Waste disposal system

Abstract

Regarding a waste treatment system equipped with a hydrothermal treatment device, the present invention provides a waste treatment system that can reduce the amount of odor released into the atmosphere with a simple configuration. [Solution] The system comprises a release steam line configured to discharge steam from a hydrothermal treatment device, a methane fermentation tank configured to generate methane gas using the liquid component of the hydrothermal treatment material, a biomass-derived material treatment device, an odor line from which odors are discharged from the biomass-derived material treatment device, and a deodorizing device configured to deodorize the odors discharged from the biomass-derived material treatment device. The release steam line is connected to the biomass-derived material treatment device and is configured to supply steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device. The biomass-derived material treatment device is configured to perform heat exchange between the steam supplied from the release steam line and biomass-derived materials.

Description

Technical Field

[0001] The present disclosure relates to a waste treatment system.

Background Art

[0002] Patent Document 1 discloses a waste treatment system in which biomass contained in waste is subjected to hydrothermal treatment with high-temperature and high-pressure steam, a liquid such as a solution or slurry is separated from the hydrothermally treated product, and the liquid is used to produce gas by microorganisms, for example, perform methane fermentation.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the waste treatment system described in Patent Document 1, steam is discharged from the hydrothermal treatment apparatus after the hydrothermal treatment reaction of biomass. This steam contains odors, and it is not desirable to release the odors directly into the atmosphere. Furthermore, when a deodorizing facility is provided to reduce the amount of odors released into the atmosphere, if the amount of steam discharged from the hydrothermal treatment apparatus is large, the deodorizing facility tends to increase in size, and the configuration of the waste treatment system tends to become complicated.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a waste treatment system including a hydrothermal treatment apparatus, which can reduce the amount of odors released into the atmosphere with a simple configuration.

Means for Solving the Problem

[0006] To achieve the above object, a waste treatment system according to at least one embodiment of the present disclosure includes: A hydrothermal treatment apparatus configured to hydrothermally treat biomass contained in waste using steam and discharge the hydrothermally treated biomass, A release steam line connected to the aforementioned hydrothermal treatment apparatus and configured to discharge steam from the aforementioned hydrothermal treatment apparatus, A methane fermentation tank configured to generate methane gas using the liquid component of the hydrothermal treatment material discharged from the hydrothermal treatment apparatus, A biomass-derived substance processing apparatus configured to process the biomass-derived substance, An odor line connected to the biomass-derived material treatment device, through which odors are discharged from the biomass-derived material treatment device, A deodorizing device connected to the odor line and configured to deodorize the odor discharged from the biomass-derived material treatment device, Equipped with, The release steam line is connected to the biomass-derived material treatment device and is configured to supply the steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device. The biomass-derived material processing device is configured to perform heat exchange between the steam supplied from the release steam line and the material derived from the biomass. [Effects of the Invention]

[0007] According to at least one embodiment of the present disclosure, a waste treatment system comprising a hydrothermal treatment device is provided that can reduce the amount of odor released into the atmosphere with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows a schematic configuration of a waste treatment system 2 according to one embodiment of the present disclosure. [Figure 2] This is a schematic cross-sectional view illustrating an example of the general configuration of the mixing and adjusting tank 8. [Figure 3]This diagram illustrates an example of a method for cleaning the drum screen 9 using steam supplied from the release steam line 24. [Modes for carrying out the invention]

[0009] Hereinafter, several embodiments of this disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described or shown in the drawings as embodiments are not intended to limit the scope of the invention, but are merely illustrative examples. For example, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" should not only strictly describe such arrangements, but also describe states of relative displacement with tolerances or angles or distances that allow for the same function to be achieved. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. For example, expressions describing shapes such as squares or cylinders shall not only represent geometrically precise shapes such as squares or cylinders, but also shapes that include protrusions, chamfers, etc., to the extent that the same effect can be achieved. On the other hand, expressions such as "to possess," "to be equipped with," "to have," "to include," or "to have" a single component are not exclusive expressions that exclude the existence of other components.

[0010] Figure 1 is a diagram showing a schematic configuration of a waste treatment system 2 according to one embodiment of the present disclosure. In the exemplary configuration shown in Figure 1, the waste treatment system 2 includes a hydrothermal treatment device 4, a rough sorting device 6, a mixing and adjustment tank 8, a drum screen 9, a screw press 10, a methane fermentation tank 12, a sludge dryer 14, and a deodorizing device 16, etc.

[0011] The hydrothermal treatment apparatus 4 is a sealed pressure vessel for hydrothermally treating biomass contained in waste. The hydrothermal treatment apparatus 4 is connected to a waste input line 18, a steam supply line 20, a hydrothermally treated material discharge line 22, and a release steam line 24. Waste containing biomass is input to the hydrothermal treatment apparatus 4 from the waste input line 18, and high-temperature, high-pressure steam (for example, steam at about 120°C to 180°C) is supplied from the steam supply line 20, heating and pressurizing the inside of the hydrothermal treatment apparatus 4 with steam. The waste input from the waste input line 18 may be paper-rich waste such as municipal solid waste, and may include methane fermentation-suitable materials (organic waste suitable for methane fermentation) such as paper and kitchen waste, and methane fermentation-unsuitable materials (waste unsuitable for methane fermentation) such as plastics, cloth and metals.

