TECHNICAL FIELD
[0001] The present disclosure relates to a waste treatment system and a waste
treatment method.
This application claims the priority of Japanese Patent Application No. 2020-
115179 filed on July 2, 2020, the content of which is 5 incorporated herein by reference.
BACKGROUND
[0002] Patent Document 1 describes a treatment device for organic waste
including organic wastewater or solid waste, for example, excess sludge from a
10 sewage treatment plant, food waste such as kitchen waste, or livestock waste. In
the treatment device, the organic waste is subjected to solid-liquid separation after
being decomposed into soluble low-molecular-weight organic matter, the separated
liquid is subjected to methane fermentation to produce biogas, and the separated solid
is composted to generate fertilizer, thereby treating the organic waste.
15
Citation List
Patent Literature
[0003]
Patent Document 1: JP4864339B
20
SUMMARY
Technical Problem
[0004] However, when treating waste with a lower moisture content than the
organic waste described in Patent Document 1, such as municipal waste, even if the
25 waste is hydrolyzed, most of objects to be treated are solids, and thus a generation
amount of biogas is small in the treatment device of Patent Document 1. Further,
3
although not only fertilizer but also fuel or the like can be produced from the
separated solids, producing biogas is more profitable than producing the fertilizer or
fuel, which may increase a waste treatment cost in the treatment device of Patent
Document 1.
[0005] In view of the above, an object 5 of at least one embodiment of the present
disclosure is to provide a waste treatment system and a waste treatment method
capable of decreasing a treatment cost of waste with low moisture content.
Solution to Problem
10 [0006] In order to achieve the above object, a waste treatment system according
to the present disclosure includes: at least one reformer for hydrolyzing waste; and a
microbial reactor for microbially degrading a reformed material containing at least a
solid among the waste hydrolyzed in the at least one reformer.
[0007] Further, a waste treatment method according to the present disclosure
15 includes: a step of hydrolyzing waste; and a step of microbially degrading a reformed
material containing at least a solid among the hydrolyzed waste.
Advantageous Effects
[0008] According to a waste treatment system and a waste treatment method of
20 the present disclosure, since valuables can be produced by microbially degrading
hydrolyzed waste without solid-liquid separation, it is possible to treat even the waste
with low moisture content at low cost.
BRIEF DESCRIPTION OF DRAWINGS
25 [0009] FIG. 1 is a schematic configuration view of a waste treatment system
according to Embodiment 1 of the present disclosure.
4
FIG. 2 is a schematic view showing an example of the configuration of a
reformer in the waste treatment system according to Embodiment 1 of the present
disclosure.
FIG. 3 is a schematic view showing another example of the configuration of
the reformer in the waste treatment system 5 according to Embodiment 1 of the present
disclosure.
FIG. 4 is a schematic view showing still another example of the configuration
of the reformer in the waste treatment system according to Embodiment 1 of the
present disclosure.
10 FIG. 5 is a schematic configuration view of the waste treatment system
according to Embodiment 2 of the present disclosure.
FIG. 6 is a schematic configuration view showing a modified example of the
waste treatment system according to Embodiment 2 of the present disclosure.
FIG. 7 is a schematic configuration view of the waste treatment system
15 according to Embodiment 3 of the present disclosure.
FIG. 8 is a graph showing an example of spectral data acquired by a nearinfrared
sensor in the waste treatment system according to Embodiment 3 of the
present disclosure.
FIG. 9 is a graph showing spectral data of a plurality of reformed materials
20 different in content of a reaction-unsuitable substance in the waste treatment system
according to Embodiment 3 of the present disclosure.
FIG. 10 is a graph showing spectral data of some reformed materials different
in concentration of the reaction-unsuitable substance in the waste treatment system
according to Embodiment 3 of the present disclosure.
25 FIG. 11 shows a calibration curve for the concentration of the reactionunsuitable
substance in the reformed material used in the waste treatment system
5
according to Embodiment 3 of the present disclosure.
FIG. 12 is a schematic configuration view of the waste treatment system
according to Embodiment 4 of the present disclosure.
FIG. 13 is a schematic configuration view showing a part of a modified
example of the waste treatment 5 system according to Embodiment 4 of the present
disclosure.
FIG. 14 is a schematic configuration view of the waste treatment system
according to Embodiment 5 of the present disclosure.
FIG. 15 is a schematic configuration view of the waste treatment system
10 according to Embodiment 6 of the present disclosure.
