methane fermentation facility 1 and become a slurry whose solid content concentration is adjusted by injecting dilution water.

  Subsequently, this slurry is sent to the adjustment tank 12 and subjected to methane fermentation while stirring at a high temperature (about 55 ° C.) or a medium temperature (about 35 ° C.) for a predetermined period (about 10 to 15 days in the case of high temperature fermentation).

  Digestion gas generated by methane fermentation is usually a combustible synthesis gas containing about 60% methane and about 40% carbon dioxide and containing a small amount of hydrogen sulfide, and is desulfurized by the subsequent desulfurizer 13. To be stored in the gas holder 14.

  On the other hand, the collected waste other than the garbage is supplied to the incinerator 31 of the incineration facility 3 together with the unsuitable fermented material sorted by the above-described sorting device 22, and enters the combustion chamber 31a of the incinerator 31 from the inlet not shown. It is thrown.

  This waste is ignited and combusted by the supply of heat and primary air in the combustion chamber 31a to generate combustion gas, and unburned gas contained in the combustion gas is provided in the upper portion of the combustion chamber 31a. Further, secondary combustion is performed by the secondary air fed from the secondary air feed pipe 31c. An air supply line (not shown) is connected to the secondary air inlet pipe 31c with a pusher blower and dampers, so that intake air can be sucked in from a facility where odor countermeasures are required. The odor sent into the furnace as secondary air is pyrolyzed and deodorized at high temperature.

  The combustion gas secondary-combusted in the combustion chamber 31a remains in the next-stage re-combustion chamber 31b at a high temperature of about 850 ° C. or more for 2 seconds or more, so that dioxins are completely decomposed into exhaust gas. Separately, the digestion gas stored in the gas holder 14 is supplied through the first supply line 41 while adjusting the flow rate, and burned in the recombustion chamber 31b. By this operation, the inside of the recombustion chamber 31b can be easily maintained at a high temperature and the amount of heat retained in the exhaust gas can be increased.

  In addition, although the method of feeding the digestion gas supplied to the recombustion chamber 31b is not particularly limited, for example, by blowing so as to form a swirling flow along the inner wall, it is advantageous because generation of a local high temperature region can be suppressed.

  The exhaust gas leaving the recombustion chamber 31b is sent to the subsequent waste heat boiler 32 to generate steam by heat exchange with the boiler water. Using this steam, power is generated by the steam turbine type power generation device 37 juxtaposed, the primary air for combustion and the fermenter 12 are heated, and supplied to various heat utilization facilities. Note that the steam from the waste heat boiler 32 may not be used for heating the fermenter 12, and the turbine waste heat or other waste heat of the power generation device 37 may be used.

  The exhaust gas recovered by the waste heat boiler 32 and cooled down to about 300 ° C. is further lowered to about 200 ° C. or less by a temperature reducing facility 33 such as a water injection type temperature control tower or a heat exchanger type heat exchanger. After that, dust and harmful gases are removed by the exhaust gas treatment facility 34 such as a bag filter, and then released from the chimney 36 through the induction fan 35.

  Here, the fermentation residue generated in the fermenter 12 is supplied to the input port (not shown) of the combustion chamber 31a through the second supply line 42 as described above, and is incinerated together with the input waste. The solid (residue) and liquid (waste liquid) in the residue can be separated and transferred and processed separately. In this case, the second supply line 42 can employ a configuration in which the liquid is separated and transferred. For example, the second supply line 42 uses a combination of solid-liquid separation means such as a sludge concentrating tank, residue transfer means such as a conveyor, and waste liquid transfer means such as piping equipped with a pump, and the residue is in the combustion chamber. The waste liquid can be supplied from the inlet 31a and incinerated, and the waste liquid can be sprayed and evaporated from a waste liquid inlet (not shown) provided on the wall surface of the combustion chamber 31a. In addition, you may process the waste liquid isolate | separated into solid-liquid using the temperature-reduction water of a temperature control tower.

  Further, in the embodiment of the present invention, it is described that only the collected garbage is supplied to the pretreatment device 2 from the collected waste to remove unsuitable fermentation, but the collected waste is separated. In the case where it is difficult to do so, the equipment cost of the sorting device 22 increases, but the entire collection waste to be incinerated can be put into the pretreatment device 2 for sorting. In addition, the main subject of methane fermentation may be other fermented products such as sludge and livestock residues, not garbage, and if the collected waste is in a good separation state, it is not provided with a sorting device 22 as it is. Garbage may be supplied to each facility.