[0012] The hydrothermal treatment device 4 hydrothermally treats biomass (e.g., methane fermentation-suitable materials such as paper and kitchen waste) contained in the waste input line 18 using high-temperature, high-pressure steam supplied from the steam supply line 20, and discharges hydrothermally treated biomass (hydrothermally treated biomass). The hydrothermally treated biomass refers to the group of substances obtained by the hydrothermal treatment of biomass (biomass modified by hydrothermal treatment), and includes biomass with lower molecular weight than the biomass input from the waste input line 18. Hereinafter, the hydrothermally treated biomass may be simply referred to as "hydrothermally treated material".

[0013] In the illustrated exemplary embodiment, the hydrothermal treatment apparatus 4 is configured to perform hydrothermal treatment of biomass in a batch process. A predetermined amount of waste is fed into the hydrothermal treatment apparatus 4 at one time from a waste input line 18, the hydrothermal reaction of biomass is allowed to proceed for a predetermined period of time, and the hydrothermally treated biomass product is discharged all at once from the hydrothermal treatment apparatus 4 to a hydrothermally treated product discharge line 22. When the hydrothermal treatment of biomass for a predetermined time in the hydrothermal treatment apparatus 4 is completed, before discharging the hydrothermally treated biomass product from the hydrothermal treatment apparatus 4, steam in the hydrothermal treatment apparatus 4 is discharged from the hydrothermal treatment apparatus 4 to a release steam line 24. In the illustrated exemplary embodiment, one end side of the release steam line 24 is connected to the hydrothermal treatment apparatus 4, and the other end side of the release steam line 24 is branched into release steam branch lines 24a to 24c described later.

[0014] By using the hydrothermal treatment apparatus 4 as described above, biomass such as paper and kitchen waste is pulverized by hydrothermal treatment, which facilitates dispersion and slurrying in the mixing adjustment tank 8 when the biomass is fed into the mixing adjustment tank 8. On the other hand, in the hydrothermal treatment apparatus 4, non-fermentable materials such as plastics retain their original shape or aggregate and grow in size.

[0015] An electric valve 23 is provided in the hydrothermally treated product discharge line 22, and when discharging the hydrothermally treated biomass product from the hydrothermal treatment apparatus 4, the discharge rate of the hydrothermally treated biomass product can be controlled by the electric valve 23 while checking the residual pressure in the hydrothermal treatment apparatus 4 (i.e., the internal pressure of the pressure vessel).

[0016] In the illustrated exemplary embodiment, the coarse sorting apparatus 6 is provided at a position between the electric valve 23 in the hydrothermally treated product discharge line 22 and the mixing adjustment tank 8. The coarse sorting apparatus 6 removes relatively large unsuitable materials for methane fermentation, such as plastics and cloth, mixed in the hydrothermally treated biomass product discharged from the hydrothermal treatment apparatus 4 to the hydrothermally treated product discharge line 22.

[0017] The mixing adjustment tank 8 is configured to adjust the properties of the hydrothermally treated biomass by mixing the hydrothermally treated biomass discharged from the hydrothermal treatment apparatus 4 with dilution water (diluent) to reduce the solid concentration of the hydrothermally treated product. In the exemplary embodiment shown in the figure, the mixing adjustment tank 8 is connected with a hydrothermally treated product discharge line 22 and a dilution water supply line 26. The mixing adjustment tank 8 receives the hydrothermally treated biomass supplied from the hydrothermally treated product discharge line 22 (the hydrothermally treated product discharged from the hydrothermal treatment apparatus 4, from which substances unsuitable for methane fermentation have been removed by the coarse sorting apparatus 6), and mixes the hydrothermally treated product with the dilution water supplied from the dilution water supply line 26 to slurry the hydrothermally treated product. Since pre-sorted food waste does not require hydrothermal treatment, the food waste may be directly charged into the mixing adjustment tank 8 and mixed with the above hydrothermally treated product and dilution water.

[0018] Further, a release steam branch line 24a is connected to the mixing adjustment tank 8, and the steam (release steam) discharged from the hydrothermal treatment apparatus 4 after the hydrothermal treatment reaction of biomass in the hydrothermal treatment apparatus 4 is completed is supplied into the mixing adjustment tank 8 through the release steam branch line 24a. Additionally, an odor line 60a is connected to the mixing adjustment tank 8, and the odor discharged from the mixing adjustment tank 8 to the odor line 60a is supplied to the deodorization facility 16 and deodorized therein. The odor discharged from the mixing adjustment tank 8 to the odor line 60a includes, for example, volatile organic compounds, hydrogen sulfide, ammonia and the like.

[0019] In the mixing adjustment tank 8, heat exchange is performed between the steam supplied from the release steam branch line 24a and the slurry of the hydrothermally treated product in the mixing adjustment tank 8, and part of the steam condenses. Therefore, compared with the case where the steam discharged from the hydrothermal treatment apparatus 4 is directly supplied to the deodorization facility 16 (the case where the release steam line 24 is directly connected to the deodorization facility 16 without being connected to the mixing adjustment tank 8), the amount of steam to be treated by the deodorization facility 16 can be reduced, and the amount of odor released to the atmosphere can be reduced with a simple configuration. In addition, since the temperature and pressure inside the mixing adjustment tank 8 can be increased by using the steam supplied from the release steam branch line 24a, the thermal energy of the steam can be effectively utilized to promote the solubilization of the hydrothermally treated product.