FIG. 16 is a schematic configuration view showing a modified example of the
waste treatment system according to Embodiment 6 of the present disclosure.
DETAILED DESCRIPTION
15 [0010] Hereinafter, a waste treatment system and a waste treatment method
according to embodiments of the present disclosure will be described with reference
to the drawings. The embodiments each indicate one aspect of the present
disclosure, do not intend to limit the disclosure, and can optionally be modified
within a scope of a technical idea of the present disclosure.
20 [0011] (Embodiment 1)

As shown in FIG. 1, a waste treatment system 1 according to Embodiment 1 of
the present disclosure includes a reformer 2 for hydrolyzing waste such as municipal
25 waste under coexistence of water or steam, and a microbial reactor 3 for microbially
degrading a reformed material hydrolyzed in the reformer 2. The municipal waste,
6
which is given as an example of waste, is characterized by mainly kitchen waste,
paper waste, plastic waste, containing a small amount of metal, and having a
relatively low moisture content. The waste to be treated by the waste treatment
system 1 is not limited to municipal waste, but waste such as sludge generated by
treating wastewater from a factory or 5 the like, agricultural waste, etc. with a higher
moisture content than the municipal waste can also be treated by the waste treatment
system 1.
[0012] The reformer 2 is, for example, a reformer for receiving waste as it is
from a vehicle, a plant, or the like where the waste is collected and hydrolyzes the
10 waste in a batch manner with steam, and specifically, the reformer 2 is a batch-type
reformer including a housing 10 with an input port 11 where the waste is input and a
discharge port 12 where the reformed material is discharged. Opening and closing
valves 18 and 19 are provided in the input port 11 and the discharge port 12,
respectively, and the housing 10 can be sealed by closing the opening and closing
15 valves 18, 19. The hydrolysis of the waste in the reformer 2 may be wet hydrolysis
in which steam contacts the waste and heats the waste, or may be dry hydrolysis in
which steam indirectly heats the waste without contacting the waste. In the case of
dry hydrolysis, moisture in the waste within the housing 10 evaporates into water
vapor, and the water vapor uniformly heats the waste within the housing 10.
20 Further, moisture is necessary for hydrolysis, and moisture is supplied by causing
moisture to adhere to the surface of the waste with the water vapor. Although one
reformer 2 is shown in FIG. 1, a configuration where a plurality of reformers 2 are
connected in series, a configuration where the plurality of reformers 2 are connected
in parallel, or a combination of the configuration where the plurality of reformers 2
25 are connected in series and the configuration where the plurality of reformers 2 are
connected in parallel may be adopted.
7
[0013] In the case of the reformer 2 performing wet hydrolysis, as shown in FIG.
2, a configuration can be adopted, as an example of the reformer 2, where the housing
10 includes at least one steam inlet 13 for causing steam to flow into the housing 10
and at least one purge nozzle 14 for purging a gas within the housing 10. Further,
in the case of the reformer 5 2 performing dry hydrolysis, as shown in FIG. 3, a
configuration can be adopted, as an example of the reformer 2, where the housing 10
includes a jacket 15 disposed so as to at least partially cover an outer surface of the
housing 10. The jacket 15 constitutes a steam passage through which steam flows.
The passage through which steam passes can also be disposed inside a reactor or on
10 an agitating shaft. In the form of FIG. 3, the jacket 15 constitutes a heating part for
hydrolyzing the waste within the housing 10 by heating moisture contained in the
waste with heat of steam while avoiding contact with the waste. The heating part
is not limited to the steam passage through which steam flows, but may be a part
constituting a passage through which any heating medium such as a combustion
15 exhaust gas flows, or a part such as an electric heater capable of indirectly heating
the waste (especially moisture in the waste) without directly contacting the waste.
In any form of the reformer 2, an agitator16 for agitating the waste within the housing
10 is provided inside the housing 10. The agitator 16 is driven by a motor 17.
[0014] As shown in FIG. 1, the configuration of the microbial reactor 3 is not
20 particularly limited, but any configuration may be adopted as long as valuables are
produced by using a biological action of microorganisms, with the reformed material
obtained by hydrolyzing the waste in the reformer 2 being a raw material, and the
configuration of the microbial reactor 3 may be, for example, a biogas fermentation
tank for producing biogas such as methane as a valuable, a saccharification tank for
25 producing sugar as a valuable from carbohydrates such as starch or cellulose, a
composting device for producing compost by composting, or the like.