  Next, an accumulation result obtained by examining the cost reduction effect when the waste combined treatment facility described in the embodiment of the present invention is compared with a conventional treatment facility will be described.

  Table 1 shows an example of an integration result comparing how much cost is required in 20 years when a waste combined treatment facility according to the present invention and a conventional treatment facility are newly established. As a comparison object, waste treatment methods are as follows: 1) Incineration of all amount (A method: incineration type), 2) Incineration + methane fermentation (B method: side-by-side type, see Fig. 3), 3) Method of the present invention (C method: It is divided into a composite type (see FIG. 1).

表１によれば、本発明に準拠したＣ方式では、発生した消化ガスをそのまま燃焼させて処理し、エネルギー回収設備を設けないことから、Ｂ方式に比べてエネルギー収入は少なくなるものの、他の建設・維持関係費用は全て低減されており、Ａ・Ｂ方式等の従来の技術に比べコストメリットの高い処理方式であることが分かる。

According to Table 1, in the C method according to the present invention, the generated digestion gas is burned as it is, and no energy recovery equipment is provided. All construction and maintenance related costs have been reduced, and it can be seen that this is a processing method with a high cost merit compared to conventional technologies such as the A / B method.

It is an equipment flow figure showing one embodiment of a waste combined treatment facility of the present invention. It is an equipment flow figure showing an example of the conventional methane fermentation facility. It is an equipment flow figure showing an example of a waste disposal facility with a conventional methane fermentation facility and an incineration facility.

Explanation of symbols

1 Methane Fermentation Facility 2 Pretreatment Facility 21 Crushing Device 22 Sorting Device 3 Incineration Facility 31 Incinerator 31a Combustion Chamber 31b Recombustion Chamber 41 First Supply Line 42 Second Supply Line

Claims (2)

A methane fermentation facility for producing a digestion gas and a fermentation residue by methane fermentation of a fermentation fermentation product of waste, and an incineration facility having an incinerator for incinerating waste unsuitable for fermentation,
The incinerator of the incineration facility has a structure in which a combustion chamber for burning the unsuitable fermentation material and a combustion gas recombustion chamber provided downstream thereof are connected,
A first supply line for supplying the entire amount of digestion gas generated in the methane fermentation facility to the recombustion chamber of the incinerator for combustion treatment;
A second supply in which the entire amount of the fermentation residue composed of the solid matter and the liquid matter discharged from the methane fermentation facility is supplied to the combustion chamber of the incineration facility without being separated from the solid matter and the liquid matter, and incinerated or evaporated. A combined waste treatment facility characterized by comprising a line. A methane fermentation facility for producing a digestion gas and a fermentation residue by methane fermentation of a fermentation fermentation product of waste, and an incineration facility having an incinerator for incinerating waste unsuitable for fermentation,
A first supply line for supplying the entire amount of digestion gas generated in the methane fermentation facility to the incinerator for combustion treatment;
A second supply line for supplying the entire amount of fermentation residue consisting of solid matter and liquid matter discharged from the methane fermentation facility to the incineration facility for incineration or evaporation treatment;
The methane fermentation facility comprises a slurry hopper that slurries the fermentation adaption, a fermenter that stores and agitate the slurry issuance adaption to ferment methane, and generates digestion gas and fermentation residue, and the fermenter In order to transfer the discharged fermentation residue, solid-liquid separation means for separating into solid and liquid,
The incineration facility includes an incinerator having a structure in which a combustion chamber for burning the unsuitable fermentation material and a combustion gas recombustion chamber provided downstream thereof, and an exhaust gas discharged from the incinerator. A waste heat boiler that recovers sensible heat to generate steam, a water injection temperature control tower that further lowers the temperature of exhaust gas from the waste heat boiler, and an exhaust gas treatment facility that purifies the exhaust gas,
The first supply line is connected to a recombustion chamber of the incinerator;
The second supply line is composed of a solid material transfer means and a liquid material transfer means separated by the solid-liquid separation means,
The waste combined treatment facility, wherein the solid material transfer means is connected to the combustion chamber, and the liquid material transfer means is connected to the temperature control tower .

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