[0020] The mixing and adjusting tank 8 and the methane fermentation tank 12 are connected by a slurry supply line 30. The slurry discharged from the mixing and adjusting tank 8 (hydrothermal treated material that has been turned into a slurry by adding dilution water in the mixing and adjusting tank 8) is supplied to the methane fermentation tank 12 after having unsuitable materials for methane fermentation removed as described later in the process of passing through the slurry supply line 30.

[0021] A measuring tank 32 is provided in the slurry supply line 30, and a slurry return line 34 is connected to the measuring tank 32, which is configured to return a portion of the slurry (hydrothermally treated slurry) discharged from the mixing and adjusting tank 8 to the slurry supply line 30 back to the mixing and adjusting tank 8. The measuring tank 32 distributes the slurry discharged from the mixing and adjusting tank 8 to the slurry supply line 30 to the mixing and adjusting tank 8 and the drum screen 9. A crushing pump 38 is provided upstream of the measuring tank 32 in the slurry supply line 30. The crushing pump 38 includes a cutter (not shown) and is configured to crush and pulverize solid matter contained in the slurry with the cutter.

[0022] Downstream of the weighing tank 32 in the slurry supply line 30, a drum screen 9 and a screw press 10 are provided as separation devices for removing impurities from the slurry discharged from the mixing and adjusting tank 8.

[0023] The drum screen 9 is configured to remove impurities from the slurry distributed from the metering tank 32. The liquid portion of the slurry distributed from the metering tank 32 passes through the drum screen 9 and is supplied to the methane fermentation tank 12. The solid portion of the slurry distributed from the metering tank 32 to the drum screen 9 that does not pass through the drum screen 9, which has relatively large particle sizes, is supplied to the screw press 10 and concentrated by a screw (not shown), separating the liquid from the solid portion, and the liquid is supplied to the methane fermentation tank 12.

[0024] A release steam branch line 24b is connected to the drum screen 9, and steam discharged from the hydrothermal treatment device 4 is supplied to the drum screen 9 from the release steam branch line 24b. An odor line 60b is connected to the drum screen 9, and the odor discharged from the drum screen 9 to the odor line 60b is supplied to the deodorization equipment 16 and deodorized there. The odor discharged from the drum screen 9 to the odor line 60b includes, for example, volatile organic compounds, hydrogen sulfide, and ammonia.

[0025] With this configuration, clogging of the drum screen 9 can be suppressed by cleaning the filtration surface (not shown) of the drum screen 9 with steam supplied to the drum screen 9 from the release steam branch line 24b. In addition, the temperature of the slurry (slurried hydrothermal treatment material) inside the drum screen 9 can be increased by exchanging heat between the steam supplied from the release steam branch line 24b and the slurry inside the drum screen 9. This reduces the amount of energy required to maintain the temperature inside the methane fermentation tank 12 at a temperature suitable for methane fermentation. Furthermore, the steam can be condensed inside the drum screen 9 by exchanging heat between the steam supplied from the release steam branch line 24b and the slurry inside the drum screen 9. This reduces the amount of steam that needs to be processed by the deodorization equipment 16, and reduces the amount of odor released into the atmosphere with a simple configuration.

[0026] Furthermore, an odor line 60c is connected to the screw press 10, and the odor discharged from the screw press 10 into the odor line 60c is supplied to the deodorization equipment 16 and deodorized there. The odor discharged from the screw press 10 into the odor line 60c includes, for example, volatile organic compounds, hydrogen sulfide, and ammonia.

[0027] In the illustrated exemplary configuration, the liquid portion separated from the solid portion by the drum screen 9 and the liquid portion separated from the solid portion by the screw press 10 from the hydrothermal treated material discharged from the mixing and adjusting tank 8 are supplied to the input pit 46 and from the input pit 46 to the methane fermentation tank 12 by a pressure pump 48. An odor line 60d is connected to the input pit 46, and the odor discharged from the input pit 46 to the odor line 60d is supplied to the deodorization equipment 16 and deodorized by the deodorization equipment 16.

[0028] The methane fermentation tank 12 generates methane gas using the liquid component of the slurry supplied from the slurry supply line 30 (the liquid component separated from the solid component by the drum screen 9 and screw press 10 from the slurry of the hydrothermal treated material discharged from the mixing and adjustment tank 8). More specifically, in the methane fermentation tank 12, the methane fermentation substrate (organic substances such as sugars, volatile fatty acids, and amino acids) contained in the liquid component of the slurry supplied from the slurry supply line 30 is decomposed by microorganisms such as methanogenic bacteria under anaerobic conditions, generating methane gas and carbon dioxide. The sludge discharged from the methane fermentation tank 12 (fermentation residue remaining after methane fermentation in the methane fermentation tank 12) is dewatered in the sludge dewatering equipment 13 via the sludge supply line 50. The dewatered sludge is supplied to the sludge dryer 14 and dried in the sludge dryer 14.