8
[0015]
Next, the operation of the waste treatment system 1 according to Embodiment
1 of the present disclosure will be described. As shown in FIG. 1, the waste
received in the housing 10 via 5 the input port 11 is heated by steam while being
agitated by the agitator 16 (see FIG. 2 or 3). Consequently, a hydrolysis reaction
occurs in the waste. Conditions for this hydrolysis are not particularly limited, but
can be set, for example, such that a cell fluid flows out from a cell contained in
kitchen waste and as such conditions, it is possible to use temperatures between
10 normal temperature and approximately 250℃ and pressures between atmospheric
pressure and approximately 40 atmospheres.
[0016] The kitchen waste in the waste mainly contains proteins, carbohydrates,
fats, and by hydrolyzing the kitchen waste, pinholes are formed in a cell membrane
and a cell wall, and the cell membrane and the cell wall are dissolved, resulting in
15 outflow of the cell fluid. Consequently, the kitchen waste is made finer, and a
polymer component is subjected to degradation. In addition, volatile fatty acid
(VFA) such as acetic acid is increased.
[0017] Hydrophobic lignin or hemicellulose forming a plant such as wood in the
waste is converted to a hydrophilic substance and dissolved by hydrolysis, thereby
20 exposing cellulose. Paper waste in the waste becomes hydrophilic due to
dissolution of chemical on a surface. Further, by being agitated with the agitator
16, the paper waste is finely pulverized, softened, and decreased in diameter.
Plastic waste in the waste is heated and softened, and is sheared by the agitation with
the agitator 16 and decreased in diameter.
25 [0018] The reformed material, which is the waste hydrolyzed in the reformer 2,
includes each of generated components generated as described above from the
9
kitchen waste, the paper waste (including wood, etc.), the plastic waste, and a small
amount of metal hardly affected by hydrolysis. Due to the relatively low moisture
content of the waste having the above-described composition, the composition of the
reformed material is mostly solid component with very little liquid. Such reformed
material is flowed out from 5 the housing 10 via the discharge port 12 and transferred
to the microbial reactor 3. If the waste has a high moisture content, such as sludge,
the amount of liquid in the reformed material also increases, resulting in a slurry
reformed material. Even in such a case, the entire amount of the reformed material
is transferred to the microbial reactor 3 without the reformed material undergoing
10 solid-liquid separation. In the microbial reactor 3, the reformed material is
degraded by being subjected to the biological action of microorganisms, producing
valuables.
[0019] The kitchen waste in the waste is made finer by hydrolysis, increasing
the surface area of a kitchen waste-derived component. Since the area subjected to
15 the biological action of microorganisms increases, the degradation is promoted. If
uneven distribution of the kitchen waste-derived components is suppressed and
homogenized by making the kitchen waste finer, it is possible to homogenize the
activity of the biological action, and the degradation is stabilized. In addition, the
increase in VFA promotes the degradation. Further, by degrading the kitchen
20 waste-derived component, fat bubbling in the microbial reactor 3 is suppressed.
The occurrence of such bubbling causes a trouble in which an overflow port (not
shown) of the microbial reactor 3 is clogged, but it is possible to suppress the
occurrence of such trouble.
[0020] Since cellulose of the paper waste or plant in the waste is exposed by
25 hydrolysis, microorganisms can easily access the cellulose, promoting the
degradation. Further, since these components become hydrophilic and are
10
decreased in diameter, these components do not float in the microbial reactor 3,
making it possible to reduce a risk of inhibiting the degradation. Since the plastic
waste in the waste is also decreased in diameter by hydrolysis, it is possible to reduce
the risk of inhibiting the degradation.
[0021] Thus, since the valuables can 5 be produced by degrading the reformed
material, which is obtained by hydrolyzing the waste in the reformer 2, in the
microbial reactor 3 without solid-liquid separation, it is possible to produce the
valuables even from the waste with low moisture content. Further, since the waste
treatment system 1 does not require a device for solid-liquid separation of the
10 reformed material and produces only the valuables with a high unit price such as
biogas, it is possible to treat the waste at lower cost, compared to a system for
performing solid-liquid separation on the reformed material, producing biogas from
the liquid which has undergone solid-liquid separation, and producing fuel, fertilizer,
etc. from the solid which has undergone solid-liquid separation.