[0029] A release steam branch line 24c is connected to the sludge dryer 14, and steam discharged from the hydrothermal treatment device 4 is supplied to the sludge dryer 14 from the release steam branch line 24c. In addition, an odor line 60e is connected to the sludge dryer 14, and the odor discharged from the sludge dryer 14 to the odor line 60e is supplied to the deodorization equipment 16, where it is deodorized. The odor discharged from the sludge dryer 14 to the odor line 60d includes, for example, volatile organic compounds, hydrogen sulfide, and ammonia.

[0030] In the illustrated exemplary configuration, odor lines 60a to 60e merge to form a combined odor line 60m, which is connected to the deodorization equipment 16. Furthermore, since a suction fan 62 is provided in the combined odor line 60m, by operating one suction fan 62, odors can be drawn from the mixing and adjusting tank 8, drum screen 9, screw press 10, input pit 46, and sludge dryer 14 and supplied to the deodorization equipment 16.

[0031] In the sludge dryer 14, heat exchange is performed between the sludge discharged from the methane fermentation tank 12 and the steam supplied from the release steam branch line 24c, thereby utilizing the thermal energy of the steam discharged from the hydrothermal treatment device 4 to dry the sludge. Furthermore, since the steam supplied from the release steam branch line 24c can be condensed by this heat exchange, the amount of steam that needs to be treated by the deodorization equipment 16 can be reduced, and the amount of odor released into the atmosphere can be reduced with a simple configuration.

[0032] Figure 2 is a schematic cross-sectional view illustrating an example of the general configuration of the mixing and adjusting tank 8 described above. In the exemplary configuration shown in Figure 2, the release steam branch line 24a includes a release pipe 25 configured to supply steam discharged from the hydrothermal treatment apparatus 4 into the mixing and regulating tank 8. The release pipe 25 protrudes into the inside of the mixing and regulating tank 8 from the inner surface 8i of the mixing and regulating tank 8. In the illustrated example, the release pipe 25 protrudes downward from the ceiling 8a of the mixing and regulating tank 8.

[0033] In this way, by supplying steam into the mixing and adjusting tank 8 from the release pipe 25 protruding from the inner surface 8i of the mixing and adjusting tank 8, steam can be supplied to a position close to the hydrothermal treatment material accumulated inside the mixing and adjusting tank 8, enabling efficient heat exchange between the steam and the hydrothermal treatment material. This allows for efficient heating of the hydrothermal treatment material and efficient condensation of the steam. As a result, the effect of promoting the solubilization of solids contained in the hydrothermal treatment material can be enhanced, and the amount of steam that needs to be processed by the deodorizing equipment 16 can be reduced.

[0034] Further, in the exemplary embodiment shown in Fig. 2, the release pipe 25 includes a steam outlet 25a inside the mixing adjustment tank 8, and the outlet 25a is located in a region S occupied by gas inside the mixing adjustment tank 8. If the steam outlet 25a of the release pipe 25 is located inside the slurry of hydrothermally treated product in the mixing adjustment tank 8, a sudden pressure change occurs when the steam from the release pipe 25 condenses, generating abnormal noise called hammering. In this regard, as shown in Fig. 2, locating the steam outlet 25a of the release pipe 25 in the region S occupied by gas inside the mixing adjustment tank 8 can suppress the occurrence of the aforementioned hammering.

[0035] Further, in the exemplary embodiment shown in Fig. 2, the mixing adjustment tank 8 includes, on an upper surface 8u of the mixing adjustment tank 8, a hydrothermally treated product inlet 52 for receiving hydrothermally treated product discharged from a hydrothermal treatment apparatus 4, a dilution water inlet 28 for receiving dilution water from a dilution water supply line 26, and a slurry inlet 29 for receiving slurry from a slurry return line 34. Further, letting L be the longitudinal dimension of the mixing adjustment tank 8, and d1 be the horizontal distance between the hydrothermally treated product inlet 52 in the mixing adjustment tank 8 and the outlet 25a of the release pipe 25, the condition d1 < L / 2 may be satisfied, or the condition d1 < L / 4 may be satisfied. That is, d1 may be smaller than half of L, or may be smaller than one quarter of L. Further, letting d2 be the horizontal distance between the outlet 25a of the release pipe 25 and the dilution water inlet 28, the condition d2 < L / 2 may be satisfied, or the condition d2 < L / 4 may be satisfied. That is, d2 may be smaller than half of L, or may be smaller than one quarter of L. Further, letting d3 be the horizontal distance between the outlet 25a of the release pipe 25 and the slurry inlet 29, the condition d3 < L / 2 may be satisfied, or the condition d3 < L / 4 may be satisfied. That is, d3 may be smaller than half of L, or may be smaller than one quarter of L.

[0000] Further, in the exemplary embodiment shown in Fig. 2, the mixing adjustment tank 8 includes on an upper surface 8u of the mixing adjustment tank 8.

[0036] As shown in FIG. 2, when a hydrothermally treated product is received from a hydrothermally treated product inlet 52 provided on the upper surface 8u of the mixing adjustment tank 8, a pile 53 formed of solid matter contained in the hydrothermally treated product is likely to be formed below the hydrothermally treated product inlet 52 in the mixing adjustment tank 8. In this regard, satisfying d1<L / 2 as described above allows steam to be injected into the pile 53 of hydrothermally treated product from a position relatively closer to the pile 53 than in a case where d1<L / 2 is not satisfied, thereby breaking up the pile 53 of hydrothermally treated product. This enhances the effect of promoting solubilization of the hydrothermally treated product. Furthermore, satisfying d2<L / 2 allows the dilution water supplied from the dilution water inlet 28 and the steam supplied from the release pipe 25 to come into contact with each other more easily than in a case where d2<L / 2 is not satisfied, facilitating condensation of the steam. This allows the condensed liquid to circulate in the mixing adjustment tank 8 to effectively break up the pile 53 of hydrothermally treated product, enhancing the effect of promoting solubilization of the hydrothermally treated product. Furthermore, satisfying d3<L / 2 allows the slurry supplied from the slurry inlet 29 and the steam supplied from the release pipe 25 to come into contact with each other more easily than in a case where d3<L / 2 is not satisfied, facilitating condensation of the steam. This allows the condensed liquid to circulate in the mixing adjustment tank 8 to effectively break up the pile 53 of hydrothermally treated product, enhancing the effect of promoting solubilization of the hydrothermally treated product.

[0037] FIG. 3 is a diagram for explaining an example of a method of cleaning the drum screen 9 using steam supplied from a release steam line 24. As shown in FIG. 3, the drum screen 9 includes a screen 43 (screen body) which is a cylindrical filter, and a casing 45 that accommodates the screen 43. The screen 43 is configured to remove contaminants from slurry (slurried hydrothermally treated product) supplied from a slurry supply line 30, and separates the slurry into a solid fraction and a liquid fraction according to particle size.

[0038] In the illustrated exemplary embodiment, the release steam branch line 24b includes an upstream line 24b1 for supplying steam discharged from the hydrothermal treatment device 4 to the screen 43 from the upstream side of the screen 43 (the inner circumference side of the screen 43 in the illustrated example), and a downstream line 24b2 for supplying steam discharged from the hydrothermal treatment device 4 to the screen 43 from the downstream side of the screen 43 (the outer circumference side of the screen 43 in the illustrated example).

[0039] Furthermore, the release steam line 24 includes a switching device 49 that can switch the line through which the steam discharged from the hydrothermal treatment device 4 flows between an upstream line 24b1 and a downstream line 24b2. The switching device 49 includes a valve 49a provided in the upstream line 24b1 and a valve 49b provided in the downstream line 24b2. The upstream line 24b1 and the downstream line 24b2 may each be provided with nozzles 51 for injecting the steam discharged from the hydrothermal treatment device 4 at multiple axial positions on the drum screen 9. This allows the steam to be dispersed on the surface of the screen 43 at multiple axial positions on the drum screen 9, thereby efficiently cleaning the screen 43. In the illustrated exemplary embodiment, the nozzles 51 of the upstream line 24b1 are located on the inner circumference side of the screen 43, and the nozzles 51 of the downstream line 24b2 are located on the outer circumference side of the screen 43.

[0040] With this configuration, by switching the line through which the steam discharged from the hydrothermal treatment apparatus 4 flows between the upstream line 24b1 and the downstream line 24b2, both sides of the screen 43 (the upstream side and the downstream side) can be effectively cleaned. This enhances the effect of suppressing screen clogging.

[0041] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate.

[0042] For example, in the embodiment described above, the steam discharged from the hydrothermal treatment apparatus 4 is supplied to the mixing and adjusting tank 8, drum screen 9, and sludge dryer 14 via the release steam line 24. However, the steam discharged from the hydrothermal treatment apparatus 4 may be supplied to only one of the mixing and adjusting tank 8, drum screen 9, and sludge dryer 14 via the release steam line 24, or to any two of the mixing and adjusting tank 8, drum screen 9, and sludge dryer 14.

[0043] Alternatively, for example, the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in one batch treatment may be distributed to the mixing and adjusting tank 8, the drum screen 9, and the sludge dryer 14. Or, of the steam discharged from the hydrothermal treatment device 4 to the release steam line 24 in N batch treatments, the steam discharged in m batch treatments may be supplied to the drum screen 9, the steam discharged in n batch treatments may be supplied to the mixing and adjusting tank 8, and the steam discharged in p batch treatments may be supplied to the sludge dryer 14. Here, N is an integer greater than or equal to 3, and m, n, and p are natural numbers satisfying N = m + n + p.

[0044] The contents described in each of the above embodiments can be understood, for example, as follows:

[0045] [1] A waste treatment system according to at least one embodiment of the present disclosure (e.g., the waste treatment system 2 described above) A hydrothermal treatment apparatus (for example, the hydrothermal treatment apparatus 4 described above) configured to hydrothermally treat biomass contained in waste using steam and discharge the hydrothermally treated biomass, A release steam line (for example, the release steam line 24 described above) is connected to the hydrothermal treatment apparatus and configured to discharge steam from the hydrothermal treatment apparatus, A methane fermentation tank (for example, the methane fermentation tank 12 described above) is configured to generate methane gas using the liquid component of the hydrothermal treatment material discharged from the hydrothermal treatment apparatus, A biomass-derived material processing apparatus (for example, the mixing and adjusting tank 8, drum screen 9, or sludge dryer 14 described above) configured to process the biomass-derived material (for example, hydrothermally treated biomass, or sludge which is the fermentation residue after methane fermentation using the liquid component of the hydrothermally treated biomass), The odor lines (for example, the odor lines 60a, 60b, 60c, 60d, or 60e, and the combined odor line 60m) connected to the biomass-derived material treatment device, from which odors are discharged from the biomass-derived material treatment device, A deodorizing device (for example, the deodorizing device 16 described above) is connected to the odor line and configured to deodorize the odor discharged from the biomass-derived material treatment device, Equipped with, The release steam line is connected to the biomass-derived material treatment device and is configured to supply the steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device. The biomass-derived material processing device is configured to perform heat exchange between the steam supplied from the release steam line and the material derived from the biomass.