15 [0022] As shown in FIG. 4, in Embodiment 1, if two reformers 2 (a first reformer
2a and a second reformer 2b) connected in series are provided, a solid-liquid
separator 70 is provided between the first reformer 2a and the second reformer 2b,
and solid-liquid separation may be performed on the reformed material of the first
reformer 2a to transfer only the solid obtained by solid-liquid separation to the
20 second reformer 2b. By solid-liquid separation, a nitrogen compound, such as
protein, that causes production of melanoidin can be separated to a liquid side,
making it possible to suppress production of melanoidin in hydrolysis in the second
reformer. Inflow of melanoidin into a methane fermentation tank serving as the
microbial reactor 3 inhibits methane fermentation. Thus, by performing solid25
liquid separation on the reformed material of the first reformer to transfer only the
solid obtained by solid-liquid separation to the second reformer, it is possible to
11
reduce a risk of inhibiting methane fermentation in the methane fermentation tank.
Since the liquid obtained by solid-liquid separation contains the nitrogen compound,
the liquid may be supplied to the methane fermentation tank by bypassing the second
reformer 2b. Whereby, the nitrogen component can be replenished to the methane
5 fermentation tank.
[0023] In Embodiment 1, the steam used for heating the waste in the reformer 2
may be supplied to the microbial reactor 3 to be used as a heat source for heat
retention during microbial reaction in the microbial reactor 3. Whereby, an
operating cost can be reduced compared to a case where a heat source necessary for
10 the operation of the microbial reactor 3 is separately prepared.
[0024] (Embodiment 2)
Next, the waste treatment system according to Embodiment 2 will be described.
The waste treatment system according to Embodiment 2 is obtained by adding, to
Embodiment 1, a separator for separating, from the reformed material, a reaction15
unsuitable substance which does not contribute to the microbial degradation in the
microbial reactor 3, that is, which is unsuitable for the degradation. In Embodiment
2, the same constituent elements as those in Embodiment 1 are associated with the
same reference characters and not described again in detail.
[0025]
As shown in FIG. 5, the waste treatment system 1 according to Embodiment 2
of the present disclosure includes a separator 4 disposed between the reformer 2 and
the microbial reactor 3. The separator 4 is for separating the reformed material into
a large particle size component and a small particle size component having a smaller
25 particle size than the large particle size component. The separator 4 is, for example,
a screen having any mesh size, and the mesh size corresponds to a particle size at a
12
boundary between the large particle size component and the small particle size
component. Other configurations are the same as those in Embodiment 1.
[0026]
In the waste treatment 5 system 1 according to Embodiment 2 of the present
disclosure, the reformed material is separated into the large particle size component
and the small particle size component in the separator 4, only the small particle size
component is supplied to the microbial reactor 3, and only the small particle size
component is degraded to produce valuables. A principal component of the large
10 particle size component is a component that has a relatively large particle size even
after hydrolysis in the reformer 2, and cannot be degraded in the microbial reactor 3,
such as those derived from plastic waste or metal. To put it another way, the large
particle size component and the small particle size component are, respectively, a
reaction-unsuitable substance and a reaction-suitable substance for microbial
15 reaction.
[0027] In Embodiment 2, since such large particle size component is separated
from the reformed material by the separator 4 and only the small particle size
component is supplied to the microbial reactor 3, it is possible to reduce the amount
of the reaction-unsuitable substance supplied to the microbial reactor 3. As a result,
20 it is possible to reduce the risk of inhibiting the degradation in the microbial reactor
3, and to efficiently perform the degradation.
[0028] Regarding the screen as an example of the separator 4, waste with a total
solid concentration (TS) of 53% is hydrolyzed (heated to predetermined
temperatures between normal temperature and 240°C while being agitated in a
25 closed container, and held for a certain period of time), and then a reformed material
of the waste is passed through the screen including a mesh. As a result, relative to
13
the recovery rate of 40 wt% in a case where the reaction-suitable substance (an
organic matter such as paper, kitchen waste, etc.) as the small particle size component
is crushed as it is in the conventional manner and separated with the screen, the
recovery rate of 80 wt% can be obtained by using the method of the present invention,
and it is possible to reduce the mixing 5 ratio of the reaction-unsuitable substance
(plastic waste, etc.) in the reaction-suitable substance to not greater than 10 wt%.