[0046] According to the waste treatment system described in [1] above, steam discharged from the hydrothermal treatment device can be supplied to the biomass-derived material treatment device via a release steam line. In the biomass-derived material treatment device, heat exchange can be performed between the steam supplied from the release steam line and the biomass-derived material, thereby condensing at least a portion of the steam. For this reason, compared to the case where steam discharged from the hydrothermal treatment device is supplied directly to the deodorization equipment (when the release steam line is connected to the deodorization equipment), the amount of steam that needs to be treated by the deodorization equipment can be reduced, and the amount of odor released into the atmosphere can be reduced with a simple configuration. In addition, since the biomass-derived material in the biomass-derived material treatment device can receive thermal energy from the steam supplied from the release steam line (steam discharged from the hydrothermal treatment device), the amount of heat contained in the steam can be effectively utilized.

[0047] [2] In some embodiments, the waste treatment system described in [1] above, The biomass-derived material treatment apparatus is a mixing and adjusting tank (for example, the mixing and adjusting tank 8 described above) configured to receive the hydrothermal treated material discharged from the hydrothermal treatment apparatus, The mixing and adjusting tank is configured to mix the hydrothermally treated material with a diluent to adjust the properties of the hydrothermally treated material. The release steam line is connected to the mixing and adjusting tank and is configured to supply the steam discharged from the hydrothermal treatment device to the mixing and adjusting tank.

[0048] According to the waste treatment system described in [2] above, by bringing the steam discharged from the hydrothermal treatment device into contact with the hydrothermal treatment material (substance derived from biomass) in a mixing and adjustment tank, the hydrothermal treatment material can be heated with steam, promoting the solubilization of solids contained in the hydrothermal treatment material, and the amount of heat contained in the steam can be effectively utilized. In addition, since at least a portion of the steam can be condensed by heat exchange with the hydrothermal treatment material in the mixing and adjustment tank, the amount of steam that needs to be treated by the deodorizing equipment can be reduced, and the amount of odor released into the atmosphere can be reduced with a simple configuration.

[0049] [3] In some embodiments, in the waste treatment system described in [2] above, The release steam line includes a release pipe (for example, the release pipe 25 described above) configured to supply the steam discharged from the hydrothermal treatment apparatus into the mixing and adjusting tank, The release piping protrudes from the inner surface of the mixing and adjusting tank (for example, the inner surface 8i described above) to the inside of the mixing and adjusting tank.

[0050] According to the waste treatment system described in the above [3], by supplying steam into the mixing adjustment tank through a release pipe protruding from the inner surface of the mixing adjustment tank, steam can be supplied to a position close to the hydrothermally treated product accumulated inside the mixing adjustment tank, and heat exchange between the steam and the hydrothermally treated product can be efficiently performed. Thereby, the hydrothermally treated product can be efficiently heated and the steam can be efficiently condensed. Therefore, the effect of promoting solubilization of solid matter contained in the hydrothermally treated product can be enhanced, and the amount of steam to be treated in the deodorization equipment can be reduced.

[0051] [4] In some embodiments, in the waste treatment system according to the above [3], the release pipe includes the steam outlet (e.g., the above-described outlet 25a) inside the mixing adjustment tank, the outlet is located in a region occupied by gas inside the mixing adjustment tank (e.g., the above-described region S).

[0052] If the steam outlet of the release pipe is located inside the slurry of the hydrothermally treated product in the mixing adjustment tank, a rapid pressure change occurs when the steam condenses, generating abnormal noise called hammering. In this regard, according to the waste treatment system described in the above [4], since the steam outlet of the release pipe is located in the region occupied by gas inside the mixing adjustment tank, the occurrence of hammering can be suppressed.

[0053] [5] In some embodiments, in the waste treatment system according to the above [4], the mixing adjustment tank includes a hydrothermally treated product inlet (e.g., the above-described hydrothermally treated product inlet 52) for receiving the hydrothermally treated product discharged from the hydrothermal treatment apparatus on the upper surface of the mixing adjustment tank (e.g., the above-described upper surface 8u), when the longitudinal dimension of the mixing adjustment tank is L, and the horizontal distance between the hydrothermally treated product inlet and the outlet in the mixing adjustment tank is d1, the condition d1<L / 2 is satisfied.

[0054] When a hydrothermally treated product is received through a hydrothermally treated product inlet provided on the top surface of the mixing adjustment tank, a pile of solid matter contained in the hydrothermally treated product is likely to be formed below the hydrothermally treated product inlet in the mixing adjustment tank. In this regard, according to the waste treatment system described in the above [5], satisfying d1 < L / 2 allows steam to be injected onto the pile of hydrothermally treated product from a position relatively closer to the pile than when d1 < L / 2 is not satisfied, thereby breaking up the pile of hydrothermally treated product. This can enhance the effect of promoting solubilization of the hydrothermally treated product.