Thus, since it is found that by using the screen, it is possible to remove, to a certain
extent, the reaction-unsuitable substance from the reformed material having
undergone hydrolysis, by providing the separator 4 between the reformer 2 and the
10 microbial reactor 3, it can be presumed that the risk of inhibiting the degradation in
the microbial reactor 3 can be reduced and the degradation can efficiently be
performed. In the present embodiment, the example of the separation based on the
difference in particle size is shown. However, as means for the separation, specific
gravity separation, wind separation, wet separation, etc. can also be used. Thus, the
15 separator 4 can also be a device using specific gravity separation, wind separation,
wet separation, etc., or a combination thereof. If the microbial reactor 3 is a
methane fermentation tank, wet separation is preferable because of the necessity of
replenishing moisture, and if the microbial reactor 3 is a composting device, wind
separation or screen separation is preferable because of the necessity of having a low
20 moisture content. An air jet spray or the like may be used to improve the recovery
rate of the small particle size component.
[0029] In Embodiment 2, when treating something like sludge with a relatively
high moisture content, since the TS of the reformed material flowing out from the
reformer 2 is low, the reaction-unsuitable substance may not successfully be
25 separated in the separator 4. In such a case, after hydrolysis is performed in the
reformer 2, the purge nozzle 14 (see FIG. 2) is opened for a certain period of time to
14
perform the same operation as vacuum drying, making it also possible to reduce the
moisture content of the reformed material and adjust the TS of the reformed material.
In this case, the purge nozzle 14 constitutes a moisture adjusting device for adjusting
the moisture content of the reformed material. Regarding this form, as shown in
FIG. 6, a drying device 71 of any 5 configuration, which serves as the moisture
adjusting device capable of adjusting the moisture content of the reformed material,
may be disposed on a reformed material transfer line 5 through which the reformer
2 and the separator 4 communicate with each other. In this case, a dehydrator may
be provided as the moisture adjusting device. Conversely, in order to increase the
10 fluidity of the hydrolyzed reformed material, the moisture adjusting device can also
adjust the TS of the reformed material by adding moisture to the reformed material
to increase the moisture content. In this case, a water spray may be provided as the
moisture adjusting device. Further, if the moisture adjusting device is configured
such that moisture is added to the small particle size component separated in the
15 separator 4 and excess moisture is removed, the moisture adjusting device can also
function as a washing device for washing the reaction-suitable substance adhering to
the reaction-suitable substance. Thus, the reaction-suitable substance can be
supplied to the microbial reactor 3 after the content of a fermentation inhibitor such
as melanoidin in the reaction-suitable substance is reduced, making it possible to
20 reduce the risk of inhibiting the reaction in the microbial reactor 3. Further, if the
moisture adjusting device is used as a washing device for washing the reactionunsuitable
substance which is the large particle size component separated in the
separator 4, it is possible to recover the small particle size component adhering to
the reaction-unsuitable substance as the reaction-suitable substance, and it is possible
25 to improve the recovery rate of the reaction-suitable substance. The moisture
adjusting device can also be disposed inside the separator 4. The reformed material
15
transfer line 5 may be a pipe if the reformed material is in the form of slurry, or may
be a conveyor or the like if the reformed material is solid. Even if the reformed
material is solid, as long as the reformed material can be pumped by air or the like,
the reformed material transfer line 5 may be the pipe.
5 [0030] (Embodiment 3)
Next, the waste treatment system according to Embodiment 3 will be described.
Relative to Embodiment 2, the waste treatment system according to Embodiment 3
is configured to estimate the content of the reaction-unsuitable substance in the
reformed material. In Embodiment 3, the same constituent elements as those in
10 Embodiment 2 are associated with the same reference characters and not described
again in detail.
[0031]
As shown in FIG. 7, in Embodiment 3, near-infrared sensors 61, 62, such as
15 hyperspectral cameras, are respectively disposed on the reformed material transfer
line 5 and a reformed material transfer line 7 through which the separator 4 and the
microbial reactor 3 communicate with each other. The near-infrared sensors 61, 62
are electrically connected to a control device 36. The specific configuration of the
reformed material transfer line 7 is the same as that of the reformed material transfer
20 line 5. Other configurations are the same as those in Embodiment 2.
[0032]
The operation in Embodiment 3 is basically the same as that in Embodiment 2.
Embodiment 3 is different from Embodiment 2 in that the near-infrared sensor 61,
25 62 acquires spectral data of the reformed material while the reformed material is
transferred from the reformer 2 to the microbial reactor 3, the acquired spectral data
16
is transmitted to the control device 36, and the control device 36 performs an
operation of estimating the content of the reaction-unsuitable substance in the
reformed material based on the spectrum data. Operations different from those of
Embodiment 2 will be described below.
[0033] FIG. 8 shows an example 5 of the spectral data acquired by the nearinfrared
sensor 61, 62. As indicated by a, b, c (not limited to three, but may be not
less than four) in FIG. 9, the control device 36 saves in advance as a database spectral
data of the reformed material different in content of the reaction-unsuitable substance.
The control device 36 identifies, by using means such as the weighted average
10 method or the kernel method, the acquired spectral data (FIG. 8) by combining a
plurality of spectral data saved as the database, and can estimate the concentration of
the reaction-unsuitable substance based on the weighted value.
[0034] As another example, for example, as shown in FIG. 10, spectral data of
several reformed materials different in concentration of the reaction-unsuitable
15 substance (10%, 50%, 100% in FIG. 10, but these are merely examples) is acquired,
a change in intensity between two different specific wavelengths (for example, 1,500
nm and 1,700 nm) in each spectrum data is read, and a relationship (calibration
curve) between the concentration of the reaction-unsuitable substance and the change
in intensity between the two different specific wavelengths is created in advance as
20 shown in FIG. 11 and is stored in the control device 36. The control device 36 can
read the absorbance at the specific wavelength of the spectral data acquired by the
near-infrared sensor 61, 62, and estimate the concentration of the reaction-unsuitable
substance in the reformed material based on this calibration curve.
[0035] As still another example, in addition to the near-infrared sensor 61, 62,
25 for example, a piezoelectric sensor or the like is provided to measure the weight of
the reformed material being transferred. It is also possible to estimate the type of
17
reaction-unsuitable substance from the spectral data acquired by using the nearinfrared
sensor 61, 62, and thus it is also possible to estimate, from the type of
reaction-unsuitable substance and the weight of the reformed material, the weight
ratio of the reaction-unsuitable substance and the reaction-suitable substance in the
5 reformed material being transferred.
[0036] Based on the content of the reaction-unsuitable substance in the reformed
material thus estimated, it is possible to detect abnormalities in the reformer 2 and
the separator 4 or abnormality in the waste input to the reformer 2.
[0037] In Embodiment 3, the content of the reaction-unsuitable substance in the
10 reformed material is estimated by the near-infrared sensor 61, 62. However, the
present invention is not limited to this mode. With the near-infrared sensor, it is
also possible to predict the property of the waste input to the reformer 2. For
example, the near-infrared sensor acquires spectral data of the waste, and from the
acquired spectral data, it is possible to grasp the percentage of
15 moisture/protein/carbohydrate/fat/plastic components, etc. Based on the property
of the waste thus acquired, it is possible to set hydrolysis conditions
(temperature/pressure/time/agitation speed, etc.) in the reformer 2. Further, it is
also possible to set separation conditions (mesh size, water content, frequency, etc.)
in the separator 4. A digital camera may be used instead of the near-infrared sensor
20 61, 62, and the property of the waste may be predicted based on an image taken by
the digital camera.
[0038] If the property of the waste is known in advance for reasons that, for
example, a waste receiving route is clear, the hydrolysis conditions in the reformer 2
or the separation conditions in the separator 4 can be set based on the property. In
25 addition, the property of the waste can be estimated with, for example, AI prediction
using information about the property of the waste such as waste collection date, event
18
calendar (information about the type of waste), past analysis result of waste, local
purchasing information or the like. That is, the control device 36 detects, as a
detection device, the information about the property of the waste as an indicator of a
hydrolysis state of the waste in the reformer 2, and then the control device 36 may
5 estimate the hydrolysis state based on this indicator.
[0039] (Embodiment 4)
Next, the waste treatment system according to Embodiment 4 will be described.
Relative to any of Embodiments 1 to 3, the waste treatment system according to
Embodiment 4 is configured to adjust the hydrolysis conditions based on the
10 hydrolysis state of the waste in the reformer 2. Embodiment 4 will be described
below with a configuration where the hydrolysis conditions are adjusted, relative to
Embodiment 2. However, Embodiment 4 may be configured to adjust the
hydrolysis conditions, relative to Embodiment 1 or 3. In Embodiment 4, the same
constituent elements as those in Embodiment 2 are associated with the same
15 reference characters and not described again in detail.