[0055] [6] In some embodiments, in the waste treatment system according to the above [4], the mixing adjustment tank includes a dilution water inlet for receiving dilution water on a top surface of the mixing adjustment tank (e.g., the aforementioned top surface 8u), where L is the longitudinal dimension of the mixing adjustment tank, and d2 is the horizontal distance between the dilution water inlet and the outlet in the mixing adjustment tank, the condition d2 < L / 2 is satisfied.

[0056] According to the waste treatment system described in the above [6], satisfying d2 < L / 2 makes it easier for the dilution water supplied from the dilution water inlet to contact the steam supplied from the release pipe, causing the steam to condense more readily than when d2 < L / 2 is not satisfied. This allows the condensed liquid to be circulated in the mixing adjustment tank to effectively break up the pile of hydrothermally treated product, thereby enhancing the effect of promoting solubilization of the hydrothermally treated product.

[0057] [7] In some embodiments, in the waste treatment system according to the above [4], the mixing adjustment tank includes a slurry inlet for receiving slurry discharged from the mixing adjustment tank and returned to the mixing adjustment tank, where L is the longitudinal dimension of the mixing adjustment tank, and d3 is the horizontal distance between the slurry inlet and the outlet in the mixing adjustment tank, the condition d3 < L / 2 is satisfied.

[0058] According to the waste treatment system described in [7] above, satisfying d3<L / 2 makes it easier for the slurry supplied from the slurry inlet and the steam supplied from the release pipe to come into contact with each other, and the steam is more likely to condense, compared with the case where d3<L / 2 is not satisfied. Thereby, the condensed liquid can be circulated in the mixing adjustment tank to effectively break up the heap of hydrothermally treated products, and the effect of promoting the solubilization of the hydrothermally treated products can be enhanced.

[0059] [8] In some embodiments, in the waste treatment system according to [1] above, The biomass-derived material treatment apparatus is a separation apparatus for removing impurities from the hydrothermally treated product (for example, the drum screen 9 described above), The release steam line is connected to the separation device, and is configured to supply the steam discharged from the hydrothermal treatment device to the separation device.

[0060] According to the waste treatment system described in [8] above, heat exchange is performed between the steam supplied from the release steam line and the hydrothermally treated product (material derived from biomass) in the separation device, thereby increasing the temperature of the hydrothermally treated product in the separation device. Therefore, in a methane fermentation tank to which the liquid component of the hydrothermally treated product discharged from the separation device is supplied, the amount of energy consumption required for maintaining the internal temperature of the methane fermentation tank at a temperature suitable for methane fermentation can be reduced. Furthermore, by performing heat exchange between the steam supplied from the release steam line and the hydrothermally treated product in the separation device, the steam can be condensed in the separation device. Thereby, the amount of steam to be treated in the deodorization equipment can be reduced, and the amount of odor released to the atmosphere can be reduced with a simple configuration.

[0061] [9] In some embodiments, in the waste treatment system according to [8] above, The separation device includes a screen for removing impurities from the hydrothermally treated product (for example, the screen 43 described above), The release steam line is configured to supply the steam discharged from the hydrothermal treatment device to the screen.

[0062] According to the waste treatment system described in [9] above, the screen can be cleaned using steam supplied from the release steam line. This helps to prevent screen clogging.

[0063]

[10] In some embodiments, the waste treatment system described in [9] above, The aforementioned release steam line is An upstream line (for example, the upstream line 24b1 described above) for supplying the steam discharged from the hydrothermal treatment apparatus to the screen in the separation apparatus from the upstream side of the screen, A downstream line (for example, the downstream line 24b2 described above) for supplying the steam discharged from the hydrothermal treatment apparatus to the screen in the separation apparatus from the downstream side of the screen, A switching device (for example, the switching device 49 described above) that can switch the line through which the steam discharged from the hydrothermal treatment apparatus flows between the upstream line and the downstream line, It is equipped with.

[0064] According to the waste treatment system described in

[10] above, by switching the line through which the steam discharged from the hydrothermal treatment device flows between the upstream and downstream lines, both sides of the screen (the upstream and downstream sides) can be effectively cleaned. This enhances the effect of suppressing screen clogging.

[0065]

[11] In some embodiments, in the waste treatment system described in [1] above, The biomass-derived material treatment device is a sludge dryer (for example, the sludge dryer 14 described above) for drying the sludge discharged from the methane fermentation tank. The release steam line is connected to the sludge dryer and is configured to supply the steam discharged from the hydrothermal treatment device to the sludge dryer.