[0040]
In Embodiment 4, the microbial reactor 3 will be described as a biogas
fermentation tank 3a for producing biogas such as methane. As shown in FIG. 12,
20 the waste treatment system 1 according to Embodiment 4 of the present disclosure
includes a gas holder 31 for storing biogas produced in the biogas fermentation tank
3a, a combustion boiler 32 for generating steam by using the biogas stored in the gas
holder 31 as fuel, a gas engine 33 driven with the biogas stored in the gas holder 31
as fuel, an exhaust gas boiler 34 for generating steam by heat of an exhaust gas from
25 the gas engine 33, and a dehydrator 35 for dehydrating a fermentation residue in the
biogas fermentation tank 3a. Although not an essential configuration, a water
19
injection pipe 37 may be provided through which the dehydrator 35 and the reformed
material transfer line 5 communicate with each other.
[0041] Each of the combustion boiler 32 and the exhaust gas boiler 34
communicates with the steam inlet 13 (see FIG. 2) or the jacket 15 (see FIG. 3) of
the reformer 2 through a steam supply 5 pipe 38, and it is configured such that steam
generated in each of the combustion boiler 32 and the exhaust gas boiler 34 is
supplied to the reformer 2. The steam supply pipe 38 is provided with steam supply
amount adjustment valve 39a, 39b for adjusting the amount of steam supplied to the
reformer 2 from each of the combustion boiler 32 and the exhaust gas boiler 34.
10 The waste treatment system 1 includes a combustion boiler controller 32a for
controlling a temperature and a generation amount of steam generated in the
combustion boiler 32, and an exhaust gas boiler controller 34a for controlling a
temperature and a generation amount of steam generated in the exhaust gas boiler 34.
Further, the waste treatment system 1 includes the control device 36, and the control
15 device 36 is electrically connected to each of the motor 17 for driving the agitator 16
of the reformer 2, the combustion boiler controller 32a, the exhaust gas boiler
controller 34a, and the steam supply amount adjustment valve 39a, 39b. Although
not illustrated in FIG. 12, the control device 36 is configured to acquire the
hydrolysis state (temperature, pressure, etc.) in the reformer 2.
20 [0042] The combustion boiler controller 32a and the exhaust gas boiler
controller 34a control the temperature and the generation amount of steam generated
in the combustion boiler 32 and the exhaust gas boiler 34, respectively, and the steam
supply amount adjustment valves 39a, 39b adjust the amount of steam supplied to
the reformer 2. Then, since these constituent elements adjust the hydrolysis
25 conditions (temperature, pressure, etc.) of the waste in the reformer 2, these
constituent elements each constitute the adjustment device for adjusting the
20
hydrolysis conditions of the waste in the reformer 2. Other configurations are the
same as those in Embodiment 2.
[0043]
From the operation of hydrolyzing the waste 5 in the reformer 2 to the operation
of producing biogas as a valuable in the microbial reactor 3, that is, the biogas
fermentation tank 3a, are the same as those in Embodiment 2. The biogas produced
in biogas fermentation tank 3a is stored in the gas holder 31. Biogas is supplied
from the gas holder 31 to each of the combustion boiler 32 and the gas engine 33,
10 according to operating conditions of the combustion boiler 32 and the gas engine 33.
In the combustion boiler 32, steam is generated by using biogas as fuel. In the
exhaust gas boiler 34, steam is generated by heat of the exhaust gas from the gas
engine. Steam generated in each of the combustion boiler 32 and the exhaust gas
boiler 34 is supplied to the reformer 2 and used to hydrolyze the waste.

We Claim:
1. A waste treatment system, comprising:
at least one reformer for hydrolyzing waste; and
a microbial reactor for microbially degrading a reformed material
containing at least a 5 solid among the waste hydrolyzed in the at least one
reformer.
2. The waste treatment system according to claim 1,
wherein the at least one reformer includes:
a housing for receiving the waste;
10 an input port for inputting the waste to the housing;
a discharge port for discharging the reformed material from the housing;
and
opening and closing valves for opening and closing the input port and
the discharge port, respectively, and
15 wherein the waste within the housing is hydrolyzed in a batch manner
while the housing is sealed by closing each of the opening and closing valves.
3. The waste treatment system according to claim 1 or 2,
wherein the at least one reformer includes a housing for receiving the
waste, and
20 wherein the at least one reformer is configured to supply steam into the
housing to heat and hydrolyze the waste within the housing with the steam.
4. The waste treatment system according to claim 1 or 2,
wherein the at least one reformer includes a housing for receiving the
waste, and
25 wherein the housing includes a heating part for hydrolyzing the waste
42
within the housing by heating moisture contained in the waste while avoiding
contact with the waste.
5. The waste treatment system according to any one of claims 1 to 4,
wherein, in the at least one reformer, hydrolysis is performed at
temperatures between normal temperature 5 and 250°C and at pressures between
atmospheric pressure and 40 atmospheres.
6. The waste treatment system according to any one of claims 1 to 5, comprising:
a first reformer and a second reformer each serving as the at least one
reformer; and
10 a solid-liquid separator for performing solid-liquid separation on a
treated object which is the waste hydrolyzed in the first reformer,
wherein the second reformer hydrolyzes only a solid separated by the
solid-liquid separator.
7. The waste treatment system according to any one of claims 1 to 6,
15 wherein the microbial reactor includes at least one of:
a biogas fermentation tank for producing biogas;
a saccharification tank for producing sugar from carbohydrate; and
a composting device for producing compost.
8. The waste treatment system according to any one of claims 1 to 7, further
20 comprising:
a separator between the at least one reformer and the microbial reactor,
the separator being configured to separate a reaction-unsuitable substance,
which is unsuitable for the microbial degradation in the microbial reactor, from
the reformed material.
25 9. The waste treatment system according to claim 8, comprising a moisture
43
adjusting device for adjusting a moisture content of the reformed material.
10. The waste treatment system according to claim 9,
wherein the moisture adjusting device is a drying device for reducing the
moisture content of the reformed material.
5 11. The waste treatment system according to claim 9,
wherein the moisture adjusting device is a washing device for washing a
reaction-suitable substance adhering to the reaction-unsuitable substance.
12. The waste treatment system according to any one of claims 8 to 10, comprising:
a dehydrator for dehydrating a residue of the microbial reactor; and
10 a water injection pipe for feeding water dehydrated by the dehydrator to
at least one of the reformed material before flowing into the separator, inside
of the reformer, or inside of the microbial reactor.
13. The waste treatment system according to any one of claims 8 to 12,
wherein the separator is a screen for separating the reformed material
15 into a large particle size component and a small particle size component having
a smaller particle size than the large particle size component, and the large
particle size component is the reaction-unsuitable substance.
14. The waste treatment system according to any one of claims 1 to 13, further
comprising:
20 a detection device for detecting an indicator of a hydrolysis state of the
waste in the at least one reformer;
an adjustment device for adjusting a hydrolysis condition of the waste in
the at least one reformer; and
a control device,
25 wherein the control device estimates the hydrolysis state of the waste
44
based on the indicator detected by the detection device, and operates the
adjustment device to adjust the hydrolysis condition of the waste based on the
estimated hydrolysis state.
15. The waste treatment system according to claim 14,
5 wherein the at least one reformer includes:
an agitator for agitating waste; and
a motor for driving the agitator,
wherein the detection device detects a torque of the motor as the indicator,
and
10 wherein the control device estimates the hydrolysis state based on the
torque of the motor.
16. The waste treatment system according to claim 14,
wherein the at least one reformer includes:
an agitator for agitating waste; and
15 a motor for driving the agitator,
wherein the detection device detects a current value of the motor as the
indicator, and
wherein the control device estimates the hydrolysis state based on the
current value of the motor.
20 17. The waste treatment system according to claim 14,
wherein the detection device detects information about a property of the
waste as the indicator, and
wherein the control device estimates the hydrolysis state based on the
property of the waste.
25 18. The waste treatment system according to claim 17,
45
wherein the control device learns a correspondence relationship among
the property of the waste, the hydrolysis condition, and the hydrolysis state,
and adjusts the hydrolysis condition based on a learned model constructed as
a result of the learning.
5 19. The waste treatment system according to any one of claims 14 to 18,
wherein the waste is heated and hydrolyzed with steam supplied to the at
least one reformer, and
wherein the adjustment device adjusts at least one of a temperature, a
pressure, and a supply amount of the steam.
10 20. A waste treatment method, comprising:
a step of hydrolyzing waste; and
a step of microbially degrading a reformed material containing at least a
solid among the hydrolyzed waste.