[0066] According to the waste treatment system described in

[11] above, the sludge can be dried using the thermal energy of the steam discharged from the hydrothermal treatment device by performing heat exchange between the sludge (a substance derived from biomass) discharged from the methane fermentation tank and the steam supplied from the release steam line in a sludge dryer. In addition, since the steam supplied from the release steam line can be condensed by this heat exchange, the amount of steam that needs to be treated by the deodorization equipment can be reduced, and the amount of odor released into the atmosphere can be reduced with a simple configuration. [Explanation of Symbols]

[0067] 2: Waste disposal system 4: Hydrothermal treatment equipment 6: Rough sorting device 8:Mixing adjustment tank 8a: Ceiling 8i: Inner 8u:Top surface 9: Drum screen 10: Screw press 12: Methane fermentation tank 13: Sludge dewatering equipment 14: Sludge dryer 16: Deodorizing equipment 18: Waste input line 20: Steam supply line 22: Hydrothermal treatment waste discharge line 23: Electric valve 24: Release steam line 24a, 24b, 24c: Release steam branch line 24b1: Upstream line 24b2: Downstream line 25: Release piping 25a:Exit 26: Dilution water supply line 28: Dilution water inlet 29: Slurry Inlet 30: Slurry supply line 32:Measuring tank 34: Slurry return line 38: Crushing pump 43: Screen 45: Casing 46: Input Pit 48: Pressure pump 49: Switching device 49a, 49b: Valve 50: Sludge supply line 51: Nozzle 52: Hydrothermal treatment material receiving port 60a, 60b, 60c, 60d, 60e: Odor lines 60m: Confluence odor line 62: Suction fan

Claims

1. A hydrothermal treatment apparatus configured to hydrothermally treat biomass contained in waste using steam and discharge the hydrothermally treated biomass, A release steam line connected to the aforementioned hydrothermal treatment apparatus and configured to discharge steam from the aforementioned hydrothermal treatment apparatus, A methane fermentation tank configured to generate methane gas using the liquid component of the hydrothermal treatment material discharged from the hydrothermal treatment apparatus, A biomass-derived substance processing apparatus configured to process the biomass-derived substance, An odor line connected to the biomass-derived material treatment device, through which odors are discharged from the biomass-derived material treatment device, A deodorizing device connected to the odor line and configured to deodorize the odor discharged from the biomass-derived material treatment device, Equipped with, The release steam line is connected to the biomass-derived material treatment device and is configured to supply the steam discharged from the hydrothermal treatment device to the biomass-derived material treatment device. The biomass-derived material treatment device is configured to perform heat exchange between the steam supplied from the release steam line and the material derived from the biomass, as a waste treatment system.

2. The biomass-derived material treatment apparatus is a mixing and adjusting tank configured to receive the hydrothermal treated material discharged from the hydrothermal treatment apparatus, The mixing and adjusting tank is configured to mix the hydrothermally treated material with a diluent to adjust the properties of the hydrothermally treated material. The waste treatment system according to claim 1, wherein the release steam line is connected to the mixing and adjusting tank and configured to supply the steam discharged from the hydrothermal treatment device to the mixing and adjusting tank.

3. The release steam line includes a release pipe configured to supply the steam discharged from the hydrothermal treatment apparatus into the mixing and adjusting tank, The waste treatment system according to claim 2, wherein the release piping protrudes from the inner surface of the mixing and adjusting tank to the inside of the mixing and adjusting tank.

4. The release piping includes the steam outlet inside the mixing and adjusting tank. The waste treatment system according to claim 3, wherein the outlet is located in the region occupied by gas inside the mixing and adjusting tank.

5. The mixing and adjusting tank includes a hydrothermal treatment receiving port for receiving the hydrothermal treatment material discharged from the hydrothermal treatment apparatus, The waste treatment system according to claim 4, wherein L is the longitudinal dimension of the mixing and adjusting tank, and d is the horizontal distance between the hydrothermal treatment material receiving port and the outlet in the mixing and adjusting tank, such that d < L / 2.

6. The mixing and adjusting tank includes a dilution water inlet for receiving dilution water, The waste treatment system according to claim 4, wherein L is the longitudinal dimension of the mixing and adjusting tank, and d2 is the horizontal distance between the dilution water inlet and the outlet in the mixing and adjusting tank, and d2 < L / 2.

7. The mixing and adjusting tank includes a slurry receiving port that receives the slurry discharged from the mixing and adjusting tank and returned to the mixing and adjusting tank. The waste treatment system according to claim 4, wherein L is the longitudinal dimension of the mixing and adjusting tank, and d3 is the horizontal distance between the slurry inlet and outlet in the mixing and adjusting tank, and d3 < L / 2.

8. The biomass-derived material processing device is a separation device for removing impurities from the hydrothermally treated material. The waste treatment system according to claim 1, wherein the release steam line is connected to the separation device and configured to supply the steam discharged from the hydrothermal treatment device to the separation device.

9. The separation device includes a screen for removing impurities from the hydrothermally treated material. The waste treatment system according to claim 8, wherein the release steam line is configured to supply the steam discharged from the hydrothermal treatment device to the screen.

10. The aforementioned release steam line is An upstream line for supplying the steam discharged from the hydrothermal treatment apparatus to the screen in the separation apparatus from the upstream side of the screen, A downstream line for supplying the steam discharged from the hydrothermal treatment apparatus to the screen in the separation apparatus from the downstream side of the screen, A switching device that can switch between the upstream line and the downstream line through which the steam discharged from the hydrothermal treatment apparatus flows, A waste treatment system according to claim 9, comprising:

11. The biomass-derived material treatment device is a sludge dryer for drying the sludge discharged from the methane fermentation tank, The waste treatment system according to claim 1, wherein the release steam line is connected to the sludge dryer and configured to supply the steam discharged from the hydrothermal treatment device to the sludge dryer.

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